A small bite equals a big problem for horses
by Sharon P. Austin, Lyme Informed Psychologist
Riders eagerly wait for the last snow and mud to clear so they can head out on the trails— enjoying the peaceful scenery and quiet of the woods and fields, leaving behind mundane arena views and the busyness of everyday life. Most trail riders carefully check and clean tack and ensure they have all the gear ready for that perfect spring-weather day. Most are not thinking about pesky, tiny ticks that lurk in the bushes and grasses, waiting for their first blood meal of the season.
Riders need to make tick awareness and tick-bite prevention a priority so that humans and equines—and even dogs—stay safely unbitten on the trails. Ticks that carry harmful disease-causing germs are increasing their range across the United States. They are spreading beyond the usual tick-heavy climates of the Northeast and upper Midwest. Their spread may be caused by warmer temperatures, more fragmented forests overlapping with human housing, more leaf litter, and an increase in the number and distribution of deer and wildlife populations (common hosts for ticks).
One tick bite can change the life of a human, dog, or horse. Though not every tick bite will transmit disease-causing germs, tick-borne diseases (TBDs) are the fastest-growing vector-borne diseases in the US. Statistics on Lyme disease in humans, the most prevalent TBD, estimates over 476,000 new cases of Lyme every year in the US alone. This number doesn't include the possible tick-borne infections/conditions that can occur following a tick (for example, Babesiosis, Anaplasmosis, Ehrlichiosis, Bartonella, Powassan virus, tick paralysis, alpha-gal meat allergy) which are transmitted by the germs carried by ticks. Lyme and many other TBDs can be debilitating or even deadly—especially if they aren’t diagnosed and treated early. Horses are also affected by many of the same diseases. No equine vaccines are available for most of the tick-started diseases. Plus, diagnosis and treatment are often complicated and unreliable. Vaccines for Lyme disease are available for dogs. Contact your veterinarian
for options.
Spring and summer are typically referred to as “tick season.” However, ticks may be active throughout the year in different regions of the US—especially if ground cover doesn’t freeze. Hard ticks typically have a two-year life cycle, with four life stages and three blood meals from “hosts” during this cycle. Humans and pets are most at risk between May and August because of the activity of the nymphs. These can be the size of a poppy seed and thus hard to find once they attach to the skin. Horses, as a large animal “hosts”, tend to be more at risk in the early spring and late fall when the adult ticks are active. Riders, don’t let your guards down at any time of year when it comes to ticks. They are incredibly tough and sneaky critters that can be active year-round.
The most common ticks that carry pathogens that can make humans, horses and dogs sick include: Blacklegged tick (Ixodes scapularis, Ixodes pacificus), Brown dog tick, American dog tick, Rocky Mountain wood tick, Lone Star tick (bite can cause alpha-gal syndrome, and may transmit Borrelia spirochetes recently discovered to cause tick-borne relapsing fever). The invasive Asian long horned tick distribution is growing in the US. More is being learned about pathogen risks.
Soft ticks, which transmit the pathogens for several tick-borne relapsing fevers, may also be a risk in barns and other rustic lodging areas where rodent, bird, or bat infestations may occur. Ticks find their hosts by detecting ammonia (which is given off by human and animal breath) and bysensing heat and vibrations. The ticks carrying most of the TBDs climb to the top of grass stems or ends of branches, waiting with outstretched legs for their potential hosts to brush up against them. Then, they hop aboard. The exception is the Lonestar tick, which will actively seek out a host rather than passively waiting for an opportunity. Ticks might attach, or they may move around a horse’s body looking for thinner-skinned areas to attach to— such as the horse’s ears, jawline, elbows, mane and tail, chest, and groin areas. Similar thin-skinned and dark areas are often the locations that ticks pick on dogs and humans.
Equine Tick Check
A horse’s hair and coloring make it difficult to see attached ticks. Riders can find the ticks on their horses more easily by feeling and scratching the skin for small, hard nodules—especially in the more common areas (see photo).
Make sure the horse is secure and comfortable before checking for ticks. With gloved fingertips, use light, consistent weight over the hair in both directions in order to better feel the skin. Spend approximately three to five minutes on each side of the horse. Focus on areas of high risk as noted above. When you find an attached tick, it is critical to remove it immediately as different ticks transmit diseases at different rates during their blood meal.
