Tapeworms in Dogs

Tapeworm, artwork
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While tapeworms are rarely a serious health risk, they can pose nutritional problems interfering with the puppy food your dog eats. It’s important to understand how your puppy contracts tapeworms to know how to get rid of the parasite and prevent its return.

What Are Tapeworms?

Tapeworms are ribbon-like flatworm parasites that live in the intestines of puppies. There are several varieties, but Dipylidium caninum is seen most often in cats and dogs.

The head of the tapeworm is called the scolex or holdfast. It is equipped with hooks and suckers that are used to anchor it to the wall of the small intestine. Tapeworms do not have a mouth. In fact, tapeworms don't even have a digestive system. Instead, they absorb nutrients through their body segments.

Called proglottids, these segments are linked together like a chain. The parasite continuously grows new segments that are added from the neck down. Adult worms continue to add segments as long as they live, sometimes attaining lengths of 2 feet or more. They are composed of hundreds of segments. Each proglottid contains both male and female reproductive organs. When mature, the segment produces up to 200 eggs. Segments farthest from the scolex are the most mature and once "ripe" they are shed from the worm's body and pass in the puppy's feces.

Immature worms must spend developmental time inside an intermediary host before being able to infest your puppy. The flea serves this purpose. If your puppy is infested with fleas, it is also highly likely to have tapeworms. That's why the incidence of tapeworms closely parallels the summer months of flea season. Tapeworm eggs are eaten by the flea larvae, which then develops as the flea itself matures. When a pet nibbles to relieve that itch, it often swallows the flea and infects itself with tapeworm.

Symptoms of Tapeworms in Dogs

Once outside the body, each segment can move independently like tiny inchworms, but when dry they look like grains of rice. Infested pups typically have segments stuck to the hair surrounding the anal area or in their bedding. Eventually, the segments dry and rupture, releasing the eggs they contain into the environment. The life cycle is complete in two to four weeks. Tapeworm eggs are passed and shed sporadically. A veterinary examination of the pup's stool for telltale evidence may often be inconclusive. It's considered diagnostic to find the segments on the pet.

Tapeworms are rarely a medical problem and are usually considered an unpleasant annoyance. The moving proglottids may cause irritation to the anal region, which may prompt puppies to excessively lick themselves or "scoot" their rear against the floor or ground. Without treatment, massive tapeworm infestations potentially interfere with digesting food or elimination. Puppies may suffer intestinal blockage should too many worms become suspended the length of the intestinal tract. Tapeworms can also make their way into the dog's stomach and cause the dog to vomit. If the dog vomits, they may vomit up the tapeworm.

Also, the hooks of the holdfast can damage the intestinal wall. Diarrhea with mucus, and occasionally blood, may be signs of tapeworm infestation. Long-term infestation can result in an unkempt, dry-looking coat, a generally unhealthy appearance, and reduced energy. Flea tapeworms are the most common kind of cestodes affecting dogs. Other species may be contracted if the dog eats wild animals like mice or rabbits.

Treatment and Prevention of Tapeworms

There are several safe and highly effective treatments for tapeworms, which may be administered either as a pill or injection. They must be prescribed by a veterinarian after the diagnosis is confirmed. Unless constantly exposed to reinfestation by fleas, a one-dose treatment will eliminate the tapeworms. Controlling fleas is the best way to prevent tapeworm infestation.

Human Health Risk

There's a human health risk associated with two species of tapeworms which dogs may expose people to if they eat the host animal. Echinococcus granulosis can be found in sheep, cattle, goats, and pigs and is found in Utah, California, Arizona, and New Mexico. Most cases in people go unnoticed. Echinococcus multilocularis affects foxes, coyotes, and rodents indigenous to Alaska, the Dakotas, and surrounding North Central states. Although human infections are rare, they can be deadly. Both of these tapeworm species may cause parasitic tumors in the liver, lungs, and brain of infected people. Check with your veterinarian to see if these types of tapeworms pose a risk in your area.

If you suspect your pet is sick, call your vet immediately. For health-related questions, always consult your veterinarian, as they have examined your pet, know the pet's health history, and can make the best recommendations for your pet.