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OBJECTIVE: To evaluate effects of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus. DESIGN: Randomized controlled crossover trial. ANIMALS: 16 cats with naturally acquired [...]

Objective: To investigate safety and effectiveness of velagliflozin oral solution as sole therapy in naïve and previously insulin-treated diabetic cats., Animals: 252 client-owned cats receiving ≥ 2 doses of velagliflozin; 214 (85%) naïve diabetics and 38 (15%) insulin-treated diabetics., Procedures: Prospective, baseline-controlled, open-label clinical field trial. Cats received velagliflozin orally, once daily. Physical examinations and blood collections were performed days 0, 3, 7, 30, 60, 120, and 180., Results: Data are median (range). Screening blood glucose (BG) was 436 mg/dL (272 to 676 mg/dL). On days 30, 60, 120, and 180, single BG after receiving velagliflozin was 153 mg/dL (62 to 480 mg/dL), 134 mg/dL (64 to 414 mg/dL), 128 mg/dL (55 to 461 mg/dL), and 125 mg/dL (77 to 384 mg/dL), respectively. Screening fructosamine was 538 µmol/L (375 to 794 µmol/L). On the same recheck days, fructosamine was 310 µmol/L (204 to 609 µmol/L), 286 µmol/L (175 to 531 µmol/L), 269 µmol/L (189 to 575 µmol/L), and 263 µmol/L (203 to 620 µmol/L). At day 180, 81% of 158 cats remaining had BG and/or fructosamine within reference ranges; 88.6% (124 of 140) and 87.7% (121 of 138) showed improvement in polyuria and polydipsia, respectively. Ketonuria developed in 35 cats (13.9%), including 18 (7.1%) that had ketoacidosis. Ketoacidosis was less common in naïve diabetic cats (11 of 214 [5.1%]) compared to insulin-treated diabetic cats (7 of 38 [18.4%]). At ketoacidosis diagnosis, 14 of 18 cats (77.8%) were euglycemic (ie, BG < 250 mg/dL). Most episodes of ketosis or ketoacidosis (30 of 35 [85.7%]) occurred within the first 14 days of treatment. Insulin-treated diabetic cats were less likely to complete the trial. No clinical hypoglycemia occurred., Clinical Relevance: Velagliflozin improved glycemic parameters and clinical signs in diabetic cats. Velagliflozin provides an alternative to insulin as a stand-alone treatment of diabetic cats.

Background: Bexagliflozin is a sodium-glucose cotransporter 2 (SGLT2) inhibitor. A pilot study has shown that bexagliflozin can decrease dependence on exogenous insulin in cats with diabetes mellitus (DM)., Objective: To evaluate the safety and effectiveness of bexagliflozin as a monotherapy for DM in previously untreated cats., Animals: Eighty-four client-owned cats., Methods: Historically controlled prospective open-label clinical trial. Cats were dosed PO with 15 mg bexagliflozin once daily for 56 days, with a 124-day extension to evaluate safety and treatment effect durability. The primary endpoint was the proportion of cats experiencing a decrease in hyperglycemia and improvement in clinical signs of hyperglycemia from baseline on day 56., Results: Of 84 enrolled cats, 81 were evaluable on day 56, and 68 (84.0%) were treatment successes. Decreases in mean serum glucose, fructosamine, and β-hydroxybutyrate (β-OHB) concentrations were observed, and investigator assessments of cat neurological status, musculature, and hair coat quality improved. Owner evaluations of both cat and owner quality of life were favorable. The fructosamine half-life in diabetic cats was found to be 6.8 days. Commonly observed adverse events included emesis, diarrhea, anorexia, lethargy, and dehydration. Eight cats experienced serious adverse events, 3 of which led to death or euthanasia. The most important adverse event was euglycemic diabetic ketoacidosis, diagnosed in 3 cats and presumed present in a fourth., Conclusion and Clinical Importance: Bexagliflozin decreased hyperglycemia and observed clinical signs in cats newly diagnosed with DM. As a once-daily PO medication, bexagliflozin may simplify management of DM in cats., (© 2023 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals LLC on behalf of American College of Veterinary Internal Medicine.)

Diabetes mellitus is a common endocrinopathy in dogs that has been associated with various biochemical changes and comorbid diseases, but hematologic abnormalities have been rarely reported. The aim of this retrospective study was to evaluate complete blood count and blood smear alterations and to describe their relationship with, and incidence of comorbid diseases in, diabetic dogs. Three-hundred twelve diabetic dogs, 286 dogs diagnosed with systemic, nondiabetic illnesses, and 506 healthy dogs were identified during the study period. Groups were compared using contingency tables and logistic regression. Associations between statistically significant complete blood count and blood smear alterations and comorbidities were evaluated using multivariable analysis. High-grade codocytosis and anisocytosis were identified more frequently in diabetic dogs, whereas high-grade reactive lymphocytosis and keratocytosis were identified less frequently (P < .001). Diabetic dogs with high-grade codocytosis had lower red blood cell, hemoglobin, hematocrit and higher white blood cell counts (P < .001). Diabetic ketoacidosis was diagnosed more frequently in diabetic dogs with high-grade codocytosis when compared with those with low-grade codocytosis (P < .001) or when compared with any other cell morphologic alterations. This study suggests that blood smear analysis should be a routine part of the evaluation of diabetic dogs., (© 2022 by American Animal Hospital Association.)

Spontaneous hypercortisolism (HC) is a common endocrine disease of senior dogs, often overlapping in selected clinical signs and hematologic and blood biochemical abnormalities with nonadrenal diseases (NADs). HC and NAD could differentially affect cortisol metabolism, which is a complex 10-enzymatic pathway process. HC might also affect blood and urine lactate levels through its effects on mitochondrial function. We aimed to differentiate between HC and NAD via a urinary cortisol metabolites and lactate panel. We prospectively recruited 7 healthy dogs and 18 dogs with HC, 15 with congestive heart failure (CHF), and 9 with NAD. We analyzed urine by gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry. We normalized urinary lactate and cortisol metabolites to urine creatinine concentration, and then compared groups using a linear-mixed model and principal component (PC) analysis. A machine-learning classification algorithm generated a decision tree (DT) model for predicting HC. The least-squares means of normalized urinary 6β-hydroxycortisol and PC1 of the HC and CHF groups were higher than those of the healthy and NAD groups ( p  = 0.05). Creatinine-normalized urinary 6β-hydroxycortisol had better sensitivity (Se, 0.78; 95% CI: 0.55-0.91), specificity (Sp, 0.89; 95% CI: 0.57-0.99), and a likelihood ratio (LR; 7), than the Se (0.72; 95% CI: 0.49-0.88), Sp (0.89; 95% CI: 0.57-0.99), and LR (6.5) of PC1 for distinguishing HC from NAD. Lactate and dihydrocortisone had the highest decreasing node-weighted impurity value and were considered the most important features in the DT model; dihydrocortisol had no role in determining whether a dog had HC.

