Evaluation of benazepril in cats with heart disease in a prospective, randomized, blinded, placebo-controlled clinical trial.

BACKGROUND: Heart disease is an important cause of morbidity and mortality in cats, but there is limited evidence of the benefit of any medication. HYPOTHESIS: The angiotensin-converting enzyme inhibitor benazepril would delay the time to treatment failure in cats with heart disease of various etiologies. ANIMALS: One hundred fifty-one client-owned cats. METHODS: Cats with heart disease, confirmed by echocardiography, with or without clinical signs of congestive heart failure, were recruited between 2002 and 2005 and randomized to benazepril or placebo in a prospective, multicenter, parallel-group, blinded clinical trial. Benazepril (0.5-1.0 mg/kg) or placebo was administered PO once daily for up to 2 years. The primary endpoint was treatment failure. Analyses were conducted separately for all-cause treatment failure (main analysis) and heart disease-related treatment failure (supportive analysis). RESULTS: No benefit of benazepril versus placebo was detected for time to all-cause treatment failure (P = .42) or time to treatment failure related to heart disease (P = .21). Hazard ratios (95% confidence interval [CI]) from multivariate analysis for benazepril compared with placebo were 1.00 (0.57-1.74) for all-cause failure, and 0.99 (0.50-1.94) for forward selection and 0.93 (0.48-1.81) for bidirectional selection models for heart disease-related failure. There were no significant differences between groups over time after administration of the test articles in left atrium diameter, left ventricle wall thickness, quality of life scores, adverse events, or plasma biochemistry or hematology variables. CONCLUSIONS AND CLINICAL RELEVANCE: Benazepril was tolerated well in cats with heart disease, but no evidence of benefit was detected.

Histological changes in the external ear canal of dogs with otitis externa.

This study aimed to better characterise the gross anatomy of the normal ear canal, and to compare histological features of the normal ear canal to those affected by chronic otitis externa. In 40 normal ears from 20 dogs, the length of the annular and auricular cartilage was 1.2 +/- 0.2 and 4.1 +/- 0.9 cm, respectively; overall length of the external ear canal was 5.3 +/- 1.0 cm. The maximal internal diameter at the distal end of the external ear canal, the proximal opening of the auricular cartilage and the proximal end of the annular cartilage was 5.8 +/- 1.5, 0.7 +/- 0.2 and 0.5 +/- 0.1 cm, respectively. Body weight correlated positively with the overall length and diameter of the distal end of the ear canal (r = 0.78, P < 0.001; r = 0.42, P < 0.05). Morphometric evaluation was carried in 28 clinically healthy ears of 14 dogs, and 15 otitic ears of 13 dogs. Histological features of this integument revealed that the density and distribution of sebaceous and ceruminous gland tissue exhibits marked variation between individuals. Nevertheless, general patterns were observed; sebaceous tissue increases gradually from the proximal to the distal parts of the ear canal, whilst ceruminous gland tissue by contrast decreases. In otitic canine ears, the distribution of sebaceous and ceruminous glandular tissue was similar to normal ears but the glands became larger and hyperplastic (P < 0.05). Density of hair follicles was not different between healthy and otitic ears (P = 0.16), but the hair follicles became hyperplastic in otitic ears.