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Background Blood l-lactate concentrations are higher in people with developing or established diabetes mellitus and insulin resistance. Objectives To investigate whether blood l-lactate concentrations are positively correlated with measures of insulin dysregulation (ID) or increased autumnal ACTH concentrations in ponies. Animals Systemically healthy client-owned ponies (n = 101). Methods Prospective case-control study. Blood samples were obtained from 101 clinically healthy ponies. Breed, weight, height, and subjective and objective measures of body condition were recorded. Blood l-lactate, glucose, triglyceride, total adiponectin, and ACTH concentrations were measured and an oral sugar test (OST) was carried out. Correlations between blood l-lactate and variables of endocrine health were determined. Results Using a seasonal cutoff point of ACTH concentrations ≥47 pg/mL, 55 ponies had increased autumnal ACTH concentrations and 45 did not. Using a basal insulin concentration of >50 μiU/mL, 42 ponies were diagnosed with ID and 58 were not. Using a 60 minutes after OST cutoff point of >45 μiU/mL, 57 ponies had ID and 37 did not. Blood l-lactate concentrations were significantly lower in obese (average body condition score ≥ 7/9) compared to nonobese ponies (0.6 mmol/L; range, 0.0-1.9 mmol/L vs 0.8 mmol/L; range, 0.3-2.7 mmol/L; P = .01). No other significant correlations were detected. No differences were detected between ponies with and without increased autumnal ACTH concentrations (0.7 mmol/L; range, 0.0-2.7 mmol/L vs 0.7 mmol/L; range, 0.3-1.8 mmol/L; P = .84) and with and without ID (0.7 mmol/L; range, 0.3-2.7 mmol/L vs 0.8 mmol/L; range, 0.0-1.6 mmol/L; P = .63). Conclusions and clinical importance Results do not support an effect of endocrine status on l-lactate concentrations in blood of ponies.

OBJECTIVE: Hyponatremia and rapid correction of hyponatremia can lead to neurological abnormalities. The objective of the study was to determine whether plasma sodium concentrations (Na⁺) and speed of correction of hyponatremia are significantly associated with neurological abnormalities in foals. DESIGN: Retrospective cohort study 2012 to 2016. SETTING: Equine hospital. ANIMALS: One hundred and nine foals

Background Blood l‐lactate and glucose concentrations were higher in ponies with gastrointestinal disease than in horses, possibly because of differences in body condition (BC). Objectives To investigate whether l‐lactate and glucose concentrations correlate with BC and differ between healthy horses and ponies. Animals Systemically healthy client‐owned ponies (n = 101) and horses (n = 51). Methods Prospective observational study. Breed, weight, height, and subjective and objective measures of BC were recorded and l‐lactate and glucose concentrations were measured. Correlations between l‐lactate and glucose concentrations and BC were established. The association between l‐lactate concentrations, equid type (pony or horse), BC, age, and glucose concentrations was investigated using a multivariable model. Results Weak but significant (P = .001) negative correlations were detected between l‐lactate concentration and average BC score (r = −0.29), heart girth:height ratio (r = −0.27), and age (r = −0.27). Glucose concentrations were significantly (P

OBJECTIVES: A recent study described increased l‐lactate concentrations in ponies with gastrointestinal disease compared to horses, but blood glucose (BG) concentrations were not considered. The study tested the hypothesis that BG and l‐lactate concentrations are correlated in horses and ponies with gastrointestinal disease and that BG concentrations, not equid type (pony vs horse), are an independent predictor of L‐lactate concentrations. It was further hypothesized that equid type was an independent predictor of BG concentrations. DESIGN: Retrospective study 2008–2016. SETTING: University teaching hospital. ANIMALS: Admission data from 545 animals (384 horses and 161 ponies) with gastrointestinal disease. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Data collected included signalment, clinicopathological findings on admission, and nature and location of the gastrointestinal lesion (strangulating vs non‐strangulating and large vs small intestinal lesion). The association between admission blood l‐lactate concentrations, equid type (pony or horse) and BG concentrations was investigated in a multivariable model. Admission l‐lactate and BG concentrations were strongly correlated (n = 522; r = 0.63; P

The glycocalyx, a gel-like layer covering the luminal surface of vascular endothelial cells has several key functions in maintaining homeostasis in the vasculature. Interest in the glycocalyx has significantly increased in the last decades and damage to this vital layer appears to influence progression and recovery in many disease processes. Pathological injury to the glycocalyx occurs in ischaemia–reperfusion, inflammation, sepsis, shock, burns and excessive shear stress. There is increasing evidence that iatrogenic interventions such as fluid therapy influence the integrity of the glycocalyx and can even worsen the initial injury from pathological events. Rapid infusion of crystalloids and colloids, hypervolaemia, hypernatraemia and hyperglycaemia have all been associated with increased glycocalyx shedding. Current treatment recommendations aim to minimise iatrogenic damage. In the future, interventions aimed at restoring glycocalyx integrity and function might become valuable tools in critical care.

