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SUMMARY

At an abattoir, lesion specimens from 140 condemned sheep livers were collected for bacteriologie culture and for pathologic examination. Grossly, 23 lesions were abscesses; from 9 of which, Fusobacterium necrophorum biovar A (3 in pure culture and 6 in mixed culture) was isolated and from 14 of which, biovar B (6 in pure culture and 8 in mixed culture) was isolated. Escherichia coli was the predominant facultative anaerobic bacterium and Clostridium perfringens was the predominant obligate anaerobic bacterium isolated from the 14 lesions with mixed bacterial infection. Histologically, these lesions had a core of coagulation necrosis, encircled by a zone of necrotic phagocytic cells and bacteria with cellular characteristics of F necrophorum biovars A or B, and a connective tissue capsule.

Of the 117 lesions without F necrophorum, 49 were culture-positive (for other organisms) and 69 were culturenegative. These 117 lesions were fibrous and were smaller than the 23 abscesses. A variety of gram-positive and gram-negative facultative anaerobic and obligate anaerobic bacteria was isolated from the culture-positive lesions, but always in low numbers. Eleven culture-negative and 18 culture-positive lesions were examined and had histologic characteristics of parasite-induced granulomas, with numerous eosinophils and epithelioid giant cells.

Results of the study indicated that the histologic appearance of ovine hepatic lesions with F necrophorum was similar to bovine liver abscesses caused by F necrophorum, but unlike bovine liver abscesses, F necrophorum biovar B was isolated more frequently than was biovar A and often in pure culture. Most of the lesions in the condemned livers were parasite-induced granulomas.

Free access
in American Journal of Veterinary Research

Abstract

Objective—To investigate differences in CSF concentrations of excitatory and inhibitory neurotransmitters in dogs with and without T2-weighted (T2W) MRI hyperintense areas in the limbic system.

Sample—Archived CSF samples and stored brain MRI images of 5 healthy research dogs (group 1), 8 dogs with idiopathic epilepsy (IE) with no abnormal MRI findings (group 2), and 4 dogs with IE with hyperintense areas in the limbic system detected by means of T2W MRI (group 3).

Procedures—Archived CSF samples and stored MRI images obtained from all dogs were evaluated. Dogs in groups 2 and 3 were matched on the basis of age and breed. High-performance liquid chromatography was used to evaluate glutamate and γ-aminobutyric acid (GABA) concentrations in CSF samples.

Results—Glutamate concentrations were higher in CSF of both groups of dogs with IE than in healthy dogs. However, glutamate concentrations in CSF were not significantly higher in dogs with IE and with hyperintense areas than in dogs with IE but no abnormal MRI findings. Concentrations of GABA in CSF were higher in group 3 than in group 2 and in group 2 than in group 1.

Conclusions and Clinical Relevance—No significant difference was evident between glutamate concentrations in CSF of dogs with IE and with and without hyperintense areas detected by means of T2W MRI. However, glutamate concentrations typically were higher in CSF of dogs with IE and MRI hyperintense areas. Future studies with larger sample sizes should be conducted to confirm this finding and to determine the clinical importance of high glutamate concentrations in CSF of dogs with IE.

Full access
in American Journal of Veterinary Research

Abstract

Objective—To devise a technique for gradual occlusion of the caudal vena cava in dogs and determine effects of complete occlusion of the caudal vena cava.

Animals—8 mixed-breed hounds that weighed between 25 and 30 kg.

Procedure—Baseline evaluation of dogs included serum biochemical analyses and determination of glomerular filtration rate (GFR) with dynamic renal scintigraphy and plasma clearance analysis. An occluder was placed around the vena cava in the region cranial to the renal veins. The occluder was attached to a vascular access port. The vena cava was gradually occluded over 2 weeks. The GFR was measured every 2 weeks after surgery, and venograms were performed every 3 weeks after surgery. Blood samples were collected every 48 hours for the first week and then weekly thereafter to measure BUN and creatinine concentrations and activities of alanine transaminase, alkaline phosphatase, and creatinine kinase. Dogs were euthanatized 6 weeks after surgery, and tissues were submitted for histologic examination. The GFR and biochemical data were compared with baseline values.

Results—Gradual occlusion of the caudal vena cava was easily and consistently performed with this method, and adverse clinical signs were not detected. Formation of collateral vessels allowed overall GFR to remain constant despite a decrease in function of the left kidney. Measured biochemical values did not deviate from reference ranges.

Conclusions and Clinical Relevance—Gradual occlusion of the caudal vena cava may allow removal of adrenal gland tumors with vascular invasion that would otherwise be difficult or impossible to resect. (Am J Vet Res 2003;64:1347–1353)

Full access
in American Journal of Veterinary Research
in Journal of the American Veterinary Medical Association

Abstract

Objective—To identify potential bacterial pathogens in normal and telangiectatic livers of mature cattle at slaughter and to identify consumer risk associated with hepatic telangiectasia.

