The sites of early viral replication in feline infectious peritonitis

The sites of early replication of feline infectious peritonitis virus were studied following oral inoculation of specific-pathogen-free (SPF) cats with virus grown in cell cultures. Viral antigen was first detected by immunofluorescence in the tonsils and small intestine within 24 h of inoculation, and was later found in caecum, colon, mesenteric lymph nodes and liver. However, histological changes in the gut did not appear until relatively late in the course of infection. Virus was recovered from the oropharynx and the faeces from as early as the second or third day after inoculation, and shedding continued until euthanasia.     

Occurrence of 'attaching and effacing' lesions in the small intestine of calves experimentally infected with bovine isolates of verocytotoxic E coli

Nine calves (five colostrum-fed, four colostrum-deprived) were challenged with two field strains of Escherichia coli which produced either verocytotoxin 1 (VT1) or verocytotoxin 2 (VT2). Although three colostrum-fed calves had blood and mucus in their faeces, no diarrhoea was observed. Three of the four colostrum-deprived calves had diarrhoea and in two of them severe lesions were detected in the small intestine. Focal changes were detected in the colon of three calves. E coli were associated with the lesions in the small and large intestine and were shown by transmission electron microscopy to be intimately attached to the enterocyte surface with effacement of microvilli (attaching and effacing lesions). This is the first report of E coli which produce VT2 being associated with disease in calves.     

Influence of obesity on plasma lipid and lipoprotein concentrations in dogs

OBJECTIVE: To determine effects of obesity and diet in dogs on plasma lipid and lipoprotein concentrations by assaying plasma leptin and ghrelin concentrations and determining total plasma cholesterol and triglyceride concentrations as well as the concentrations of cholesterol and triglycerides in various lipoprotein classes (ie, very-low-density, low-density, and high-density lipoproteins). ANIMALS: 24 Beagles; 12 lean (mean [+/- SEM] body weight, 12.7 +/- 0.7 kg) and 12 chronically obese (21.9 +/- 0.8 kg) dogs of both sexes, between 1 and 9 years old. PROCEDURES: Total plasma cholesterol and triglyceride concentrations; lipoprotein cholesterol and triglyceride concentrations; and plasma ghrelin, leptin, free fatty acids, insulin, and glucose concentrations were measured and compared between lean and obese dogs, both of which were fed a complete and balanced maintenance diet. Chronically obese dogs were subsequently fed a high-protein low-energy diet to evaluate effects of diet composition on plasma lipid and lipoprotein measurements. RESULTS: Chronic obesity resulted in a significant decrease in plasma ghrelin concentration and a significant increase in plasma leptin, cholesterol, and triglyceride concentrations in dogs. High total plasma cholesterol and triglyceride concentrations resulted from increased cholesterol and triglyceride concentrations in all lipoprotein fractions. In obese dogs, modification of diet composition resulted in beneficial effects on plasma lipid and leptin concentrations, even before weight loss was observed. CONCLUSIONS AND CLINICAL RELEVANCE: Correlations exist between obesity and plasma measurements (ie, lipoproteins, leptin, insulin, and ghrelin) commonly associated with obesity. Modification of diet composition to control energy intake improves plasma lipid and leptin concentrations in obese dogs.     

In vitro development of zygotes from prepubertal gilts after microinjection of DNA.

The effect of pronuclear microinjection of DNA and culture in excised mouse oviducts on the development of porcine zygotes was assessed in this study. Precocious ovulation was induced in prepubertal gilts with pregnant mare's serum gonadotrophin and hCG. Zygotes received either pronuclear microinjection of buffer alone, buffer containing a DNA construct, or no microinjection. Zygotes were cultured in vitro in either modified Krebs-Ringer bicarbonate medium (KRB) for 144 h or in mouse oviduct (MO) explant culture with KRB for 48, 72, 96, or 120 h. Pronuclear microinjection of DNA resulted in a lower (P less than .05) cleavage index (CI) than did buffer or no microinjection (CI 2.16 +/- .10 vs 2.80 +/- .13 and 2.93 +/- .10). The CI loss was greatest for DNA-injected zygotes at the two-cell stage of development. Coculture of zygotes in MO resulted in a higher CI (P less than .01) than did culture in KRB. Culture in MO for 72 h was the most beneficial system compared with MO for 48, 96, or 120 h (P less than .05; CI 3.25 +/- .12 vs 2.66 +/- .18, 2.79 +/- .14, and 2.40 +/- .14, respectively). Microinjection of DNA, not merely the mechanical procedure, was detrimental to early zygote development and may be the cause of low pregnancy rates.     

