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Background Lagenidium giganteum forma caninum infection causes severe cutaneous and disseminated disease in dogs. Currently, diagnosis requires culture and rRNA gene sequencing. Objective To develop and evaluate an ELISA for quantitation of anti-L. giganteum f. caninum IgG in canine serum. Animals Sera were evaluated from 22 dogs infected with L. giganteum f. caninum, 12 dogs infected with Paralagenidium karlingii, 18 dogs infected with Pythium insidiosum, 26 dogs with nonoomycotic fungal infections or other cutaneous or systemic diseases, and 10 healthy dogs. Methods Antigen was prepared from a soluble mycelial extract of L. giganteum f. caninum. Optimal antigen and antibody concentrations were determined by checkerboard titration. Results were expressed as percent positivity (PP) relative to a strongly positive control serum. Results Medians and ranges for PP for each group were: L. giganteum f. caninum (73.9%, 27.9–108.9%), P. karlingii (55.0%, 21.0–90.6%), P. insidiosum (31.3%, 15.8–87.5%), nonoomycotic fungal infection or other cutaneous or systemic diseases (19.2%, 3.2–61.0%), and healthy dogs (9.9%, 7.6–24.6%). Using a PP cutoff value of 40%, sensitivity and specificity (with 95% CI) of the ELISA for detecting L. giganteum f. caninum infection in clinically affected dogs were 90.9% (72.2–97.5%) and 73.2% (60.4–83.0%), respectively. Specificity in dogs infected with P. karlingii was 41.7% (19.3–68.1%) and with P. insidiosum was 66.7% (43.8–83.7%). Conclusions and Clinical Importance Quantitation of anti-L. giganteum f. caninum antibodies for detection of this infection in dogs has moderately high sensitivity but poor specificity, the latter because of substantial cross-reactivity with anti-P. karlingii and anti-P. insidiosum antibodies.

A 4-year-old male neutered Labrador Retriever with severe gastrointestinal signs, but no respiratory signs, was diagnosed with multifocal pyogranulomatous gastritis, enteritis, and lymphadenitis with intralesional hyphae and multifocal pyogranulomatous pneumonia with intralesional yeast. Based on cytologic evaluation, histologic examination with special stains, and immunohistochemical analysis of tissues collected antemortem or at necropsy, dual infections with Pythium insidiosum and Blastomyces dermatitidis were detected and are reported for the first time.

An 18-year-old Arabian mare was examined with a large mass on the left hind pastern and fetlock. The mare was located in the Central Valley of northern California, and had never been out of the state. Routine histopathological processing and examination of biopsy samples from the mass showed several hyphal organisms that were delineated with a silver stain. Using immunohistochemistry the organism was diagnosed as Pythium insidiosum. The owner declined debulking surgery, and despite treatment with an immunotherapeutic vaccine, the horse's condition deteriorated leading to euthanasia.

An oomycotic pathogen in the genus Lagenidium was isolated from tissues obtained from 6 dogs with progressive cutaneous disease. Initial clinical findings in 5 dogs included multifocal cutaneous lesions, subcutaneous lesions, or both associated with regional lymphadenopathy: the 6th dog initially was presented for evaluation of mandibular lymphadenopathy. Cutaneous lesions were ulcerated, exudative regions (often with necrosis and draining tracts) or multiple firm dermal or subcutaneous nodules. Two dogs subsequently developed hemoabdomen from great vessel rupture and died acutely. Four dogs were euthanized because of progression of subcutaneous lesions or lymphadenopathy. On postmortem examination, regional granulomatous lymphadenitis was found in all 6 dogs, great vessel invasion in 3 dogs, pulmonary lesions in 2 dogs. ureteral obstruction in 1 dog, mediastinal lymphadenitis in 1 dog, and hilar lymphadenitis with invasion of the distal esophagus and trachea in 1 dog. Histologically, lesions were similar to those associated with pythiosis and zygomycosis and were characterized by severe eosinophilic granulomatous inflammation (often with numerous large multinucleated giant cells) centered around broad (7-25 micro), infrequently septate hyphae. Immunoblot analysis of the serologic response of 4 dogs to a soluble mycelial extract of Lagenidium giganteum indicated that each dog's serum recognized at least 10 different antigens of L. giganteum. Culture of infected tissues yielded rapid growth of colorless to white submerged colonies. Microscopically, mature hyphae in culture were broad (25-40 micro), segmented, and occasionally branching and produced motile laterally biflagellate zoospores in water culture. This report is the 1st description of infection caused by an oomycete other than Pythium insidiosum in any mammalian species.

