toxocara canis symptoms in dogs

Toxocara canis, a common intestinal parasite in dogs, often flies under the radar until symptoms start to show—and by then, it might have already caused discomfort or worse. These roundworms thrive in a dog’s digestive tract, especially in puppies, who can pick them up from their mother’s milk or contaminated soil. Spotting the signs early matters, not just for your pet’s health but for your family’s too, since humans can accidentally ingest eggs from infected feces.​

In puppies, the symptoms tend to be more noticeable. You might see a potbellied appearance, even if they’re eating regularly—those worms take up space and steal nutrients. Vomiting or diarrhea, sometimes with visible worms (long, thin, and white, like spaghetti), is another red flag. Lethargy creeps in too; a normally playful pup might drag their feet on walks or skip mealtimes. Adult dogs often show fewer signs, but don’t be fooled—they can still carry the parasite and spread eggs. Watch for sudden weight loss despite a good appetite, or a dull coat that lacks its usual shine. In severe cases, worms can block the intestines, leading to painful bloating or even emergency surgery.​

Understanding how transmission happens helps in prevention. Dogs pick up Toxocara canis by sniffing or licking contaminated areas—think public parks where other dogs have pooped, or even your own backyard if waste isn’t cleaned up promptly. This is where local laws come into play: most European countries and U.S. states require pet owners to scoop feces immediately, not just for cleanliness but to stop parasite spread. Fines for leaving dog waste in public spaces can run into the hundreds, and for good reason—one infected dog’s stool can contain millions of eggs, ready to infect others.​

Veterinary care is non-negotiable. Puppies should be dewormed regularly, starting at 2-3 weeks old, as part of their routine checkups—this is often mandated by local animal welfare laws to prevent outbreaks. For adult dogs, annual fecal tests can catch infestations early, even when symptoms are mild. If you suspect Toxocara canis, don’t wait: your vet can prescribe dewormers that kill the worms, but delaying treatment can lead to anemia or stunted growth, especially in young dogs.​

Staying proactive protects everyone. Along with prompt waste cleanup, washing your hands after handling your dog or gardening reduces human risk—kids, who often put hands in their mouths, are most vulnerable. By learning to recognize the symptoms, sticking to deworming schedules, and following local regulations, you’ll keep your dog healthy and your community safe. After all, a happy, parasite-free pup is a better companion for those long walks in the park—where you’ll both feel good knowing you’re doing your part.