Quantitative observations on experimental reo-like virus (rotavirus) infection in colostrum-deprived calves.

Ten calves were challenged with one of two strains of reo-like virus (rotavirus). Changes in the daily faecal and urinary outputs were monitored and packed cell volume, plasma sodium, potassium and urea levels were measured. Faeces were examined for the presence of rotavirus by direct electron microscopy and immunofluorescence in cultures of PK(15) cells. All calves excreted rotavirus in the faeces for several days. Two calves remained clinically normal throughout the experiment, but in the remaining calves, faeces became mucoid in consistency and yellow-white in colour. In only two calves did the daily faecal output exceed 500 g with a fall in the dry matter content to less than 10 per cent. Slightly elevated blood urea levels and hyperkalaemia were the only changes observed in blood chemistry and these quickly returned to normal. Virus antigen was observed in the epithelial cells by immunofluorescence in the proximal and middle small intestine of calves. Pathological lesions occurred predominantly in the proximal small intestine of nine calves examined.     

Pretreatment with feline interferon omega and the course of subsequent infection with feline herpesvirus in cats

OBJECTIVE: Recombinant feline interferon omega (rFeIFN-omega), a type I IFN, may have the potential to limit virus replication and associated clinical signs when administered early on in the course of feline herpesvirus type 1 (FHV-1) infection and reactivation, respectively. The effect of rFeIFN-omega pretreatment on the course of subsequent FHV-1 infection in cats was investigated. ANIMALS STUDIED: Nine SPF cats were divided into an IFN group (n = 5) and a control-group (n = 4). PROCEDURES: The IFN group was pretreated for 2 days with 10 000 units rFeIFN-omega twice a day topically into both eyes and 20 000 units rFeIFN-omega once a day orally, whereas the control group was mock-treated. Subsequently all cats were infected with FHV-1. Samples for FHV-1 DNA detection and quantitation, virus isolation, and titration of FHV-1 antibodies were collected. Clinical and ocular signs were recorded and scored. RESULTS: Courses of median individual clinical and ocular scores and virus load did not differ significantly between both groups using anova for repeated measurements. Analysis (anova) of each individual ocular parameter revealed significantly high scores for epithelial keratitis (P = 0.016) in the IFN group compared to the control group. Periods of virus shedding did not differ significantly between both groups using the Wilcoxon rank sum test. CONCLUSIONS: Results indicated a lack of beneficial effects of rFeIFN-omega pretreatment in the course of primary FHV-1 infection in cats.     

Concurrent cryptosporidium and coronavirus infections in an Arabian foal with combined immunodeficiency syndrome

Combined immunodeficiency syndrome is an inherited disorder of the Arabian breed of horses. Affected foals usually die of infectious disease within the first few months of life, and the respiratory tract is the commonest site of infection. This report describes the clinical and pathological features of a case which showed signs of alimentary and respiratory infections. Intestinal infection by coronavirus (not previously recorded in cases of the syndrome) and cryptosporidia was identified. Histopathological evidence also suggested the presence of an adenovirus infection.     

Megaesophagus in 15 Llamas: A Retrospective Study (1985–1993)

Megaesophagus was diagnosed in 15 llamas on the basis of survey and contrast radiography. Age of onset ranged from 13 months to 9.5 years. Clinical signs varied, with salivation being the most common; regurgitation or dysphagia were noted in only 33% of the cases. Duration of the disorder ranged from 1 week to 5 years. Organophosphate toxicity was the cause of megaesophagusin 1 llama. While most cases were of unknown etiology, the 3 with histological abnormalities included 1 with vagal neuropathy and 2 with a degenerative myopathy of esophageal muscles. The causes in most were undetermined.