The Other Tick Borne Disease

By Abbie Branchflower

For those that live in Connecticut, tick-borne diseases are a familiar threat. While Lyme Disease may be the primary concern for many (it is after all named after Connecticut’s own town of Lyme) it is not the only ailment of concern. Ehrlichiosis is another serious illness transmitted by ticks, but with a proper understanding of the disease and prompt treatment, it can be completely cured.

A handout by Vetlearn, an internet collection on diseases affecting animals, explains that Ehrlichiosis is ultimately caused by Anaplasma Phagocytophilumbacterium. This is transmitted through the bite of an infected tick, often a black-legged (deer) tick. A horse with a 100 percent healthy immune system should be able to fight off infection; however, any suppression to the system whatsoever leaves a horse at high risk of infection.

According to Dr. Claudia Sandoval, a veterinarian at Fairfield Equine Associates in Newtown, the tell-tale sign most commonly associated with Ehrlichiosis is a high fever of 103 degrees or more. This fever occurs early on in the disease’s progression but can last more than a week if left untreated. The fever is not accompanied by a cough or loose manure. A horse’s regular temperature is 99-101.5 degrees.

Additional symptoms of Ehrlichiosis include: lethargy, anorexia, weakness, and edema (swelling) in one or more lower limbs.

Dr. Thomas B. Massie, Jr, founder of Rose Hill Veterinary in Virginia, notes that symptoms generally appear 10-20 days after infection. After this point the horse will deteriorate in condition quickly. In the next three to four days colicky symptoms and jaundice (a yellowing of the sclera and mucus membranes) often occur.

By contrast, “Lyme disease differs in that it rarely causes high fevers, swollen limbs and changes in mucous membranes,” reports Dr. Sandoval. She added that symptoms of Lyme disease often include sensitivity when grooming and stiffness in the legs.

As described by the Merck Veterinary Manual, confirmation of Ehrlichiosis depends on blood analysis. It can be detected earlier through observance of clinical symptoms, response to treatment, and environmental considerations.

Proper Treatment

It is important to call your veterinarian immediately if you suspect your horse has Ehrlichiosis, veterinarians.

According to Dr. Massie’s article, with early and proper treatment, prognosis is good and the horse will often appear normal within 24-36 hours and be completely recovered in a week’s time. However, if treatment is left until the disease reaches the chronic stage there can be long term problems. Interestingly, once cured from Ehrlichiosis, horses are thought to be immune to the disease for one to two years, as reported in the Vetlearn handout.

As with many health issues prevention is key in protecting horses from Ehrlichiosis. While there is no vaccine, several precautions can be taken to minimize a horse’s exposure to the disease. Prevention methods include: carefully checking horses daily for ticks and removing those found, spraying property boundaries with tick repellants, employing landscape management practices that discourage ticks, topical treatments — including sprays — for horses, and certain supplements that are geared toward discouraging ticks. I

t is important to check that any methods employed to deter ticks are not going to pose a danger to horses and others residing on the property.

When removing ticks it is important that all of the tick is detached. Ticks should not be squeezed as they are extracted as this can result in them vomiting the bacteria into the horse’s bloodstream as they are eliminated. There are a variety of special tools on the market to help remove ticks, including “tick keys” which are sold at many pet stores.

Ehrlichiosis can affect horses of all ages and types, and while least common in winter, unless ticks are completely dormant, is a consistent threat.

The bacterium that causes the disease is prevalent in New England but with proper management and swift treatment, Ehrlichiosis can be managed and your horses kept free from the disease.