Which statement is true about Dirofilaria infection in the cat?

Which statement is true about Dirofilaria infection in the cat?

• A. The lifespan of heartworms in cats is shorter than in dogs
• B. Microfilariae are commonly seen in cat infections
• C. Adult worm burden in cats is similar in numbers to that of the dog
• D. Dirofilaria causes a severe anemia in cats

Answer: (A)

In cats, adult heartworms tend to have a shorter lifespan than in dogs. This happens because cats are imperfect hosts for Dirofilaria immitis: their immune responses are often more aggressive against the worms, and the overall worm burden is usually low. As a result, adult heartworms in cats typically live for only about 2–3 years, whereas in dogs they can persist longer if untreated. Microfilariae are not commonly seen in feline infections because most cats do not have circulating microfilariae, or they are present only transiently. The worm burden in cats is generally much lower than in dogs, so it's unusual for a cat to host as many adult worms as a dog. Additionally, while heartworm disease can cause various issues, severe anemia is not a defining feature in cats; the more typical problems relate to respiratory signs and inflammatory responses. So the statement about shorter lifespan of heartworms in cats is the best descriptor of how feline infections usually differ from canine ones.

In cats, adult heartworms tend to have a shorter lifespan than in dogs. This happens because cats are imperfect hosts for Dirofilaria immitis: their immune responses are often more aggressive against the worms, and the overall worm burden is usually low. As a result, adult heartworms in cats typically live for only about 2–3 years, whereas in dogs they can persist longer if untreated.

Microfilariae are not commonly seen in feline infections because most cats do not have circulating microfilariae, or they are present only transiently. The worm burden in cats is generally much lower than in dogs, so it's unusual for a cat to host as many adult worms as a dog. Additionally, while heartworm disease can cause various issues, severe anemia is not a defining feature in cats; the more typical problems relate to respiratory signs and inflammatory responses.

So the statement about shorter lifespan of heartworms in cats is the best descriptor of how feline infections usually differ from canine ones.