In recent weeks, we’ve received several photos from our clients showing horses with round spots around the mouth caused by Habronemiasis.
Habronemiasis is an infection with Habronema worms, which live in the horse’s stomach. It’s a condition described worldwide, but it rarely occurs. In the Netherlands, only a few cases have been recorded in recent years.
Life cycle of Habronema worms
Habronema worms live in the horse’s stomach and produce eggs that are excreted with the manure. The larvae can infect fly maggots in the horse’s manure. Once the maggots mature into flies, they can deposit the larvae onto moist areas of the horse’s body, such as wounds or mucous membranes. Larvae placed around or in the mouth are swallowed and can complete their life cycle.
We’ve added a video of a gastroscopy. After about 30 seconds, you can see botfly larvae.
We do want to emphasise that there is no reason to “panic”. Many videos are being shared that might make you fear this could happen to your horse too. We understand that emotion, but hopefully we can ease your concerns.
Don't forget that usually only the videos where things go wrong are shared. The horses that are healthy all year round and never develop symptoms don’t appear in those videos. We believe it’s very important to keep horse owners well informed so that, if symptoms do appear, treatment can begin on time to prevent serious issues.
How does Habronemiasis develop?
Larvae that are deposited elsewhere on the body will penetrate the skin or mucous membranes and eventually die. The dying or dead larvae cause an inflammatory response, where the body tries to encapsulate them. This manifests as small lumps that later turn into ulcers. Larvae are most often deposited on existing wounds, the inner corner of the eye, mucous membranes of the eye, mouth corners, or genital mucosa.
This condition is well documented in literature but rarely seen in practice. As a result, little research has been done into Habronemiasis. Hypersensitivity to the larvae likely plays a major role. This means not every horse infected with larvae will actually develop the condition.
It is also thought that multiple infections are needed before the typical symptoms appear. In the past, this disease was not seen in the Netherlands. In recent years, however, some cases have been reported. Whether this is due to climate change or reduced deworming is still unclear.
Treatment and prevention
If you suspect your horse has Habronemiasis, always contact your vet.
Treatment usually involves administering a dewormer containing moxidectin or ivermectin. As prevention, it’s important to minimise fly contact — using fly masks, fly rugs, and repellents. Regular manure testing and deworming if necessary are also important. That’s why we advise following the Worm&Co schedule.
Source: paardenkliniekderaaphorst.nl
NL
DE
FR
.jpg)