Canine Tick Check
On a dog, there are seven critical areas to check for ticks. Make sure to check the dog’s head, ears (both on the outside and deep within), toes (between and on the bottom of the foot near pads), tail (especially the underside), groin, eyelids (careful not to confuse ticks with skin tags), under the collar, and armpits. Owners should search for ticks in the same way horses are checked—carefully feeling through the hair to the skin. For canines with thick fur, a fine comb can catch ticks.
Human Tick Check
As with horses and canine companions, the common areas to check are the hairline, nape of the neck, inside and behind the ears, armpits, belly button, groin area, between the toes, behind the knees, and all gear (boots, backpacks, saddles, saddle pads). It is best to look in a full-length mirror to check for ticks on the whole body. Make sure an adult checks children after every ride.
Proper tick removal is essential. Wear gloves and always use fine-tipped tweezers for humans, canines, and equines. Firmly grasp the tick as close to the skin as possible. With a steady motion, pull straight up. Be careful not to twist, crush or jerk the tick as this may agitate the tick and increase the chance of disease transmission. Never apply baby oil or petroleum, nail polish, essential oils, or a lit match to remove the tick. These methods may also increase the risk of disease transmission.
Thoroughly wash the bite area with a mild antiseptic and apply a triple antibiotic ointment, then wash your hands and tweezers. If any signs or symptoms of infection occur, consult a physician for humans and call a veterinarian for animals. Never wait for the results of testing to seek medical/veterinary attention if symptoms manifest.
Save the tick. Place the tick in a small airtight container or sealable bag. Identification and testing of the tick may aid in the early diagnosis of potential diseases. Contact individual laboratories for their specific requirements for storage and shipping. Visit coloradoticks.org for tick-testing options.
Tick Testing
Human and equine testing for Lyme and other TBDs is limited and often unreliable. Initial symptoms may be mild or vague, often making TBDs difficult to diagnose, especially in horses. The identification of the tick species and pathogens present in the tick may aid in healthcare decisions after the bite. Typically, the earlier diseases are diagnosed and treated, the better the outcome will be. Tick identification and testing also contribute to surveillance of both species and pathogens in your location.
Carry a Tick Removal Kit
A kit should include gloves, fine-tipped tweezers, magnifying glass, alcohol sanitizer, triple antibiotic ointment, identification chart for ticks, small zip-lock bag, and a marker. A light and mirror are handy as well for hard-to-see areas.
Checking for ticks is one of the ways to help with the prevention of TBDs. Another critical step is prevention. There are steps you can take to minimize tick bites while on the trails. Wear permethrin-treated clothing and gear designed for humans, horses, and canine companions. For humans, apply skin repellants effective against ticks before heading out on the trails. Repellents approved by the EPA for effectiveness against ticks include products containing DEET, Picaridin, IR3535, Oil of Lemon Eucalyptus, or 2-undecanone. Reapply as recommended on the product label (https://www.epa.gov/insect-repellents/find-repellent-right-you).
For horses, use only repellants intended for use on horses. Do not apply higher concentrated repellents on horses as they can burn the skin. Some research shows repellants may not be as effective as advertised for equines: Poh, K., Cole, Z., Smarsh, D., Springer, H., Kelly, K., Kenny, L. & Machtinger, E. (2023), Topical permethrin may increase black-legged tick (Ixodes scapularis) repellency but is associated with cutaneous irritation in horses). Natural repellents made with essential oils may need to be applied more often to maintain effectiveness. More research is needed on effectiveness of these products.
Trim horses and dogs of extra hair and keep animals clean, as cleaner animals are easier to check for ticks. Trim horses’ tails so that they aren’t hanging low to the ground.
For dogs, there are oral, topical, collar, and vest (Permethrin) tick-repellant options. Consult with your veterinarian for best recommendations for your canine companions.
When possible, walk in the center of trails avoiding rubbing up against brush and grass. Throw outdoor exposed clothing directly in a dryer on high heat for 10 minutes to kill any ticks that may have hitchhiked with you inside. Shower as soon as possible when returning indoors. Check for ticks immediately upon return.
Pasture Management for Prevention
Mow grass and pastures regularly: keep brush and overgrown pastures mowed to help to reduce rick habitat. Remove leaf litter in and around pastures and barns. This removes humid environments preferred by ticks. Create a border around pastures: mow a grass border (at least three feet) between pastured and wooded areas to reduce ticks in the pasture.