Pituitary glands from 141 feline autopsy cases were reviewed histologically. Adenoma and hyperplasia were the most common lesions at 13 cases each. Pituitary adenoma was more likely than hyperplasia to be associated with clinical evidence of endocrinopathy or an intracranial mass ( P < .001). A histochemical and immunohistochemical panel was applied to 44 autopsy- or hypophysectomy-derived pituitary adenomas in 43 cats from 2 diagnostic laboratories. Adenomas were differentiated from hyperplasia by the presence of disrupted reticulin fibers. One cat had a double (somatotroph and melanotroph) adenoma. Twenty somatotroph adenomas consisted of periodic acid-Schiff (PAS)-negative acidophils that expressed growth hormone; 16/20 had hypersomatotropism; 17/20 had diabetes mellitus. Eleven melanotroph adenomas consisted of PAS-positive basophils or chromophobes that expressed melanocyte-stimulating and adrenocorticotrophic hormones; 5/11 had hypercortisolism; 6/11 had diabetes mellitus. Eleven gonadotroph adenomas consisted of PAS-negative chromophobes that expressed follicle-stimulating and/or luteinizing hormones. Two thyrotroph adenomas consisted of PAS-negative basophils or chromophobes that expressed thyroid-stimulating hormone. Pituitary-dependent disease was not recognized in cats with gonadotroph or thyrotroph adenomas. The Ki-67 proliferation index in hypophysectomy specimens was lower in somatotroph than in melanotroph adenomas. Fourteen cats with hypophysectomy-treated somatotroph or melanotroph adenoma had an 899-day median survival time versus 173 days in 17 nonsurgical cases. After adjusting for age, adenoma size and type, hypophysectomized cats had an overall better survival time than nonsurgical cases ( P = .029). The study results underscore the value of hypophysectomy and trophic hormone immunohistochemistry in the treatment and classification of feline pituitary adenomas.

Replacement of islets/β-cells that provide long-lasting glucose-sensing and insulin-releasing functions has the potential to restore extended glycemic control in individuals with type 1 diabetes. Unfortunately, persistent challenges preclude such therapies from widespread clinical use, including cumbersome administration via portal vein infusion, significant loss of functional islet mass upon administration, limited functional longevity, and requirement for systemic immunosuppression. Previously, fibril-forming type I collagen (oligomer) was shown to support subcutaneous injection and in situ encapsulation of syngeneic islets within diabetic mice, with rapid (<24 h) reversal of hyperglycemia and maintenance of euglycemia for beyond 90 days. Here, we further evaluated this macroencapsulation strategy, defining effects of islet source (allogeneic and xenogeneic) and dose (500 and 800 islets), injection microenvironment (subcutaneous and intraperitoneal), and macrocapsule format (injectable and preformed implantable) on islet functional longevity and recipient immune response. We found that xenogeneic rat islets functioned similarly to or better than allogeneic mouse islets, with only modest improvements in longevity noted with dosage. Additionally, subcutaneous injection led to more consistent encapsulation outcomes along with improved islet health and longevity, compared with intraperitoneal administration, whereas no significant differences were observed between subcutaneous injectable and preformed implantable formats. Collectively, these results document the benefits of incorporating natural collagen for islet/β-cell replacement therapies.

Background: No gold standard assay for serum total thyroxine (TT4) concentration in small animals exists. The Microgenics DRI TT4 (MTT4) assay is used by most reference laboratories., Hypothesis/objectives: IDEXX Catalyst Total T4 (CTT4) and Immulite 2000 TT4 (ITT4) results will agree with MTT4 results., Animals: Residual small animal sera were randomized before reanalysis (dogs, CTT4 versus MTT4: n = 176, ITT4 versus MTT4: n = 74; cats, CTT4 versus MTT4: n = 319, ITT4 versus MTT4: n = 79)., Methods: Validation and method comparison study. Serum TT4 concentration was measured on all analyzers. Pairwise Pearson correlation, cumulative sum linearity test, regression, and Bland-Altman method were performed., Results: CTT4 versus MTT4 in dogs: constant bias (y-intercept) was 0.10 μg/dL (95% confidence interval [CI], 0.05-0.15), proportional bias (slope) was 0.86 μg/dL (95% CI, 0.83-0.89); in cats, constant bias was 0.13 μg/dL (95% CI, 0.08-0.20) and proportional bias was 1.01 μg/dL (95% CI, 0.98-1.03), but the test for linearity failed. Bland-Altman plots identified increasing disagreement with increasing serum TT4 concentrations. ITT4 versus MTT4 in dogs, constant bias was 0.14 μg/dL (95% CI, 0.04-0.22) and 0.22 μg/dL (95% CI, 0.09-0.33) for cats; proportional bias was 0.76 (95% CI, 0.72-0.80) for dogs and 0.71 (95% CI, 0.69-0.74) for cats., Conclusions and Clinical Importance: Differences in CTT4 and MTT4 results affect interpretation at higher serum TT4 concentrations. The ITT4 proportional bias will underestimate serum TT4 concentrations in dogs and cats, compared to MTT4. Serial TT4 measurements should be done using the same assay., (© 2020 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Hypophysectomy specimens from 16 dogs with pituitary adenoma were evaluated with periodic acid-Schiff (PAS), reticulin, and immunohistochemistry for adrenocorticotrophic hormone (ACTH), melanocyte stimulating hormone (MSH), growth hormone (GH), and Ki-67. The reticulin network was obliterated in all adenomas. One adenoma expressed ACTH and GH. Eight corticotroph adenomas were basophilic to chromophobic, and PAS- and ACTH-positive. Seven melanotroph adenomas were distinguished from corticotroph adenomas by expression of MSH. Pituitary-dependent hypercortisolism was diagnosed in 5 of 8 dogs with corticotroph and 4 of 7 with melanotroph adenoma. Pituitary height/brain area (P/B) ratio was elevated in all dogs. Previous canine hypophysectomy studies suggested that melanotroph adenomas were larger and carried a worse prognosis than corticotroph adenomas; however, in this study, corticotroph adenomas in comparison to melanotroph adenomas were larger (median P/B ratio: 1.06 versus 0.76), more proliferative (median Ki-67 index: 9.47% versus 1.99%), and associated with shorter survival (median: 300 versus 793 days). Recommended immunohistochemistry for PAS-positive pituitary adenomas includes ACTH and MSH to distinguish corticotrophs from melanotrophs and Ki-67 for proliferation index.

To optimize the histologic evaluation of hypophysectomy specimens, sections of 207 canine pituitary glands (196 postmortem, 11 hypophysectomy specimens) were reviewed. Adenohypophyseal proliferation was the most common (n = 79) lesion. Proliferative lesions were sparsely to densely granulated; the granules were usually basophilic to chromophobic and periodic acid-Schiff-positive. Adenohypophyseal proliferation was classified as hyperplasia (n = 40) if ≤2 mm diameter with intact reticulin network, as microadenoma (n = 22) for 1-5 mm homogeneous nodules with lost reticulin network, or as macroadenoma (n = 17) for larger tumors. Craniopharyngeal duct cysts were common incidental lesions and the only lesion in 15 dogs. Uncommon diagnoses included lymphoma (n = 4), hemorrhagic necrosis (n = 4), metastatic carcinoma (n = 3), hypophysitis (n = 3), ependymoma (n = 2), craniopharyngioma (n = 2), and 1 case each of metastatic melanoma, pituicytoma, gliomatosis, germ cell tumor, meningioma, and atrophy. The pituitary histologic diagnosis was associated with hyperadrenocorticism (HAC; P < .001) and adrenocortical histologic diagnosis ( P = .025). Both HAC and adrenocortical hyperplasia showed a positive trend with the degree of adenohypophyseal proliferation. The association of adrenocortical hyperplasia with HAC was not significant ( P = .077). Dogs with adenohypophyseal proliferations were older than dogs with normal pituitary glands ( P < .05). Brachycephalic breeds were overrepresented among dogs with pituitary macroadenoma or craniopharyngeal duct cysts, but the association was not statistically significant ( P = .076). Adenohypophyseal hyperplasia was more common than adenoma among postmortem specimens, but was unexpected in >80% of cases. Pituitary macroadenoma was the most common diagnosis in hypophysectomy specimens.

