The weather has become cool and wet again. Many of you may remember from my past articles that, with the Fall comes a 70% surge in fleas and ticks. So, what does this have to do with tapeworms? Well, the vast majority of tapeworms picked up by dogs and cats are from ingesting fleas who carry the eggs inside of them. This happens as part of the normal grooming process, especially with cats. However, another species of tapeworm is caught by eating small rodents and dead animals. Since critters are fat and slow in the Fall as they prepare for winter, these tapeworms see a spike in their population during this time of year as well.
Regardless of source, when one of our pets ingests a tapeworm egg, it will go through the same process. The shell of the egg is dissolved away and the young worm will swim its way down the intestines until it finds a place to attach. It attaches to the wall of the intestine with a series of small hooks called the rostellum along with several suckers. It immediately begins absorbing nutrients from your pets through is skin while it begins to grow body segments that trail down the intestinal tract. After about 3 weeks, the worm is ready to reproduce. To do this, it will fill the last body segment with eggs and then detach it. It actually retains the ability to move and will pass out of the pet with the stool or they can literally crawl out while they sleep. They will look like wriggling piece of rice until they dry out, at which point they look like large sesame seeds.
Vets find tapeworms very frustrating due to this lifecycle as it makes it difficult to catch and diagnose. The fecal samples we send out to check for worms are actually processed and then examined microscopically for the eggs from those worms. Since the tapeworms do not lay actual eggs, they are almost never seen. Instead, we must rely on the attentiveness of our owners to notice the egg sacs on their pet’s fur or bedding. DNA tests are available, but they are fairly expensive for the typical client to use as a regular annual screening. So, most vets find it difficult to recommend them unless a dog has severe clinical signs without another diagnosis.
While there are some tapeworm preventives for dogs, they typically lack efficacy against other parasites that can be more dangerous and their use keeps us from using other products due to side effects from over-medicating. However, there are several topical preventives for cats and we recommend their use on any cats that go outdoors.
Luckily, treating tapeworms is pretty easy and inexpensive. We use a drug called praziquantel that has been around for ages and we have not really seen any tapeworms developing a resistance to it. We typically send home two doses used 10 days apart. However, if we diagnose the worm that comes from eating infected meat and animals, we will use a combination of medications since the pets may have other worms from this as well. With other worms, we would recheck a couple of stool samples after treatment, but that is obviously pointless with these critters, so we just ask owners to watch for the egg sacs again.