Control rodent and rodent habitats around barn, outbuildings and home. Keep woodpiles away from buildings, clean and seal stonewalls, avoid feeding birds, keep horse feed and other rodent attractants in rodent proof containers, use “tick tubes” in woodpiles and stonewalls or other rodent nesting habitats to reduce ticks. Fence wildlife (deer/elk) out of barn areas where possible. Large mammals are typically the last host meal for ticks: high density white-tailed deer populations are typically associated with higher black-legged tick populations, the ticks that carry pathogens for several diseases including Lyme disease.
Consider topical insecticides for horses: Use a topical insecticide that includes a label claim for ticks on horses housed in a pasture. Consider acaricides for treatment of barns, outbuildings, and pastures: Acaricides can be used to treat the inside of barns, particularly cracks and crevices in stables and barns.
Tick-borne Disease Symptoms for Humans
Tick-borne diseases often mimic the flu. Symptoms include fever, rashes (of any kind), muscle and/or joint pain or swelling, chills/sweats, nausea/diarrhea/vomiting, severe headache, fatigue, lymph node enlargement, and cognitive impairment. More serious, acute presentations may include seizures, carditis, and facial palsy. Late stage and persistent symptoms can impact any organ or system in the body, may be waxing and waning in presentation, may progressively worsen, and may mimic other disease conditions.
Tick-borne Disease Symptoms for Animals
Canine companions may also experience fever, lethargy/depression, swelling in limbs/lameness, lack of appetite, vomiting/diarrhea, or discharge from eyes or nose.
Lyme disease occurs in horses, but it isn’t well understood nor are there good diagnostic tests. In addition, not all horses bitten by ticks carrying Lyme will develop the disease. It may take up to six weeks for symptoms to appear. These may include neuroborreliosis, uveitis, intermittent shifting limb lameness, stiffness, muscle tenderness, low grade fever, loss of appetite, poor performance, depression and other behavioral changes. Prognosis in seropositive horses with mild symptoms is good through the treatment with antibiotics. Prognosis with severe cases is poor. Please consult a veterinarian for treatment options. Again, this is why it is critical to save the tick and get it tested.
Equine granulocytic anaplasmosis (formerly equine Erhlichiosis) is another common TBD in horses. Horses show signs of illness 10 to 45 days after infection. Common clinical signs include lethargy, fever, swollen limbs, possibly incoordination, and muscle swelling. It is more easily treated with a short course of antibiotics. Please consult with your veterinarian for treatment options.
Equine Piroplasmosis is a tick-borne disease caused by protozoan parasites, Babesia caballi and Theileria equi. It is found outside the US and is carefully monitored by the USDA though isolated outbreaks of the disease have occurred infrequently in southern states. This disease is known to affect horses, donkeys, mules and zebras. Symptoms include swollen limbs, fever, and small bleeds around the nose, mouth, eyes, and vulva. Less common signs include incoordination, muscle swelling, and colic symptoms. It is treated similarly to Lyme disease.
Equine infection with other TBDs, such as Babesiosis, Bartonella, and Powassan fever, is even less understood in horses. Tick paralysis is more prevalent in some regions than others. Consult a veterinarian with concerns.
Go out and have fun but protect horses, canine companions and yourself. Keep yourself informed and help raise awareness about the prevalence of ticks and Lyme and other tick-borne diseases for humans, equines, and canine companions.
*COTBDAA doesn't provide medical/veterinary advice. Please consult your medical/veterinary provider before making decisions about diagnosis or treatment. COTBDAA does provide patient support and access to resources. Please do not hesitate to reach out!
For additional resources on the numerous tick species and the pathogens they typically carry, as well as prevention and patient resources, visit Colorado Tick-Borne Disease Awareness Association. Additional patient resources can be found at Lyme Disease Association, Bay Area Lyme Foundation, and Global Lyme Alliance. Or contact the local advocacy group in your state.
For information about the numerous tick species and the pathogens they typically carry, as well as prevention and patient resources, visit the Colorado Tick-Borne Disease Awareness Association's website https://coloradoticks.org/.
Patient resources can be found at Lyme Disease Association, Bay Area Lyme Foundation, and Global Lyme Alliance. Or contact the local advocacy group in your state.
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