Background: Radioactive iodine therapy is considered the treatment of choice for hyperthyroidism in cats, but the availability of this modality is limited by costs and hospitalization requirements. Administration of recombinant human thyroid stimulating hormone (rh-TSH) to humans with thyroid neoplasia or nodular goiter can increase thyroidal iodine uptake, thereby allowing the use of lower radioactive iodine doses for treatment. Veterinary studies of this subject are limited, and results are conflicting., Objective: To investigate the effects of rh-TSH administration on thyroidal iodine uptake in hyperthyroid cats., Animals: Ten client-owned hyperthyroid cats., Methods: In this prospective clinical study, cats were administered saline (placebo), 50 μg rh-TSH (low-dose), and 100 μg rh-TSH (high-dose) in randomized crossover design with treatments separated by 7-10 days. After each treatment, thyroid scintigraphy was performed by administering 300 μCi 123 I and assessing radionuclide uptake 8 and 24 hours later. Serum thyroid hormone concentrations were measured at each visit., Results: Thyroidal percent iodine uptakes (mean ± SD at 8 and 24 hours) in cats treated with placebo (25.2 ± 13.4%, 30.0 ± 12.8%), low-dose (24.1 ± 12.5%, 29.4 ± 13.7%), and high-dose rh-TSH (24.2 ± 16.3%, 30.8 ± 15.3%) were not different (P = .76). Independent of rh-TSH administration, percent iodine uptakes were positively correlated with serum thyroid hormone concentrations., Conclusions and Clinical Importance: One-time administration of rh-TSH, even at high doses, would not be expected to lower radioactive iodine doses needed for treatment of hyperthyroidism in cats. Investigations of alternate strategies to increase thyroidal uptake of radioactive iodine are warranted., (© 2018 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Objectives: The aim of this study was to identify distinguishing characteristics between dogs diagnosed with amegakaryocytic thrombocytopenia and those diagnosed with presumed primary peripheral immune-mediated thrombocytopenia. Presenting clinical and clinicopathologic data and outcomes were compared between the two groups., Methods: Retrospective study performed on seven client-owned dogs diagnosed with amegakaryocytic thrombocytopenia and 34 client-owned dogs with primary peripheral immune-mediated thrombocytopenia., Results: All dogs in the amegakaryocytic thrombocytopenia group were anaemic on presentation with a median haematocrit of 23% (range 9·4 to 36), while the primary peripheral immune-mediated thrombocytopoenia group had a median presenting haematocrit of 35% (range 10 to 53). Dogs with amegakaryocytic thrombocytopenia had a median of five (range 4 to 7) clinical signs of bleeding compared to a median of three (range 0 to 6) in the primary peripheral immune-mediated thrombocytopenia group with 86% (6 of 7) of amegakaryocytic thrombocytopenia dogs requiring a blood transfusion compared to 41% (14 of 34) of primary peripheral immune-mediated thrombocytopenia dogs. Six of the seven amegakaryocytic thrombocytopenia dogs did not survive to discharge, while only five of the 34 primary peripheral immune-mediated thrombocytopenia dogs did not survive to discharge., Clinical Significance: The clinical presentation of dogs with amegakaryocytic thrombocytopenia and primary peripheral immune-mediated thrombocytopenia is similar, but dogs with amegakaryocytic thrombocytopenia had a more severe clinical course compared to primary peripheral immune-mediated thrombocytopenia dogs. The prognosis for dogs with amegakaryocytic thrombocytopenia is poor., (© 2016 British Small Animal Veterinary Association.)

Background: The effect of feeding a limited iodine diet on radioactive iodine uptake in the thyroid glands of hyperthyroid cats is unknown., Objectives: To determine how feeding limited dietary iodine affects radioactive iodine uptake by the thyroid glands of hyperthyroid cats., Animals: Eight geriatric cats with spontaneous hyperthyroidism., Methods: Prospective study of eight client owned hyperthyroid cats fed a commercially available iodine limited diet for 6 months. Clinical signs were evaluated and TT4 and fT4 were measured during consumption of the diet. Uptake of (123)I was determined before and 8-16 weeks after exclusive consumption of the diet., Results: Clinical signs of hyperthyroidism resolved in all cats, but there was no significant increase in body weight. TT4 and fT4 decreased into the reference range by 8-16 weeks in all cats. Mean TT4 before consumption of the diet was 9.7 μg/dL (SD 5.2) and after consumption of the diet was 3.1 μg/dL (SD 0.9). Scintigraphy revealed unilateral uptake of isotope in 5 cats and bilateral uptake in 3 cats. Mean percentage uptake of (123)I by the thyroid gland at 8 hours after isotope administration was 16.2 (SD 11.8) before diet consumption and 34.6 (SD 11.7) 8-16 weeks after exclusive consumption of the diet. The percentage increase was variable between cats (38-639%)., Conclusions and Clinical Importance: Limited iodine diets increase iodine uptake in the autonomous thyroid glands of hyperthyroid cats. Further studies are necessary to determine if consumption of a limited iodine diet changes sensitivity of the thyroid gland to (131)I treatment., (Copyright © 2015 by the American College of Veterinary Internal Medicine.)

Background: Exclusive feeding of an iodine-restricted diet has been proposed as a method for controlling clinical manifestations of hyperthyroidism in hyperthyroid cats., Objectives: To determine the effect of feeding an iodine-restricted diet on TT4 concentrations and clinical signs in cats with spontaneous hyperthyroidism., Animals: Forty-nine client-owned cats with spontaneous hyperthyroidism., Methods: Retrospective case series. Hyperthyroid cats were exclusively fed a commercially available iodine-restricted diet. Clinical response was assessed by change in weight and heart rate and serum TT4, blood urea nitrogen (BUN), and creatinine concentrations at various times during dietary management (21-60 days, 60-180 days)., Results: Serum TT4 normalized in 20/48 cats (42%) and 39/47 cats (83%) at 21-60 days and 61-180 days, respectively. Cats in which the TT4 concentrations were still above reference range at 21-60 days had a significantly higher starting TT4 than those that normalized their TT4 levels during the same time period (P = .038). Body weight did not significantly increase (P = .34) nor heart rate decrease (P = .64) during the study. There was a significant decrease in serum creatinine (P = .028). Cats in the low reference range for serum TT4 concentrations did not have a significant increase in body weight (P = .41) nor creatinine (P = .54) when compared to those with high reference range., Conclusions and Clinical Importance: Restricted-iodine diets were effective at maintaining serum TT4 concentrations within reference ranges for a majority of cats with spontaneous hyperthyroidism over 1 year, although not all clinical signs of hyperthyroidism improved., (Copyright © 2015 The Authors. Journal of Veterinary Internal Medicine published by Wiley Periodicals, Inc. on behalf of the American College of Veterinary Internal Medicine.)