BackgroundVenous air embolism is a potentially life-threatening complication of IV catheter use in horses. Despite widespread anecdotal reports of their occurrence, few cases have been reported in the literature and the prognosis is currently unknown.Hypothesis / ObjectivesOur objective was to describe the surrounding circumstances, clinical signs, treatment, progression and outcome of venous air embolism in hospitalized horses.AnimalsThirty-two horses with acute onset of compatible clinical signs associated with IV catheter disconnection or damage.MethodsMulticenter retrospective study. Data extracted from clinical records included signalment, presenting complaint, catheter details, clinical signs, treatments and outcome. ResultsMost cases resulted from extension set disconnection occurring within approximately 24 hours after catheter placement. In fewer horses, extension set damage was cited as a cause. Common clinical signs included tachycardia, tachypnea, recumbency, muscle fasciculations and agitation, with abnormal behavior including kicking and flank biting. Less commonly, pathological arrhythmias or more severe neurologic signs, including blindness and seizures, were noted. Progression was unpredictable, with some affected horses developing delayed-onset neurologic signs. Mortality was 6/32 (19%), including 2 cases of sudden death and other horses euthanized because of persistent neurologic deficits. Negative outcomes were more common in horses with recorded blindness, sweating or recumbency, but blindness resolved in 5/8 affected horses. Conclusions and clinical importanceThe prognosis for resolution of clinical signs after air embolism is fair, but permanent neurologic deficits or pathologic cardiac arrhythmias can arise. Unpredictable progression warrants close monitoring. Systematic clinic-based surveillance could provide additional useful information to aid prevention.

A neurofibroma of granular cell subtype is described in a 7-year-old horse. The horse had a 3-month history of ataxia affecting the forelimbs and hindlimbs, suggesting a C1-C6 neuroanatomical localization. Post-mortem examination revealed an intradural mass arising from the right sixth cervical spinal nerve and compressing the spinal cord. Histologically, the mass was composed largely of wavy spindle cells (a mixture of Schwann cells, perineurial cells and fibroblasts) intimately associated with ropy collagen fibres. Approximately 25% of the spindle cells were swollen and contained densely-packed, eosinophilic and periodic acid-Schiff-positive cytoplasmic granules. Immunohistochemistry for S100 and glial fibrillary acidic protein antigens labelled a proportion of neoplastic cells, while the cytoplasmic granules were positive for S100 and neuron specific enolase. This is the first report of a neurofibroma with granular cell differentiation in an animal. Granular cell differentiation in other peripheral nerve sheath tumours of animals is briefly discussed.

Background Serum bile acid concentrations (SBA) and a histopathological biopsy score [Equine Vet J 35 (2003) 534] are used prognostically in equine hepatic disease. Hypothesis Histopathologic features and scores, but not SBA, differ between survivors and nonsurvivors and correlate with histopathologic evidence of hepatic inflammation and fibrosis. Animals Retrospective study. Records (1999–2011) of horses with hepatic disease diagnosed by biopsy and with concurrent measurements of SBA. Methods Retrospective cohort study. Biopsies were examined for inflammatory cell infiltration including type and distribution, fibrosis, irreversible cytopathology affecting hepatocytes, hemosiderin, or other pigment deposition and bile duct proliferation. SBA, histopathological findings and a histological score [Equine Vet J 35 (2003) 534] were compared between short- (survival to discharge) and long-term (>6 months) survivors and correlations between SBA and histopathological findings investigated. Results Of 81 cases 90% survived short-term and 83% long-term. Short-term and long-term nonsurvival were associated with SBA (P = .009; P = .006), overall (P = .001; P = .002) and parenchymal (short-term only; P = .01) inflammation, portal and bridging fibrosis (all P 2 and, less so, SBA >20 μmol/L are specific but not sensitive indicators of nonsurvival.

