Retrospective evaluation of the effect of trilostane on insulin requirement and fructosamine concentration in eight diabetic dogs with hyperadrenocorticism.

OBJECTIVES: To describe the effect of trilostane on insulin requirements and serum fructosamine in dogs with diabetes mellitus (DM) and hyperadrenocorticism (HAC). METHODS: Observational retrospective study of eight dogs. RESULTS: Median fructosamine concentration at presentation was 401 µmol/L (range 244 to 554 µmol/L). Median insulin dose at presentation was 1·1 IU/kg/dose (0·4 to 2·1 IU/kg/dose) administered twice daily in five animals and once in three. Four dogs had their insulin dose prospectively reduced at the start of trilostane therapy. The HAC was controlled within 28 days in seven dogs. The remaining case was controlled by 17 weeks. Two dogs died within 40 days of starting trilostane. The median fructosamine concentration was 438 µmol/L (range 325 to 600 µmol/L) after stabilisation of the HAC. One case had a consistent reduction in serum fructosamine concentration over the first four months. The median insulin dose after stabilisation of HAC was 1·5 IU/kg dose (range 0·25 to 3·0 IU/kg/dose). Insulin requirements were reduced in two cases after treatment with trilostane. Four dogs required increased insulin doses. CLINICAL SIGNIFICANCE: Insulin requirements and fructosamine concentrations do not consistently reduce during trilostane treatment for HAC. Prospective studies are required to provide recommendations regarding reductions in insulin doses with trilostane treatment.

Study of the effects of once daily doses of trilostane on cortisol concentrations and responsiveness to adrenocorticotrophic hormone in hyperadrenocorticoid dogs.

The effects of trilostane, a 3beta-hydroxysteroid dehydrogenase inhibitor on basal cortisol concentrations and the results of ACTH stimulation tests in dogs with pituitary-dependent hyperadrenocorticism were investigated. In eight of nine dogs trilostane suppressed the concentration of cortisol below the lower limit of the reference range (<50 nmol/l) for a mean (sd) of 3.5 (2.3) hours during the day, but for no longer than 13 hours. In another 10 dogs, there was a clear difference between the post ACTH cortisol concentrations observed four and 24 hours after the administration of trilostane. Furthermore, in the six dogs whose clinical signs were poorly controlled the post-ACTH concentrations observed four and 24 hours after the administration of trilostane were always higher than the equivalent cortisol concentrations in the four dogs whose clinical signs were controlled. A short duration of drug action may be responsible for the failure of some dogs to respond adequately to once daily trilostane administration.

Haptoglobin concentrations in dogs undergoing trilostane treatment for hyperadrenocorticism.

BACKGROUND: Increased concentrations of haptoglobin (Hp), a moderate acute phase protein, have been demonstrated in dogs with hyperadrenocorticism (HAC). Monitoring serum concentrations of Hp in hyperadrenocorticoid dogs before and after trilostane administration may provide valuable information on the response to therapy. OBJECTIVE: The aim of this study was to measure Hp concentrations in dogs with spontaneously occurring HAC at the time of diagnosis and after treatment with trilostane. METHODS: Serum Hp concentration was measured using an automatic biochemical assay based on Hp-hemoglobin binding and utilizing SB-7 reagent in 12 dogs with spontaneous HAC before and after treatment with trilostane (30 or 60 mg PO q 12-24 h). Post-treatment Hp concentrations were measured at the time the owner reported an improvement in clinical signs. Pretreatment and post-treatment Hp values were compared with reference values and with values from 4 healthy control dogs. RESULTS: Two dogs with HAC had pretreatment Hp values within the reference interval; 10 dogs had moderate (n = 8) or marked (n = 2) increases in Hp concentration. After treatment with trilostane, Hp concentration remained within the reference interval (n = 2), decreased to within the reference interval (n = 3), or remained moderately increased (n = 7; 3-10 g/L). Overall, a significant decrease was observed in Hp concentration after trilostane treatment compared with pretreatment values (P <.005). Both untreated and treated dogs with HAC had significantly higher Hp concentrations (P <.001) when compared with control dogs. CONCLUSIONS: Clinical control of HAC did not closely relate to serum Hp concentration. Further studies are required to assess whether this is because of inadequate control of disease or because a build-up of cortisol precursors or secondary effects of HAC affect Hp concentration.

Diagnosis and management of hepatic copper accumulation in a Skye terrier.

A one-year-old, neutered female Skye terrier presented with anorexia, vomiting, seizures and ascites. Portal venography demonstrated the presence of multiple acquired portosystemic shunts. Hepatic biopsy confirmed the presence of copper accumulation and fibrosis. Treatment included ursodeoxycholic acid therapy, colchicine and oral zinc. To the authors' knowledge, this is the first case report detailing successful management of Skye terrier hepatopathy.

Canine and feline pyothorax: a retrospective study of 50 cases in the UK and Ireland.

Fifty cases (36 dogs and 14 cats) with a confirmed diagnosis of pyothorax were evaluated from five referral institutions in the UK and Ireland. Aetiology, clinical presentation, diagnosis, treatment and outcome of all cases were examined. The underlying cause of pyothorax was determined in 18 per cent of cases. Positive bacteriological cultures of the pleural fluid were obtained in 68.7 per cent of the animals. Treatment modalities included surgery and medical management, involving thoracostomy tube placement, thoracic aspiration, thoracic lavage and antimicrobial therapy. A successful outcome was achieved in 86 per cent of patients.

Oesophageal stricture in a cat due to oral administration of tetracyclines.

A three-year-old, male neutered domestic shorthair cat was presented with dysphagia and regurgitation following treatment with oral doxycycline and oxytetracycline for Haemobartonella felis infection. Fluoroscopy confirmed the presence of multiple strictures along the entire length of the oesophagus. Balloon dilatation was performed successfully on two occasions and the symptoms resolved. To the authors' knowledge, this is the first report of oesophageal strictures associated with oral administration of tetracyclines in a cat in the UK.