Background: The ACTH stimulation test is currently required for definitive diagnosis of hypoadrenocorticism. Increased cost of synthetic ACTH (cosyntropin) has prompted a search for alternative diagnostic methods., Objective: The purpose of this study was to determine whether a cortisol-to-ACTH ratio (CAR) can be used to differentiate dogs with hypoadrenocorticism from normal dogs and those with nonadrenal illness., Animals: Eight healthy dogs (H), 19 dogs with nonadrenal illness (NAI), and 15 dogs with hypoadrenocorticism (HAD)., Methods: Dogs in the HAD group were retrospectively identified from PUVTH medical records. The NAI group consisted of hospitalized dogs with clinical signs, clinicopathologic findings, or both, consistent with a diagnosis of hypoadrenocorticism, but in which hypoadrenocorticism was ruled out based on ACTH stimulation test results. Healthy dogs were recruited from hospital staff and students. Endogenous ACTH concentrations and cortisol concentrations before and after ACTH stimulation were measured in all dogs., Results: Baseline cortisol concentration was significantly lower, and ACTH concentration was significantly higher, in the HAD group versus the H and NAI group (P < .001). However, there was overlap among groups. Cortisol-to-ACTH ratio was significantly lower in the HAD group versus the H and NAI groups (P < .001), and there was no overlap between the HAD group and the other 2 groups., Conclusions and Clinical Importance: CAR can be used for definitive diagnosis of primary hypoadrenocorticism., (Copyright © 2014 by the American College of Veterinary Internal Medicine.)

Background: Spontaneous hyperadrenocorticism (HAC) is rare in cats. Clinical findings, diagnostic test results, and response to various treatment options must be better characterized., Objectives: To report the clinical presentation, clinicopathologic findings, diagnostic imaging results, and response to treatment of cats with HAC., Animals: Cats with spontaneous HAC., Methods: Retrospective descriptive case series., Results: Thirty cats (15 neutered males, 15 spayed females; age, 4.0-17.6 years [median, 13.0 years]) were identified from 10 veterinary referral institutions. The most common reason for referral was unregulated diabetes mellitus; dermatologic abnormalities were the most frequent physical examination finding. Low-dose dexamethasone suppression test results were consistent with HAC in 27 of 28 cats (96%), whereas ACTH stimulation testing was suggestive of HAC in only 9 of 16 cats (56%). Ultrasonographic appearance of the adrenal glands was consistent with the final clinical diagnosis of PDH or ADH in 28 of 30 cats (93%). Of the 17 cats available for follow-up at least 1 month beyond initial diagnosis of HAC, improved quality of life was reported most commonly in cats with PDH treated with trilostane., Conclusions and Clinical Importance: Dermatologic abnormalities or unregulated diabetes mellitus are the most likely reasons for initial referral of cats with HAC. The dexamethasone suppression test is recommended over ACTH stimulation for initial screening of cats with suspected HAC. Diagnostic imaging of the adrenal glands may allow rapid and accurate differentiation of PDH from ADH in cats with confirmed disease, but additional prospective studies are needed., (Copyright © 2014 by the American College of Veterinary Internal Medicine.)

This report offers a consensus opinion on the diagnosis of spontaneous canine hyperadrenocorticism. The possibility that a patient has hyperadrenocorticism is based on the history and physical examination. Endocrine tests should be performed only when clinical signs consistent with HAC are present. None of the biochemical screening or differentiating tests for hyperadrenocorticism are perfect. Imaging can also play a role. Awareness of hyperadrenocorticism has heightened over time. Thus, case presentation is more subtle. Due to the changes in manifestations as well as test technology the Panel believes that references ranges should be reestablished. The role of cortisol precursors and sex hormones in causing a syndrome of occult hyperadrenocorticism remains unclear., (Copyright © 2013 by the American College of Veterinary Internal Medicine.)

Hypoadrenocorticism or Addison's disease (AD) is a functional disorder in which insufficient mineralocorticoid and glucocorticoid hormones are produced by the adrenal cortex. Human AD is usually attributed to lymphoplasmacytic adrenalitis with autoimmune destruction of the adrenal cortex. Lymphoplasmacytic adrenalitis is also reported in some descriptions of canine AD; however, the histological aspects of adrenalitis or adrenocortical atrophy have not been well characterized because microscopical examination is not required for diagnosis of AD. In this study, sections of adrenal glands from 33 dogs with adrenalitis were compared with those of 37 dogs without adrenal lesions. The affected dogs were classified clinically as having AD (n = 3), being suspected of having AD (n = 17), not having AD (n = 11) or were unclassified (n = 2). The adrenal inflammation was lymphoplasmacytic in 17 dogs, lymphocytic in four, lymphohistiocytic in one, granulomatous in three and neutrophilic in eight cases. Adrenal glands from control dogs lacked leucocyte infiltration and had a cortical to medullary area ratio of 1.1-7.2. All three dogs with AD, 8/17 dogs with suspected AD and 1/11 dogs without AD had a cortical to medullary area ratio <1.1. Because the area ratio was correlated (r = 0.94) with a linear cortical to medullary thickness ratio, a thickness ratio <1.1 could also indicate severe adrenocortical atrophy. Severe adrenocortical atrophy was associated typically with lymphoplasmacytic infiltration and nearly complete loss of cortical cells; however, the zona glomerulosa was partially spared in three dogs with lymphoplasmacytic adrenalitis and severe cortical atrophy. In contrast, non-lymphoid inflammation was generally part of systemic disease, multifocal and was unaccompanied by severe adrenocortical atrophy., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Background: Dogs with immune-mediated thrombocytopenia (ITP) are at risk of hemorrhage when platelet count is <50,000/μL. Treatment with vincristine (VINC) or human intravenous immunoglobulin (hIVIG) decreases platelet recovery time compared with treatment with corticosteroids alone., Objectives: To compare the effect of hIVIG versus VINC on platelet recovery in dogs with ITP., Methods: Prospective, randomized study. Twenty dogs with idiopathic ITP (platelet count <16,000/μL) were enrolled. All dogs were treated with corticosteroids. Dogs were randomly assigned to receive a single dose of hIVIG (0.5 g/kg) or VINC (0.02 mg/kg). Outcome measures were platelet recovery time, duration of hospitalization, and survival to discharge., Results: There was no significant difference in age, sex, weight, or initial platelet count between dogs treated with hIVIG (n = 10) and dogs treated with VINC (n = 10). Median platelet recovery time for both groups was 2.5 days (P = .51). Median hospitalization time for all dogs that survived to discharge was 4 days and not different between groups (P = .29). Seven of 10 dogs in the hIVIG group and 10 of 10 in the VINC group survived to discharge. Survival analysis did not identify any significant difference between the groups at discharge, 6 months, and 1 year after entry into the study. No adverse effects were reported in either group., Conclusions and Clinical Importance: Vincristine should be the first-line adjunctive treatment for the acute management of canine ITP because of lower cost and ease of administration compared with human intravenous immunoglobulin (hIVIG)., (Copyright © 2013 by the American College of Veterinary Internal Medicine.)