Objective—To examine factors associated with short- and long-term prognosis for horses undergoing repeated celiotomy within 14 days after the first colic surgery. Design—Retrospective case series. Animals—95 horses that had undergone 2 celiotomies within a 14-day period between 2005 and 2013 at 3 equine referral hospitals. Procedures—Historical, clinical, and laboratory data were compared between horses that did not survive and horses that did survive to hospital discharge (short-term survival rate) and to > 3 and > 6 months after hospital discharge (long-term survival rates). Results—Strangulating small intestinal lesions were the most common finding during the first celiotomy (60/95 [63.2%]), and persistent gastric reflux was the most common reason for the second celiotomy (56/95 [58.9%]). Reasons for a second celiotomy were not associated with survival rate. For horses that had long-term follow-up, 22 of 92 (23.9%) survived > 6 months after hospital discharge. Two of 13 horses with intestinal resections during both surgeries survived to > 6 months after hospital discharge. Compared with horses not undergoing intestinal resection, significantly fewer horses requiring resection during 1 or both surgeries survived to hospital discharge and to > 3 and > 6 months after hospital discharge. Incisional infections occurred in 68.4% (26/38) of horses that survived to hospital discharge, and 31.6% (12/38) developed incisional hernias or dehiscence. Conclusions and Clinical Relevance—Results indicated that the prognosis for horses undergoing repeated celiotomy is guarded, and intestinal resection negatively affects the long-term survival rate.

Objectives To investigate whether acupuncture can alter gait in horses as assessed by objective and subjective parameters. Study design Prospective, randomized, singleblinded, crossover study. Animals Eight adult horses. Methods Horses were randomly assigned to a treatment (three acupuncture treatments in 8 days) or control group. Subjective and objective gait analyses were performed before and after each treatment and at 1, 3 and 7 days after the last treatment (time-points 1–9, respectively). Horses were assessed at the trot in a straight line on a hard surface and on the lunge on the left and right reins on a soft surface (conditions 1–3, respectively). After 12 weeks, groups were reversed. Objective gait analysis was performed using inertial sensors and subjective analysis by two board- certified surgeons who reviewed video-recordings. Each limb was assessed for lameness before and after treatment. Lameness and global scores were assigned using 4-point scales. Assessors were blinded to treatment status. The effects of treatment (yes/no), time (1–9) and horse under conditions 1 –3 were compared using a linear mixed-effects model and a generalized estimating equation. Results Treatment decreased hip hike difference under all conditions [condition 1: control, 6.3 ± 6.4 mm versus treatment, –0.2 ± 6.4 mm (p = 0.007); condition 2: control, 9.7 ± 7.8 mm versus treatment, 2.8 ± 7.8 mm ( p = 0.032); condition 3: control, 7.3 ± 6.3 mm versus treatment, –2.7 ± 6.4 mm ( p = 0.003)]. Other parameters also improved significantly under conditions 1 and 3. Based on subjective gait analysis, treatment decreased lameness [odds ratio (OR) 0.51, 95% confidence interval (CI) 0.34–0.78; p = 0.002] but not global (OR 0.53, 95% CI 0.24–1.10; p = 0.12) scores. Conclusions and clinical relevance Acupuncture can change horses' gaits to a degree appreciable by objective and subjective analyses.

Protein kinase C (PKC) is an important regulator of platelet activation and different isoenzymes can play positive and negative regulatory roles. The PKC isoenzymes expressed in equine platelets have not been documented but pharmacological inhibition has suggested a role for PKC delta (δ) in modulating responsiveness to platelet activating factor (PAF) ( Brooks et al., 2009 ). Here the PKC isoenzyme profile in equine platelets has been characterised and PKCδ activation by PAF investigated. Platelet lysates were probed by Western blotting using a panel of antibodies against individual PKC isoenzymes. PKCδ and eight other isoenzymes were identified, namely classical PKCs alpha (α), beta (β), (both βI and βII) and gamma (γ), the novel PKCs epsilon (ɛ), eta (η) and theta (θ) and atypical PKC zeta (ζ). Having shown PKCδ to be present, a method was developed to measure PAF-induced isoenzyme translocation by preparing cytosolic and membrane fractions from digitonin permeabilised platelets. Phorbol 12-myristate 13-acetate (PMA) was shown to cause translocation of PKCδ to the membrane within 5 s. PAF also caused PKCδ translocation although the response occurred more slowly; a significant, 7.6 ± 1.2 fold, increase in band density compared to unstimulated platelets was observed at 15 min; p = 0.036, n = 3. These data support a role for PKCδ in regulating PAF-induced functional responses in equine platelets.

