For Immediate Release
August 13, 2012
Public Information Officer
Montana Department of Livestock
Hot, Dry Temperatures Prompt Bluetongue Concern
High temperatures and low precipitation could increase the potential for an outbreak of bluetongue, according to state animal health officials and Montana State University-Extension faculty.
“Extreme conditions in parts of the state closely resemble those of 2007, when an outbreak affected hundreds of sheep in eastern Montana,” said Dr. Greg Johnson, veterinary entomologist for MSU-E.
That epidemic, the state’s first since the 1960s, resulted in a 30-day quarantine of 16 counties, preventing the transfer and sale of market animals and costing producers in excess of $750,000.
State veterinarian Dr. Marty Zaluski said that while bluetongue outbreaks are not common in Montana, producers should consider treating their sheep against the biting midges that cause the virus.
“Currently, there are two registered treatments for repelling insects on sheep,” Zaluski said.
The treatments are the 9.5 gram Python insecticide ear tag and Permethrin CDS, a pour-on that can be applied as a ventral spray to the belly of sheep. Treatments should be applied between mid-August and September 1.
A non-contagious disease of ruminants, bluetongue is spread when a midge bites an infected animal then bites a healthy animal. Sheep, whitetail deer and antelope are especially susceptible to the disease, which can cause death.
Producers should inspect their sheep frequently to look for signs of the virus. Common symptoms include a crusty, swollen muzzle, lesions or bleeding in the mouth or on the skin and sometimes lameness. In sheep, the mouth can become swollen and the tongue can swell and turn blue color because of damage to blood vessels and lack of oxygen.
Producers also should look for the following signs of the disease:
- Depression with heavy breathing or panting;
- High fever;
- Open sores on the tongue, mouth, or nostrils;
- Redness of the skin, face, neck, and possibly body;
- Lameness accompanied by an engorged reddish–blue area around the base of the horns and on the coronary bands of the feet;
- Loss of condition and muscular weakness;
- Loss of wool.
For additional information on bluetongue, please see: