Phycomycosis caused by Basidiobolus haptosporus in two horses

Basidiobolus haptosporus was isolated from a horse with a rapidly progressive ulcerative lesion of the ventral midline. The pathologic findings of an irregular line of yellow material composed of hyphae, eosinophils, and granulomatous inflammation between the superficial edematous tissue and the underlying muscle, and hyphae in tissue sections intimately surrounded by granular eosinophilic cuffs were considered diagnostic for this and one other case diagnosed retrospectively. Both horses were successfully treated by surgery and potassium iodide.     

Myotonia associated with hyper-adrenocorticism in two dogs

Two dogs developed a disabling gait abnormality characterised by stiffness. The abnormality was consistent with a diagnosis of myotonia secondary to hyper-adrenocorticism. The first dog had iatrogenic hyperadrenocorticism, and its signs improved substantially after corticosteroid administration was gradually withdrawn. The second had pituitary-dependent hyperadrenocorticism, but myotonic signs progressed despite effective mitotane therapy. Procainamide administration reduced the myotonic stiffness in the second case.     

Pseudogout in two dogs

Extract

Pseudogout is a common condition in elderly people in which sudden onset of intense joint pain and synovitis develop. Peri-synovial calcium crystal deposition is the cause of the synovitis rather than the uric acid deposition in common gout. It is a rare condition in dogs, having only been reported twice before. Two dogs presenting with acute lameness and pyrexia showed many macrophages and occasional neutrophils containing intracellular crystals on cytological examination of synovial fluid. The crystals were single or multiple, small to large, clear, square or rhomboid-shaped, weakly birefringent and resembled those described for pseudogout. Occasional crystals were also present free in the matrix. Non-steroidal anti-inflammatory drugs that are effective in reducing pain in people with pseudogout provided no relief to either patient, but twice daily oral prednisolone therapy was successful. Dosage was gradually tapered as clinical signs improved over a period of 6 weeks.     

Retinopathy associated with ivermectin toxicosis in two dogs

CASE DESCRIPTION: 2 dogs (dogs 1 and 2) were examined for sudden onset of blindness. Both dogs had mild obtundation and mydriasis in both eyes. It was thought that dog 1 may have ingested ivermectin; dog 2 had been treated with ivermectin for demodectic mange. CLINICAL FINDINGS: On initial examination, both dogs had mydriasis and decreased pupillary light reflexes in both eyes. Dog 1 had an absent menace response bilaterally. Fundic examination of both eyes in both dogs revealed regions of multifocal retinal edema and folds with low-lying retinal separation. The electroretinogram was extinguished in dog 1 and attenuated in dog 2. Ivermectin was detected in serum samples from both dogs. TREATMENT AND OUTCOME: Both dogs made a complete clinical recovery following cessation of exposure to ivermectin; electroretinographic findings improved, and retinal edema resolved with some residual chorioretinal scarring. CLINICAL RELEVANCE: To our knowledge, this is the first report of resolution of retinal edema and electroretinographic changes associated with ivermectin toxicosis in dogs. In dogs that develop blindness suddenly, fundic examination, electroretinography, and assessment of serum ivermectin concentration are diagnostically useful, even if exposure to ivermectin is unknown.     

GH-producing mammary tumors in two dogs with acromegaly

Two intact female dogs were admitted for growing mammary tumors. They had symptoms of acromegaly including weight gain, enlargement of the head, excessive skin folds, and inspiratory stridor. Serum concentrations of growth hormone (GH), insulin-like growth factor-I (IGF-I), and insulin were elevated in the two cases. From these findings, both dogs were diagnosed with acromegaly. In case 1, the GH, IGF-I, and insulin levels subsided after removal of the focal benign mammary tumors and ovariohysterectomy. In case 2, those levels subsided after removal of only focal mammary carcinoma. In both cases, immunohistochemical investigations for GH were positive in the mammary tumor cells but not in the normal mammary glands. We concluded that GH-producing mammary tumors caused the present acromegaly.     

Electrocardiographic abnormalities associated with tetanus in two dogs

Bradycardia, sinus arrest, and second-degree atrioventricular block developed in 2 dogs with tetanus. Clinical signs attributable to bradycardia were not apparent. Administration of atropine resulted in resolution of the arrhythmias. Both dogs responded well to supportive treatment; the bradycardia resolved within 4 days of onset without specific treatment. Tetanus should be included in the differential diagnosis when increased neuromuscular excitability and bradycardia are evident, as is found in toxicity with acetylcholinesterase inhibitors, increased intracranial pressure, and other neurologic disorders.     

