Top Parasitology Concerns in the Northeastern United States

Several parasites pose health risks to companion animals in the northeastern region of the United States. Veterinary nurses must understand parasite risks and preventive strategies to explain them effectively to pet owners. This article highlights the top regional parasites veterinary nurses should be familiar with to facilitate client education and bolster pet health.

Download this handout you can share on social media and with clients to educate them on the top parasites of concern in your region.

Black-Legged Ticks

The black-legged (or deer) tick—Ixodes scapularis—is responsible for transmitting Lyme disease and anaplasmosis, and it flourishes in the Northeast. Seropositive dogs that develop or are at risk for clinically significant illness require treatment. Depending on the tick’s life stage, Ixodes species’ activity peaks between late summer and winter.¹ However, it is important to remember that the black-legged tick is active year-round.

Key prevention strategies include¹:

• Applying species-appropriate acaricidal preventives (e.g., fipronil, amitraz, isoxazolines, pyrethroids) year-round
• Vaccinating dogs for Lyme disease and reducing tick exposure
• Screening dogs for tick-borne diseases annually

Giardia

Giardia species are common intestinal parasites that infest dogs and cats. Retrospective analyses of fecal flotation and antigen tests on healthy and sick pets revealed a 6.6% positivity rate in cats and an 11.6% positivity rate in dogs in the Northeast,^2,3 meaning that 1 in 15 cats and 1 in 8 dogs are likely to be infected in this area. Giardia cysts are immediately infective; can contaminate water, food, and surfaces; and have zoonotic potential as well as high potential to infect other pets in the household.⁴

Key prevention strategies include⁴:

• Bathing pets to remove cysts after treatment with metronidazole or fenbendazole
• Disposing of fecal waste immediately and cleaning contaminated surfaces
• Practicing good hygiene and handwashing

Roundworms

Retrospective analyses of fecal flotation and antigen test results have revealed roundworms to be the most common intestinal parasite of cats in the Northeast.³ In 1 study, 8% of cats (almost 1 in 13) tested positive for ascarids (e.g., Toxocara cati).³ According to the CAPC, that number may be as high as 25%, or 1 in 4 cats.⁵ Dogs in this region have a lower risk of roundworm infection than cats, with a positive test result rate of 2.3% (1 in 45).² In humans, roundworm larval migration can be dangerous, leading to organ damage or blindness.⁵

Key prevention strategies include⁵:

• Deworming puppies and kittens starting at 2 weeks of age
• Administering a species-appropriate monthly parasite preventive containing milbemycin oxime, pyrantel pamoate, selamectin, or moxidectin
• Performing fecal flotation or antigen testing 4 times during a puppy or kitten’s first year and twice yearly for adults

Fleas

Fleas are most active in the Northeast during the summer but survive on warm hosts or pupate indoors even when winter temperatures are low. Flea allergy dermatitis is a common sequela of flea infestation on pets, and fleas can transmit disease (e.g., murine typhus, bartonellosis, tapeworm infection) to pets or people.⁶

Key prevention strategies include⁶:

• Administering species-appropriate preventives (e.g., imidacloprid, fipronil, isoxazolines, spinosad, selamectin) year-round
• Reducing flea exposure with environmental decontamination

Heartworm

Dirofilaria immitis infection rates are relatively low in the Northeast. CAPC reports that fewer than 1% of heartworm test results in this area are positive, but D immitis has been found in all 50 states, which puts all pets at risk for infection.⁷ Additionally, heartworm disease incidence has increased nationally in recent years, partly attributable to changing weather patterns and increased canine travel.⁸

Key prevention strategies include⁸:

• Administering year-round topical, oral, or injectable preventives such as ivermectin, milbemycin oxime, selamectin, or moxidectin
• Performing once- or twice-yearly heartworm antigen and microfilariae testing on dogs

Following strategic prevention recommendations allows veterinary nurses and pet owners to work together to prevent and manage parasitic infections in pets, ensuring the health and wellbeing of companion animals in the Northeast.