I’ve been reading a lot of online posts recently from sheep owners about a condition called “bottle jaw.” Many of them have never seen or heard of it and need advice from other sheep farmers.
To be honest, I have never seen this condition (nor do I hope to!). But as any livestock owner knows, if you keep animals long enough you’ll see all kinds of health conditions. In a nutshell, the condition called bottle jaw is when the sheep has swelling under her jaw, which results from an accumulation of fluid there.
Barber Pole Worm
According to the Cornell Small Farms Program, in nearly all cases this swelling is caused by a pesky parasite called the barber pole worm. The technical name for this worm is Haemonchus contortus.
What I find so concerning about this particular parasite is that there really are no early warning signs, and even a really bad infestation does not always have any telltale signs, including bottle jaw or diarrhea. That’s why some people say their sheep “just died out of the blue.”
The barber pole worm lives in a sheep’s stomach and pierces holes to drink blood. If left long enough, the worms can cause the sheep to become anemic and eventually die. By the time you notice the swelling under the jaw, the barber pole infection has probably been pretty substantial.
Avoiding infection from the barber pole worm is possibly easier said than done. However, one thing you can do is to make sure that the pastures your sheep graze have at least 4 inches of growth.
Sheep will graze grass lower than that, but worms generally are found in the lower part of the grasses and other plants. Therefore, if you practice rotational grazing, your sheep may benefit from grazing in pastures that have taller grass.
In addition, there is some evidence that younger sheep and lambs are probably more susceptible to worms. So keep a close eye on them. Older sheep often develop some immunity to this parasite … but it’s not a given.
Not Always Barber Pole Worm
One other thing to consider is that not all cases of a swollen jaw in sheep are caused by the barber pole worm. For example, there could be an infection or swelling caused by an injury or a bite of some kind. Problems caused by high blood pressure could cause swelling in this area.
There is also a condition in lambs called “milk goiter” that can cause swelling near the upper neck or jaw area. Generally, milk goiter happens when a lamb receives a large amount of milk from the ewe. Most often it will shrink after a short time.
If you do see signs of barber pole worm infection, the best thing to do is call your large animal vet and find out what type of wormer they recommend. They may even ask you to bring in a fecal sample to confirm the type of worm. (And there can be more than one kind at the same time.)
It’s important to stay ahead of worm infestations in your sheep. With just a few precautions, you should be able to raise your healthy flock with very few problems.