Summary Reasons for performing study: Sporadic measurement of serum triglycerides in depressed and inappetant clinically ill horses revealed severe hypertriglyceridaemia without visible evidence of lipaemia on several occasions, leading to the inclusion of serum triglyceride concentrations in the routine serum biochemistry evaluation of our hospital. Since then, more cases have been identified and treated for hypertriglyceridaemia, raising questions about the prevalence, predisposing factors and significance of these findings. Hypotheses: 1) Severe hypertriglyceridaemia without visible opacity of the serum occurs more commonly in clinically ill and inappetant horses than previously described and 2) appropriate treatment using i.v. dextrose and/or partial parenteral nutrition would decrease serum triglycerides to normal limits and might result in improved appetite and attitude of the patient. Methods: The laboratory computer database from 2000 and 2001 was searched for increased serum triglycerides (>5.65 mmol/l) in any horse breed, ponies and miniature breeds excluded. Data analysed included subject details, diagnosis, clinical and laboratory parameters, treatment, response to treatment and outcome. Results: Severe hypertriglyceridaemia was identified in 13 horses, with serum triglyceride concentrations 6.17–18.29 mmol/l, while none showed visible lipaemia. All horses had clinical and laboratory findings consistent with systemic inflammatory response syndrome and all but one had an increased serum creatinine concentration. Treatment with i.v. dextrose and/or partial parenteral nutrition resulted in decrease of the serum triglycerides to normal limits. Conclusions: Severe hypertriglyceridaemia occurs in inappetant and clinically ill horses without evidence of serum opacity more commonly than previously described. The presence of systemic inflammatory response syndrome might predispose horses to hypertriglyceridaemia, while the increased creatinine concentration might be a predisposing factor or result of the condition. Horses identified in our study readily responded to treatment and appetite and attitude improved coincident with decrease of the serum triglycerides to normal limits. Potential relevance: Hypertriglyceridaemia could perpetuate inappetance and depression in clinically ill horses and potentially predispose to fatty infiltration of the liver and other organ systems.

Summary Reasons for performing study: Few reports exist in the veterinary medical literature describing clinical and pathological findings resembling conditions described as (ALI) and acute respiratory distress syndrome (ARDS) in man. Objectives: To document history, clinical, laboratory and diagnostic findings, treatment and outcome of foals age 1–12 months diagnosed with ALI/ARDS at a referral hospital. Methods: Medical records, including radiographic, cytological, microbiological, serological and post mortem findings, were reviewed in a retrospective manner to identify foals with acute onset of respiratory distress, a partial pressure of arterial oxygen (PaO2) to fraction of oxygen in inspired gases (FiO2) ratio of ≤300 mmHg, pulmonary infiltrates on thoracic radiographs or post mortem findings consistent with ALI/ARDS. Results: Fifteen foals age 1.5–8 months were included in the study. Seven foals had previously been treated for respiratory disease, and all foals developed acute respiratory distress < 48 h prior to presentation. Findings on presentation included tachycardia and tachypnoea in all foals, with fever recorded in 8 cases. Eight cases met the criteria for ALI and 7 for ARDS. Radiographic findings demonstrated diffuse bronchointerstitial pattern with focal to coalescing alveolar radiopacities. An aetiological agent was identified in foals ante mortem (n = 6) and post mortem (n = 4). All foals were treated with intranasal oxygen and antimicrobial drugs; 13 received corticosteroids. Nine patients survived, 4 died due to respiratory failure and 2 were subjected to euthanasia in a moribund state. Follow-up was available for 7 foals; all performed as well as age mates or siblings, and one was racing successfully. Conclusions: A condition closely meeting the human criteria for ALI/ARDS exists in foals age 1–12 months and may be identical to previously described acute bronchointerstitial pneumonia in young horses. Potential relevance: ALI/ARDS should be suspected in foals with acute severe respiratory distress and hypoxaemia that is minimally responsive to intranasal oxygen therapy. Treatment with systemic corticosteroids, intranasal oxygen and antimicrobials may be beneficial in foals with clinical signs compatible with ALI/ARDS.

