Idiopathic thrombocytopenia in Cavalier King Charles Spaniels.

OBJECTIVE: To determine the prevalence of asymptomatic idiopathic macrothrombocytopenia in the population of Cavalier King Charles Spaniels (CKCS) in New South Wales (NSW) and to determine if it exhibits an autosomal recessive inheritance pattern. We also aimed to determine if significant differences existed when counting platelets manually, by auto analyser or by blood smear estimation in CKCS and mixed breed dogs. METHODS: Blood was collected from 172 dogs (152 CKCS and 20 mixed breed) and placed into sodium-citrate anticoagulant. Platelet counts were performed manually, by auto analyser and by blood smear estimates in CKCS and mixed breed dogs. Blood smears were also examined for platelet clumping and erythrocyte, leukocyte and platelet morphology. Pedigree analysis was performed to determine if an autosomal recessive inheritance pattern was supported. RESULTS: A statistically significant difference was found in platelet counts between CKCS and mixed breed dogs (P < 0.0001). CKCS had a platelet count that was 32% that of the controls (95% confidence interval, 28 to 37%). There was no significant difference between methods used to count platelets. Thirty percent of CKCS had macrothrombocytes. Pedigree analysis and examination of obtained and expected segregation ratios from 17 CKCS families supported an autosomal recessive pattern of Mendelian inheritance. CONCLUSIONS: A high prevalence of idiopathic macrothrombocytopenia exists in CKCS in NSW and automated or blood smear estimates are sufficient to count platelet numbers. Data supports an autosomal recessive inheritance pattern.

Inflammatory cerebrospinal fluid analysis in cats: clinical diagnosis and outcome.

The medical records of 62 cats with clinical signs of central nervous system disease and accompanying inflammatory cerebrospinal fluid (CSF) analysis were examined retrospectively to determine if signalment, clinical signs, CSF analysis and ancillary testing could accurately predict the type of central nervous system disease that was present. An inflammatory CSF was defined as one in which a total nucleated cell count was greater than 5 cells/microl or one in which the total nucleated cell count was normal but the nucleated cell differential count was abnormal. Sex, degree of CSF inflammation, neuroanatomical location and systemic signs provided little contributory information to the final diagnosis. In 63% of the cases a presumptive diagnosis could be made based on a combination of clinical signs, clinicopathological data and ancillary diagnostic tests. CSF analysis alone was useful only in the diagnosis of cats with feline infectious peritonitis, Cryptococcus species infection, lymphoma and trauma. Overall, despite extensive diagnostic evaluation, a specific diagnosis could not be made in 37% of cats. The prognosis for cats with inflammatory CSF was poor with 77% of cats surviving less than 1 year.

Spontaneous hepatic rupture in six cats with systemic amyloidosis.

Spontaneous hepatic rupture, secondary to the accumulation of hepatic amyloid, was diagnosed in six cats over a two-year period. Previous reports of feline hepatic amyloidosis have documented clusters of cases from breeding catteries. Most affected cats have been Siamese or a related breed and the disease is generally regarded as familial. In contrast, the cases presented here were sporadic, with relatives and other cats in the household not clinically affected. They included a Devon rex, a breed not previously reported with this condition, and a domestic shorthair. Clinical signs in three of these cases had, prior to referral, been misinterpreted as resulting from blunt trauma, immune-mediated haemolysis or a coagulopathy. Antemortem diagnostic features, including new data on the value of hepatic ultrasonography and fine-needle aspirate cytology, are reported. These cases illustrate how the course of this disease can vary between individuals and that, despite the dramatic underlying pathology, hepatic amyloidosis can present a diagnostic challenge and should be suspected in any young adult cat with consistent clinical signs, irrespective of breed or environment.

Perirenal pseudocysts in 26 cats.

OBJECTIVE: To evaluate clinical features, anatomical location, nature of pseudocyst fluid, results of surgical treatment and links with underlying renal disease in cats with perirenal pseudocysts. DESIGN: A retrospective study of 26 affected cats, including 8 treated surgically. RESULTS: Nineteen (73%) affected cats were male. The median age was 11 years. Most presented for abdominal enlargement and had varying degrees of renal dysfunction on presentation. Thirteen cats (50%) had bilateral pseudocysts. The pseudocyst fluid was a transudate or modified transudate in all cases. All surgically treated cats had subcapsular perirenal pseudocysts. Associated renal lesions were identified in all cats that had renal biopsies or detailed ultrasonographic examinations. Surgery relieved clinical signs but did not stop progression of renal disease. Cats survived a median of 9 months after surgery and survival was correlated statistically to degree of azotaemia at presentation. Percutaneous drainage of pseudocysts was ineffective in controlling long-term fluid accumulation. CONCLUSIONS: Subcapsular perirenal pseudocysts are formed in cats by accumulation of transudate between the capsule and parenchyma of the kidney as a result of underlying parenchymal disease. Pseudocyst formation can occur at variable stages of renal dysfunction. Resection of the pseudocyst wall is usually effective in eliminating signs but does not stop progression of renal disease. The prognosis for cats with pseudocyst formation is related to the degree of renal dysfunction at time of diagnosis.

Plasma cortisol concentrations in normal dogs given hydrocortisone sodium succinate.

