STUDIES ON VENEREAL TRANSMISSION OF CAMPYLOBACTER FETUS BY IMMUNISED BULLS

Temporary contamination of the penis and prepuce with Campylobacter fetus subsp. venerealis and Campylobacter fetus subsp. venerealis biotype intermedius may occur when immunised bulls mate with infected heifers. However, 2 experiments showed that this contamination was not a significant cause of genital infection in susceptible heifers that subsequently mated with bulls.     

Accumulation pattern and insecticidal effect of aldicarb in cotton following soil treatment for the control of the tobacco whitefly (Bemisia tabaci)

The accumulation pattern of the pesticide aldicarb [2-methyl-2-(methylthio) propionaldehyde O-(methylcarbamoyl)-oxime] and of its sulfoxide and sulfone metabolites was studied in field-grown cotton, following soil treatments at various intervals from planting. Control of the tobacco whitefly(Bemisia tabaci) was determined and correlated with the concentration of aldicarb and of its metabolites in cotton leaves. The main constituent found in the leaves was aldicarb sulfoxide, which reached its maximum concentration there at about 22 days post-treatment. Late application of the insecticide (mid-July) resulted in higher concentrations toward the end of the growing season and so gave improved control of the pest. Results are presented for residues in young and mature leaves and in the seeds.     

THE INFLUENCE OF AGE ON THE SUSCEPTIBILITY OF BULLS TO CAMPYLOBACTER FETUS SUBSP VENEREALIS

Observations were carried out on 22 Hereford bulls to determine the age at which they bacame carriers of C. fetus. During preliminary investigations, 5 bulbs were repeatedly exposed to the organism by artificial or natural means from the age of 18 months. All animals became longterm carriers on reaching an age of between 40 and 70 months. Prior to this, a temporary carrier state lasting from 4 to 29 days was produced in 4 bulls. In a subsequent experiment, 17 bulls of 3 different age groups were artificially exposed to C. fetus on 5 occasions over a 2-year period. Thirteen bulls became long-term carriers, including 9 (53%) when less than 4 years old. A transient carrier state occurred in 4 bulls, 2 of which subsequently became long-term carriers. It usually lasted 1-2 weeks, although in 1 animal the organism persisted for 11 weeks. These results are discussed in relation to the findings of other workers and it is concluded that the use of young bulls to limit the spread of C. fetus in infected herds is of dubious value.     

Clinical Vignette

This 12-month-old, outdoor intact male cat (Fig. 1) was examined because of an untreated draining nasal lesion. The lesion. initially appeared as small punctures, and progressed ovcr 2 months to an ulcerated draining nodule that gradually enlarged to involve the whole muzzle, extending bilaterally to the medial canthi and having multiple drainage points through overlying necrotic skin. Results of serum feline leukemia virus antigen and feline immunodeficiency virus antibody tests were negative.