Objective: To determine the effect of natural exposure to domoic acid (DA) on eosinophil counts and adrenal gland function in California sea lions (Zalophus californianus)., Design: Cross-sectional prospective study., Animals: 39 California sea lions., Procedures: Adult female sea lions admitted to a rehabilitation hospital during 2009 were classified into 1 of 3 groups (acute DA toxicosis, chronic DA toxicosis, or no DA exposure) on the basis of clinical signs, DA concentration in urine or feces, and hippocampal morphology. Endoparasite burden, eosinophil count, and serum cortisol and plasma ACTH concentrations were determined for each sea lion. For a subset of 8 sea lions, fecal glucocorticoid concentration after IM administration of cosyntropin was determined., Results: Sea lions exposed to DA (acute DA toxicosis, n = 11; chronic DA toxicosis, 19) had higher eosinophil counts and lower serum cortisol concentrations, compared with values for sea lions with no DA exposure (9). Eosinophil count was not associated with endoparasite burden. Serum cortisol concentration was associated with plasma ACTH concentrations in sea lions from the no DA exposure group but not in sea lions in the acute or chronic DA toxicosis groups. Following cosyntropin injection, fecal glucocorticoid concentrations increased in all sea lions evaluated except 1., Conclusions and Clinical Relevance: In adult sea lions, eosinophilia may be a cost-effective biomarker for DA exposure and may reflect alterations in hypothalamic, pituitary gland, or adrenal gland function. Domoic acid exposure may have subtle health effects on marine animals in addition to induction of neurologic signs.

The effects of age, concurrent illness, and administered medications complicate diagnosis of thyroid dysfunction in geriatric patients. Interpretation of thyroid hormone testing should take these factors into account. The most common thyroid disorder in dogs is acquired hypothyroidism. Therapeutic monitoring should be utilized for monitoring treatment of canine hypothyroidism. The most common thyroid disorder in cats is benign hyperthyroidism. Diagnosis is most often complicated by the presence of concurrent illness. Treatment should be individualized based on individual case characteristics and presence of concurrent illness. Some older cats have a palpable goiter months to years before development of clinical signs of hyperthyroidism.

Objective: To evaluate and compare characteristics of a commercially manufactured protamine zinc insulin (PZI) product and PZI products obtained from various compounding pharmacies., Design: Evaluation study., Sample: 112 vials of PZI (16 vials of the commercially manufactured product and 8 vials from each of 12 compounding pharmacies) purchased over an 8-month period., Procedures: Validated methods were used to analyze 2 vials of each product at 4 time points. Appearance, endotoxin concentration, crystal size, insulin concentration in the supernatant, pH, total insulin and zinc concentrations, and species of insulin origin were evaluated., Results: All 16 vials of commercially manufactured PZI met United States Pharmacopeia (USP) specifications. Of 96 vials of compounded PZI, 1 (1 %) contained a concentration of endotoxin > 32 endotoxin U/mL, 23 (24%) had concentrations of insulin in the supernatant > 1.0 U/mL, and 45 (47%) had pH values < 7.1 or > 7.4; all of these values were outside of specifications. Several vials of compounded PZI (52/96 [54%]) did not meet specifications for zinc concentration (0.06 to 0.1 mg/mL for 40 U of insulin/mL, 0.075 to 0.12 mg/mL for 50 U of insulin/mL, and 0.15 to 0.25 mg/mL for 100 U of insulin/mL), and total insulin concentration in 36 [38%] vials was < 90% of the labeled concentration., Conclusions and Clinical Relevance: Only 1 of 12 compounded PZI products met all USP specifications in all vials tested. Use of compounded PZI insulin products could potentially lead to serious problems with glycemic control in veterinary patients.

Background: Vaccination is often cited as a potential cause of immune-mediated thrombocytopenia (ITP) in dogs. Although an association has been documented in humans, particularly in children, this relationship has not been definitively established in dogs., Objectives: To identify the presence of an association between recent vaccination and ITP in dogs., Animals: Forty-eight client-owned dogs with presumptive idiopathic ITP and 96 age-matched, client-owned dogs with non-immune-mediated disease., Methods: Retrospective, case-control study. Dogs were identified through the Veterinary Medical Database (VMDB) and Hospital Information System at Purdue University., Results: The median age at presentation for dogs with ITP was 7 years (range: 2-15 years). The majority of the ITP group was comprised of mixed breed dogs (38%); no pure breed was represented by more than 3 cases. The number of dogs that were vaccinated within 42 days of diagnosis of ITP did not differ significantly (P = .361) between cases of presumptive ITP (4/48, 8%) and the control group (13/96, 14%)., Conclusions and Clinical Importance: This study failed to confirm the presence of an association between presumptive idiopathic ITP in dogs and recent vaccination; however, the possibility of an association cannot be completely ruled out based on the small sample populations and requires further investigation., (Copyright © 2011 by the American College of Veterinary Internal Medicine.)

A 4 yr old spayed female Labrador retriever was referred for acute respiratory distress and was found to have bilateral laryngeal paralysis. Physical examination and biochemical testing were consistent with systemic lupus erythematosus (SLE) and did not reveal a likely alternative cause for the laryngeal paralysis. Following immunosuppressive and supportive treatment, the dog regained normal laryngeal function. At a scheduled follow-up examination 6 wk later, normal laryngeal function was confirmed via sedated laryngeal examination. Laryngeal paralysis associated with SLE has been reported in humans, but this is the first known report of acquired laryngeal paralysis associated with SLE in the dog.

A 15-year-old, spayed female domestic shorthair cat was evaluated for 1-year duration of cyclic intermittent estrous behavior. Diagnostic testing performed before referral, including baseline progesterone concentration, human chorionic gonadotropin (hCG) hormone stimulation test and surgical exploratory laparotomy, had remained inconclusive for a remnant ovary. Evaluation of sex hormones before and after adrenocorticotropic hormone (ACTH) administration revealed increased basal concentrations of androstenedione, estradiol, progesterone, and 17α-hydroxyprogesterone and normal ACTH-stimulated hormone concentrations. Enlargement of the right adrenal gland was identified by abdominal ultrasound. The cat underwent an adrenalectomy and histopathology of the excised adrenal gland was consistent with an adrenocortical carcinoma. Clinical signs resolved immediately following surgery, and most hormone concentrations declined to within or below the reference interval (RI) by 2 months after surgery., (Copyright © 2011 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.)

Unlabelled: ARTICLE RATIONALE: Since the late 1970s, there has been a significant increase in the prevalence of feline hyperthyroidism (FH). It is now recognized worldwide as the most common endocrinopathy of older cats, resembling toxic nodular goiter of older humans in iodine-deficient areas. The purpose of this article is to identify the potential for iodine concentrations in the diet to contribute to the etiology of FH. HISTORICAL CONTEXT: Iodine concentrations of commercial cat foods vary widely. A review of historical iodine recommendations revealed that the units of iodine supplementation changed in the 1970s. Given this change, foods minimally supplemented since the late 1970s would have been iodine deficient for most cats., Practical Relevance: Iodine supplementation of commercial cat foods should be evaluated in the light of the iodine recommendations revised in 2006. Foods may remain deficient in iodine if supplemented at the minimum recommended concentration, possibly contributing to the development of FH., (Copyright 2010 ISFM and AAFP. Published by Elsevier Ltd. All rights reserved.)

