Cardiac glycoside poisoning in sheep caused by Urginea physodes (Jacq.) Bak. and the isolated physodine A

Urginea physodes (Jacq.) Bak., a species closely related to or possibly synonymous with U. pusilla, is described and its distribution given. Four bufadienolides were isolated from U. physodes and the approximated LD50 and cumulative effect of some of them determined in guinea pigs. The most toxic one proved to be mildly cumulative. Typical signs of acute cardiac glycoside poisoning, involving the locomotory, gastro-intestinal, respiratory and cardiac system, were seen in the field cases and/or were experimentally induced by the plant. Similar signs could also be induced by injecting the isolated bufadienolide, physodine A, to a sheep.     

Disseminated Mycobacterium paratuberculosis infection in a cow

A cow with chronic diarrhea and weight loss caused by localization of Mycobacterium paratuberculosis in the intestinal tract (Johne's disease) had gross and microscopic changes indicative of a disseminated infection. A direct association between the remote lesions and the intestinal infection was shown by isolation of M paratuberculosis from renal tissue, detection of intracellular M paratuberculosis antigen(s), using an indirect immunoperoxidase method, and by the characteristic granulomatous nature of the lesions. This case illustrates the potential for extra-intestinal lesions in M paratuberculosis infection of cattle and should cause veterinarians to consider mycobacterial disease when confronted with multinodular lesions of the bovine kidney. The immunoperoxidase method was useful in determining the cause of the inflammatory lesion in which intact organisms were not evident.     

Persistence of colonies of Anaplasma marginale in overwintering Dermacentor variabilis

Dermacentor variabilis were infected as nymphs with Anaplasma marginale by allowing the ticks to feed on a single infected donor calf. Two weeks after molting to the adult stage, the ticks were allotted into 1 of 3 groups and were allowed to overwinter at room temperature (25 C) in the laboratory (group 1), cold storage (4.5 C) in the laboratory (group 2), or outdoors in leaf litter (group 3). Persistence of A marginale was assessed by determining density of colonies (number of colonies/0.1 mm2 of gut tissue examined) in tick gut specimens at 3, 5, 7, 9, and 12 months after molting to the adult stage. Colonies of A marginale were found in all groups at every density evaluation period. Highest colony densities were observed uniformly in specimens collected at month 7 (May); densities decreased at month 9 and were lowest at month 12. Statistical analysis indicated that ticks subjected to cold storage and to outdoor conditions had similar colony densities of A marginale; the density curve in these 2 groups indicated significant quadratic effects over time, with peak densities in May. Mean colony density in ticks kept at room temperature fit a different quadratic equation. The morphologic data indicated that A marginale overwinters in Dermacentor variabilis, and that increasing numbers of organisms are found from January to May.     

Haematogenous osteomyelitis in cattle

The examination of 70 cattle with haematogenous osteomyelitis resulted in the classification of the bone lesions into two main groups: the physeal type, in which an infection, usually of metaphyseal bone, originated at or near the growth plate, usually in the distal metacarpus, metatarsus, radius or tibia, and the epiphyseal type, in which an infection originated near the junction of the subchondral bone and the immature epiphyseal joint cartilage, most often in the distal femoral condyle epiphysis, the patella and the distal radius. Combinations of physeal and epiphyseal defects and even diaphyseal involvement were occasionally seen. Epiphyseal osteomyelitis was mostly caused by salmonella infection, physeal by Corynebacterium pyogenes, salmonella and other bacteria. The salmonella affected animals were with one exception less than 12 weeks old and the majority had had some previous illness or came from a problem herd. The C pyogenes affected calves were in almost all cases more than six months old. The prognosis of the metaphyseal infection was in general satisfactory, and surgical intervention (osteotomy or sequestrectomy) was often required. The prognosis of the epiphyseal type was grave but two of the three animals in which physeal and epiphyseal defects were accompanied by diaphyseal lesions recovered.     

Efficacy of dichlorvos, fenbendazole, and ivermectin in swine with induced intestinal nematode infections

Anthelmintic efficacies of dichlorvos, fenbendazole, and ivermectin were compared in specific-pathogen-free crossbred weanling pigs inoculated with Ascaris suum, Trichuris suis, and Oesophagostomum dentatum. On postinoculation day (PID) 50, 24 pigs in each treatment group were treated orally with 43 mg of dichlorvos/kg of body weight, 3 X 3 mg of fenbendazole/kg, or 300 micrograms of ivermectin/kg, SC. Twenty-four pigs were not treated. On posttreatment day 7 (PID 57), 12 pigs from each treatment group (phase I) were slaughtered, and the anthelmintic efficacy of each treatment was determined. Efficacies against A suum, T suis, and O dentatum, respectively, were: dichlorvos, 100%, 99.9%, and 100%; fenbendazole, 100%, 99.8%, and 100%; and ivermectin, 98.7%, 53.9%, and 87.6%. Weight gains and feed conversions of the remaining pigs were monitored until they reached market weight (phase II). The average weight gains (kg) and feed conversions (kg of feed/kg of gain) at posttreatment day 81 (PID 131), respectively, were: 73.6 and 3.44 for nontreated controls, 78.9 and 3.31 for dichlorvos-treated pigs, 72.1 and 3.36 for fenbendazole-treated pigs, and 74 and 3.48 for ivermectin-treated pigs. Differences in average weight gains and feed conversions were not significant (P greater than 0.05).