Ticks: Assessing The Risk - Rhinebeck Animal Hospital

Ticks are small arachnids that feed on animal blood as part of their complicated life cycles. Though different species of ticks have varying life cycles, they all try to feed on our dogs or cats at some point in their life cycle. When they feed they can spread serious diseases. Here is what you need to know about them and how to keep your pets safe!

Ticks look for a host through a process called "questing". Questing is when they climb to the edge of tall grass, plants or brush, put out their front legs and wait for a warm animal or person to brush by. Ticks are attracted to heat and carbon dioxide which are produced during respiration. Once they find a host they then crawl around the host until they find a suitable feeding area. The area of the body they are looking for depends on the species and the size of their "mouthparts". Tick mouthparts include a "hypostome", shaped like a tiny saw. Once the tick finds a suitable place to feed, they slice into the skin with this saw and create an area of hemorrhage under the skin. It is from this area of hemorrhage that they then feed. Ticks feed differently from mosquitoes; they seek out and extract blood from a vein. While the tick is feeding, it is not just sucking blood, but also regurgitating salvia, toxins, diseases, and blood back into the host. A fully engorged tick will take about ½ of a milliliter of blood to be full, but will have sucked and regurgitated 15 milliliters of blood to get this ½ milliliter!

In the Hudson River Valley, we have at least 3 species of ticks well established, with another reported to be moving our way, if it’s not already here!

The most common tick we encounter in the Hudson Valley is the Black Leg Tick or Deer Tick (Ixodes scapularis). This tick transmits bacteria such as Borrelia burgdorferi and B. mayonii (which cause Lyme disease), Anaplasma phagocytophilum (anaplasmosis), B. miyamotoi disease (a form of relapsing fever), Ehrlichia muris eauclairensis (ehrlichiosis), Babesia microti (babesiosis), and Powassan virus (Powassan virus disease). Deer ticks quest year round! The nymphs quest in the spring and summer while the adults quest in the summer, fall and even winter! As soon as the temperature gets above freezing, they are there waiting to take their next blood meal.

The second most common tick we see is the American Dog Tick (Dermacentor variabilis). These large ticks transmit Francisella tularensis (tularemia) and Rickettsia rickettsii (Rocky Mountain spotted fever). They are active in the spring, summer, and fall. These ticks prefer dogs but are happy to bite cats and humans as well.

The third most common tick in our area is the Brown Dog Tick (Rhipicephalus sanguineus). The brown dog tick is the primary factor for Rocky Mountain Spotted Fever (Rickettsia rickettsii). The Brown Dog tick primarily feeds on dogs but can bite humans and cats as well. The scariest thing about this tick is that it can complete its whole life cycle by just feeding on dogs, meaning they can infest homes!

The fourth tick that has been reported in our area is the Lone Star Tick (Amblyomma americanum). As their name suggests, these ticks are mainly from the southeastern United States but have been migrating north, and according to the Centers for Disease Control and Prevention (CDC) are here already! These ticks are highly aggressive and tend to pursue hosts in large numbers. It is not uncommon to find hundreds or even thousands of embedded ticks on pets in the south! They transmit Ehrlichia chaffeensis and E. ewingii (which cause human ehrlichiosis), Francisella tularensis (tularemia), Heartland virus (Heartland virus disease), Bourbon virus (Bourbon virus disease), and Southern tick-associated rash illness (STARI). In humans that have been bitten by the Lone Star Tick, an allergic reaction associated with consumption of red (mammalian) meat has been reported.

Now that we have learned about the ticks in our area, let's discuss the ways we can prevent them on our pets. It is important to do a risk assessment when choosing the right products for your pets, and sometimes we need to use more than one product to make the risk of our pets contracting a potentially fatal disease as small as possible. Different products intercept the tick at different stages of questing. Some products work as a repellent, and others work when they are ingested by the tick. So we will split the products into two general groups: topical and oral.

Many of the topical products such as Fipronil, Imidacloprid, Dinotefuran, and Selamectin are available from your veterinarian while others are available over the counter. These topical products may also have some repellent properties. It is important to note that many topical products may also contain Permethrin; while safe in dogs, it is fatal to cats. This is why A DOG PRODUCT SHOULD NEVER BE USED ON A CAT. Imidacloprid also comes as a very effective collar for both dogs and cats.

Some newer types of tick prevention are orally administered. These medications all work similarly; they are ingested by the pet and go to work systemically. The medication itself has no interaction with the dog or cat's nervous system but works to kill ticks and fleas when they bite the animal. They are a medication class called Isoxazolines. In some cases where tick risk is high, especially where the Lone Star Tick is well established, using multiple methods may be required. Sometimes it is not enough to just do the oral prevention; you may need to add in a collar or a topical preventative as well. So please assess your pets tick risk and choose a prevention plan that suits them the best!

The last thing I will touch on here is the Lyme vaccine. The only tick-borne disease mentioned above with an available vaccine is the Lyme Disease. The Lyme vaccine is for dogs and works to help prevent Lyme disease if the ticks break through our tick prevention. The newer Lyme vaccines work to combat the Borrelia spp. in the tick as well as in the dog. The vaccine is very effective, but not 100%, which is why we recommend combining it with a tick preventative mentioned above. If you are worried about your dog having a reaction to the vaccine, it is uncommon and quickly treatable. That being said, we have never had a dog die from the vaccine, but do lose about 2-3 dogs a year to "Lyme nephritis". Lyme nephritis is a complication of Lyme Disease where the Borrelia spp. and the dog's immune system both attack the dog's kidneys; it is almost always fatal. We do not know which dogs will respond to the Borrelia spp. in this way, but when they do it is very sad.   

In conclusion, there are many kinds of ticks in our area carrying many different, serious and deadly diseases. They are very sturdy and flexible to many climates and should be treated as a constant threat. Fortunately, we have preventatives to protect our dogs and cats, so please choose a prevention strategy that matches your pets’ risk level wisely. Your pet should be on year-round prevention, with no exceptions. Dogs should be vaccinated for Lyme yearly if they live in the Hudson Valley. It is important to make sure that cats, even those who are exclusively indoors, are on prevention, as ticks can easily make their way indoors to feed. Your veterinarian is a valuable resource in determining your pets' risk level, as well as the best course of action for ensuring the best protection.

Should you have any questions, comments or concerns, please don't hesitate to contact us by phone at 845-876-6008, or by e-mail at [email protected].

Thank you for choosing us to be part of your pet's healthcare team!

With warmest regards,Your friends at Rhinebeck Animal Hospital