Flatworms always fascinated me in high school science classes. Students would bisect them and observe the two parts not only go about their business unaffected, but later become two distinct worms. A worm in a lab is one thing; thinking about them inside your dog is somewhat less agreeable. Tapeworms in dogs are parasitic flatworms that grow to maturity inside a dog’s small intestine. This is a mug shot of the head, or scolex, of your typical dog tapeworm.
In limited numbers, tapeworms are one of the least harmful parasites a dog can have; indeed, symptoms can be difficult to discern. Tapeworm in puppies can be more serious, since puppies with tapeworms may experience problems putting on weight. Fortunately, tapeworms are easy to treat, and controlling their primary modes of transmission, fleas and raw meat, should make prevention relatively simple.
There are two major kinds of tapeworms that affect dogs. The less common variety, Taenia serialis, gestates inside animals like rabbits, various rodents, and sheep. Dogs that come across an infected animal and dine upon their flesh ingest the larval Taenia worms, which then grow to maturity inside the dog. The much more common tapeworm, Dipylidium caninum, is what we’ll focus on here. These tapeworms are similar in requiring an intermediate host, in this case, fleas. An infected animal releases tapeworm segments or eggs in its feces. Fleas ingest the eggs which grow inside of them to a larval stage. These fleas find their way to the nearest dog.
During regular grooming, of course, a dog not only scratches, but licks and chews at herself. On occasion, a dog will ingest an infected flea. Tapeworm larvae travel the digestive tract before attaching the hooks of their scolex to the dog’s small intestine, where they grow by absorbing nutrients through their skin. Adult tapeworms in dogs can be anywhere from four to 28 inches long. Each segment of the tapeworm is filled with eggs. Periodically, segments break off, to be released in the dog’s feces so that the cycle may start afresh.
It can be difficult to know whether a dog has tapeworms. Unlike other parasitic infestations, such as heartworm, mange, or ear mites, which have clear and obvious external calling cards, tapeworm symptoms are somewhat more subtle. More worms, more problems, of course, and, left unchecked, a dog with many tapeworms may begin losing weight. They may also present problems for neglected or malnourished dogs, older dogs, puppies, and dogs with compromised immune systems.
That said, there are some tapeworm symptoms that you can look out for. The first would be scooting, best defined as what you see when a dog slides her butt across the ground or the floor. There are several reasons a dog may drag her rear against the ground, so a closer look may be required. To be ingested by fleas, tapeworm eggs must be very small indeed, but tapeworm segments are visible to the naked eye. Like other broken flatworms, segments that emerge in fresh feces may still move under their own power. These segments, white at first, and turning a golden color once dry, resemble grains of rice. These segments may also be seen on or around the dog’s anus after defecation. A stool sample containing such a segment can be diagnosed quickly by a veterinarian.
Fortunately, how to get rid of tapeworms in dogs is simple once the problem has been determined. The scolex, the head of the tapeworm, is the source of its power. To eliminate the infestation, the head of the tapeworm must be destroyed. Segments that emerge in feces or appear around the anus do not affect the tapeworm itself, which grows further reproductive segments.
In some cases, the scolex of a tapeworm may become dislodged from the intestine. The worm may pass whole in the dog’s feces, or be vomited out. Once a diagnosis has been confirmed, veterinarians can administer, either orally or by injection, medications like niclosamide and praziquantel. Both are safe and effective, and unless there is a serious infestation, the tapeworms will dissolve before they’re even passed in feces. Those medications are also available at pet stores in over the counter forms.
Tapeworms are not technically zoonotic, though yes, humans can get tapeworms from dogs. It’s going to sound weird, and kind of foul, but ingesting a flea from an infected dog can lead to a person getting a tapeworm. It is not likely, but during times of the year when fleas are prevalent, it’s possible. For Taenia tapeworms, you’d have to eat uncooked or undercooked rabbits, rodents, or sheep. Again, not likely, but possible.
Just to be clear, though both Dipylidium and Taenia tapeworm eggs are distributed in dog feces, dogs cannot get tapeworm from eating poop. The former can only be acquired from ingesting infected fleas, and the latter from eating infected raw meat. Tapeworm eggs are like caviar to fleas, so, in order to prevent the most common tapeworms in dogs, flea prevention should be at the top of your to-do list.
Be vigilant! Achieving an effective and decisive victory against tapeworms in dogs is a battle won, but the struggle continues. Even a dog recently cured of tapeworm infestation needs to ingest only one flea for tapeworms to return. Has your dog dealt with tapeworms in the past? How did you and your dog handle the invading parasites? Share your experiences with tapeworm in the comments!
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