Which age group of dogs is most commonly affected by Toxocara canis?

Toxocara canis is a type of roundworm that primarily affects puppies, making them the most commonly affected age group. Puppies are particularly vulnerable to infections because they may be exposed to roundworm eggs in their environment or through their mother's milk, as the parasite can be transmitted transplacentally (from mother to pup before birth) or through the lactation process.

In young dogs, the immature immune system is less equipped to handle parasitic infections, which also makes them a key target for Toxocara canis. Symptoms in infected puppies can include poor growth, vomiting, diarrhea, and a pot-bellied appearance. In contrast, older dogs and senior dogs generally have a more developed immune response that can help mitigate the impact of infections, although they can still be affected, the prevalence and severity of Toxocara in those age groups is much lower.

This understanding reinforces the importance of regular veterinary checks and deworming protocols for puppies to prevent and manage infections from Toxocara canis effectively.