Pathophysiologic mechanism of cardiac dysfunction in experimentally induced heartworm caval syndrome in dogs: an echocardiographic study

In dogs with experimentally induced heartworm infection, the onset of caval syndrome (CS) was characterized by a murmur, loudest over the tricuspid valve, and a large worm mass in the right ventricular lumen detectable during diastole by use of M-mode echocardiography. Two-dimensional echocardiography indicated that the worm mass was located in the right atrium and venae cavae and was "flowing" into the right ventricle during rapid diastolic filling. Paradoxical septal motion and vigorous right ventricular cranial wall motion also were observed. Other echocardiographic changes included decreased size of the left atrium and ventricle, aortic root, and ratio of left-to-right ventricular diastolic luminal diameter, compared with values obtained 6 months after experimentally induced heartworm infection. Right ventricular end diastolic diameter increased considerably. Most echocardiographic indices of left ventricular function (fractional shortening, velocity of circumferential fiber shortening, ejection fraction, and preejection period) were not altered appreciably, but estimates of cardiac index and stroke volume were markedly decreased. Electrocardiography revealed ventricular and supraventricular premature complexes in 7 of the 8 dogs studied, evidence of right ventricular enlargement in 6 of the 8 dogs studied, and increased mean heart rate, compared with that measured 6 months after inoculation of infective larvae, before the onset of CS. Cardiac catheterization was performed in 3 days at the onset of CS. Severe pulmonary arterial and right ventricular hypertension and decreased cardiac index (compared with values obtained before inoculation) were observed. Evidence of right ventricular inflow obstruction was not detected. Mean aortic blood pressure decreased with the onset of CS, but right ventricular end diastolic pressure increased.(ABSTRACT TRUNCATED AT 250 WORDS)     

Feline struvite crystalluria: a comparison of some commercially available dry cat diets in New Zealand

Thirteen adult cats were each fed consecutively five test diets: firstly a complete canned diet, and then four commercially available dry cat diets (New Formula Biscats, Cat Chow, Go-Cat and Whiskettes) for 7,13, 5, 4 and 4 weeks respectively. Urine samples were tested for pH and presence of struvite crystals. Body weight was recorded weekly. Urine pH was ranked from acid to alkaline as follows: Whiskettes (pH 5.8), canned diet (pH 5.9), Biscats (pH 6.1), Cat Chow (pH 6.45) and Go-Cat (pH 6.5). The pH of urine when cats were fed Whiskettes, Biscats and canned diet was not significantly different. Biscats produced a urine pH significantly higher than Whiskettes but, in each case, these three diets produced a significantly lower urine pH than Cat Chow and Go-Cat. Struvite crystals occurred spontaneously in 9% of urine samples from cats when fed Whiskettes and Biscats, 71% when fed Cat Chow and 38% when fed Go-Cat: spontaneous struvite was not seen in any cat fed CX9. Haematuria was seen in 2.9% (2/69) urine samples from cats fed Cat Chow. One tom cat had a blocked urethra after 24 days on Go-Cat. No abnormalities were observed in any cat when fed canned diet, Biscats or Whiskettes. It was concluded that of the four dry cat diets tested only Biscats and Whiskettes produce urine with an acceptably low rate of spontaneous struvite crystalluria.     

Vitamin E, selenium and polyunsaturated fatty acids in clinically normal grower (9-16 weeks old) pigs and their feed: their relationship to the vitamin E/selenium deficiency ("VESD") syndrome

Vitamin E, selenium and polyunsaturated fatty acids (PUFAs) were determined in feed used at three piggeries over.a four week period and compared with corresponding concentrations in clinically normal grower pigs at slaughter. Mean values were vitamin E: 59 IU/kg (feed), 6 micromol/kg (liver), 1.7 micromol/l (serum); and selenium: 310 microg/kg (feed), 5200 nmol/kg (liver), 1700 nmol/l (blood). Alpha-tocopherol accounted for 80% of the mean vitamin E activity in the feed and over 95% that in the liver and serum. The mean ratio of PUFA to total fatty acid (FA) in the feed (38%) was similar to that in the serum (36%) and liver (39%), but the ratio of peroxidisable PUFA (PPUFA) to FA increased from 1.7% in the feed to 4.2% in the serum and 10.8% in the liver. The ratio of alpha-tocopherol (mmol) to PPUFA (mol) in the liver varied from 0.16 to 0.48. The relationship of these data to the VESD syndrome is discussed in the light of other published data.     

Acquired hydrocephalus and hydromyelia in a cat with feline infectious peritonitis: A case report and brief review

A one-year-old domestic long-haired cat was referred to the New York State College of Veterinary Medicine because of acute onset of paraparesis and hyperesthesia associated with trauma. Myelography and cerebrospinal fluid analysis revealed severe hydromyelia and myelitis, respectively. The definitive diagnosis of feline infectious peritonitis was made by histological examination at necropsy. Lesions were confined exclusively to the brain and spinal cord. Partial occlusion of the third and fourth ventricles with pyogranulomatous debris caused hydrocephalus and subsequent hydromyelia. The hydromyelia may have been the primary means of compensation for the hydrocephalus, thus masking subclinical disease.     

A study of periodontal disease in sheep over a twelve month period

Sheep affected by broken mouth periodontal disease (P.D.) were examined over a twelve month period for different clinical parameters. It is suggested that P.D. in sheep is an episodic phenomenon similar to human P.D., and that only a few animals with signs of P.D. may undergo clinically significant destruction over a yearly period. No single parameter could reliably predict future deterioration in other parameters.