Studies on bovine demodecosis in northern Nigeria

Summary The study reported in the present paper discusses the clinical and histological picture of bovine demodecosis and the morphology of Demodex mites as seen in four cows suffering from generalized demodecosis. There were no clinical signs of other skin affections. Changes in both the number and the appearance of visible skin lesions were seen and related to the level of nutrition and the exposure to sunshine of the cattle. Histological sections of some skin nodules showed the presence of mite colonies in the hair follicles. Only adults were seen in the sebaceous glands. Microscopical study of the morphology of the mites revealed the presence of two types of demodicids in the skin lesions and three types from epilated eyelashes. Morphological criteria are presented to aid in identification of species and of life stages.     

Pasteurella haemolytica infections in sheep

Summary Pasteurella haemolytica causes two distinct disease syndromes in sheep. P. haemolytica biotype A causes septicaemia in young lambs and pneumonia in all ages of sheep. Biotype T produces an acute systemic disease affecting principally the upper alimentary tract and lungs in young adult sheep. The bacteriology, epidemiology and clinical and necropsy findings of the two diseases are described and the current situation regarding their experimental reproduction and immunology is reviewed.     

Salmonella serotypes encountered in animal feed additives in Lebanon.

Animal feed-additive samples (n = 300) were examined for the presence of salmonellae, using the selenite-F broth-enrichment method followed by subculturing on Salmonella-Shigella and brilliant green agar with sulfadiazine selective agar plates. Samples consisted of a variety of feed additives: 119 bone meal samples, 77 meat meal samples, 40 fish meal samples, and 64 miscellaneous meal samples. Results of examination found 49 (41.2%) of the bone meal samples, 6 (7.8%) of the meat meal samples and 2 (5%) of the fish meal samples contained salmonellae. Of 57 isolates representing 24 serotypes, 4 most frequently isolated serotypes were Salmonella meleagridis (35.1%), Salmonella tennessee (7%), Salmonella chester (5.2%), and Salmonella senftenberg (5.2%). This study shows a high Salmonella-contamination rate of bone meal compared with meat meal and fish meal samples. Of 12 known positive bone meal samples that were examined, 100% of 25-g samples, compared with 70% to 100% of 2.5-g samples and 30% to 90% of 0.25-g samples and 30% to 90% of 0.25-g samples, were positive for salmonellae.     

Microbiology of normal and seborrheic canine skin.

Quantitative and qualitative bacterial assays were performed on the skin of 15 normal and 32 seborrheic dogs. Nonionic detergent scrubs were made on areas demarcated by glass sidearm cylinders. Quantitative analysis was accomplished by the serial dilution technique, and the bacteria were identified by individual and colonial morphology and by enzyme production. Areas measured on control dogs had a markedly lower total bacterial count than similar areas measured on seborrheic animals. Control dogs had a flora consisting primarily of coagulase-negative cocci, whereas seborrheic dogs usually had a cutaneous flora composed primarily of Stahylococcus aureus, coagulase-positive.     

Comparison of the specificty of human and bovine tuberculin PPD for testing cattle. 1--Republic of Ireland.

A tuberculin testing trial in cattle was carried out in the Republic of Ireland to compare the specificity for bovine tuberculosis of a human purified protein derivative (PPD) tuberculin (Weybridge) with that of a bovine PPD (Rotterdam), and to determine whether discrimination between specific and non-specific reactions to mammalian tuberculin is better with doses of tuberculins smaller than those traditonally used for testing cattle. Tests were carried out in 510 cattle, 395 of which were shown by post mortem examination to be tuberculous and 115 non-tuberculous. Three dilutions at five-fold intervals of both mammalian tuberculins were used together with two dose levels of avian tuberculin PPD (Weybridge), and all reactions were measured both by increase in skin fold thickness and by diameter of induration. In the environment of this trial, the bovine PPD was shown to be more specific for bovine tuberculosis than the human PPD, and particularly in differentiating from "skin tuberculosis". There was no indication of greater specificity at lower doses of tuberculin. Measurement of induration diameter proved a satisfactory alternative method of reading tuberculin reactions in cattle under field conditions.