Today’s post is going to be something of a shift from the usual. The focus will be on a specific disease, primarily of range cattle; and hopefully we’ll get into a fair amount of detail. Those of you with an immunological or evolutionary curiosity might also find something of interest, too. So don’t leave just yet.
Today’s subject is actually a parasite that’s known as Tritrichomonas foetus. (Bonus points will be awarded to anyone successfully getting that mouthful out without hurting themselves.) Tritrichomonas foetus is more commonly referred to as “T. fetus” or simply “trich” (pronounced trik) understandably.
When someone mentions parasites, most folks have a tendency to picture worms. But there are several other varieties of parasites, and Trich belongs to a group known as protozoa. (Maybe you’re familiar with coccidia or giardia? I hope not in a personal way! But they are also protozoa.)
For the most part, protozoa that parasitize animals, aren’t actually invaders of the body’s cells. They actually reside “outside the body proper” in very close proximity. Now some of you will object to your intestinal tract (or other places) being described as outside the body. But from the standpoint of an intact system, that really is the case. Food, and other things, are put into our digestive tract so that nutrients can be absorbed into our bodies. The relationship is intimate without a doubt. But still, technically, that stuff is outside.
And that’s the niche these beasties exploit – by being outside and away from direct attack from most of our body’s defenses but yet close enough to pick up a bunch of goodies to live on.
Change scenes from the digestive tract to the reproductive tract and you have a fairly good visualization of Trich and how it can be successful (from a parasite’s point of view). It hides out in all sorts of nooks and crannies that are in this environment. This venereal disease causing organism proceeds to hitch a ride whenever it can – moving between bulls and cows.
The usual effect of this culprit hits the cow a month or so after the cow becomes pregnant. The cow undergoes an early term abortion that is often not noticed. There’s also an effect on the bull, who becomes persistently infected – which also isn’t noticeable. And most importantly is the effect on the rancher, who becomes poorer because there are fewer calves to sale. This part is very noticeable – after it’s too late to intervene.
In the beginning I mentioned something about immunology and evolution. Some researchers are studying bovine trich as a model for the human disease. That link gets fairly detailed. But it also shines a bit of light onto the (1) difficulties in treating/immunizing against something that lives outside us but very close and personal, and (2) raises the question of why only humans and cattle. I’ll leave that for you to ponder.
Now for the second part of this post. Obviously Trich is a problem, and not an easily managed one. By and large the cows will cycle a few times and clear the parasite. So managing the problem boils down to testing bulls and culling any positive ones. Developing a plan with your vet and neighbors is probably a good place to start dealing with Trich, if you haven’t done so already.
A few years back Arizona implemented a rule to screen incoming bulls to prevent more from entering the state. It has caused some heartburn among some on occasion. But it is an effective prevention. But as some of you likely already noted, that rule won’t have any effect on Trich that is already in the state.
Because of this situation, sporadically some folks will tell me that regulation needs to be promulgated to deal with it. Others sometimes say they see no need for more government intervention when neighbors can deal with the problem on their own.
What I will share with you is information on how 3 other states have chosen to deal with this problem in their states. These are simply ones that I could find online easily and that provide examples.
This post has probably given some folks more to chew on than usual. So until next time, enjoy the ride.