A case-control study of Nocardia mastitis in Nova Scotia dairy herds

A case-control study was conducted to identify herd production, housing, and hygienic and therapeutic factors associated with a diagnosis of Nocardia mastitis in dairy herds in Nova Scotia. The data were collected by on-farm interviews with owners of 54 case and 54 control herds.

Logistic regression was used to study risk factors. The use of dry cow products containing neomycin, including two specific dry cow products, was strongly associated with a diagnosis of Nocardia mastitis in a herd. Other factors which increased the risk of Nocardia mastitis were higher levels of production, larger herd size, and a large percentage of cows treated with dry cow products. These results are compared to results from a similar study carried out in Ontario.

     

Meat inspection in New Zealand: prospects for change

Regulatory authorities are facing increasing challenges with respect to the newly-recognised public health risks associated with meat products. Meat inspection resources should be allocated according to their maximum ability to reduce food-borne hazards, rather than according to the classical rules of meat inspection. Scientific evaluation of routine post-mortem inspection procedures for each class of livestock, introduction of the Hazard Analysis Critical Control Point approach to process control, on-line testing for microbiological hazards and residues, and effective management of production, processing and inspection data are central to this process. The meat inspection system that has evolved in New Zealand reflects a response to non-scientific forces such as market requirements and industrial practices rather than scientific discipline. In the future, the daily routine of meat inspectors will be extended well beyond their current slaughterfloor responsibilities, and veterinarians will require specialist skills. Science should be the basis for international food regulation and policy concepts such as equivalence or mutual acceptance are achievable on this basis.     

Comparative studies of BHV-1 variants by in vivo--in vitro tests.

The new encephalitogenic BHV-1.3 and previously characterized BHV-1 strains were studied with reference to their immunogenic and protective potency and their antigenic relationships using "in vitro" and "in vivo" tests. The "in vitro" results obtained by neutralization kinetics showed that the Los Angeles (LA) strain (BHV-1.1) and a vaginal isolate L-114 strain (BHV-1.2) had antigenic similarities. Conversely, the behavior of the encephalitogenic strain A-663 (BHV-1.3), was significantly distinct. The "in vivo" protection test was carried out in calves using LA and A-663 strains. Post-vaccination antibodies and challenge with A-663 strain showed that the immunogenic behavior and protective capacities of both strains were similar. Neutralization kinetics differences between BHV-1.1 and BHV-1.3 did not alter the "in vivo" protection against BHV-1.3 challenge.     

The histological appearance of peroral gastric biopsies in clinically healthy and vomiting dogs.

A survey of the histology of gastric biopsies in 501 dogs, consisting of 19 clinically healthy dogs and 482 vomiting dogs is presented. Whole stomachs of four young clinically healthy laboratory dogs were used as controls. Eleven percent of forceps biopsies were unsuitable for examination; all suction biopsies were of good quality. Slight to severe gastritis was found in 168 vomiting dogs (35%), whereas five dogs (26%) of the clinically healthy group showed a mainly slight gastritis. Superficial and diffuse gastritis were the most prominent findings in the 168 dogs with gastritis. A single type of gastritis was found in 114 dogs, a combination of different types in 54 dogs. Gastric atrophy was seen in 23 (5%) vomiting dogs and in three (15%) clinically healthy dogs, atrophy with a slight to severe fibrosis in 21 (4%) vomiting dogs, and in 84 (17%) vomiting dogs and two (11%) healthy dogs, gastric fibrosis was present. Carcinomas were seen in 26 vomiting dogs, of which 17 also had gastritis. A differential diagnosis of granulomatous gastritis/carcinoma had to be made in one case. Seven dogs showed a lymphosarcoma, and in six other dogs a differential diagnosis of lymphosarcoma and/or gastritis was made. One adenomatous polyp was seen. In one clinically healthy dog an adenomyoma was diagnosed. Ulceration was found in 24 dogs, but only five of these lacked other lesions. Other biopsy findings were pseudopyloric metaplasia, hyperplasia, cysts, calcification and edema. Some dogs showed "antralization".