MASTITIS IN CATTLE

Wairarapa Times-Age, 29 October 1941, Page 3

MASTITIS IN CATTLE

SILVER OXIDE TREATMENT

EXPERIMENTS IN U;S.A

NOT A “CURE ALL.”

A great deal of excitement was created in the dairy world recently with respect to a discovery of a promising treatment for mastitis in cattle. An optimistic report appearing in a national publication implied that treatment with colloidal silver oxide seemed to be the answer to the dairyman’s prayer. The treatment was first administered at the Connecticut Agricultural Experiment Station, but more exhaustive tests were made by the experiment station of the Pennsylvania State The Connecticut station has sought to counteract the impression given by the published report. “There is no sure cure for any type of mastitis,” its spokesman subsequently announced. There still appears, however, much ground for hope in the situation. “It has been established, by work at this station,” the Connecticut researchers reported, “that streptococcus agalactiae mastitis can be eradicated by periodic laboratory tests and segregation and gradual replacement of infected animals with' first-calf heifers, preferably raised on the home farm.”

The work that' .was started at Connecticut was carried on more fully at the Pennsylvania station. This is the report of the Pennsylvania workers: “Twenty-three cows with 67 quarters infected with streptococcus agalactiae received injections of novoxil liquid (silver oxide) in the infected quarters. Ten of the cows showed clinical symptoms of catarrhal (chronic) mastitis in 19 of the infected quarters. The streptococcus agalactiae infection was destroyed in 88.1 per cent of the infected quarters. The infection was destroyed in all infected quarters in 82.7 per cent of the cows treated, thus freeing them of the infection entirely. Fifty-two and sixtenths per cent of the quarters showing clinical symptoms of catarrhal mastitis recovered from the symptoms, and the infection was destroyed.” What does this mean from the standpoint of the practical dairy farmer? Does it mean that the treatment will cure some 80 per cent of his mas-titis-infected cows as it seems to have done at the experiment station? This seems doubtful at this stage of, experimentation, because in the experiment station herd there were two kinds of mastitis-infected cows. Of the 23 cows under test, only 10 of them had “clinical symptoms of catarrhal (chronic) mastitis.” Presumably the other 13 cows had infections so light that the usual symptoms associated with this disease were not present. Of the 10 cows showing “clinical symptoms,” only about half recovered as a result of the treatment. The cows which the average dairy farmer recognises as having mastitis are probably only those showing “clinical symptoms.” Thus, if the treatment were applied under normal working , conditions, cures might be expected, on the basis of what is now known, in about half of the cows treated rather than in the 82 per cent successfully treated at the station. Moreover, this treatment has no ability to restore udder tissue deadened as a result of the ravages of the disease. It can only kill the organisms that cause the damage. Thus, it seems that silver oxide bears promise of being of value in the treatment of mastitis, but the chances seem to be against its having the cureall properties that were hoped foi- it in the first flush of enthusiasm following its discovery. Experimentation, of course, will be continued and additional discoveries made. In the meantime, so little is positively known about the possible benefits as well as the possible hazards that no individual dairy farmer should try the treatment except one so situated as to carry on trials under regulated conditions similar to experiment station conditions.