Dexamethasone and mastitis in cows

Abstract

Extract

Sir, — The use of corticosteroids to induce early parturition to obtain a concentrated calving period has been widely accepted in New Zealand. Retention of the placenta following treatment with corticosteroids has been described by Adams (1969 Adams, W. M. 1969. The elective induction of laborand parturition in cattle. J. Am. vet. Med. Ass., 154: 261–265.  [Google Scholar]), Lauderdale (1972 Lauderdale, J. W. 1972. Effects of corticoid administration on bovine pregnancy. J. Am. vet. med. Ass., 160: 867–871.  [Google Scholar]) and Jochle et al. (1972 Tochle, W., Esparza, H., Gimenez, T. and Hidalgo, M. A. 1972. Inhibition or corticoid-induced parturition by progesterone in cattle: Effect on delivery and calf viability. J. Reprod. Fert., 28: 407–412.  [Google Scholar]). Welch et al. (1973 Welch, R. A. S., Newling, P. and Anderson, D. 1973. Induction of parturition in cattle with corticosteroids: An analysis of field trials. N.Z. vet J., 21: 103–108. [Taylor &; Francis Online] , [Google Scholar]), using dexamethasone trimethylacetate* *Opticortenol: Ciba-Geigy. in the Huntly and Bay of Plenty areas, reported that calf mortality was disturbingly high — 31.3% and 17.1% for the respective areas. Despite having no apparent effect on milk production or subsequent fertility it is possible pre-existing infections may be exacerbated by the use of corticosteroids.     

Renal excretion of digoxin in swine and goats.

In experiments on swine and goats the renal excretion of digoxin was examined, and it was found that the renal clearance of non-protein-bound digoxin in swine was lower than creatinine clearance which expresses filtration clearance. Correlation analysis showed that the renal clearance of digoxin in swine was not significantly influenced by the concentration of non-protein-bound digoxin in plasma and the pH of the urine, while there was a significant positive correlation between the clearance and the urine flow rate (Table 4). On the other hand, the renal clearance of digoxin in goats was significantly influenced by the concentration of non-proteinbound digoxin in plasma and by urine pH (Table 4). From these results it is concluded that glomerular filtration and back-diffusion are involved in the renal handling of digoxin in both swine and goats. In addition active tubular secretion is also involved in the renal excretion of digoxin in goats.     

Studies on gangrenous mastitis in goats

One hundred and fifty goats were diagnosed as having proven gangrenous mastitis. The disease was categorized into early, intermediate and late stages. Gangrenous mastitis in goats is typified by a sudden onset, dark hyperemia, and edema with progressive discoloration of the distal part of the udder. The disease affected lactating goats but not the dry ones. Coagulase positive Staphylococcus aureus was isolated from 60% of composite and half milk samples obtained from the diseased goats. The histopathological changes mainly comprised proliferation of connective tissue, thrombosis and necrosis involving a group of lobules. Treatment of the early and intermediate stages of the disease was successful through the administration of systemic and intramammary terramycin together with diuretics and topical antiseptic cream. The late stage of the disease was successfully treated only through surgery.