Calcium urolithiasis in two dogs with parathyroid adenomas

Primary hyperparathyroidism resulted in calcium urolith formation and calcium nephropathy in 2 dogs. Uroliths composed of calcium phosphate were surgically removed from the bladder of one dog 3 months after surgical removal of a parathyroid adenoma. Five years later, hypercalcemia and urolithiasis had not recurred. In a second dog, calcium oxalate renal and bladder uroliths remained unchanged in size at 11 months after removal of a parathyroid adenoma. The possibility of primary hyperparathyroidism should be considered in any dog with calcium urolithiasis.     

Presumed brain infarctions in two dogs with systemic leishmaniasis

Clinical signs and magnetic resonance imaging findings of multiple brain infarcts in two dogs infected with Leishmania spp. are reported. Clinical signs of intracranial dysfunction were peracute and there was no further deterioration. Magnetic resonance images of the brain were consistent with multifocal, non-haemorrhagic, ischaemic lesions. Routine serum biochemistry revealed hyperproteinaemia and hyperglobulinaemia. Serum antibody titres were highly positive for Leishmania infantum and Leishmania amastigotes were seen within bone marrow macrophages in both cases. Canine leishmaniasis can cause cerebrovascular alterations, such as vasculitis, that might predispose dogs to brain infarcts.     

Polymyositis associated with Ehrlichia canis infection in two dogs

Clinical, haematological, biochemical, electrophysiological and pathological features of two dogs infected with Ehrlichia canis and with concurrent signs of polymyositis are presented. Both dogs had a history of relatively acute onset, progressive tetraparesis, hyporeflexia and generalised muscle wasting. Skeletal muscles were atrophic and characterised histologically by plasmocytic, lymphocytic and immature lymph-oreticular cellular infiltrates with accompanying areas of necrosis. Histopathological similarities between ehrlichiosis and polymyositis are noted and a probable aetiological relationship is inferred.     

Essential thrombocythaemia in two dogs

In this report two dogs with essential thrombocythaemia (ET) are described. Both dogs were presented more or less at the same time with a combination of reduced exercise tolerance and pale mucous membranes without any report of blood loss. Moderate-to-severe, Coomb's-negative anaemia and thrombocytosis (> 1249 x 10'/l) were present. In addition, the peripheral blood smear revealed the presence of basophilia and large numbers of abnormally shaped megakaryocytes in the bone marrow of both dogs. Treatment with vincristine (0.7 mg/m2 once intravenously) and hydroxyurea (500 mg/m2 p.o. per day) was started. Because of insufficient response to treatment after 3 weeks, the dosage of hydroxyurea was increased in both dogs to 2000 mg/m2 p.o. per day. The dogs deteriorated further, however, and were euthanized at 6 weeks after the start of treatment. Blood examination revealed pancytopenia in both dogs, most likely due to the myelosuppressive effects of high-dose hydroxyurea. A survey of veterinary literature on ET is presented, including a comparison of ET in humans.     

Broncho-oesophageal fistula in two dogs

Two clinical cases of broncho-oesophageal fistula in the dog are presented. While both cases illustrate the value of oesophagoscopy as a diagnostic tool, one case depicts the complications which may be associated with positive contrast oesophagography. These two cases support previous observations that broncho-oesophageal fistulae are frequently of foreign body aetiology and usually extend from the caudal oesonhaaus. via the nleural suace. to the caudal or middle right lung lobes.     

Intra-abdominal cryptococcosis in two dogs

Intra-abdominal cryptococcosis was diagnosed in two young dogs. The first, an entire male border collie, was presented with vomiting. An abdominal mass detected during physical examination proved to be cryptococcal mesenteric lymphadenitis on exploratory laparotomy. The second dog, a female neutered giant schnauzer, was presented with neurological signs suggestive of encephalopathy. Intestinal cryptococcal granulomas were detected in an extensive diagnostic investigation which included abdominal ultrasonography. The gastrointestinal tract was considered the most likely portal of entry for cryptococcal organisms in both cases. Both dogs were treated using surgery and multiagent antifungal chemotherapy. The first case succumbed despite therapy, while the second dog was treated successfully as gauged by return to clinical normality and a substantial decline in the cryptococcal antigen titre which continued to fall after cessation of treatment.