by Laura Weis
Thawing temperatures and longer days are early harbingers of spring, but unfortunately so is the appearance of ticks and the diseases they carry. Ticks can be active anytime the temperature climbs above 45 degrees, which means that the month of March signals the beginning of consistent tick problems in Pennsylvania.
Understanding the Problem
All ticks feed on the blood of their host animals, and most go through four life stages and often prefer different host species for each stage. Ticks can sense their hosts’ body heat, breath and odor, as well as moisture, vibrations and even shadows. Ticks cannot jump or fly. They find potential host animals by attaching to grass or leaves with their hind legs, holding their front legs outstretched in a behavior called “questing”. When a promising host brushes past, they quickly climb aboard, attach and begin feeding.
Although there are more than 25 species of ticks in the Commonwealth, just four species account for over 90 percent of the ticks submitted for identification.
*The American dog tick (Dermacentor variablis) is the most common species in this area, and as its name suggests, the preferred hosts for the adult tick are dogs. The immature forms can be found on small rodents and deer. This species of tick does not spread Lyme disease, but it does carry Rocky Mountain spotted fever, tularemia and cause tick paralysis.
*The blacklegged tick (Ixodes scapularis, also commonly called the deer tick) prefers brushy or wooded areas. It is the most common vector for Lyme disease in the eastern part of the United States. This tick lives for two years and prefers birds and small mammals during the larval and nymphal stages, and deer or bears as an adult, but will readily feed on humans or pets during any of those stages. Most people and dogs are infected with Lyme by the tick in the nymph stage, as it is less than two millimeters in size and difficult to detect.
*The lone star tick (Amblyomma americanum) is named for a white spot on the body of the adult female. This tick is an aggressive biter of humans and pets and spreads Rocky Mountain spotted fever and ehrlichiosis, but it is unlikely to transmit Lyme disease. The young forms of the lone star tick are found on both small and large animals, and the tick prefers shaded areas with tall grass and brushy undergrowth.
*The ground hog tick (Ixodes cookei) prefers to feed on woodchucks, does not transmit Lyme disease and is not known to carry other diseases that affect pets or people.
Ticks are tricky to identify. In Pennsylvania, residents can submit ticks to the local Penn State extension office for free identification—preserve the tick in alcohol in a small vial or jar. The University of Rhode Island maintains a useful website, TickEncounter.org. Photos of ticks can be uploaded for identification, ticks can be submitted through this site for testing for most of the tick-borne diseases and there are regional maps of tick prevalence and risks.
Most tick prevention and elimination strategies focus on the use of pesticides, either in the environment or on a pet. While sometimes these chemicals in spot-on, oral or collar forms are a necessary compromise in tick-infested areas, a multi-layered approach to tick control can help to reduce reliance on harsh pesticides.
Some forms of natural tick control for pets include collars, sprays and spot-on products that use repellent herbs and essential oils. While not as effective as chemical methods, these products are a useful part of a multi-modal approach to tick prevention and control, and they have far fewer potential detrimental effects.
Most ticks prefer shaded areas with taller grass, shrubs or forest margins. Tick exposure can be reduced by creating a mulch barrier of two to three feet at the edge of wooded areas or setting fence lines nine feet away from the edge of the woods. The tick population around a yard can also be controlled by keeping grasses short and eliminating brush piles and vegetative debris that create ideal nesting spaces for small rodents that carry ticks.
Ticks dislike the odors of some strong-smelling plants. Integrating mint, rosemary, garlic, rue and wormwood plantings will help reduce tick populations. Chrysanthemums and marigolds planted along a property’s edge will also discourage ticks and fleas. If space and zoning allow, chickens and guinea fowl love to eat ticks and can help to reduce their numbers.
While these methods will help in a controlled space, walking through woods or open fields is likely to result in heavy tick exposure during much of the year. A dog should be carefully inspected for ticks after outdoor adventures. The best way to find ticks on a dog is to comb through the dog’s coat using a small-toothed comb. A tick can be removed by using tweezers to grasp the tick as close to the skin as possible and pulling in a steady motion to remove the body and parts that are embedded in the pet. However, even with daily checks, it is still easy to miss ticks, especially the immature forms.
Vigilant use of these prevention strategies will minimize tick exposure and disease risk.
Dr. Laura Weis and her husband, Dr. Ransome Weis, own and operate Doylestown Veterinary Hospital & Holistic Pet Care, and Holiday House Pet Resort & Training Center, in Doylestown. She focuses on homeopathy and nutrition counseling for her clients within the full-service veterinary practice. Call 215-345-6000 to request an appointment. March 2019