Insulin resistance is defined as decreased sensitivity to insulin. Insulin resistance is an important component of the pathogenesis of type 2 diabetes mellitus (DM), and resolution of peripheral insulin resistance in cats with type 2 DM together with good glycemic control may result in diabetic remission. In insulin-dependent diabetic cats, insulin resistance is manifested clinically as an inadequate response to an appropriate pharmacologic dose of insulin. This article focuses on the clinical problem of insulin resistance in insulin-dependent diabetic cats., (Copyright 2010 Elsevier Inc. All rights reserved.)

Primary esophageal squamous cell carcinoma causing stricture was diagnosed in a cat via endoscopy and computed tomography. Difficulty in making this diagnosis via endoscopic biopsy alone is described. Although balloon dilatation was unsuccessful, supportive care via gastrostomy tube feeding and administration of piroxicam successfully allowed a 16-week survival from the time of presentation and a 4-week survival from the onset of treatment with piroxicam.

Unfractionated heparin therapy was initiated at a standard dosage of 300 IU/kg subcutaneously q 6 hours to 18 dogs with immune-mediated hemolytic anemia. Heparin's prolongation of activated partial thromboplastin time and change in factor Xa inhibition (anti-Xa activity) were serially monitored during the first 40 hours of therapy. During the initial 40 hours, only eight of 18 dogs had attained anti-Xa activities of > or =0.35 U/mL. No dogs had clinical signs of hemorrhage. Fifteen dogs survived to discharge; 11 dogs were alive at 1 year, and thrombosis was identified in three of six nonsurvivors that were necropsied.

Background: Although definitive diagnosis of hypoadrenocorticism usually is made by an adrenocorticotrophic hormone (ACTH) stimulation test using 250 microg/dog of synthetic ACTH (cosyntropin/tetracosactrin), increased costs have prompted a search for less-expensive diagnostic methods., Hypothesis: A low-dose ACTH stimulation test (5 microg/kg) will distinguish between dogs with nonadrenal illness and hypoadrenocorticism. Additionally, administration of cosyntropin will not affect the results of another ACTH stimulation test performed 24 hours later., Animals: Eight healthy adult dogs and 29 hospitalized dogs with suspected hypoadrenocorticism., Methods: In this prospective study, each healthy dog received 4 ACTH stimulation tests. Dogs received either 5 microg/kg or 250 microg/dog of cosyntropin on day 1 and the alternate dose on day 2. The opposite dosing sequence was used after a 2-week washout period (days 15 and 16). Dogs with suspected Addison's disease received 2 ACTH stimulation tests, 24 hours apart, using either a dose of 5 microg/kg cosyntropin or 250 microg/dog on the 1st day and the alternate dose on the 2nd day., Results: In healthy dogs, poststimulation cortisol concentrations on days 2 and 16 and days 1 and 15 were equivalent (90% confidence interval [CI]: 86.7-101.2%). In dogs with suspected Addison's disease, mean (+/-SD) cortisol responses to ACTH in the 5 microg/kg dose (16.2+/-7.7 microg/dL) and 250 microg/dog dose (15.9+/-6.3 microg/dL) were statistically equivalent (90% CI: 91.2-105.4%)., Conclusions and Clinical Importance: Low-dose ACTH stimulation testing distinguishes between dogs with nonadrenal illness and hypoadrenocorticism. Additionally, the administration of 2 ACTH stimulation tests on consecutive days does not affect results of the second test.

Canine hypothyroidism may present with a wide range of clinical signs. The most common clinical signs are those of a decreased metabolic rate and dermatologic manifestations; however, many other clinical signs have been associated with hypothyroidism. There is strong evidence for a causal relation between hypothyroidism and a variety of neurologic abnormalities; however, the association between hypothyroidism and other manifestations, such as reproductive dysfunction, clinical heart disease, and behavioral abnormalities, is less compelling. Further studies are necessary to determine the full spectrum of disorders caused by hypothyroidism.

Objective: To compare dogs with glucocorticoid-deficient hypoadrenocorticism (GDH) with those with mineralocorticoid- and glucocorticoid-deficient hypoadrenocorticism (MGDH) and determine prevalence, historical and clinicopathologic markers, and outcome of dogs with GDH., Design: Retrospective case series., Animals: 46 dogs with hypoadrenocorticism., Procedures: Records in the veterinary medical database at Purdue University were searched for dogs in which hypoadrenocorticism had been diagnosed at the Veterinary Teaching Hospital from 1985 to 2005. Data pertaining to signalment, history, a minimum clinicopathologic database, treatment, and outcome were collected. Dogs with hypoadrenocorticism were classified as having MGDH if hyponatremia, hyperkalemia, or both were detected and as having GDH if hyponatremia and hyperkalemia were absent. Dogs were excluded if they had ever been treated with mitotane or had been treated with > 1 dose of corticosteroids within a month prior to the ACTH-stimulation test., Results: 35 dogs with MGDH and 11 dogs with GDH met the inclusion criteria. Dogs with GDH were older at the time of diagnosis and had a longer duration of clinical signs prior to diagnosis than those with MGDH. Dogs with GDH were more likely to be anemic, hypoalbuminemic, and hypocholesterolemic than dogs with MGDH., Conclusions and Clinical Relevance: GDH was more common than reported in a referral hospital population of dogs with primary hypoadrenocorticism. Definitive diagnosis of GDH remains a clinical challenge. Absence of a stress leukogram in dogs with signs of illness (especially relating to the gastrointestinal tract) warrants further investigation. Most dogs with primary cortisol deficiency do not develop mineralocorticoid deficiency.

Background: Intensive vaccination protocols have been suggested as partially responsible for an increased prevalence of autoimmune diseases in dogs in recent years. The aim of this study was to determine whether repeated routine vaccination in dogs is associated with an increased prevalence of thyroiditis., Methodology/principal Findings: We conducted a prospective experimental study with 20 healthy purpose-bred Beagles. Five dogs were vaccinated with a multivalent vaccine and a rabies vaccine. Five dogs received only the multivalent vaccine, and 5 dogs received only the rabies vaccine. Five dogs were unvaccinated controls. The multivalent vaccine was administered at 8, 10, 12, 16, 20, 26, and 52 weeks of age and every 6 months thereafter. The rabies vaccine was administered at 16 and 52 weeks of age and then once a year. Blood samples were collected 1 week before euthanasia for evaluation of thyroid profiles and measurement of antibodies directed against canine thyroglobulin. Dogs were euthanized at 5.5 years of age, and the thyroid glands were evaluated histopathologically. Thyroiditis was present in 8 of 20 (40%) dogs at postmortem examination. No association was found between a dog being vaccinated and the prevalence of thyroiditis at postmortem examination. However, the power of the study to detect such an association was low because of the unexpected high prevalence of thyroiditis in the unvaccinated control dogs. Thyroid function tests were abnormal in 2 of 8 dogs with thyroiditis but were normal in all dogs without thyroiditis., Conclusions/significance: There was no evidence to support an association between routine vaccination and thyroiditis at postmortem examination in beagle dogs after repeated vaccination.

