Tapeworms in Dogs and Cats

TapewormsTapeworms are a common finding in dogs and cats in Florida. They present as small, white to off-white, flat segments usually seen on the stool or on the animal’s perineum (around the anus). The worm segments are usually around a quarter inch long, although they can be much longer.

Tapeworms and Intermediate Hosts

Tapeworms are in a class of internal parasite that has an obligatory immature stage that has to go through an intermediate host. The most common tapeworm we see uses the common dog flea as its intermediate host. The other tapeworm – which is much less common – travels through mice, rats, and other small rodents.

What this means is that the dog or cat has to eat the intermediate host to spread to its next carrier. For instance, in a house that has two dogs, just because Buddy has tapeworms does not mean that Lady will have them, too. For Buddy to have gotten tapeworms he had to eat a flea that had the larval form of tapeworm in it. When he ate the flea he then developed the adult form of the worm.  For Lady to get tapeworms she would also have to eat a flea with the tapeworm larva in it. That is, if Lady ate one of the tapeworms that Buddy passed, she WOULD NOT get tapeworms. Tapeworms can ONLY be passed by ingestion of the intermediate host, which in this case is a flea.

So we often get the question that if we are going to worm Buddy for tapeworms, shouldn’t we just go ahead and worm Lady as well? Not necessarily. While the fact that Buddy has tapeworms means that he must have had some fleas at some point in the recent past, it does not automatically mean that Lady has tapes, too. However, if Buddy has been exposed to fleas, then so has Lady, and so she has a decent chance of having tapeworms, also.

In these cases we usually opt to worm Buddy and wait and see if Lady has them, too. The easiest way to diagnose tapeworms is to just visually see them on the pet’s stool, or on the hairs of the perineum.

Diagnosing Tapeworms

Tapeworms on poop
Tapeworm segments on a dog’s stool

Tapeworms do not usually show up readily on the routine fecal float exam that we do in the office. That’s because the fecal float relies on free-floating worm eggs in the stool. When we diagnose worms in pets with a float we are looking for the eggs that the worm passes, not the worm itself. However, tapeworms don’t pass discreet eggs. Instead, they pass egg packets – called proglottids. It’s actually these proglottids that clients see on their pet’s stool.

So if you suspect that your pet might have tapeworms simply keep an eye on their stools and on their rear ends to see if they’re passing any proglottids, and if so we’ll worm them appropriately. And in Florida, we highly recommend year-round flea control for all dogs and cats that go outside.