Recurrent airway obstruction (RAO) in mature horses is characterized by reversible airway obstruction and neutrophilic inflammation; there is also functional activation of circulating platelets and neutrophils. This study was undertaken to determine if changes in activation marker expression and heterotypic aggregate formation can be used as an indicator of this increased functional responsiveness. In vitro conditions for flow cytometric measurement of CD13, CD41/61 and CD62P expression on activated cells and heterotypic aggregate formation were established. Values were then compared before and after antigen challenge of RAO and healthy horses. Platelet adhesion to serum-coated plastic was measured as a functional marker of platelet activation. In vitro activation resulted in increased expression of neutrophil CD13 and platelet CD41/61 and CD62P. Activation of both cell types caused a significant increase in neutrophil–platelet aggregates. In horses with RAO, but not controls, there was a significant increase in the percentage of CD13 positive neutrophils at 10 h and 24 h and in the mean fluorescence intensity at 10 h. This was accompanied at 24 h by an increased mean platelet side scatter and thrombin-stimulated platelet adhesion. In conclusion, CD13 expression can be used as an indicator of equine neutrophil activation both in vitro and in vivo . Equine platelet activation in vitro can be detected by measuring CD41/61 or CD62P expression, and PAF-activated platelets and neutrophils form aggregates. However, despite evidence of circulating platelet activation, neither a change in expression of platelet activation markers, nor heterotypic aggregate aggregate formation could be detected.

BACKGROUND: Information about treatment protocols, adverse effects and outcomes with intrapleural recombinant tissue plasminogen activator (rTPA) use in horses with fibrinous pleuropneumonia is limited.HYPOTHESIS/OBJECTIVES: Describe factors that contribute to clinical response and survival of horses treated with rTPA intrapleurally.ANIMALS: Horses with bacterial pneumonia and fibrinous pleural effusion diagnosed by ultrasonography, that were treated with rTPA intrapleurally.METHODS: Retrospective multicenter case series from 2007-2012. Signalment, history, clinical and laboratory evaluation, treatment, and outcome obtained from medical records. Regression analysis used to identify associations between treatments and outcomes.RESULTS: Thirty three hemithoraces were treated in 25 horses, with 55 separate treatments. Recombinant tissue plasminogen activator (375-20,000 μg/hemithorax) was administered 1-4 times. Sonographically visible reduction in fibrin mat thickness, loculations, fluid depth, or some combination of these was seen in 32/49 (65%) treatments. Response to at least 1 treatment was seen in 17/20 (85%) horses with sonographic follow-up evaluation after every treatment. Earlier onset of rTPA treatment associated with increased survival odds. No association was found between cumulative rTPA dose or number of rTPA doses and survival, development of complications, duration of hospitalization or total charges. Clinical evidence of hypocoagulability or bleeding was not observed. Eighteen horses (72%) survived to discharge.CONCLUSIONS AND CLINICAL IMPORTANCE: Treatment with rTPA appeared safe and resulted in variable changes in fibrin quantity and organization within the pleural space. Recombinant tissue plasminogen activator could be a useful adjunct to standard treatment of fibrinous pleuropneumonia, but optimal case selection and dosing regimen remain to be elucidated.

Objective—To create a mathematical model to assist in early prediction of the probability of discharge in hospitalized foals ≤ 7 days old. Study Design—Prospective study. Animals—1,073 foals. Procedures—Medical records from 910 hospitalized foals ≤ 7 days old for which outcome was recorded as died or discharged alive were reviewed. Thirty-four variables including historical information, physical examination findings, and laboratory results were examined for association with survival. Variables associated with being discharged alive were entered into a multivariable logistic regression model. Accuracy of the model was validated prospectively on data from 163 foals. Results—Factors in the final model included age group, ability to stand, presence of a suckle reflex, WBC count, serum creatinine concentration, and anion gap. Sensitivity and specificity of the model to predict live discharge were 92% and 74%, respectively, in the retrospective population and 90% and 46%, respectively, in the prospective population. Accuracy of an equine clinician's initial prediction of the foal being discharged alive was 83%, and accuracy of the model's prediction was 81%. Combining the clinician's prediction of probability of live discharge with that of the model significantly increased (median increase, 12%) the accuracy of the prediction for foals that were discharged and nonsignificantly decreased (median decrease, 9%) the accuracy of the predication for nonsurvivors. Conclusions and Clinical Relevance—Combining the clinician's initial predication of the probability of a foal being discharged alive with that of the model appeared to provide a more precise early estimate of the probability of live discharge for hospitalized foals.

