Comparison Between a γ-IFN Assay and Intradermal Tuberculin Test for the Diagnosis of Bovine Tuberculosis in Field Trials in Brazil

Bovine tuberculosis is a major problem in Brazil. The intradermal tuberculin test is the standard test for detection of bovine tuberculosis in Brazil but can lack both sensitivity and specificity. The purpose of this study was to compare a bovine γ-IFN assay with the tuberculin test under field conditions in Brazil. A total of 1632 animals from 13 dairy farms were tested using the single cervical tuberculin test (SCTT). Among those animals, about 15% of each herd, 220 in total, represented a high-risk group and were selected to be tested using the γ-IFN test. Of the 1632 animals tested, 207 presented significant reactions representing 12.7% of the cattle studied. In the selected group the number of animals positive by the γ-IFN assay was 126/220 (57.3%) and the total number of reactive cows on SCTT was 106/220 (48.2%). The real number of infected cattle, following standards, was 120/220 (54.5%). From these results the relative sensitivity rate of γ-IFN test was 100% including the false-positive results and 88.3% for the SCTT — a significant (P < 0.01) difference in favour of the γ-IFN test of 11.7%. The γ-IFN assay also identified some positive animals 60–120 days earlier than the SCTT. In conclusion, we believe that the γ-IFN assay can be used alone or in combination with the SCTT, as a valuable tool for the control of bovine tuberculosis in the Brazilian national herd.     

Comparison of three serologic techniques for detection of antibody to Mycoplasma pulmonis

A comparison of three micro-assay detection systems for naturally occurring and experimentally induced rat antibody to Mycoplasma pulmonis was performed. The micro-enzyme linked immunoabsorbent assay was found superior to counter immunoelectrophoresis or complement fixation techniques when comparing sensitivity, duration of antibody response, or technical requirements. The primary immune response was routinely detected at 3 weeks after antigen exposure when using the enzyme linked or complement fixation assays.     

Prevalence of Giardia in the feces of pups

Fecal specimens were collected from 117 healthy pups (79 privately owned pups and 38 pups from an animal shelter) and analyzed for Giardia. Giardia cysts or trophozoites were found in 35.9% of the dog feces.     

ANGIOGRAPHIC EVALUATION OF BOVINE FOOT ABNORMALITIES

Angiography of normal and diseased feet in cattle was carried out. In osteomyelitis of distal phalanx there was a narrowing of the digital artery with diminished vascular supply to the affected digit. An area of bone necrosis was found to be avascular. With overgrown hooves, narrowing of both the medial and lateral digital arteries with ill-defined laminar vessels was seen. The vascular pattern in cattle with cork screw claws was characterized by a dilated tortuous digital artery and a crowded arterial network resulting in increased vascular supply in the affected claw. Abrupt stricture of common digital artery, a crowded vascular network in the area of the middle phalanx and filling defects of terminal arches were demonstrated in animals with exostosis     

Ear temperatures in the horse during recovery from anesthesia

Ear temperatures were measured during and after halothane anesthesia in 16 horses and ponies. Aural hypothermia developed during recovery and persisted for more than one hour following standing. The decreased ear temperature was attributed to decreased peripheral perfusion and was considered to be related to other cardio-pulmonary and neuro-endocrine derangements that occur during recovery.     

Genetic diversity among Australian and New Zealand isolates of Leptospira interrogans serovar pomona

Restriction endonuclease analysis of 16 Australian and 4 New Zealand isolates of Leptospira interrogans serovar pomona showed that they could be divided into 3 genetic groups. Most of the isolates closely resembled the serovar kennewicki reference strain, and they all differed from the reference strain of serovar pomona. Based on these findings, it is suggested that vaccine manufacturers re-evaluate their choice of serovar pomona vaccine strain.