Roundworm is a parasite usually present in the intestines of dogs and can result in an infection called toxocariasis.

How it spreads : Most commonly, roundworm eggs are present in the infected dogs' poop. People and animals can be exposed to this disease by swallowing roundworm eggs from a polluted environment (contaminated with dog poop). 

Who is at risk : Roundworms can infect anyone. 

Signs in dogs : Most commonly infected dogs don't show any typical signs, but some might have dehydration, mild diarrhea, a rough coat, and a pot-bellied appearance.

Symptoms in people : Roundworms can cause two types of illness in people. The first is ocular toxocariasis, which occurs when roundworm larvae migrate to the eye. It can result in severe eye inflammation, damage to the retina, vision loss, etc. Meanwhile, the second illness, visceral toxocariasis, occurs due to the migration of roundworm larvae into body organs, including the central nervous system, lungs, liver, etc. This infection can cause abdominal pain, fatigue, fever, coughing, or wheezing.