Clinical impression suggests that some gastrointestinal lesions are more common in certain horse types. The study tested the hypothesis that relative prevalence of acute gastrointestinal lesions differs between equid types. In a retrospective caseâ€"control study, records (2010â€"2015) were reviewed for equids with acute gastrointestinal disease. Signalment, details of gastrointestinal lesions and diagnoses were recorded. Animals were categorised as miniature type, pony, Arabian, light breed or draft type. Exclusion criteria were no recorded breed/size/diagnosis, age less than one year and donkeys. Using binary logistic regression the influence of type, sex and age on lesion location, nature and diagnoses were investigated. 575 animals (33 miniature types, 136 ponies, 335 light breed types, 17 Arabians and 54 draft types) were included. Using light breed types as reference, ponies (including miniatures) had decreased odds of colon displacements (OR 0.11; 95 per cent CI 0.05 to 0.24; P0.001) and ponies alone had increased odds of strangulation of the small intestine by lipomas (OR 2.3; 95 per cent CI 1.3 to 4.1; P=0.004). Miniature types had decreased odds of strangulating small intestinal lesions (OR 0.1; 95 per cent CI 0.01 to 0.83; P=0.033) and draft types had increased odds of caecal conditions (OR 9.0; 95 per cent CI 2.3 to 34.8; P0.001). In conclusion, equid type influences development of gastrointestinal lesions.

A retrospective questionnaire-based survey was used to determine the perceived efficacy of Newmarket bloodroot ointment in treating equine sarcoids. In 49 horses with 74 sarcoids, 64 sarcoids responded either completely (n = 49) or partially (n = 15) while 10 did not respond or worsened. Sarcoids < 2 cm responded better to treatment (P < 0.001) than did larger sarcoids.

To discuss controversies surrounding antimicrobial use in critically ill horses.PubMed searches from 1970-present for terms including, but not limited to: "horse," "foal," "antimicrobial," "prophylaxis," "infection," "surgery," "sepsis," and "antimicrobial resistance."Increasing bacterial antimicrobial resistance has changed first-line antimicrobial choices and prompted shortening of the duration of prophylactic and therapeutic treatment. The need to decrease bacterial resistance development to critically important antimicrobials has been highlighted.Veterinary medicine has followed a similar trend but often without a high-level evidence. Common dilemmas include diseases in which the theoretically most effective drug is a reserved antimicrobial, the inability to differentiate infectious from noninfectious disease, the duration and necessity of prophylactic antimicrobials and use of antimicrobials in primary gastrointestinal disease. These problems are illustrated using examples of purulent infections, neonatal sepsis, colic surgery, and treatment of colitis. Although enrofloxacin, cephalosporins, and doxycycline, in contrast to gentamicin, reach therapeutic concentrations within the lungs of healthy horses, the first two should not be used as first line treatment due to their reserved status. Due to the high risk of bacterial sepsis, antimicrobial treatment remains indispensable in compromised neonatal foals but shortening the length of antimicrobial treatment might be prudent. One prospective randomized study demonstrated no difference between 3 and 5 days of perioperative antimicrobial treatment in colic surgery but shorter durations were not evaluated. High-level evidence to recommend antimicrobial treatment of adult horses with undifferentiated diarrhea does not exist.Few evidence-based recommendations can be made. Commonly used antimicrobial combinations remain the mainstay for treating purulent infections. Antimicrobial treatment for compromised foals should not extend beyond recovery. Continuation of prophylactic antimicrobials3 days is likely unnecessary after colic surgery; shorter durations might be equally effective. Antimicrobial prophylaxis in adult horses with diarrhea is unlikely to be beneficial.

Background Reproducible and accurate recognition of presence and severity of ataxia in horses with neurologic disease is important when establishing a diagnosis, assessing response to treatment, and making recommendations that might influence rider safety or a decision for euthanasia. Objectives To determine the reproducibility and validity of the gait assessment component in the neurologic examination of horses. Animals Twenty-five horses referred to the Royal Veterinary College Equine Referral Hospital for neurological assessment (n = 15), purchased (without a history of gait abnormalities) for an unrelated study (n = 5), or donated because of perceived ataxia (n = 5). Methods Utilizing a prospective study design; a group of board-certified medicine (n = 2) and surgery (n = 2) clinicians and residents (n = 2) assessed components of the equine neurologic examination (live and video recorded) and assigned individual and overall neurologic gait deficit grades (0–4). Inter-rater agreement and assessment-reassessment reliability were quantified using intraclass correlation coefficients (ICC). Results The ICCs of the selected components of the neurologic examination ranged from 0 to 0.69. “Backing up” and “recognition of mistakes over obstacle” were the only components with an ICC > 0.6. Assessment-reassessment agreement was poor to fair. The agreement on gait grading was good overall (ICC = 0.74), but poor for grades ≤ 1 (ICC = 0.08) and fair for ataxia grades ≥ 2 (ICC = 0.43). Clinicians with prior knowledge of a possible gait abnormality were more likely to assign a grade higher than the median grade. Conclusion and Clinical Importance Clinicians should be aware of poor agreement even between skilled observers of equine gait abnormalities, especially when the clinical signs are subtle.

