How to Prevent Potomac Horse Fever

Potomac horse fever (PHF) is a serious threat to equines. Caused by Neorickettsia risticii, it is believed that horses unwittingly inhale, eat or drink this bacteria. While some horses display no symptoms at all or only become mildly ill, PHF is fatal to many. Neorickettsia risticii are tiny bacteria that take up residence in flukes. The flukes live in water sources--ponds, streams, ditches as well as standing pools of water. Certain types of fly larvae ingest the flukes and end up playing host to Neorickettsia risticii. When the flies emerge from the water as adults, they become a problem for horses. PHF is not completely understood, and research is still being compiled. What is known is that in spite of your best efforts, your horse may still become ill. However, working to prevent this disease should be your goal. There are many things you can do, and these steps can help to reduce other equine diseases too.

Instructions

1. Know the life cycle. Because Neorickettsia risticii bacteria infest other insects, it is important to understand the life cycle of the insects involved. Neorickettsia risticii begin life in flukes, or flatworms, that live in water sources. The flatworms then become food for fly larvae. While reasons are not clear, it is thought that horses can ingest Neorickettsia risticii while drinking from an infected water source and from inhaling or swallowing certain types of adult flies.

2. Get the vaccination. There is a PHF vaccination your horse can receive. The problem is that even though your horse receives some immunity from this booster, he is still at risk of catching PHF. In spite of this threat, most horse owners believe it is worth it to have their horses vaccinated. Speak with your veterinarian to see if your horse is a good candidate for the PHF shot.

3. Keep water sources clean. Because Neorickettsia risticii live inside of flukes, make sure your horse's water buckets and troughs are clean. Do not allow water to stand and become infected with insects and larvae. This helps with mosquito populations as well.

4. Turn off the lights. Keeping barn lights on at night attracts all kinds of bugs, including those that are infected with Neorickettsia risticii bacteria. When you are through riding and working with your horse, turn off the lights. Your horse will appreciate not having to deal with insects all night too.

5. Know the symptoms. PHF symptoms include diarrhea, loss of appetite, fever and lower extremity swelling. Conditions quickly deteriorate if your horse does not receive medical attention, including laminitis (severe swelling of the laminae in a horse's hooves). If your horse prevents with a fever, colic symptoms or diarrhea, call the vet immediately. Quick treatment for PHF often saves the horse's life.

Tips & Warnings

• If your horse displays odd symptoms, call the vet. PHF can mimic other serious equine diseases.