Prolonged depression of thermoregulation after xylazine administration to cats

Xylazine administered subcutaneously (s.c.; 1–4 mg/kg) or intravenously (i.v.; 0.5-2 mg/kg) to cats consistently caused dose-related decreases in body temperature which were maximal 3–4 h after injection and lasted for at least 12 h. Otherwise the animals appeared to have recovered fully from the central nervous system effects of the drug within 1.5–3.5 h. Xylazine-induced hypothermia developed more rapidly in cats placed in a 4°C environment and, in contrast, was replaced by a hyperthermic response in cats placed in a 32°C environment. These changes in body temperature were not opposed by compensatory thermoregulatory effector activity such as shivering or tachypnea. This pattern of responses at varied environmental temperatures is indicative of a general depression of the thermo-regulation. Thus, animals given xylazine should not be exposed to extreme heat or cold for several hours to avoid development of hyper- or hypothermia.     

CLINICAL ASSESSMENT OF RENAL FUNCTION IN THE DOG WITH A REDUCTION IN NEPHRON NUMBER*

The viewpoint presented is that, because compensatory functional adjustment of the residual nephrons occurs in chronic renal disease, reduction in nephron number usually exceeds 70% before a diagnosis is made. The case that earlier diagnoses are likely if laboratory medicine values are measured and interpreted with a maximum of efficiency is then made. The laboratory data more commonly used in practice for the clinical assessment of renal function in the dog are presented and some comparisons with findings in man are made. The information originates from clinical and experimental observations of the authors, as well as from a literature review. The laboratory data presented and discussed includes glomerular filtration rate and the clearance of nitrogenous waste (urea and creatinine), plasma protein concentration, plasma osmolality, renal concentrating capacity, and urinary constituents, particularly its protein concentration and sediment (centrifuge deposit). All parameters recommended for the clinical assessment of chronic renal failure are considered qualitatively, and some are also dealt with quantitatively.     

Colorectal polyps of the dog: a clinicopathologic study of 17 cases.

Seventeen cases of colorectal polyps in the dog were seen at the Ontario Veterinary College over a 12-year period. The mean age of occurrence was 6.9 years, and males and females were almost equally affected. The Collie was the most frequently affected breed (4/17). The clinical signs were typically dyschezia, periodic intermittent diarrhea and melena, and rectal prolapse of the polyp. The histopatholic classifcation were hyperplastic polyp (1), papillary adenoma (1), tubular adenoma (4), papillotubular adenoma (10), and unclassified (1). Severe epithelial atypia, likely carcinoma in situ, was apparent in 5 of the papillotubular adenomas. Retrospective analysis of survival data after polypectomy suggested a good prognosis, but the results were inconclusive and it is possible that some of the polyps represented premalignant lesions. Large polyps (greater than 1 cm in diameter) frequently had marked epithelial atypia and were considered more likely to recur or to become malignant.     

Observations on the selenium status of cattle in the north-east of Scotland.

Cattle on 18 of 21 farms in north-east Scotland were found to have low whole blood activities of the selenium-containing enzyme, glutathione peroxidase (less than 5 units per ml whole blood), and a low blood concentration of selenium (less than 0.05 mg per litre). These cattle had all been fed on locally produced feedstuffs without any mineral supplementation. The low selenium status in cattle occurred on farms with soils derived from a range of parent material, no one particular type predominating.     

Effects of small and large face masks and translaryngeal and tracheostomy intubation on ventilation, upper-airway dead space, and arterial blood gases

Pulmonary function was examined in pentobarbital-anesthetized dogs that were spontaneously breathing through a large poorly fitted face mask, a small snug-fitted face mask, an endotracheal tube, and a tracheostomy tube. Increasing upper-airway dead space volumes were associated with higher minute ventilation and faster breathing rates. Minute and tidal alveolar ventilation, calculated ideal alveolar oxygen, alveolar-arterial oxygen gradient, venous admixture, arterial pH and blood gases, cardiac output, and systemic and pulmonary arterial blood pressure were not changed. The functional dead space of each mask was considerably less than that measured by water displacement. The small mask only slightly increased, and the endotracheal tube slightly decreased, the dead space estimated for a nasally breathing healthy dog.     

Surface proteins of Breda virus

The serotypes 1 and 2 of Breda virus from feces of experimentally infected gnotobiotic calves were studied with respect to their sedimentation and density properties in sucrose gradients and their structural polypeptides; Berne virus, the proposed prototype of the new family Toroviridae, was included for comparison. After Breda-1 virus had been stored at 4 C for a prolonged period, it showed a heterogeneous sedimentation behavior (480 to 520 Svedberg units [S]) and density (1.18 to 1.21 g/ml) indicative of its poor state of preservation. In contrast, freshly prepared Breda-2 virus sedimented at 350 S and showed a buoyant density of 1.18 g/ml; these values compare well with those of Berne virus (400 S and 1.16 g/ml, respectively). Efficient purification of the Breda viruses could be achieved by a 2-step method, involving pelleting by ultracentrifugation followed by isokinetic and isopyknic sucrose gradient centrifugation. Radioiodinated purified virus showed polypeptides with apparent molecular weights of 105,000, 85,000 37,000, and 20,000; another labeled protein of 65,000 D is of doubtful virus specificity. Mouse immune serum raised against Breda-2 virus recognized the polypeptides of the homologous virus and the 2 highest molecular weight proteins of Breda 1 virus in radioimmune precipitation. The same serum inhibited hemagglutination of the heterologous serotype to a low, but significant, degree and efficiently neutralized the infectivity of Berne virus. These observations are taken as indications that the 105,000- and 85,000-D polypeptides represent surface structures of torovirions, probably peplomeric proteins.     

Trichostrongylus angistris n. sp. from the red duiker Cephalophus natalensis A. Smith, 1834 and a redescription of Trichostrongylus minor M?nnig, 1932

Trichostrongylus angistris n. sp. was found in the abomasa of 13 red duiker Cephalophus natalensis A. Smith, 1834, culled in the Charter's Creek Nature Reserve, Natal. The species is closely related to Trichostrongylus minor M?nnig, 1932 and can be differentiated from it by the shorter dorsal ray and the different shape of the gubernaculum and spicules. The shoes of the spicules of T. minor are set at an angle to the long axis, while those of T. angistris are curved. Upon re-examination, the Trichostrongylus spp., tentatively identified as Trichostrongylus capricola Ransom, 1907 and Trichostrongylus vitrinus Looss, 1905, proved to be T. angistris. In this paper, T. angistris is compared with T. capricola and T. vitrinus and T. minor is redescribed.