Several types of worms can show up in vomitus of dogs. They are usually roundworms and can be seen in vomit and in stool-- so you know the next important step to take, right? Please see your vet to treat the worm infestation and prevent recurrence as well as infection to anyone in your family! Yep, people can be infected too. Most victims are children. They are infected by inadvertantly consuming worm eggs in soil (typically by getting dirty fingers in their mouths). The worm gets lost in the human body (classically in the eye), dies, and generates an extreme inflammatory reaction. If the worm dies within the human eye, blindness usually results.
For this reason, it is important for parents to be aware of this hazard. Proper hand-washing will prevent infection. Monthly pet deworming will reduce environmental contamination. Public leash laws and restriction of dog walking are meant to reduce fecal contamination of public areas. Stray cats should be kept away from children’s sandboxes.