A neonatal foal with signs of rectal bleeding was diagnosed with an intraluminal rectal mass and intussusception on surgical exploration of the abdomen. Histologically, the mass consisted of cystic spaces lined by simple columnar epithelium with numerous goblet cells and was surrounded by thin bands of smooth muscle in a myxomatous stroma. Although the mass shared similarities with retrorectal cystic hamartoma (tailgut cyst) and juvenile polyps, described in human medicine, location and histologic findings were not entirely consistent with either condition.

Appropriate durations of perioperative antimicrobial therapy following exploratory coeliotomy in horses are controversial, and with the rising prevalence of multiresistant bacteria there is a strong incentive to use antimicrobials for the shortest time possible. Following exploratory coeliotomies, incisional infections are an important cause of morbidity in horses and could be influenced by the duration of systemic antimicrobial therapy. The aim of this study was to investigate whether 72 hours of perioperative antimicrobial therapy is as effective as 120 hours at preventing the development of postoperative incisional infections. Horses undergoing exploratory coeliotomy at two referral hospitals were assigned randomly into Group 1 (receiving 72 hours of perioperative antimicrobial therapy) and Group 2 (receiving 120 hours of perioperative antimicrobial therapy). Only horses recovering from surgery and surviving for >120 hours were included in the study. Ninety-two horses met the criteria for inclusion in the study, 42 in Group 1 and 50 in Group 2. The overall incisional complication rate was 42.2 per cent, and no significant difference in the number of incisional complications in the two groups was identified. Results of the study suggest that there is no benefit in using 120 hours over 72 hours of perioperative antimicrobial therapy to prevent incisional infections.

Activated platelets can contribute to host defense through release of products with bactericidal actions such as antimicrobial peptides and reactive oxygen species (ROS), as well as by forming heterotypic aggregates with neutrophils and enhancing their antimicrobial properties. Whilst release of vasoactive mediators from equine platelets in response to stimuli including bacterial lipopolysaccharide (LPS) has been documented, neither ROS production, nor the effects of activated platelets on equine neutrophil ROS production, have been reported. This study first sought evidence that activated equine platelets inhibit bacterial growth. Platelet superoxide production in response to stimuli including Escherichia coli -derived LPS and lipoteichoic acid (LTA) from Staphylococcus aureus was then determined. The ability of LPS and LTA to up-regulate platelet P-selectin expression and induce platelet–neutrophil aggregate formation was investigated and the effect of co-incubating activated platelets with neutrophils on superoxide production measured. Growth of E. coli was inhibited in a time-dependent manner, and to a similar extent, by addition of platelet rich plasma (PRP) or platelet poor plasma (PPP) obtained by centrifugation of PRP. Activation of platelets in PRP by addition of thrombin led to a significant increase in the inhibitory action between 0.5 and 2 h. Although phorbol myristate acetate (PMA) caused superoxide production by equine platelets in a protein kinase C-dependent manner, thrombin, platelet activating factor (PAF), LPS, LTA and formyl-methionyl-leucyl phenylalanine (FMLP) were without effect. LPS and LTA did induce platelet activation, measured as an increase in P-selectin expression (% positive cells: 17 ± 3 (un-stimulated); 63 ± 6 (1 μg/ml LPS); 64 ± 6 (1 μg/ml LTA); n = 5) but not platelet superoxide production or heterotypic aggregate formation. Co-incubation of activated platelets with neutrophils did not increase neutrophil superoxide production. This study has demonstrated for the first time that when activated, equine platelets, like those of other species, are capable of releasing ROS that could assist in bacterial killing. However, the findings suggest that neither superoxide production by platelets nor enhancement of production by neutrophils is likely to play a significant role. Nevertheless, as has been reported in man, equine PPP and PRP did inhibit E. coli growth in vitro , and addition of thrombin significantly increased the inhibitory effect of PRP. This suggests that products released from activated platelets could contribute to antimicrobial activity in the horse. The factors in equine plasma and released by activated platelets that are responsible for inhibiting bacterial growth have yet to be determined.