Sample Population—50 normal livers and 50 severely telangiectatic livers.

Procedure—Normal and telangiectatic livers were collected at slaughter for aerobic and anaerobic bacterial culture. Isolates were identified, and patterns of isolation were analyzed. Histologic examination of all livers was performed.

Results—Human pathogens isolated from normal and telangiectatic livers included Escherichia coli O157:H7 and group-D streptococci. Most livers in both groups contained bacteria in low numbers; however, more normal livers yielded negative culture results. More group-D streptococci were isolated from the right lobes of telangiectatic livers than from the left lobes, and more gram-negative anaerobic bacteria were isolated from left lobes of telangiectatic livers than from right lobes. All telangiectatic lesions were free of fibrosis, active necrotizing processes, and inflammation.

Conclusions and Clinical Relevance—The USDA regulation condemning telangiectatic livers is justified insofar as these livers contain more bacteria than normal livers do; however, normal livers contain similar species of microflora. Development of telangiectasia could not be linked to an infectious process. The finding of E coli O157:H7 in bovine livers suggests that information regarding bacterial content of other offal and muscle may identify sources of this and other potential foodborne pathogens and assist in establishing critical control points for the meat industry. (J Am Vet Med Assoc 2001;219:36–39)

Full access
in Journal of the American Veterinary Medical Association

Objective—

To evaluate the potential food safety risks constituted by recumbent cattle that are slaughtered for edible beef.

Design—

Prospective case series.

Animals—

Thirty cattle in recumbency that passed a routine antemortem inspection at a US federally inspected abattoir.

Procedure—

Aerobic, bacteriologic culture of blood samples taken immediately prior to slaughter and of spleens taken during viscera inspection. Gross lesions were recorded, and samples of liver, lung, kidney, and heart were collected from each animal for routine light microscopic examination.

Results—

Bacteremia caused by Salmonella dublin was documented in 1 cow that had arthritis. Two other cows were condemned after postmortem inspection: 1 because of pneumonia and pleuritis and the other because of vegetative endocarditis. Three carcasses were retained and later condemned because of antibiotic residues in tissues; 1 of these cows had mastitis, 1 had liver abscesses, and 1 was the cow with vegetative endocarditis. Sarcocystosis was found in 27 of 30 hearts, but other clinically important histologic lesions were observed only in liver samples. In 11 of the 30 cows, multifocal, microscopic foci of hepatitis were observed, suggesting that terminal embolic bacterial showering of the liver had occurred in these animals. Liver samples were not submitted for bacteriologic culture.

Clinical Implications—

Most recumbent cows slaughtered for edible beef are not contaminated by bacteria; however, the viscera from these animals may present a food safety danger. Efforts should be made to develop rapid tests to identify bacteremic animals at slaughter and to more fully evaluate terminal showering of viscera by bacteria in cattle at slaughter.

Free access
in Journal of the American Veterinary Medical Association

Abstract

Objective—To determine the prevalence of and clinical features associated with incidental adrenal gland lesions (IAGLs) discovered during abdominal ultrasonography in dogs.

Design—Retrospective case series.

Animals—151 dogs with an IAGL and 400 control dogs.

Procedures—Reports of ultrasonographic examinations of the abdomen of dogs performed during a 3.5-year period were reviewed. Adrenal glands were classified as having an IAGL if a nodule or mass was described or the width of either gland was ≥ 10 mm. For dogs with an IAGL, information regarding signalment, concurrent disorders, and outcome was obtained from the medical record. Findings were compared with those in a control population of 400 dogs examined during the same period.

Results—An IAGL was detected in 151 of 3,748 (4%) dogs. Dogs with an IAGL were significantly older (median age, 11.25 years) and heavier (median body weight, 21 kg [46.2 lb]) than the control population (median age, 9.5 years; median body weight, 14 kg [30.8 lb]). Malignant tumors were reported in 6 of 20 (30%) dogs that underwent adrenal glandectomy or necropsy and had a maximum IAGL dimension that ranged from 20 to 46 mm; benign lesions all had a maximum dimension < 20 mm. Various coincidental conditions were reported in dogs with an IAGL, including nonadrenal gland malignant neoplasia in 43 (28.5%) dogs.

Conclusions and Clinical Relevance—IAGLs were more likely in dogs ≥ 9 years of age. On the basis of this small data set, malignancy should be suspected for IAGLs ≥ 20 mm in maximum dimension.

Full access
in Journal of the American Veterinary Medical Association
in Journal of the American Veterinary Medical Association