Aust. E.V.A. restrictions remain

Press, 13 December 1989, Page 54

Aust. E.V.A. restrictions remain

By

JEFF SCOTT

Australian authorities have not relented with their equine viral arteritis (E.V.A.) restrictions, which means all colts entered in next month’s standardbred yearling sales in Christchurch will require testing before they enter the ring. “It will be up to the vendors to get their colts tested and the results will be displayed, either positive or negative, on a sheet at the Addington Showgrounds during the sale,” said Peter Lagan, a representative of the auctioneers, Pyne Gould Guinness, Ltd. “Some colts will test positive and quite simply they cannot be sent to Australia if this is the case,” said Mr Lagan. If a colt is positive to E.V.A., the Australian import restrictions state this particular horse must be test-bred with two mares to determine whether he is a shedder of E.V.A. before he can be cleared to land in Australia. Just how many colts entered

in next month’s sales will be positive to E.V.A. is uncertain, however it would be naive to presume the sale will go totally unscathed.

The auctioneers are remaining positive in spite of the E.V.A. repercussions. Wayne Francis, the syndicate manager for the Addington and Alexandra Breeding Companies, which have 26 colts entered over the two days, said yesterday tests had yet to be carried out on their draft, while Roydon Lodge Stud, which have 19 colts entered, are still awaiting the results of E.V.A. tests taken on their entries.

An E.V.A. survey of all, standardbred stallions undertaken by the Ministry of Agriculture and Fisheries from September 1 is nearing completion, according to Dr Joanna McKenzie, of the Invermay (Palmerston North) branch. Results to date from 231 stallions tested revealed 88 (38

per cent) had positive blood counts to E.V.A. There are still approximately 40 stallions still to be tested.

Of the positive stallions so far, 29 have been tested further to determine whether they are carriers (shedders) of the virus, with 13 being declared inherited carriers. Dr McKenzie is not at liberty to disclose the names of these stallions at this time. “The results are what we expected. We estimated between 20 and 30 standardbred stallions in N.Z. would be carriers,” she said. A shedder stallion will still be allowed to stand publicly, but he will be required to stay on the same stud until his retirement from breeding. Mares bred with a shedder stallion will need to remain at the stud for 42 days after coming into contact with the stallions. On a stud which houses several stallions, the mares visiting the shedder stallion will need to be grazed

separately from the other mares. . . , The E.V.A. virus originates from North America and has been introduced to N.Z. and Australia by imported U.S. stallions. The major risk with E.V.A. is that the virus can cause abortion in pregnant mares if these mares come in contact with an infected horse.

Although ’here is no history of E.V.A. causing disease in New Zealand, M.A.F. last year launched a preliminary indepth survey into its presence in New Zealand and suspended the importation of further United States stallions for some time.

They have subsequently implemented an erradication programme; but are relying on the support of all studmasters’ help in the programme. The surfacing of E.V.A. and the Ministry’s actions has tried the patience of many and is set to test the tolerance of more in the months ahead. Dr McKenzie estimates

E.V.A. will be stamped out in; New Zealand by the time the, present stallions end them; breeding careers, using thq, above-mentioned precautions. « Dr McKenzie believes the, Australian restrictions on horse imports surrounding E.V.A. wilP remain in place for at least another year. "

“I understand the Australian; authorities are not starting their E.V.A. stallion survey un* til March and it will take at least six months to identify the prevalence of E.V.A. there,’» she said. “

The New Zealand survey of 340 thoroughbred stallions for E V.A. this year has resulted iff 10 blood positives, however all of these have been noncarriers, according to Dft McKenzie. '

“This is due to the United States thoroughbred authorities implementing a vaccination programme which has noj been used there by the standardbred authorities,” she said"