Eight cases of chronic ulcerative mycosis affecting populations of channel catfish Ictalurus punctatus, black bullhead Ameiurus melas, and bluegill Lepomis macrochirus cultured in recreational fishing ponds were submitted to the Louisiana Aquatic Diagnostic Laboratory between April 2000 and January 2002. Diseased clinical specimens presented with multiple foci of skin ulceration, typically overlying more extensive areas of granulomatous myositis that extended to the vertebral column in advanced cases. Lesions were predominated by fields of plump macrophages and multinucleated giant cells surrounding nonseptate, thick-walled hyphae with nonparallel cell walls suggestive of an oomycete. Because deep ulcerative mycoses in other fish species in the western Atlantic (USA), Australia, and Southeast Asia have been attributed to Aphanomyces spp., diagnostic methods were employed to isolate and identify this oomycete along with other potential pathogens. The organism was isolated from sites deep in the mu...

The purpose of this study was to evaluate the application of previously described Pythium insidiosum- and Lagenidium-specific nested PCR assays to the detection of oomycete DNA in animal tissues. DNA was extracted from 15 frozen and 10 ethanol-fixed tissues obtained from six animals with pythiosis, five animals with lagenidiosis, one animal with nonoomycotic skin disease and two animals without skin disease. First-round PCR, which utilized universal fungal primers ITS1 and ITS2P, amplified a single product of the expected size for each of the P. insidiosum- and Lagenidium-infected tissues, but not for tissues obtained from animals without fungal disease. Second-round PCR using the P. insidiosum-specific primers PI1 and PI2 produced a single 105-bp product for the P. insidiosum-infected tissues, but not for any of the other tissues. Second-round PCR using the Lagenidium-specific primers LAG1 and LAG2 produced a single 76-bp product for the Lagenidium-infected tissues, but not for any of the other tissues.

Pythiosis (caused by the aquatic oomycete Pythium insidiosum) is a devastating and often fatal cause of either severe transmural gastroenteritis or locally invasive subcutaneous disease in dogs living in the southeastern United States. Although early diagnosis is essential for successful treatment, tools available for this task are limited. Therefore, we developed and evaluated an enzyme-linked immunosorbent assay (ELISA) for the detection of anti-P insidiosum antibodies in canine serum. A soluble mycelial extract of P insidiosum was utilized as antigen in the ELISA, which was used to evaluate serum from 43 dogs with pythiosis, 8 dogs with lagenidiosis (another canine oomycosis), 16 dogs with nonoomycotic fungal or algal infections, 22 dogs with nonfungal gastrointestinal or skin disease, and 55 healthy dogs. Results were expressed as percent positivity (PP) relative to a strong positive control serum run on each plate. Medians and ranges for each of the 5 groups were as follows: pythiosis (81.7%, 50.6-98.5%), lagenidiosis (17.3%, 11.3-29.2%), other fungal or algal infections (8.2%, 4.7-15.4%), nonfungal gastrointestinal or skin disease (6.2%, 3.9-20.7%), and healthy dogs (6.7%, 3.0-15.2%). When using a cutoff value of 40% PP, the sensitivity and specificity of the ELISA both were 100%. In addition, ELISA values measured after successful surgical therapy in 2 dogs showed a decrease of anti-P insidiosum antibody concentrations into the normal range as early as 2 months after treatment. We conclude that the ELISA is a sensitive and specific test for the diagnosis of canine pythiosis, and may be a useful tool for monitoring response to medical or surgical therapy.

Dysautonomia was diagnosed in 11 young (median age, 14-months), predominantly medium- to large-breed dogs from 1988 to 1995. Clinical signs caused by autonomic dysfunction of the urinary, alimentary, and ocular systems were most common. Dysuria, mydriasis, absence of pupillary light reflexes, decreased tear production, dry mucous membranes, weight loss, and decreased anal tone were present in over 75% of affected dogs. Ocular pharmacological testing with a dilute (0.1%) solution of pilocarpine was used to demonstrate iris sphincter receptor function in all dogs. A low-dose (0.0375 mg/kg s.c.) bethanechol test and pharmacological testing with phenylephrine and epinephrine also demonstrated cholinergic and adrenergic receptor function in 4 dogs. All dogs died or were euthanized as a results of autonomic dysfunction. Neuronal depletion, with associated gliosis and minimal inflammation were noted histologically in the autonomic ganglia of each dog. The pelvic, ciliary, celiac, cranial cervical, and cranial and caudal mesenteric ganglia were affected in all dogs. The cause of autonomic failure in these dogs was not determined.