OBJECTIVE: To evaluate the effects on plasma cortisol concentration of a continuous infusion of a readily available steroid with equipotent glucocorticoid and mineralocorticoid effects. PROCEDURE: Plasma cortisol concentrations were measured before and regularly after hydrocortisone sodium succinate was administered as a continuous intravenous infusion over 6 h at 0.32 and 0.65 mg kg-1 h-1 to 12 healthy dogs weighing 12 to 22 kg. RESULTS: The infusion at both does rates produced significant and stable increases in plasma cortisol concentrations. The plateau concentrations produced by the large and small doeses were respectively above and below plasma cortisol concentrations likely to provide adequate glucocorticoid and mineralocorticoid activity in stressed dogs with significantly decreased adrenal function. CONCLUSION: This paper presents information regarding the changes in plasma cortisol concentrations in 12 normal dogs given an hydrocortisone sodium succinate infusion at two dose rates. The marked and continuous increase in plasma cortisol concentrations suggests a continuous HSS infusion may be a possible alternative to desoxycorticosterone acetate and dexamethasone in the treatment of acute adrenal dysfunction.

Nasopharyngeal cryptococcosis.

Naturally occurring cryptococcosis in five cats, a dog and a koala is described. Involvement of the nasopharynx was documented in all patients, and nasopharyngeal mass lesions accounted for the major presenting complaints in four. Signs referable to nasopharyngeal disease included snoring, stertor, inspiratory dyspnoea and aerophagia. Diagnoses were made by caudal rhinoscopy using a retroverted flexible endoscope, vigorous orthograde flushing with saline, or at necropsy. Concurrent cryptococcal rhinitis was present in all cases, although involvement appeared limited to the caudal nasal cavity in most cases. Typical signs of nasal cavity disease, such as sneezing and nasal discharge, were often absent. Treatment of nasopharyngeal cryptococcosis should include physical dislodgement or debulking of lesion(s) to provide immediate alleviation of upper airway obstruction, followed by systemic antifungal therapy to eliminate residual infection from the nasal cavity. Infections caused by Cryptococcus neoformans var gattii accounted for a disproportionately large number of these cases.

Effect of chronic hypocortisolaemia on plasma cortisol concentrations during intravenous infusions of hydrocortisone sodium succinate in dogs.

Intravenous infusions of hydrocortisone sodium succinate (HSS) were given at 0.625 mg kg-1 hour-1 and 0.312 mg kg-1 hour-1 to six dogs. Plasma cortisol concentrations were measured by radioimmunoassay at 0, 15, 30, 45 and 60 minutes and then every 30 minutes for a further five hours. Chronic hypocortisolaemia was induced and maintained with mitotane and the HSS infusions were repeated after 31 and 50 days. No statistically significant difference was observed in the plasma cortisol concentrations after either period of hypocortisolaemia, but the plasma cortisol concentrations tended to be higher in most of the dogs.

Chronic intestinal pseudo-obstruction in a dog.

A three-year-old neutered female Border Collie was presented with inappetence, vomiting and diarrhoea. Abdominal radiographs revealed an obstructive pattern but no physical obstruction was evident at laparotomy. A diagnosis of chronic intestinal pseudo-obstruction was made based on histopathological changes in intestinal biopsies. Treatment was unsuccessful and the dog deteriorated progressively until euthanased five weeks after presentation.

Treatment of feline hyperthyroidism using orally administered radioiodine: a study of 40 consecutive cases.

Forty cats with hyperthyroidism were treated using 200 to 300 (typically 250) MBq [corrected] of orally administered 131I. Thirty-six cases (90%) were successfully treated, as assessed by resolution of clinical signs and reduction in plasma thyroxine concentrations to normal or reduced values after treatment. Although higher doses of 131I appear to be required when the radioisotope is administered orally rather than intravenously, a less stressful administration procedure and greater availability of therapy capsules offer useful advantages for treating thyrotoxic cats.

Carbamazepine--erythromycin interaction leading to carbamazepine toxicity in four epileptic children.

We report four cases of carbamazepine toxicity in children associated with the concurrent administration of erythromycin. They all developed clinical toxicity (ataxia, dizziness, nausea, and vomiting) when erythromycin administration was begun; symptoms disappeared after erythromycin was discontinued. Serum carbamazepine levels were measured before, during, and, in most cases, after the toxic episodes. In all cases, there was a sharp increase in carbamazepine concentration after erythromycin therapy was begun and a rapid fall once erythromycin was discontinued. Our data support the previous suggestion that erythromycin interferes with the liver microsomal metabolism of carbamazepine with a subsequent increase in blood levels of the drug.

Calcification of basal ganglia and cerebellar roof nuclei in mentally defective patient with hidrotic ectodermal dysplasia. Analysis of intracranial concretions by electon microprobe.

This report describes, for the first time, an analysis by electron microprobe of concretions in the brain of an individual with striopallidodentate calcification. We also report the unique association of this intracranial syndrome with hidrotic ectodermal dysplasia. An institutionalized male with impaired intellectual function and hidrotic ectodermal dysplasia was known since the age of 3 years to have bilateral radiopaque densities in the region of the basal ganglia on skull roentgenogram. He died at age 29 in congestive heart failure from rheumatic pancarditis. At autopsy, concretions were identified in globus pallidus, caudate nuclei, thalamus, and dentate nuclei. Mineral deposits within the brain, analyzed by energy dispersive x-ray microanalysis, consisted predominately of calcium and phosphorus. Trace amounts of magnesium, iron, and silicon also were detected.