“We’re trying to find the
– DR. JAG DHANDA, CFIA
Manitoba’s second outbreak of anaplasmosis in less than a year has cattle producers wondering about the effectiveness of federal livestock disease control measures.
Producers at a recent Manitoba Cattle Producers Association district meeting learned that nearly half the cattle in a southeastern Manitoba cow-calf operation have the parasitic blood disease.
The disease was confirmed in the herd Oct. 9, the meeting was told. Four cattle died after showing symptoms consistent with anaplasmosis. Forty-three out of 93 animals in the herd, located in the Rural Municipality of Stuartburn, have tested positive for the disease.
The farm is under quarantine. Producers within two kilometres of the affected farm are being contacted and their herds tested. The Canadian Food Inspection Agency is tracking cattle movements in and out of the infected herd.
Earlier this year, 312 cattle in eight herds in the Lac du Bonnet district tested positive for anaplasmosis. Infected cattle were removed and ordered slaughtered. Seven herds have so far been released from quarantine. About 3,000 cattle in the region have been tested.
The Lac du Bonnet outbreak was the first in Manitoba in 40 years. The one before that occurred in Marchand in 1969-70, when 232 reactors out of 1,717 cattle tested were slaughtered.
Ray Armbruster, an MCPA district director, said the association is watching the situation closely and collecting information for its members on available drugs and treatment.
“We know it’s there. We’re getting all the information we can,” he said.
Anaplasmosis, a reportable livestock disease in Canada, is caused by a parasitic micro-organism of red blood cells. It affects domestic and wild ruminants, including cattle, sheep, goats and deer, but only causes clinical signs in cattle.
Once infected, an animal is a carrier for life, although its meat may still be used for human consumption.
The origins of both the Stuartburn and Lac du Bonnet outbreaks are as yet unknown.
“We’re trying to find the smoking gun,” said Dr. Jag Dhanda, a CFIA disease control specialist in Saskatoon.
In a separate case, anaplasmosis was confirmed this summer in a cattle operation in the Nicola Valley near Vernon, British Columbia. Dhanda said two animals have so far tested positive, the farm is under quarantine and further testing is underway. Final results are slow in coming because the cattle are in the mountains and have to be rounded up.
Armbruster wondered if outbreaks so close together could have anything to do with looser federal disease testing requirements on imported cattle imposed five years ago.
Anaplasmosis is carried by biting insects (or vectors). Canada used to require anaplasmosis testing for live cattle from the United States during the vector season. However, since 2004, new rules have admitted feeder cattle from 39 U. S. states considered low risk for the disease without testing.
Ottawa made the change at the behest of the cattle industry, which saw it as a trade barrier with the U. S., Canada’s most valuable market for beef and live cattle. U. S. cattle producers viewed Canada’s earlier anaplasmosis testing requirement as a non-tariff trade barrier.
However, some veterinarians and producers at the time warned the action could put Canada’s cattle herd at risk.
Armbruster acknowledged there’s no proof that the recent cases are connected to the looser import protocol.
And even though Canada is no longer anaplasmosis free, its trade status is unaffected because the disease is endemic in many countries, Dhanda said.
But anaplasmosis can affect production, because older animals can become poor-doers and even die from it, said Armbruster, who chairs MCPA’s animal health committee.
Anaplasmosis is blood-borne and may be transmitted via contaminated instruments such as hypodermic needles and dehorning equipment. Veterinarians recommend producers change needles frequently and disinfect dehorning equipment in between use to limit exposure. [email protected]