H. —29.

W ALL ACE VILLE VETERINARY LABORATORY. REPORT OF C. S. M. HOPKIRK, D.V.Sc., OFFICER IN CHARGE. This report deals with the two aspects of veterinary work, the one diagnostic in character and the other investigational. It is difficult to separate the two classes of work entirely. The work of the subsidiary laboratory at Hamilton, and the investigational work of the Field Veterinary Officer stationed at Hamilton, is also included. The New Plymouth Laboratory was closed down at the end of the last year following the transfer of Mr. W. M. Webster to Waliaceville. Mr. D. A. Gill» who has been on leave in Sydney, accepted the position of District Superintendent of the Wellington District, and consequently has not returned to Waliaceville. Mr. H. A, Reid, 0.8. E., F.R.C.V.S., D.V.H., F.R.S.E., has been stationed in the laboratory temporarily to assist with the work. Dr. M. M. MacOwan is still holding a Carnegie Scholarship at Waliaceville, and is carrying out portions of work for the Department in conjunction with Dr. I. J. Cunningham's nutritional investigation. The staff otherwise is carrying out its several duties well, and is to be commended for its thoroughness. The actual specimens put through the two laboratories for the year may be tabulated as follows :—

CATTLE DISEASE. Diagnostic Routine.—Of the 285 cattle specimens, the most important have been suspected Johne's disease gut. Sixty-three specimens were received on account of this disease, thirty-nine specimens being definitely positive. Sixteen new affected farms have been detected, making a total of forty known affected farms. The Johnin kindly presented by Mr. Dunkin is in use, but the exact reliability is as yet not defined. There have been two cases of positive Johne's disease not picked up by Johnin. Milk Samples for Biological Test for Tuberculosis.—Seven hundred and seven samples were inoculated into guinea-pigs. Of these eight were positive : Auckland, 4; Wellington, 1 ; Hawera, 1 ; and Dunedin, 2. Ten per cent, of guinea-pigs died from peritonitis. In this work the abortus infection present was noted as in past years, and gave the following results, Number of guinea-pigs examined for abortion lesions, 637; lesions in spleen, 100; positive sera from guinea-pig : 106 ; positive cultures from cream, 24. Blackleg Vaccine. —The vaccine is still proving efficient, a total of 37,010 doses having been issued for use over the year. No definite cases of death due to failure of the vaccine to immunize have come under notice. In specimens of blackleg received for diagnostic purposes, the unusual almost invariably turn out to be from cases of malignant oedema. Contagious Abortion. The number of blood samples coming forward for examination from the field—9B6—is unsatisfactory, and suggests that no effort is being made to combat the disease and to clean up farms. This, no doubt, is due to the apathy of the farmer on this question. A number of cases of undulant fever reported during the year by the Health Department made it necessary to test the blood and culture the milk from the resultant positive cases in suspected herds, in order to find whether massive excretion of organisms was taking place. This work also is unsatisfactory, as no power exists to have suspected dangerous cows destroyed or otherwise controlled.

4—H. 29.

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• Wallaeeville. Hamilton. Mastitis milk samples— Routine— Positive .. .. .. 380 219 Negative .. .. .. 457 630 Miscellaneous milks .. .. .. .. 2,695 Mastitis control— Group A .. .. .. 2,389 25,652 Group B .. .. .. 1,445 6,501 Group C .. .. .. 274 2,434 Quarter samples .. .. .. .. 1,425 Contagious abortion — Whey samples— Positive ...... .. 38 Negative .. .. .. .. 261 Blood samples— Positive .. .. .. 326 76 Negative .. .. .. 683 250 Milk biological examination for tuberculosis .. 707 Cattle specimens .. .. .. 285 3 Cattle bloods .. .. .. .. 70 Sheep specimens .. .. .. .. 427 Sheep bloods .. .. .. .. 254 Pig specimens .. .. .. .. 121 Pig bloods . . .. .. .. 8 Poultry specimens .. .. .. 126 Poultry bloods .. .. .. .. 284 Horses .. .. .. .. .. 32 Dogs .. .. .. .. .. 4 Bat bloods .. .. .. .. 174 Bone analyses .. .. .. .. 128 Miscellaneous .. .. .. .. 157 156 Totals .. .. .. 8,731 40,340 Blackleg vaccine issued .. .. .. 18,175 doses 18,835 doses Tuberculin issued .. .. .. 2,267 c.c.