Seasonal Routine Care Recommendations:
POTOMAC HORSE FEVER question and answer!
**Mid-summer vaccination recommended for all patients who received a Potomac vaccine this spring in the months of February, March and April**
1. What is Potomac horse fever?
It is an infection caused by the bacterium Neorickettsia risticii. It can cause mild colic, fever, and diarrhea in horses of all ages, as well as abortion in pregnant mares.
2. How does my horse get Potomac?
N. risticii’s life cycle is complicated; the bacterium has been identified in flukes (flatworms) that develop in aquatic snails and are released into bodies of water. Aquatic insects (e.g., damselflies, dragonflies, and mayflies) might then pick up infected immature flukes. Horses grazing near freshwater creeks, rivers, or on irrigated pasture can ingest the insects carrying PHF and potentially become infected. Horses can also ingest dead aquatic insects that might have inadvertently landed in their water buckets or hay/pasture. With that being said, horses do not necessarily need to be in close vicinity to a water source to become exposed to PHF.
3. Should I be concerned about my horse infecting other horses with Potomac?
The condition is not contagious horse to horse; however, other diseases with similar clinical signs as PHF (such as salmonella) are contagious. So until the cause of illness is known, take hygiene and biosecurity precautions such as separating the sick horse from other horses, washing hands after working with each horse, using disinfectant footbaths, and not sharing grooming equipment among horses, especially if one of them has diarrhea.
4.When is my horse most at risk?
PHF typically occurs in the late spring, summer, and early fall months, when temperatures are warmest.
Ways to protect my horse:
- Vaccination- safe and fewer side effects than the disease itself. Due to the prevalence in our area and the protection of the vaccine being only 3-4 months, we recommend vaccinating 2-3 times yearly. Mid-summer vaccination recommended for all patients who received a Potomac vaccine this spring in the months of February, March and April If your horse has not received a Potomac booster this spring/summer yet, then it is highly encouraged to book them an appointment!
- Restrict horses’ grazing near creeks, streams, small ponds, and other bodies of water during summer months.
- Use preventive measures in your barn to decrease fly and other insect populations and keep your horse’s food covered.
- Clean water buckets/troughs thoroughly daily and remove any insects/larvae from water.
- Remember, VLAC is the best resource for your horse’s health and care: Don’t hesitate to contact us if you have questions or concerns!