Roundworms (Toxocara canis)
Why they matter: Extremely common in puppies and can be zoonotic.
How dogs get them: Often from the mother (before birth or through nursing) or by ingesting eggs from the environment.
Common signs: Pot-bellied appearance, poor growth, vomiting/diarrhea, or no signs at all.
Diagnosis: Fecal testing (microscopic exam; sometimes antigen testing).
Treatment & prevention: Prescription deworming and consistent parasite prevention; repeat treatments are commonly needed in puppies.Human risk: Yes—roundworms can infect people, and children are at higher risk. Good hand hygiene and prompt stool cleanup are important.