Electroejaculation in the domestic cat

A method of electroejaculation for tomcats is described. Normal sperm counts in 4 cats ranged from 6 to 13 times 10Vejaculate. There was a great deal of variation between collections from the same cat indicating the necessity for at least 5 collections when assessing the fertility of a tomcat. Sperm counts were higher in the latter half of the year, at the time of increased sexual activity for cats in the Brisbane area. The volume of semen collected by electroejaculation increased in direct proportion to the length of electrical stimulation, hence, volume is not a reliable criterion for the appraisal of semen. However, results have indicated that semen volume tends to increase from July to December, thus indicating increased accessory gland activity during the breeding season. As this procedure does not cause any apparent discomfort or harmful effects there seems no reason to assume that it could not be used routinely on stud cats.     

Echocardiography in the domestic cat.

Echocardiographic examinations were performed on 25 normal healthy cats placed in left lateral recumbency. The cats were representative of serveral breeds, consisted of 12 males and 13 females, and weighed between 2 and 6.5 kg. Twelve measurements from the echocardiograms of each cat were made for the purpose of compiling a small data base (reference values). These measurements included wall thicknesses, luminal dimensions, and contractile indices. Left ventricular wall thickness averaged 0.37 +/- 0.08 cm, and the septal wall thickness averaged 0.45 +/- 0.09 cm. The average left ventricular lumen in diastole was 1.48 +/- 0.26 cm, and in systole, it was 0.88 +/- 0.24 cm, which resulted in an average shortening fraction of 41 +/- 7.3%. Velocity of circumferential shortening, an index of contractility, averaged 2.86 +/- 0.78 cm. In eight additional cats, both ventricles were catheterized for echographic chamber identification and then cineangiographic procedures. Then these cats were euthanatized, and postmortem measurements were compared with echocardiographic and cineangiographic measurements. According to the three methods of determining wall thickness, differences were less than 15%, where the range of deviations was between 0 and 0.5 mm and the average deviation was -0.01 +/- 0.26 mm.     

Adrenocortical function and plasma biochemical values in dogs after subconjunctival treatment with methylprednisolone acetate

The effects of subconjunctivally administered methylprednisolone acetate on adrenocortical function and blood composition were studied in five dogs. Two 10 mg doses of methylprednisolone acetate were injected at an interval of 21 days. Plasma cortisol concentrations (COR), ACTH-stimulated cortisol concentrations and other blood components were determined regularly. The normal plasma COR (5.7 +/- 2.62 ng/ml) was one of the lowest reported in the literature for the dog, possibly because of the specificity of the high performance liquid chromatographic assay and the experimental environment. Plasma COR was depressed only after the first administration of methylprednisolone acetate. ACTH stimulated COR was significantly depressed nine and 20 days after the first and second subconjunctival injection respectively. Otherwise blood composition was unchanged.     

Pharmacokinetics of cefotaxime in the domestic cat

Cefotaxime was administered as single IV or IM dose for the purpose of examining its pharmacokinetics in healthy cats. The mean predicted plasma concentration of cefotaxime in 6 cats at 0 time after a single IV dosage of 10 mg/kg of body weight was 88.9 micrograms/ml. The mean plasma concentrations decreased to 10.8 micrograms/ml at 2 hours, 3.7 micrograms/ml at 3 hours, and 0.5 microgram/ml at 6 hours. The half-life was 0.98 +/- 0.25 hour (mean +/- SD), and the total body clearance was determined to be 2.76 +/- 1.25 ml/min/kg. After a single IM injection of 10 mg/kg of body weight, the mean maximum observed plasma concentration was 36.2 micrograms/ml at 0.75 hour. The mean absorption half-life was 0.24 hour. In 2 animals, the bioavailability of an IM injection was 98.2% and 93.0%.     

