Lyme disease seems to be the “disease du jour” in many regions, and with good reason. It’s spreading throughout the country and can be very difficult to treat. Horses do not always have as much long term trouble as humans and may be more responsive to treatment, especially if the disease is caught early, but many can and do develop chronic problems. Natural treatment is very important to their recovery and maintenance.
What is Lyme, anyway?
Lyme disease is caused by a tiny corkscrew-like bacterium called a spirochete. The scientific name is Borrelia burgdorferi. The tiny deer tick Ixodes is the main transmitter, but there is evidence that many other biting insects may be involved, including flies, other ticks and even mosquitoes.
The problem with Lyme infections is that the bacteria that cause them can transform into three distinct phases, two of which are very hard to treat.
Phase One: The spirochete is the main infectious form and can drill into the tissue and even into bone. This usually causes acute symptoms such as skin rash, flu-like symptoms or mild fevers in horses, and a sudden onset of fatigue or not feeling well even without much of a fever. It is at this stage that both antibiotics and natural treatments have the most success.
Phase Two: When the bacteria feels threatened by treatment or the immune system, it can convert to cell walldeficient mode and form tightly knit groups. In this form, antibiotics and the immune system have a hard time finding the bacteria, making the disease hard to treat. More chronic signs are seen and are very difficult to pinpoint. In humans, this phase can cause autoimmune disease in which the body begins to attack itself. We have little data to tell exactly what happens in horses at this stage, but many chronic Lyme cases can be assumed to be in this phase.
Phase Three: The cyst form is a dormant or non-reactive form of the bacteria. It sits quietly inside cells, waiting for the immune system to become weakened by outside forces before changing back to the infective spirochete form. Antibiotics and natural and immune system treatments usually fail to have much effect. The key at this stage is to maintain a healthy immune system and lifestyle. If Lyme is present, this is the best form to have since there are no active symptoms.
Lyme can affect any system in the body, even though we mostly think of it as a musculoskeletal disease. It is known as an imitator disease since it can look like many other conditions. In humans, about 25% of cases show a classic red bull’s eye rash on the skin; in horses, however, we cannot see a rash even if it were to occur. And in many cases, thanks to the horse’s hair and skin color, we do not even see the tiny ticks, even if we look carefully every day.
Diagnosing Lyme can be very difficult. Symptoms are often vague and can mimic many musculoskeletal or behavioral problems. Mild or inconsistent lameness or stiffness is common, may not be apparent to the veterinarian or may be difficult to pinpoint. One of the more consistent findings in my practice is fatigue, crankiness or unwilling behavior. Horses seem to have no energy. Some horses have mild neurological signs that we may have called EPM (Equine Protozoal Myelitis) in the past. Other infections are possible, since the immune system is weak, so it is important to check for other tick borne diseases.
In the later stages, human doctors find many conditions related to Lyme, such as mental illness, neurological symptoms, chronic fatigue and fibromyalgia. We do not have specific data for horses, but behavioral problems – especially anger, irritability or lack of ability to focus – are all present in the equine. Chronic pain, especially in the muscles and connective tissues, may occur. Palpating a Lyme horse often reveals hard stiff muscles.
Blood tests are available and can be helpful, but are not totally reliable. Some human infectious disease experts feel there are other tick borne diseases that we have not yet named. In my practice, I have seen horses that had all the symptoms of Lyme, yet tested negative and responded extremely well to antibiotic and other treatments. It is important to get a complete blood test called an ELISA, and a Western Blot test, and not just rely on a simple SNAP test. The more extensive test gives more accurate information. I often suggest a complete tick panel, which looks for other tick diseases that may also be present.
Treat ing Lyme
Treatment needs to be multifaceted, including both antibiotic and natural treatments. Human Lyme doctor experts all agree with this, and I have found it to be true. It is a very difficult disease to treat just naturally. It requires a broad natural approach, using nutrition, lifestyle, herbal and homeopathic medicines for the best results.
You need to be in charge of your horse’s treatment, since you are the one present every day. Find yourself a good holistic or integrative veterinarian or put together a team who is familiar with Lyme disease. Use all the tools and therapies available, but when something is not working, stop spending the money and look elsewhere. In general, most therapies take several days to a month to show good results. After two months with no results, move on.
The antibiotics used for Lyme disease are oral doxycycline or intravenous oxytetracycline. Horses that only partially respond to the oral drugs usually will do best using intravenous drugs. Research shows that intravenous is often better, but clinically I have good results with and some extra management.
Horses need to be outside, have friends to interact with, and not be on the road showing every weekend. Adequate sleep is also important; horses in busy barns or small stalls where they cannot lie down often do not get enough sleep.
Dietary and immune support
•Feed programs should include as much whole food as possible. The more processed the food, the higher the oxidation level, causing the horse to use up antioxidants that he critically needs to help fight Lyme disease.
•Other types of immune system support include good old vitamin C, which regulates the immune system and helps heal the connective tissues of the joints. Doses range from 4 to 5 grams up to 6 to 8 grams per day, though I usually use the lower doses.
•Vitamin C pairs well with glutathione, an antioxidant used in most cells to protect them from toxin damage. It is difficult to supplement as most oral forms are inactivated upon digestion. Intravenous glutathione can be given, but requires a veterinary prescription and care when administering it. There is one oral equine product available (Immusyn® from Vitaflex.com). Acetyl glutathione is better absorbed in humans, though has not been used much in the equine.
•Other nutrients that help increase glutathione levels are selenium, many of the B vitamins, n-acetyl-cysteine, alpha lipoic acid (about 800 to 1000 mg), and glutamine. Glutamine is an amino acid that when fed at about 5 to 15 grams per day also helps heal the gut wall after it has been damaged by drugs.
•Vitamin D in D3 form seems to be very important in Lyme disease treatment. Horses kept inside most of the time may not make enough vitamin D from sunlight and most supplements do not contain the active D3 form. Horses in northern regions where days are short in winter also need extra vitamin D. Doses of up to 20,000 IU can safely be used, with 10,000 IU being perhaps the most useful.
Several herbs have been used in humans and some in horses. In general I have found equine doses of herbs to be about two to four times higher than the human dose; with Lyme disease, I think these doses need to be higher to get good results. Teasel, cat’s claw and Japanese knotweed are some of the beneficial human herbs.
How to prevent Lyme
Although it’s difficult, the best way to prevent Lyme disease is to avoid ticks and blood-sucking insects. An environmentally friendly farm with good manure handling can help keep biting insects away. Guinea hens love to eat ticks, and chickens can also do a fair job. If you live in the woods, these birds may be the only way to keep the tick population down.
No Lyme vaccines have been approved for horses and many veterinarians, including myself, see many problems in horses after using the dog vaccine. It does not seem to work, and horses who have been vaccinated often seem to become chronically sick with Lyme, especially if they were infected before receiving the vaccine.
In the end, a healthy immune system is the most important way you can protect your horse from Lyme disease.
Joyce Harman, DVM , MRCV S, graduated in 1984 from Virginia Maryland Regional College of Veterinary Medicine. She is certified in veterinary acupuncture and chiropractic and has completed advanced training in homeopathy and herbal medicine. Her practice in Virginia uses 100% holistic medicine to treat all types of horses. Her publications include The Horse’s Pain-Free Back and Saddle-Fit Book – the most complete source of information about English saddles – and The Western Saddle Book is on its way. harmanyequine.com.