DISEASES OF ANIMALS

Taranaki Daily News, 4 June 1935, Page 2

DISEASES OF ANIMALS

RELATIONSHIP TO MAN INFECTIONS BORNE BY MILK. INCIDENCE OF TUBERCULOSIS. Diseases of animals and their relationship to man formed the subject of an address giVen on Friday by Mr. J. Hill Motion at the inaugural proceedings of the New Plymouth sub-branch of the Royal Sanitary Institute. In Great Britain, since certain Acts of Parliament in 1925, said Mr. Motion, it had been made compulsory for every local authority to appoint a full-time veterinary surgeon Whose duty was the control of the milk and meat, supply and the control of animal diseases, more particularly those which could be transmitted to man. Mr. Motion dealt only with the milk-borne diseases, bovine tuberculosis, septic sore throat, typhoid fever, scarlet fever, diphtheria, infantile diarrhoea, undulant fever, foot and mouth disease, and anthrax. In many instances these diseases arose from contamination after the milk had left the udder, and for that reason were usually dealt with by the medical officer or sanitary inspector, in the hope of finding a “carrier” amongst those handling the milk. Since foot and mouth disease, and anthrax were of no importance in the Dominion, all that concerned the veterinarian would be bovine tuberculosis, undulant fever, and perhaps septic sore thrOat. He had been more than surprised at the incidence of septic sore throat in New Zealand, remarked Mr. Motion. He had no evidence in support but he put forward suggestion that the incidence of septic throat might be connected with that of mammitis. Tuberculosis in bo vines had engaged the attention of both medical and veterinary experts for more than half a century. It was definitely established that the disease could be transmitted from bovine to man by the ingestion of diseased meat or infected milk. In all countries schemes had been launched to control the spread of tuberculosis amongst dairy stock. Where financial assistance was not forthcoming, schemes of isolation wore attempted. Where special grants were set aside for the work tuberculin testing of all dairy Stock had been introduced and all reactors eliminated from the herds. This achieved wonderful success in Denmark. SERIOUSNESS OF SCOURGE. In order to show ’ the seriousness of bovine scourge, Mr.' Motion quoted figures from the Sick Children’s Hospital at Edinburgh. Here it was stated that 90 per cent, of all cases of tuberculosis was of bovine origin. Figures were not available for New Zealand in this respect, but undoubtedly the question was very important and something should be done about it. Study of the incidence of tuberculosis in diary stock in various countries produced the following figures: Scotland about 45 per cent, Denmark about 40 per cent., Canada perhaps 5 to 10 per cent., certain parts of U.S.A, up to 30 per cent, [n New Zealand recent figures put the incidence at 9 per cent. This was probably accurate, said the speaker, but he had tested several herds giving an inc? dence as high as 50 per cent, or 60 per sent. Where the disease had been allowed to progress uncontrolled or where the animals were housed for perhaps six ■nonths of the year the incidence would >f necessity he greater, and in such :ountries the herd incidence might rise is high as 60 to 80 per cent. All animals grouped as tuberculin vould not be a danger to the public xealth, but only those classed as "open”, iases, or animals coughing up the infecion, liberating it by the bowel, or giyng tuberculous milk. About five per :ent. of all tuberculous cows would give he infection by . the udder, so the incilence for this source of infection was tot great. The lesson to be learned from his Would be that there was greater risk if infection from the house cow than here would be from the mixed milk rom a large herd. Bad milk from a lerd was considerably diluted before it eached the market.

The dairy commission reported very fully and very wisely on the mattei* of bovine tuberculosis, and recommended a scheme for New Zealand which would provide the sum of £1,000,000 for a three years’ campaign against the scourge, permitting a generous compensation for condemned animals and an adequate and skilled staff for the elimination of all reactors. QUICK SPREAD. Only a person who had tested cows continually knew how quickly tuberculosis could spread. The figures quoted were perhaps alarming, but the incidence was steadily decreasing under schemes of eradication. Tuberculosis eradication had already been attempted tn Great Britain, Canada and U.S.A. In Britain in 1924 £750,000 had been set aside for the effort, in Canada it proceeded so rapidly that every cow was tested, and in U.S.A, preventive measures had reduced incidence to 3 per cent, New Zealand had made a few isolated attempts to check tuberculosis but had taken no concerted action.

Nothing was done in New Zealand with regard to undulant fever, continued Mr. Motion, and no scheme had been launched to combat' it. The dairy commission did not include its consideration in its report, evidently deciding it was of insufficient importance. For many years medical experts in Denmark and America, had been focussing considerable attention on undulant fever, which arose from infection of the human subject with Bang’s bacillus, the organism responsible for contagious abortion in bo vines. In Denmark 500 cases of undulant fever had been diagnosed and it was apparent that most of the cases were amongst persons coming directly in contact with the dairy cow. A blood test of all the veterinary sur-

geons in the country revealed 90 per cent, positives. The incidence amongst town dwellers was very low. This was in the position also in Holland. The opinion now prevailing about undulant fever was that the danger from ingestion was not so great as had hitherto been thought. It was principally an occupational disease rather than a public danger. The incidence of contagious abortion infection amongst dairy cows in most countries was very high, in many herds Up to 90 per cent. There were practically no large dairy herds free from abortion infection, and very few small pnes. The infection present in the milk of aborting and even non-aborting cows was high, and from figures from experts in all parts of the dairying world it was reasonable to assume that about 30 pet cent, infection was common in ordinary market milk. Yet the incidence of the disease in town dwellers was not high. Anthrax was -comparatively unknown in New Zealand. An outbreak at Dargaville.some time ago was the first for 20 years. The germs lived in the soil for years and once infected blood was spilled on the soil an outbreak might occur years later. Cases of anthrax generally arose from cows eating infected food, bone meal, bean meal or cotton cake. New Zealand placed an embargo on these foods.

In conclusion Mr. Motion briefly discussed meat inspection, meat poisoning, actinomycosis and parasitic diseases such as measles in pork and beef. Cow pox, ring worm and excema were unpleasant but not serious diseases. He mentioned the excellent work done by bacteriologists. They were the men behind the scenes and it behoved medical, and veterinary experts to help them in every possible way by sending all ihe required data as they wanted it.