Parasite Feeding Frenzy

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Understanding the feeding habits of each parasite can help veterinarians determine an optimal treatment protocol.

For fleas, ticks and mosquitos, blood isn’t just a common denominator – it’s the common denominator. While each has different feeding behaviors, they all require blood to survive and reproduce, “and this is the time during which transmission of infectious agents occurs,” said Anne Dagner, DVM, veterinary marketing manager for Ceva Animal Health.

Pets are at variable risk depending on the parasites they are exposed to, and understanding the feeding habits of each parasite can help veterinarians determine an optimal treatment protocol, especially as this affects disease transmission, Dr. Dagner said. A parasite that leaves the pet between blood meals may require a different management approach than one whose adult stage stays on the pet full time.


Dangers

Each time a tick bites a dog, it cuts into the skin using chelicerae, creating a microlaceration, and inserts the hypostome for feeding. Besides the trauma of this feeding method, small amounts of saliva can be very reactive at the site. Fleas are also well known for causing inflammation, as in the common condition, “flea allergy dermatitis.” Some dogs have even demonstrated immune mediated hypersensitivity to fleas, leading to localized swelling.

Most importantly, ticks, fleas and mosquitos are vectors of disease in our companion animals, said Dr. Dagner. Indeed, the risk of disease transmission is one of the primary drivers for the need for ectoparasite control in pets. In addition to disease in companion animals, several vector-borne pathogens are zoonotic, giving veterinarians a role to play in mitigating human illness as well.

Diseases of concern carried by ectoparasites include:

  1. Lyme disease (Borrelia burgdorferi) – transmitted by hard-bodied ticks (Ixodes spp).
  2. Ehrlichiosis (Ehrilicia spp) – transmitted primarily by the brown dog tick (Rhipicephalus sanguineus).
  3. Heartworm disease (Dirofilaria spp) – transmitted by mosquitos.
  4. Bartonellosis (Bartonella spp) – transmitted via fleas.
  5. Tapeworms (Dipylidium caninum) – transmitted via fleas.

 

Depending on geographic area, other vector-borne diseases may include the Rickettsiaceae family (including Rocky Mountain Spotted Fever), Babesiosis (Babesia spp) and plague (Yersinia pestis). Ticks may also facilitate allergic diseases such as Alpha-gal syndrome (seen in humans).

“In all cases, a bite and blood meal are the pathway for transmission,” said Dr. Dagner. “Managing flea, tick and mosquito populations and minimizing their opportunities for feeding are key parts of a parasiticide recommendation.”

Why timing of treatment matters

Dr. Dagner said timing is important to understand in terms of interrupting the parasite life cycle, such as choosing a treatment that includes an insect growth regulator (IGR) to inhibit immature stages of the flea. Addressing all life stages, or integrated parasite management, when possible, offers more complete population control than focusing on adults only.

“Timing also comes into play when considering the onset and duration of action of a product,” she said. Clients need clear instruction to ensure they are using the recommended product in the most effective manner. “No matter the timing, however, we have to remember that disease transmission times differ, so preventing exposure to parasites before they can bite the pet is still the primary goal.”

Steps for veterinarians to improve compliance

Veterinarians can improve client compliance by utilizing their full health care team and taking advantage of tools provided by product manufacturers. “Everyone in the practice who talks to clients about parasiticides should be educated about recommended products, to the degree their role allows,” said Dr. Dagner. “This ensures a consistent message no matter who a pet owner talks to. A consistent message increases the pet owner’s understanding of the value of the medication and improves the likelihood that it is administered properly.”

Utilizing the whole health care team also saves time. For instance, a veterinary technician can include a few questions about lifestyle and activity level in a history, which then allows the veterinarian to quickly make a recommendation tailored to the risks likely to be encountered. A dog who regularly goes with owners hiking in the woods, for instance, may need a repellent more than one who only ever walks leashed on city streets.

“Many product manufacturers offer tools to educate clients and remind them of administration and application schedules,” Dr. Dagner said. “Taking advantage of these materials reinforces the message from the hospital and helps clients treat their pets successfully.”

 

U.S. map with forecasted ehrilichiosis prediction

 

Bug Bite

Mosquitoes’ method of feeding on more than one pet increases the opportunity to transmit disease between individuals. This is one reason heartworm disease can be difficult to control in a population, since some meals the mosquito takes may be on pets not covered by heartworm prevention. Medication recommendations must take into account the status of the greater population, Dr. Dagner said.

 

Dr. Anna Dagner headshot

Anne Dagner, DVM, Veterinary marketing manager, Ceva Animal Health

 

 

 

Photo credit:

istockphoto.com/takasuu

Map graphic credit: Source: Companion Animal Parasite Council

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