Potomac Horse Fever Alert! – A wet, rainy spring and summer in Central Virginia results in higher than average cases of many insect borne diseases including Potomac Horse Fever (PHF). This is a disease caused by a bacterial organism that infects a water fluke that in turn infects a snail that is then ingested by your horse while grazing. Fresh water snails and other water insects are more likely to travel across your pasture when the grass is wet. They can thrive in water troughs and even under wet stall mats. The symptoms of PHF are vague and sometimes hard to distinguish. The hallmark signs are fever and diarrhea, but these are not always obvious. We have seen fever without diarrhea and diarrhea without fever. A horse’s normal rectal temperature should be between 98 and 102 degrees F. A horse with PHF usually will have a temperature between 102.5 and 105 degrees F. In complicated cases, a horse may develop swollen legs and sever fluid and protein loss requiring hospitalization and IV fluids. There is a vaccine that will give some protection in the face of the disease. The vaccine will not prevent the disease, but it has been shown to limit the severity of the disease. James River Equine highly recommends vaccinating. We once had two cases of PHF in the same week. One horse had been vaccinated in early spring (March). It required fluids and hospitalization for over a week. The other horse had been vaccinated in June and only required IV antibiotics at the farm. It never developed diarrhea. We believe the level of antibody protection lasts about three months, so the second horse had a higher titer and therefore was able to fight the infection fairly easily at minimal cost. If your horse was vaccinated by Dr. Shane in the spring, it is time to call now to booster PHF and get the titer up to a protective level. James River Equine has always vaccinated against PHF as part of our regular recommended vaccine protocol.
When we have a mild, wet winter in Central Virginia we see a higher insect population as well as more lush, sugar laden grass. This can lead to fatter horses with more potential for laminitis and founder in Spring. If your horse is a pony breed or is prone to obesity (“cresty” neck, fat over ribs, hard to find hip bones), then your horse may be in danger of laminitis or founder. A study is being conducted by the American Association of Equine Practitioners to unlock the causes and treatment of pasture associated laminitis. Dr. Shane is participating in this study. If your horse does have a first time bout of laminitis, Dr. Shane may ask permission to take a blood sample and measurements to be sent to a national research center. Of course, the best treatment is prevention. Keeping your founder prone horse/pony off the green grass or limiting sugar intake with a muzzle is always recommended. There is a new blood test that can help determine if your horse is “living on the edge” of founder. When we are at your farm for the spring visit, be sure and ask Dr. Shane about your horse’s risk of laminitis or founder.
The only phone number for James River Equine Services is 434-953-6034. Please update all your lists in your barn and on your phone contact list to reflect our office number as 434-953-6034. This is also the emergency phone number to use in case of an emergency. The message at night will always give you the number of the doctor on duty for that night.