Medication against ovine coccidiosis—A review

Data published since 1940 on the use of drugs to prevent or treat ovine coccidiosis are presented in the form of tables. These highlight the differences in conditions of husbandry and mode of administration. Such differences partly account for the variability of response to medication. Drugs that have proved useful under certain conditions include amprolium, monensin and lasalacid for prevention, and sulphonamides for treatment.     

Equine Cryptorchidism: Pre-surgical Considerations and Surgical Management

Horses with undescended testes are frequently presented to the veterinary surgeon for castration. The pertinent pre-operative evaluations and diagnostic procedures that should be made prior to either surgical intervention or referral of such cases are outlined. Several accepted anesthetic and surgical techniques are similarly reviewed. Case histories of 58 horses referred during a two year period are reviewed and correlated with the findings of a recent study of equine testicular development and descent.     

Orthotopic Osteochondral Transplantation of the Canine Proximal Femur

An 18-week study was conducted to evaluate orthotopic osteochondral transplantation of the proximal femur in the dog. Eighteen dogs were divided into 3 groups of 6 each. The first group received autografts, the second received fresh allografts, and the third received grafts that had been frozen in a bone bank for 24–28 days. The grafts were fixed in position using dynamic compression plates. The grafted limbs were maintained in a sling and thus were nonfunctional and non-weight bearing throughout the 18-week study. Postoperatively the dogs were given oral tetracycline to assess osteo- cyte viability. The dogs were radiographed at 2–week intervals and 1 dog in each group was euthanatized every 3 weeks. The femurs were examined using standard histopathologic and fluorescent labeling techniques. All femoral heads were luxated by the 2nd postoperative week. The bones of all the femoral heads underwent avascular necrosis and degenerative changes were present in the transplanted cartilage by the 6th postoperative week. During the first 18 weeks following transplantation there was little radiographic and histologic difference among the 3 types of grafts regarding the nature and rate of bone healing. Based on the data obtained from techniques utilized in this study, the femoral head, neck, and articular cartilage did not survive, while the femoral diaphysis did survive the transplantation process. Different techniques may alter to some degree the results obtained.     

Demonstration of antibodies to Eimeria species in lambs by an enzyme-linked immunosorbent assay

Soluble extracts were prepared from sporulated oocysts, unsporulated oocysts and merozoites of Eimeria crandallis, E faurei and E ovinoidalis. They were assessed for antigenicity and specificity by ELISA using rabbit antisera to sporulated oocysts or merozoites. Antibody levels were examined in sera from colostrum-deprived coccidia-free lambs, conventionally reared lambs and lambs which had received experimental infections. Maternal antibody was demonstrated in colostrum and in serum taken at 24 hours from all conventionally reared animals but not colostrum-deprived animals. Antibody levels in conventional animals dropped over the first five weeks of life and rose again during the next five weeks. Antibody was not detected in coccidia-free animals. Monospecific infections of E faurei or E ovinoidalis demonstrated antibody responses to primary and secondary infections. Some specificity of response was suggested with E faurei infection. The antigen preparations showed considerable cross-reactions between species. These serum antibody responses, although appearing too late for individual diagnosis, may assist diagnosis on a flock basis.     

The effect of artificial photoperiod at the end of the breeding season on plasma testosterone concentrations in stallions

Testosterone concentrations in stallions showed a seasonal trend with peak concentrations in the spring (April and May in Britain) and lowest concentrations in the period from December to February. The effect on this pattern of changing the length of the photoperiod at the end of the normal breeding season (mid-summer's day) was studied in 2 experiments. In the first experiment artificial illumination was organised from 21 June to mimic the effect of transfer to a southern hemisphere spring and summer, that is short days becoming longer. The stallions had low concentrations of testosterone in February and high concentrations in April. Concentrations in July, August and September were extremely low with a return to high values in late November/early December. In the second experiment, illumination was maintained at the equivalent of a 16 1/2-hour day from 21 June to mid December. These stallions had high testosterone concentrations in April, after which they fell until August, later rising to a maximum in October. These results are discussed in relation to transfer of stallions between the northern and southern hemispheres.     

Encephalitis, proventricular and ventricular myositis, and myenteric ganglioneuritis in an umbrella cockatoo

Myenteric ganglioneuritis and encephalomyelitis were diagnosed in an umbrella cockatoo. The cockatoo exhibited clinical signs that were milder than those associated with this syndrome, such as anorexia, muscle wasting, regurgitation, depression, and changes in fecal consistency. The gross lesions also differed from earlier reports in that only the duodenum and proximal jejunum were grossly dilated. Normally the proventriculus and ventriculus are dilated without visible intestinal changes. The histopathological lesions, however, such as perivascular cuffs in the brain stem and muscular mass of the ventriculus and proventriculus, were similar to earlier reports. A virus was suspected, although transmission and isolation of a virus has not occurred in other reports and was not attempted in this case.     

Surgical Stabilization of the Equine Cervical Spine

The Cloward technique for intervertebral fusion was utilized on 12 horses ranging from 3 months to 2 years of age. Of the 12 horses, 9 had been diagnosed as having equine cervical vertebral malformation (CVM) or "wobbles," and 3 were normal controls. A large hole was drilled from the ventral border of the vertebral bodies spanning the intervertebral disc and the vertebral end plates of the 2 articulating vertebrae. Frozen homologous bone dowels of slightly larger diameter from equine cadaver ilia were inserted in the holes. No adverse postoperative complication arose. Clinical improvement was seen in all horses with CVM. Three months postoperatively, partial or complete fusion was evident radiographically in 11 of the 12 horses. Necropsies were performed 3–6 months postoperatively to evaluate the quality of the fusion. Cadaver manipulation demonstrated reduced intervertebral movement at the operative site in all cases. The articulations of the equine cervical spine can be operatively fused by the Cloward technique, and surgically induced trauma is minimal. This technique can be used for stabilizing subluxations and may be applicable for treating fractures and osteolytic processes that have weakened vertebrae.