Summary Reason for performing study: Platelet activation occurs in human obstructive airway diseases and in laboratory animal models. However, there is limited evidence that platelets may be involved in equine recurrent airway obstruction (RAO) and other inflammatory diseases. This study investigated whether platelet activation also occurred in RAO. Hypothesis: Platelet function is altered in ponies with active RAO. This alteration can be detected ex vivo by measuring platelet adhesion. Methods: An in vitro platelet adhesion assay measuring acid phosphatase (AcP) activity colorimetrically was adapted for use with equine platelets and responses to selected agonists were established. Platelet adhesion and aggregation was evaluated in vitro on platelets isolated from 6 ponies with RAO before, during and after a 7 h natural antigen challenge. Three ponies with no history of airway disease were also studied. Results: Adhesion of equine platelets to serum coated plastic was detected at concentrations of 10–100 times 109/l. Adhesion increased in response to stimulation with platelet activating factor and thrombin, but not equine interleukin 8. Prior to the antigen challenge, adhesion of nonstimulated platelets was low and increased significantly (P

Objective—To determine the phosphodiesterase (PDE) isoenzymes in equine platelets and evaluate their influence on platelet adhesion. Sample Population—Platelets obtained from healthy New Forest Pony geldings that ranged from 12 to 20 years of age (mean ± SEM, 17.3 ± 1.1 years). Procedures—PDE isoenzyme activity in equine platelets was determined by use of a 2-step radioactive assay. Functional importance of PDE isoenzymes was established by use of selective inhibitors in a colorimetric adhesion assay. Results—PDE1, PDE2, PDE3, and PDE5 and small amounts of PDE4 were found in equine platelets. Inhibition of PDE3 abolished platelet adhesion almost completely, whereas inhibition of PDE4 and PDE5 had little effect. Conclusions and Clinical Relevance—Function of equine platelets can be influenced by inhibition of PDE3. Selective PDE3 inhibitors may be clinically useful to regulate platelet function. They offer the advantage of increased potency with fewer adverse effects, compared with those for nonselective PDE inhibitors.

A nutritional plan should be incorporated into every treatment plan of the critically ill patient. Weight loss and cachexia are the result of prevalence of catabolic processes over anabolic processes in addition to absolute or relative increased demands and decreased food intake.

CHOLESTEROL granulomata – benign choroid plexus masses often detected at equine postmortem examinations – are sometimes associated with central neurological signs (Ivoghli and others 1977, Johnson and others 1993, Jackson and others 1994, King 1997). Antemortem diagnosis was impossible until advent of magnetic resonance imaging (Maulet and others 2008) and CT (Vink-Nooteboom and others 1998, Vanschandevijl and others 2008). These two cases are the first to illustrate diagnosis using standing (unanaesthetised) CT (CT Lightspeed QX/i; GE medical systems) and describe the long-term follow-up of one case, revealing that the prognosis for some cases is fair. Case 1: A 12-year-old Irish Draught cross gelding was presented with a 10-day history of intermittent lethargy and abnormal head carriage. On presentation, episodes of generalised muscle rigidity and ataxia were noticed by the owner; the horse was obtunded with reduced tongue tone and drooping of the lower lip and reluctant to flex or extend the neck and back. Neurological signs had improved following administration of methylprednisolone, penicillin and flunixin meglumine. On presentation to the Royal Veterinary College, the horse was obtunded; menace responses were reduced bilaterally, but pupillary light reflexes were intact. Mild superficial gluteal muscle fasciculations were evident. The horse had an exaggerated guarding response to deep palpation of the neck at C5 to C7. The neuroanatomical localisation suggested forebrain involvement, but based on cervical discomfort on …

Background: Limited research has been undertaken to determine the impact of horse age, sex and number of riders on horse performance in British Eventing (BE) horse trials. Improved understanding of this can aid professionals in planning a competition horse’s career. Objectives: To investigate the impact of age, sex and number of riders on the peak performance of horses at each of the main levels of BE competitions. Methods: The best score from each horse competing in BE horse trials in the years 2008 to 2018 were recorded, principal component and hierarchical cluster analysis was performed. Basic data analysis was used to identify variables associated with particular better-performing clusters of horses. The interplay of the combinatory variables was then used to map out the trends in career trajectory for horses competing at each level of competition in the best and worst performing clusters.Results and conclusions: The peak performance of mares was worse than geldings and stallions at all levels. At Novice to Advanced, stallions did not perform as consistently with multiple riders as geldings. The age at which the best performing groups peaked was similar for mares and geldings in all classes, although stallions peaked at an older age than mares and geldings at Novice and Intermediate level. All horses were a minimum of four years old at the time of competition, as per British Eventing rules. Keywords: equine, competition, show jumping, dressage, training