The Scoop on Poop

Intestinal Parasites 101, Roundworms

So, what is the scoop on poop? Why does your veterinarian insist on fresh fecal samples nearly every time you bring your pet in for a visit? How many times have you gone to all the trouble to collect the nasty smelling poo in a baggie only to rush out of the house without it? Well, it's all about worms, intestinal worms, that is. It's one of those topics one doesn't want to discuss at the dinner table, but it may be more important than you realize. In addition to harming your pets, some intestinal parasites have zoonotic potential, which is a fancy way of saying people can "catch" them from animals.

The biggest trouble-maker in this part of the world is the roundworm. It's a nasty little worm that attaches to the wall of the small intestine and sets up housekeeping. They actually aren't all that small either as they range from 5-7 inches long. They have a somewhat complicated method of outwitting unsuspecting pet owners. An adult dog can encounter roundworms via ingesting an infected rodent or rabbit or from the roundworm eggs contaminating the soil. The worms can encyst in the liver or muscle of the dog and go into a dormant phase where they are not susceptible to deworming medications. That is, until the dog becomes pregnant. Then, viola, they come out of the cysts and head for the uterus. The larvae pass directly into the uterus and infect the fetal puppies before birth! In both cats & dogs, the larvae also travel to the mammary glands and enter the mother's milk and pass directly to the puppies or kittens.  Because of these multiple methods of infecting the youngsters, the vast majority of puppies & kittens have roundworm infestations. Studies indicate up to 90-98% of puppies have roundworms infestations.

So what's the big deal? Well, they can wreak havoc on the puppies and kittens and cause a range of problems from minor to serious. Their migration includes a trip through the lungs & can lead to pneumonia. They can cause vomiting, diarrhea, unthriftiness and intestinal obstructions. The pot-bellied appearance is classic for a heavily infected puppy or kitten.  For more information on roundworms in pets, see this article.

But there's also that zoonotic potential too. Since humans are not the typical host, the roundworm larvae behaves differently in a human. Typically when a child gets infected, the confused roundworm larvae will migrate through the tissues and may migrate through the eye, brain, liver or lungs. If the larvae end up in the eye, they can cause permanent blindness. Now before you think you need to get rid of your dog or cat, please realize this is not a common occurrence. The other reality check is that there are other potential sources of roundworm infestation that  you might never suspect. The eggs can be in the soil from prior fecal contamination from previous pets or from wildlife, most especially raccoons. Roundworm eggs can survive for years in soil! But did you know that 15% or more of packaged commercial potting soil contains viable roundworm eggs? As someone who doesn't normally wear gloves while gardening, I find that pretty disconcerting. This means the indoor only cat even has possible exposure if you have houseplants. So on that long list of things to keep out of your toddler's reach, add potted plants and flowers. Of course, the kids are at the biggest risk of roundworm contamination since their hand washing skills aren't as well-developed and they are still exploring much of their environment with their hands which then enter their mouths.

If you have an outdoor sandbox, keep it covered whenever it's not in use to prevent the neighborhood cats & raccoons from using it as a giant litter box and potentially inoculating the sand with roundworm eggs. Encourage frequent hand washing after digging in the soil or sandbox. It may be prudent to avoid uncovered sandboxes in public playgrounds altogether. In addition to continuing to have your pet checked regularly for intestinal parasites, regular deworming is recommended by the CAPC, the Companion Animal Parasite Council. The easiest way to do this with adult pets is to use a monthly heartworm preventive medication that also eliminates common intestinal worms. There are several products currently available for both dogs & cats and you may already be using one without realizing it. Some popular brands include HeartgardPlus, Interceptor, Sentinel and Trifexis for dogs and Revolution for Catsto name just a few. It is also very helpful to scoop the stools while they are fresh, before the eggs can embryonate to the infective larval stage. For more on the roundworm in humans, see the CDC page on Toxocara (roundworms).

So, this may have been more than you truly wanted to know about roundworms, but hopefully it will help prevent some children from getting exposed. 

Next we'll look at hookworms & whipworms. Meanwhile, just keep scooping that poop and taking samples to your veterinarian regularly. It is for a good cause!