Granulocytopenia associated with thymoma in a domestic shorthaired cat

A 5-year-old, spayed female cat was referred because of a mass in the cranial mediastinum noted on thoracic radiographs. A thymoma was diagnosed following ultrasound and biopsy of the mass. Treatment was initiated with coarse-fraction radiation therapy using external-beam therapy (four fractions of 5 Gy). The mass responded, but granulocytopenia developed. Bone marrow examination showed a myeloid to erythroid ratio of approximately 1:1, with a left shift within the myeloid line. These findings, as well as the lack of toxic changes within the peripheral blood neutrophils, suggested immune-mediated destruction of peripheral granulocytes. Immune suppression with prednisone and cyclosporine was instituted. After 7 weeks, the neutrophil count returned to normal. The tumor was removed, and cyclosporine was reduced and eventually discontinued 3 weeks postsurgery.     

Adrenocortical involution in rats during oestrus synchronisation with medroxyprogesterone

Daily treatment of female rats with medroxyprogesterone acetate in aqueous suspension resulted in adrenocortical atrophy. The doses given were those used for oestrus synchronisation. Intramuscular injections of 2-0 mg medroxyprogesterone acetate were used to investigate the atrophic process. Adrenocortical involution was associated with extensive single cell deletion (apoptosis). It is suggested that theses changes were due to suppression of pituitary ACTH secretion. The cytological changes support the concept that single cell death plays an important role in organ remodelling. Biochemical determinations of DNA, RNA, protein and dry matter, and histological examination, did not reveal significant changes in the liver.     

Fucosidosis in a domestic shorthair cat

This paper documents the first reported case of fucosidosis in a cat. The cat presented with signs of forebrain and cerebellar dysfunction and a magnetic resonance imaging scan of the brain suggested a degenerative or metabolic disease process. A fine needle aspirate of grossly normal lymph nodes revealed vacuolated lymphocytes and a renal biopsy of an irregular shaped kidney identified vacuolated tubular epithelial cells. A white cell lysosomal enzyme screen revealed negligible α-fucosidase activity. Fucosidosis should be considered in the differential diagnosis of young cats with cerebellar dysfunction and must be added to the list of lysosomal storage diseases affecting the cat.     

Feline central retinal degeneration in the domestic cat

The literature on taurine deficiency in the cat is reviewed and six cases occurring in general small animal practice in Britain are reported. The histological findings in one case are described.     

Leptospirosis in a British domestic cat

A leptospire was isolated from thoracic fluid, aqueous humour, and kidney of a cat, which at gross post-mortem had widespread haemorrhages and excess straw-coloured fluid in the thoracic and peritoneal cavities.
Histopathological examinations revealed severe centrilobular necrosis of the liver, and vascular lesions with haemorrhage were present in lung and brain.
Spirochaetes were demonstrable in lung, kidney and brain by silver impregnation techniques.
Strong fluorescence was observed in lung, liver, brain and kidney with bratislava antiserum.     

Transitional cell carcinoma in the domestic cat.

In 17 cases of transitional cell carcinoma in cats the most common site for primary neoplasia was the urinary bladder; metastasis was recorded in five of the cases. Nine of the cases have been reported previously; the eight additional carcinomas from the files of the New York State College of Veterinary Medicine were highly invasive and had a desmoplastic response. According to WHO guidelines they were classified as nonpapillary, infiltrating; papillary, infiltrating; and variants of transitional cell carcinoma.     

Clinical use of echocardiography in the domestic cat

Echocardiograms were obtained from unanesthetized cats positioned in left lateral recumbency. Information regarding chamber wall thickness, lumen dimensions, valve motion, and indices of contractility was obtained. In three cases, echocardiographic manifestations typical of cardiac dilatation, cardiac hypertrophy, and pericardial effusion were recorded. Unlike thoracic radiographs, which portray pulmonary features as well as a cardiac silhouette, the echocardiogram provided an opportunity to measure each component comprising the cardiac silhouette--namely, the pericardial sac, cardiac musculature, and the cardiac chambers.