Hookworms & Roundworms

by matthew vetpetbox March 07, 2019

Worms that live in the intestines (intestinal parasites) are very common in dogs and cats, especially the hookworm & roundworm. It’s important to know a bit about these worms to determine if your pet has them, how he may have gotten them and how to prevent re-infection or spreading them to others (including humans!). Which worms can be transmitted to people? Hookworms & Roundworms!

HOOKWORMS
- People become infected when the hookworm larvae penetrate unprotected skin, especially when walking barefoot or sitting on contaminated areas.
- This can result in a disease called “cutaneous larva migrans”, when the larvae migrate through the skin and cause inflammation.
- Prevent infection by:
  - wearing shoes and taking other protective measures to avoid skin contact with sand or soil
  - prompt disposal of feces after your pet poops can prevent eggs from hatching and contaminating soil
  - More on hookworms:
    - All About Hookworms
ROUNDWORMS
- People become infected with roundworms by accidental ingestion of infected eggs. These eggs go on to migrate towards the liver, lung, eye and brain, causing major problems, often called “visceral and ocular larva migrans.”
- The Center for Disease Control (CDC) reports that 13.9% of the adult population in the U.S. has antibodies (which means they’ve been exposed) to the roundworm (Toxocara). In addition, a study in the Veterinary Record reported that up to 15% of commercial potting soil contained roundworm or hookworm eggs or both!
- As stated above, humans get infected by accidental ingestion, so the most vulnerable population are children, who stick their fingers in their mouths after playing outside in dirt or sand. This also reminds us of the importance of frequent hand washing, washing fruits and vegetables well, and keeping sandboxes covered when not in use.
- Although very rare, people can get roundworms by eating under-cooked meat that contains roundworm larvae, as well. As with hookworms, prompt disposal of feces after you puppy poops can prevent eggs from hatching and contaminating soil.
- Prevent infection by:
  - washing hands & foods
  - avoid under-cooked meat
  - prompt disposal of feces after your pet poops can prevent eggs from hatching and contaminating soil
  - More on Roundworms:
    - Neglected Parasitic Infections in the United States: Toxocariasis.
    - Toxocariasis FAQs.

Common questions vets are asked about intestinal parasites:
- Why do I have to give several days of de-wormer, sometimes weeks apart?
  - We prescribe de-wormers this way because we are targeting different life cycle stages of the parasite we are trying to get rid of. Many worms migrate around the body and we need to aim to get them when they are most vulnerable in the intestine. De-wormers act on the worms that are in the intestine at the time the medication is given. After these worms are forced out of the intestine, they can be replaced by more worms that are still migrating there. Therefore, we give multiple de-wormers. We don’t want to leave any worms behind!
- Why am I seeing MORE worms after the de-wormer was given?
  - Don’t worry! This is normal. Many of our de-wormers work by basically paralyzing the worm, so it lets go of the intestine and can be pushed out of the body in the feces, where the adult worm will quickly die in the environment. Some worms can be quite long (an adult roundworm can be up to 7” long) so don’t be alarmed when you see this. It’s gross, but normal.
- How does a well-dewormed mother dog give her puppies worms?
  - Most de-wormers act on intestinal parasites that are present in the intestine at the time that the medication is given. As previously mentioned, many times worms can migrate around the body. Often, these worms “take a break” and rest (called encysting) in different parts of the body until a major stressor, like pregnancy, occurs. This awakens the sleeping worms and allows them to migrate to areas, like the mammary glands, where they go on to infect the puppies through breast milk.
- What’s the deal with pin worms (the kind of worm children commonly get)? Did my child get them from our dog?
  - Human pinworms are very host-specific, in this case meaning that they only transmit between humans. Dogs and cats don’t get pinworms. So, kids get pinworms from each other. There was one report a long time ago, of a mountain gorilla getting human pinworms while in captivity. So, unless your kids been hanging out with a mountain gorilla, it’s most likely that he got them from a friend (a human one)!
- What are the white things stuck in the fur around my pet’s rear? I think they’re moving!
  - Most likely, you’re seeing tapeworm segments that have broken off the parent tapeworm that is inside your puppy. They are white and look like flat grains of rice that expand and contract. You’ll probably see your puppy dragging his rear on the carpet or grass too because, as you can imagine, they itch and probably tickle a bit. Keep in mind that pets usually get tapeworms from fleas, so you should contact your veterinarian about those too!