Ultrasonographic evaluation of the adrenal glands was performed in 14 fasted healthy adult dogs. Frequency of visualization was 100% for both the left and right adrenal glands. Moderate correlation was present between Ultrasonographic and gross measurements of thickness for both left (rs= 0.727; p < .005) and right (rs= 0.537; p < .05) adrenal glands. However, no correlation was found between Ultrasonographic and gross measurements for length or width of either adrenal gland. Differentiation of adrenal cortex and medulla was possible in 79% of left adrenal glands and 64% of right adrenal glands. The echogenicity of the adrenal glands was less than that of the renal cortex in all dogs. Factors which made evaluation of the adrenal glands more difficult included pyloric gas, intestinal gas, and deep-chested body conformation.

Abdominal ultrasonography was performed in seven cats with intestinal lymphoma and four cats with gastric lymphoma. Ultrasonographic abnormalities included the presence of a hypoechoic mass associated with the gastrointestinal tract, focal or diffuse thickening of the gastric wall, symmetric thickening of the bowel wall, loss of the normal layered appearance of the gastrointestinal wall, and abdominal lymphadenopathy. The thickness of the stomach wall ranged from 8 to 22 mm in cats with gastric lymphoma, and the thickness of the bowel wall ranged from 5 to 20 mm in cats with intestinal lymphoma. Fine needle aspiration of a gastrointestinal lesion was performed without complication in six cats, and was diagnostic for lymphoma in five out of six. Results of this study indicate that ultrasonography is an effective noninvasive means of identifying lesions consistent with alimentary lymphoma in cats.

Two diabetic dogs were presented for anorexia, persistent fever, and poor control of hyperglycemia. Both had neutrophilia with left shift, hypoalbuminemia, and increased serum alkaline phosphatase (SAP) activity. Radiography indicated intrahepatic gas densities in 1 dog and a hepatic mass in the other. Abdominal sonography demonstrated multiple well-demarcated hypoechoic hepatic lesions consistent with abscesses. Both dogs were successfully treated by surgical resection of the abscessed liver lobes in conjunction with antibiotics and supportive therapy. Good control of hyperglycemia was achieved in both dogs after recovery. Intracellular and extracellular Gram-negative rod-shaped bacteria were abundant in the abscesses from both dogs. These cases suggest an association between diabetes mellitus and hepatic abscessation.

Gastrointestinal signs are common in dogs with uremia. Structural changes in the stomach associated with uremia in dogs include ulceration, edema, necrosis, gastric wall thickening, submucosal arteriopathy, and mineralization of the gastric mucosa and submucosa. Upon ultrasonographic evaluation of the abdomen in four dogs with severe uremia due to chronic renal disease, a thickened gastric wall, thickened rugal folds, and a hyperechoic line at the mucosal-luminal interface due to mineralization of the gastric mucosa were found. Ultrasonography was more sensitive than survey radiography for the identification of gastric lesions associated with uremia in these dogs.

Oomycetes such as Pythium insidiosum are soil- or water-dwelling organisms that belong to the Kingdom Stramenopila. Recently, a member of the genus Lagenidium has been recognized as a second canine pathogen in the class Oomycetes, causing multifocal ulcerative cutaneous lesions, subcutaneous pyogranulomatous nodules and draining tracts, often with dissemination to lymph nodes and abdominal great vessels. This report describes the clinical, cytologic and pathologic features of Lagenidium spp. infection associated with hypercalcaemia in a dog. A 1.5-year-old female border collie was referred for evaluation of progressive ulcerative skin lesions. Physical examination revealed pyrexia, generalized lymphadenopathy and multiple draining tracts, nodules and ulcers with eschars involving the distal aspect of all four limbs. Serum biochemical analysis revealed hyperglobulinaemia, hypoalbuminaemia and hypercalcaemia. Cytologic evaluation of fine-needle aspirates from lymph nodes and cutaneous lesions revealed pyogranulomatous inflammation surrounding multiple poorly staining broad (14–21 μm) hyphae. These right-angle branching hyphae were infrequently septate with irregular nonparallel walls. Thoracic radiography was normal. Abdominal ultrasonography showed no great vessel involvement. Euthanasia was elected, and necropsy revealed severe pyogranulomatous dermatitis and lymphadenitis involving the prescapular, popliteal, superficial inguinal, gastric, lumbar and external iliac lymph nodes. Histologically, all lesions were characterized by severe pyogranulomatous inflammation centred around broad, poorly septate hyphae. Parathyroid glands were histologically normal. Granulomatous disease associated with oomycosis should be considered as a differential diagnosis for hypercalcemia in canine patients with subcutaneous nodules or ulcerative dermatopathy associated with lymphadenopathy. Funding: Self-funded.