Source: Pennsylvania State University
These ticks can cause physical harm to animal hosts and transmit pathogens that cause diseases. Control of important ticks affecting livestock and horses includes recognizing important species, removing ticks, and preventing and controlling ticks in the environment.
What ticks are likely to be found on livestock and horses?
While there are over 20 species of ticks in Pennsylvania, only a few are pests of livestock and horses. Most of these ticks are three-host ticks, meaning they bite a different animal during each of their three life stages, larva, nymph, and adult. Usually, these ticks choose progressively larger animals for each life stage. This means that adult ticks are the most common life stage found on livestock and horses. However, occasionally nymphs will also be found.
Blacklegged tick (Ixodes scapularis)
Also known as the “deer tick,” this species is very common throughout Pennsylvania. Adults are active in the late fall and early spring.
Pathogens: This species can transmit the pathogens that cause Lyme disease to susceptible animals, including horses, and Anaplasma phagocytophila, the cause of equine granulocytic anaplasmosis. Cattle, sheep, and goats are not susceptible to Lyme disease infection and do not experience disease related to A. phagocytophila in the United States.
Lone star tick (Amblyomma americanum)
Lone star ticks are found in the southern and southeastern parts of Pennsylvania. Adults and nymphs are around in the spring and early summer. It can be found mostly in the coastal plain but is also found in the piedmont. The larvae, called seed ticks, prefer humans.
Pathogens: Though this tick can carry pathogens that can cause disease in humans, they are not considered a major vector for diseases of horses and livestock.
American dog tick (Dermacentor variabilis)
American dog ticks are found throughout Pennsylvania and appear as adults in late spring and summer. While dogs are the preferred host of the adult, but it has been recorded on numerous wild and domestic animals and humans.
Pathogens: This tick may cause annoyance to domestic livestock, but it is not a known vector of pathogens cause disease in livestock or horses. However, American dog tick bites can cause paralysis in livestock, people, and dogs.
Winter tick (Dermacentor albipictus)
Winter ticks are commonly found on forested ungulates like deer and elk throughout Pennsylvania. However, it will also feed on domestic animals if given the opportunity. It is a one-host tick—meaning that it completes its entire life cycle on a single host—so all life stages may be present on large animals.
Pathogens: This tick can transmit Anaplasma marginale, the pathogen that causes anaplasmosis in cattle. This disease is not
common in Pennsylvania, but with movement of cattle, it is still a risk. In addition to ticks, it can be passed from animal to animal when needles are reused.
Asian longhorned tick (Haemophysalis longicornis)
This species is invasive to Pennsylvania and has been recovered from the central and eastern counties. In its native range in Asia, this species prefers cattle as hosts. Unlike our native ticks affecting livestock and horses, this tick is parthenogenic (females can reproduce without a male) and all life stages may be found on large animals. In the United States, this species has been recovered primarily from deer, sheep, cattle, and other ungulates although it has also been found on domestic pets and people.
Pathogens: This tick is known to carry Theileria orientalis, a pathogen that causes theileriosis in cattle. Historically, the genotypes
of T. orientalis in the United States were very mild, but in 2017, a pathogenic genotype (Ikeda) was identified in cattle in Virginia. It is thought that this genotype was introduced with this invasive tick species. Theileriosis has been associated with anemia, ill-thrift, abortions, and death in cattle of all ages in Virginia.
Cattle and other livestock pastured near wooded areas or in brushy fields may be at risk for tick bites. Photo Credit: flikr.com/photos/usdagov
Why should I control and remove ticks?
Ticks can transmit pathogens and cause other physical problems to animals. Ticks cause local irritation to skin which may result in hair and blood loss from rubbing on trees and fences. Secondary infections may be present in these open wounds. Heavy infestations of ticks may cause losses to physical condition in cattle including weight loss and anemia and reduced milk production. Horses are also susceptible to Lyme disease and equine granulocytic anaplasmosis, and cattle to bovine anaplasmosis. Saliva from certain tick species can also cause tick-bite-associated paralysis. In addition, many ticks in Pennsylvania found on livestock and horses will also bite other animals, so handling animals with tick burdens may increase the risk of bites to humans and pets.
Where should I look for ticks on my animals?
Once a tick has located an animal host, they will identify a suitable area to bite. While ticks can be found anywhere on the body, ticks usually select areas that are warmer and more protected with thinner skin, like the chest, under the jaw, flank, and underbelly; mane, ears, eyelids or brisket area; or elbow. In many cases, there is a local skin reaction that can be felt as a small lump.
How do I remove a tick from my animal?
Should you find a tick on your animal, it should be removed immediately. Tick removal from animals is the same as with people. It is important to not crush or squish the tick as the tick may regurgitate potential pathogens into your animal through the bite which may increase the risk of pathogen transfer. In addition, do not apply any agents to the tick like oils, petroleum jelly, heat or fire, paint, nail polish remover, or similar. Using a sharp pair of forceps or tweezers, grasp the tick as close to the skin as possible and pull straight away from the skin slowly. Ticks can be placed in a small plastic bag in the freezer and saved for future pathogen testing if desired.
How to I prevent ticks from getting on my livestock or horses?
Tick prevention starts in the environment and is aided with on-animal control methods. Pasture modifications can be made to reduce contact animals have with wooded perimeters where ticks are often found. Moving fence lines 10 feet from the edge of the woods and keeping vegetation in those corridor areas mowed short and free of debris can prevent tick movement towards pastured animals. Eliminating brush and woody debris like fallen branches from the perimeter of pastures can reduce small mammal habitat, which in turn reduces immature tick hosts. Because ticks are susceptible to drying out, they are not found in sunny areas with low cut grass. Mowing grasses in pastures and reducing weeds eliminates suitable sites for ticks to search for hosts, and cutting overhanging branches to allow sunlight can reduce humidity which can help dry ticks out and kill them. It is not necessary to chemically treat pastures for ticks. However, if pastures include wooded edges, these areas can be treated with acaricides to reduce tick presence.
If possible, animals should be checked for ticks frequently. Daily checks are recommended for horses in areas at risk for tick bites since the pathogen that causes Lyme diseases can transmit in a little as a day. As ticks are often small before they feed, thoroughly checking animal skin with both hands and eyes may be more effective than using your eyes alone.
Pyrethroid products such as permethrin or cypermethrin wipe-on or spray repellents, shampoos, dusts, ear tags, pour-on products, or similar applied to animals can be helpful. However, many topical treatments are not meant for extended protection and generally last four to eight hours. These products also do not guarantee prevention of tick bites, so checking animals for ticks should be continued even with application. Make sure that all products used are labeled for use on the animal they are intended, and follow all label application, safety, and disposal instructions.
Moving the fence line away from the wooded or brushy habitat can reduce risk of tick contact. Photo Credit: Erika Machtinger
Always refer to the insecticide labels for current and specific instructions for use and application. It is important to read, understand, and follow all insecticide label precautions. Before applying any product (including natural or biological control products), read the label and note application rates. In addition, only apply products that are labeled for use in the state of application. Check with local, county, or state regulations before using any product.
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