In mid-October, I was involved in a series of seminars with dairy farmers about how farmers actually treat cows and calves on their farms.
Each seminar started with a short introduction, followed by a discussion among farmers about how they might treat certain diseases like clinical mastitis, calf scours and calf pneumonia. Everyone was encouraged to share not only their specific treatments like antibiotics but also to share extra things they did to help their cows and calves feel better and get better.
Each seminar is different because it is driven by the sharing of information among the different farmers. Almost always, the seminar ends with a bunch of questions. Some questions get asked only occasionally while some get asked at almost every seminar. Here are the answers to some of those recurring questions and common misconceptions.
There are lots of misunderstandings about the treatment instructions on drug labels. Many times, farmers end up over-treating diseases such mild mastitis (ones where the cow isn’t sick) because they do not realize that most intra-mammary drugs only need to be repeated 1 or 2 times. There have been a few heated debates about what the drug labels say. This is always a good time to go to the Compendium of Veterinary Products. It is available online and contains the most recent drug labels. Some of the label instructions on the package itself might not be the most up to date because it might have been purchased months or years earlier.
Is there a limit to how much of a drug can be given at one site? That discussion can get heated. Many of the newer antibiotics and some of the older ones state on the label that there is a maximum amount that can be injected at one site. Going over that volume might lead to the treatment being less effective (because the drug might not be taken up as well when it is given as one large volume) and will almost certainly lead to longer withdrawals. The volume limits per injection site are high enough that there isn’t usually a problem if you are treating calves. But there likely will be a problem if you’re treating cows, especially mature Holsteins, at the size they are now.
Another common question is about whether or not to change drug treatments and when. Many of our antibiotics belong to only a few families. An antibiotic family is a group of related drugs. Often, if one antibiotic in the family does not work, then going to another drug in the same family is unlikely to lead to a cure. Many farmers don’t know which antibiotic products contain the same or very similar drugs. That makes it tough to make a good second treatment choice without consulting their veterinarian.
I often get asked: Is it a good idea to increase the dose of a drug? That increase could occur in a couple of ways. One way would be to change the frequency of treatment – treating cases of mastitis twice a day rather than once a day, according to the label. Another way is to intentionally treat with more than the calculated dose. Most of the time, increasing either the number of doses or the amount of the dose doesn’t really improve the chances of a cure. It just makes it more difficult to determine the appropriate withdrawal.
From the seminar discussions it was pretty clear that farmers want to treat their animals effectively. But with all the jobs occupying the farmers’ minds, it’s no surprise that the one involving the treatment of cows can be misunderstood.
Dr. Robert Tremblay is a veterinarian for Boehringer-Ingelheim and lives near Guelph.
