Earlier this year, Health Canada announced the approval of the new veterinary product, Imrestor. This announcement was quite interesting for a few reasons. Imrestor was simultaneously approved both in the United States and Canada. That approach displayed a level of cooperation between two different regulatory authorities that ensured that Canadian farmers would have timely access to a new and quite innovative product. To show that this cooperative approach was not a one-time occurrence, a few weeks later, Health Canada announced that it had approved another product, Metacam, for the management of pain in sheep. That approval process was completed simultaneously with regulators in New Zealand and Australia. This was equally great news because there was no other product approved for the management of pain in sheep.
These collaborative efforts can really help our Canadian farmers gain access to products at the same time as livestock producers in other countries. That helps our farmers remain competitive in a marketplace that tends to reward continual improvements in production efficiency.
Beyond the unique approval timeline, Imrestor is quite interesting in itself. It is one of what looks like a new group of products that could become more and more important in livestock products. Imrestor is given to cows and fresh heifers to stimulate their immune system. The idea is that the stimulation will reduce their susceptibility to mastitis in that high-risk period, the first month of lactation. Farmers can already give vaccines to stimulate the immune system, but Imrestor is quite different.
Vaccines must include material from the actual microbes, viruses or bacteria that cause the disease. After vaccination, the cow’s immune system develops immunity against those exact microbes, producing what is called specific immunity. If the vaccine doesn’t contain the exact microbe that causes the disease, then the cow will not be protected by vaccination. Imrestor stimulates one component of the immune system so that it will protect better no matter what microbe is causing the infection. It stimulates non-specific immunity. In the most general terms, Imrestor targets the disease, in this case, mastitis, rather than the microbes that cause the disease. It helps make cows more resistant to mastitis, no matter what is causing the mastitis.
Imrestor is one of a new category of products that stimulate non-specific immunity. Although it is not available in Canada yet, another non-specific immune stimulant was approved recently in the U.S. That immune stimulant targets pneumonia (also called BRD) in beef cattle. It is designed to be administered at times when cattle are felt to be at high risk of developing BRD.
Both these products have arrived at a time when the use of antimicrobial drugs in livestock production is coming under greater scrutiny. Mastitis in fresh cows is one of the most common reasons that cows are treated with antimicrobial drugs. BRD is the most common reason that beef calves are treated with antimicrobials. Using non-specific stimulators of immunity along with vaccines should reduce the number of animals that get sick and reduce the severity of their illness. Both of those benefits should reduce the need for farmers to use antimicrobial drugs. Anytime you reduce the number of cattle that get sick or that end up needing to be treated, it is way better for the cattle and the farmer or rancher too.
Dr. Robert Tremblay is a veterinarian for Boehringer-Ingelheim and lives near Guelph.