Objective: To evaluate adrenal sex hormone concentrations in response to ACTH stimulation in healthy dogs, dogs with adrenal tumors, and dogs with pituitary-dependent hyperadrenocorticism (PDH)., Design: Prospective study., Animals: 11 healthy control dogs, 9 dogs with adrenal-dependent hyperadrenocorticism (adenocarcinoma [ACA] or other tumor); 11 dogs with PDH, and 6 dogs with noncortisol-secreting adrenal tumors (ATs)., Procedure: Hyperadrenocorticism was diagnosed on the basis of clinical signs; physical examination findings; and results of ACTH stimulation test, low-dose dexamethasone suppression test, or both. Dogs with noncortisol-secreting ATs did not have hyperadrenocorticism but had ultrasonographic evidence of an AT. Concentrations of cortisol, androstenedione, estradiol, progesterone, testosterone, and 17-hydroxyprogesterone were measured before and 1 hour after i.m. administration of 0.25 mg of synthetic ACTH., Results: All dogs with ACA, 10 dogs with PDH, and 4 dogs with ATs had 1 or more sex hormone concentrations greater than the reference range after ACTH stimulation. The absolute difference for progesterone, 17-hydroxyprogesterone, and testosterone concentrations (value obtained after ACTH administration minus value obtained before ACTH administration) was significantly greater for dogs with ACA, compared with the other 3 groups. The absolute difference for androstenedione was significantly greater for dogs with ACA, compared with dogs with AT and healthy control dogs., Conclusions and Clinical Relevance: Dogs with ACA secrete increased concentrations of adrenal sex hormones, compared with dogs with PDH, noncortisol-secreting ATs, and healthy dogs. Dogs with noncortisol-secreting ATs also have increased concentrations of sex hormones. There is great interdog variability in sex hormone concentrations in dogs with ACA after stimulation with ACTH.

Thirteen dogs with primary immune-mediated hemolytic anemia received fresh-frozen plasma within 12 hours of admission, in addition to unfractionated heparin and other therapies, such as prednisone, azathioprine, and packed red blood cell transfusion. Antithrombin activity was quantified prior to transfusion and at 30 minutes and 48 hours after transfusion. Plasma antithrombin activity did not change significantly after a single plasma transfusion. There were no deaths in the first 48 hours of treatment. Thromboembolism was identified at necropsy in six of 10 dogs that died within 12 months of admission. There was no significant difference in the incidence of thromboembolism between the current treatment group and a historical control group.

Objective: To determine whether the increasing prevalence of feline hyperthyroidism is the result of aging of the cat population and whether consumption of canned foods at various times throughout life is associated with increased risk of hyperthyroidism., Design: Retrospective and case-control studies., Study Population: Medical records of 169,576 cats, including 3,570 cats with hyperthyroidism, evaluated at 9 veterinary school hospitals during a 20-year period, and 109 cats with hyperthyroidism (cases) and 173 cats without hyperthyroidism (controls)., Procedure: Age-adjusted hospital prevalence of hyperthyroidism was calculated by use of Veterinary Medical Database records. On the basis of owners' questionnaire responses, logistic regression was used to evaluate associations between consumption of canned food and development of hyperthyroidism., Results: Age-specific hospital prevalence of feline hyperthyroidism increased significantly from 1978 to 1997. Overall, consumption of pop-top canned (vs dry) food at various times throughout life and each additional year of age were associated with greater risk of developing hyperthyroidism. In female cats, increased risk was associated with consumption of food packaged in pop-top cans or in combinations of pop-top and non-pop-top cans. In male cats, increased risk was associated with consumption of food packaged in pop-top cans and age., Conclusions and Clinical Relevance: These findings suggest that the increasing prevalence of feline hyperthyroidism is not solely the result of aging of the cat population and that canned foods may play a role.

A placebo-controlled experiment was performed to evaluate the effect of potassium bromide on the canine thyroid gland. Basal total thyroxine, free thyroxine, and basal thyrotropin serum concentrations were evaluated over a 6-month period in potassium bromide-treated and control dogs. A thyrotropin-releasing hormone stimulation test was also performed in all dogs at the beginning and conclusion of the study. Thyroid histopathology was compared between treated and control dogs at the end of the study. No difference was detected in any parameter between the two groups at the end of the study. A decline in thyroid hormone concentrations over the course of the study did occur in both groups of dogs. Potassium bromide does not appear to have a significant effect on canine thyroid function or morphology.

Background: The concentration of canine adrenocorticotropic hormone (ACTH) is usually determined by radioimmunoassay. However, chemiluminescent assay techniques have many advantages for clinical endocrine testing., Objectives: The objectives of this study were to validate a commercially available chemiluminescent assay for determination of canine ACTH concentration and to determine whether protease inhibitors are appropriate for use in the chemiluminescent assay system., Methods: Biological specificity was evaluated by treatment of 3 dogs with ovine corticotropin-releasing hormone (CRH) followed by serial measurements of ACTH and by comparison with a previously validated immunoradiometric assay. All samples were collected both in the presence and absence of aprotinin, a protease inhibitor. The assay was further evaluated by measurement of intra-assay precision, interassay precision, and recovery after dilution., Results: Baseline ACTH concentrations ranged from 5.6 to 15.3 pg/mL, and maximum ACTH concentrations of 158 to 1240 pg/mL were observed 30-60 minutes after CRH administration. Plasma samples collected with aprotinin had significantly lower ACTH concentrations than did samples collected without aprotinin. The intra-assay coefficients of variance (CVs) ranged from 4.1 to 8.2%, and interassay CVs ranged from 4.6. to 14.8%. Recovery after dilution with canine plasma ranged from 93.4 to 103.0% of predicted concentration; however, inadequate recovery was observed with other diluents. There was a high correlation with the immunoradiometric assay (r =.925) but a significant negative bias (-32.9, 95% confidence interval -50.8 to -14.9)., Conclusions: This chemiluminescent assay is a valid technique for measurement of ACTH in canine plasma. ACTH concentration measured by chemiluminescence is lower than that measured by immunoradiometry. Aprotinin decreases the measured concentration of ACTH, and this effect should be taken into account when interpreting results. Diluents supplied with the kit should not be used for dilution of canine samples.

Objective: To determine whether routine vaccination induces antibodies against bovine thyroglobulin and autoantibodies against canine thyroglobulin in dogs., Design: Prospective study., Animals: 20 healthy research Beagles and 16 healthy pet dogs., Procedure: For the research Beagles, 5 dogs were vaccinated with a multivalent vaccine and a rabies vaccine, 5 dogs received only the multivalent vaccine, 5 dogs received only the rabies vaccine, and 5 dogs were unvaccinated controls. The multivalent vaccine was administered at 8, 10, 12, 16, 20, 26, and 52 weeks of age and every 6 months thereafter. The rabies vaccine was administered at 16 and 52 weeks of age and then once per year. Blood was collected from all dogs at 8, 16, and 26 weeks of age and then 4 times yearly. Assays for antibodies directed against bovine and canine thyroglobulin were performed prior to and 2 weeks after each yearly vaccination. For the pet dogs, blood was collected prior to and 2 weeks after 1 vaccination., Results: In the research Beagles, there was a significant increase in anti-bovine thyroglobulin antibodies in all vaccinated dogs, compared with control dogs. There was a significant increase in anti-canine thyroglobulin antibodies in the 2 groups of dogs that received the rabies vaccine but not in the group that received the multivalent vaccine alone. In the pet dogs, there was a significant increase in anti-canine thyroglobulin antibodies after vaccination but no significant change in anti-bovine thyroglobulin antibodies., Conclusions and Clinical Relevance: Recent vaccination may result in increased anti-canine thyroglobulin antibodies. Whether these antibodies have a deleterious effect on canine thyroid function is unknown.

An 11-year-old spayed female Labrador Retriever and a 9-year-old castrated male miniature Poodle were evaluated because of clinical signs of hyperadrenocorticism. Cortisol testing did not support a diagnosis of hypercortisolemia in either dog; however, imaging studies revealed unilateral adrenal tumors in both dogs. Serum concentrations of 17-hydroxyprogesterone, progesterone, and estradiol were high in both dogs, and androstenedione concentrations were also high in 1 dog. It is suspected that sex hormone secretion by the adrenal tumors in these dogs resulted in clinical signs of hyperadrenocorticism. Clinical signs and hormonal abnormalities resolved in the male dog after surgical resection of the tumor. There was no improvement in clinical signs after treatment with mitotane in the female dog, which died 2 months after diagnosis. Histologic evaluation confirmed the presence of adrenocortical carcinoma in both dogs.

A seven-year-old, neutered male domestic shorthair cat was evaluated for poorly regulated diabetes mellitus and increased skin fragility. Imaging studies revealed a right adrenal gland tumor, but cortisol testing did not support a diagnosis of hyperadrenocorticism. Serum concentrations of progesterone and testosterone were increased compared with a group of normal cats, and the clinical signs were attributed to hyperprogesteronemia. At necropsy, a diagnosis of adrenocortical adenocarcinoma was confirmed, and immunohistochemical staining confirmed the presence of progesterone within the tumor. Clinical signs of hyperadrenocorticism in cats may occur due to increased serum concentrations of hormones other than cortisol.

Objective: To evaluate effects of dietary insoluble fiber on control of glycemia in cats with naturally acquired diabetes mellitus., Design: Randomized controlled crossover trial., Animals: 16 cats with naturally acquired diabetes mellitus., Procedure: Cats were fed a diet high in insoluble fiber (HF) containing 12% cellulose (dry-matter basis) or a diet low in insoluble fiber (LF) for 24 weeks; they were fed the other diet for the subsequent 24 weeks. Caloric intake and insulin treatment were adjusted to maintain stable body weight and control of glycemia, respectively. Cats were allowed an adaptation period of 6 weeks after initiation of a diet, after which control of glycemia was evaluated at 6-week intervals for 18 weeks. Variables assessed included serum glucose concentration measured during the preprandial state, blood glycated hemoglobin concentration, serum glucose concentration measured at 2-hour intervals for 12 hours beginning at the time of the morning insulin injection, 12-hour mean serum glucose concentration, and mean fluctuation in serum glucose concentration from the 12-hour mean serum glucose concentration., Results: Mean daily caloric intake, body weight, or daily insulin dosage did not differ significantly between cats when fed HF and LF diets. Mean preprandial serum glucose concentration, most post-prandial serum glucose concentrations, and the 12-hour mean serum glucose concentration were significantly lower when cats consumed the HF diet, compared with values when cats consumed the LF diet., Conclusions and Clinical Relevance: These results support feeding a commercially available diet containing approximately 12% insoluble fiber (dry-matter basis) to cats with naturally acquired diabetes mellitus.

This investigation was designed to compare in vitro dissolution profiles from sodium iodide capsules with radioiodide thyroid uptake in hyperthyroid cats using sodium iodide capsules prepared with a formulation exhibiting a complete release of radioiodide (I-123) in vitro and a formulation with an incomplete release of radioiodide. In vitro dissolution profiles for I-123 sodium iodide capsules with two different formulations were determined using the USP XXIII dissolution test. The two formulations studied in vitro were sodium phosphate dibasic powder with 1% magnesium stearate and calcium phosphate dibasic powder with 3% magnesium stearate. By 20 min after initiation of the dissolution test, over 95% of the I-123 was released from capsules of sodium phosphate dibasic powder. The capsules of calcium phosphate dibasic powder reached 75% at 65 min, with no further release occurring thereafter. There was a statistically significant difference in the dissolution profiles of the two formulations. The thyroid uptake of I-123 from capsules exhibiting complete release and incomplete release of radioiodide was determined in hyperthyroid cats. At 4 hr, the mean percentage thyroid uptake value for sodium phosphate dibasic powder with 1% magnesium stearate (complete release formulation) was 12.0% compared to 9.4% for calcium phosphate dibasic powder with 3% magnesium stearate (incomplete release formulation); at 24 hr, the values were 34.4% compared to 23.7%. The data suggest that the incomplete dissolution profile observed in vitro may correlate with a reduction in the bioavailability of the radioiodide in vivo. However, using the Wilcoxon signed rank test, statistically significant differences did not occur between the complete release formulation and incomplete release formulation at either 4 hr or 24 hr (p > .05). The results of the in vivo study with five hyperthyroid cats were not conclusive due to the variability in response between individual cats.

Objective: To determine whether measuring change in serum thyroid-stimulating hormone (TSH) concentration in response to thyrotropin-releasing hormone (TRH) administration can be used as a test of thyroid function in dogs suspected of having hypothyroidism., Design: Case-cohort study., Animals: 13 healthy dogs, 20 hypothyroid dogs, and 18 euthyroid dogs with concurrent diseases., Procedure: Blood samples were collected before and 30 minutes after TRH administration, and serum TSH concentration was measured. The 13 healthy dogs were used to establish a reference range for change in TSH concentration after TRH administration. The remaining 38 dogs were categorized as hypothyroid or euthyroid on the basis of baseline total thyroxine (T4) and TSH concentrations, T4 concentration 4 hours after TRH administration, and clinical response to administration of sodium levothyroxine., Results: Median baseline TSH concentration was 0.25 ng/ml (range, 0.03 to 0.44 ng/ml) in healthy dogs, 0.93 ng/ml (0.21 to 3.5 ng/ml) in hypothyroid dogs, and 0.21 ng/ml (0.03 to 0.63 ng/ml) in euthyroid dogs with concurrent diseases. Median percentage change in TSH concentration after TRH administration was 207% (range, 25 to 2,200%) in healthy dogs, 24% (-21 to 134%) in hypothyroid dogs, and 167% (69 to 1,800%) in euthyroid dogs with concurrent diseases. Overall accuracy of using the TRH-induced change in TSH concentration to identify hypothyroid dogs was 90%., Clinical Implications: Although percentage change in TSH concentration in response to TRH administration can be used to differentiate euthyroid from hypothyroid dogs, the test has little advantage over measurement of baseline TSH and total or free T4 concentration.