Table of Contents
What are Tapeworms?
Tapeworms have a flat, segmented appearance and are commonly acquired by ingesting an insect or animal meat that is carrying tapeworms. They attach to and live in the intestines of their “host” human or animal and use the nutrients from the host’s diet to survive and grow.
Over time and with heavy tapeworm infections, the host animal or human can become malnourished because the tapeworms are depleting nutrients that would otherwise be used to nourish the host.
There are thousands of different species of tapeworms. However, only two commonly infect dogs – Dipylidium caninum and Taenia. Tapeworms are relatively common and they do not usually cause severe illness in dogs. Tapeworms are easily treatable and are also preventable in dogs.
How Do Dogs Get Tapeworms?
Dissimilar to many other intestinal parasites, dogs cannot get tapeworms by being directly exposed to tapeworm segments in another dog’s feces.
The most common way dogs become infected with tapeworms is by swallowing a flea infected with the immature form of tapeworms via the following life cycle:
- Tapeworm eggs are found in the environment.
- Fleas ingest tapeworm eggs. Inside the flea, the eggs mature into a form of tapeworm that is not yet an adult.
- While grooming themselves, dogs will inadvertently ingest a flea infected with immature tapeworms.
- After about a month, the immature tapeworm will mature into the adult form (the flat, segmented worms we are most familiar with) in the dog’s small intestine.
- Dogs will then shed tapeworm eggs in their feces, leaving them in the environment for the life cycle to repeat.
Although much less common than flea ingestion, dogs can also become infected with tapeworms by eating a rodent or rabbit carrying immature tapeworms.
Can Dog Tapeworms be Passed to Humans?
Most species of tapeworms cannot be passed directly from dogs to humans.
Like dogs, a human must ingest an infected flea to become infected with the common dog tapeworm, Dipylidium caninum. Since we do not groom ourselves as dogs do, this is very rare. Regardless, if a human lives with a dog with fleas, their chance of contracting tapeworms is higher because fleas are in the environment.
A particular species of tapeworm called Echinococcus can be passed directly from dog to human. Echinococcus tapeworms cause hydatid disease, a severe illness in humans. Thankfully, this tapeworm is scarce in the United States. Dogs contract Echinococcus by eating infected rodents or rabbits.
Symptoms of Tapeworms in Dogs
The most common symptoms of tapeworms in dogs are:
- Finding tapeworm segments in your dog’s feces, around their anus, or bedding – tapeworm segments are about the same size and shape as a grain of rice. Segments can be white but become yellow and smaller as they dry out over time. Finding tapeworm segments is typically the first or only symptom of tapeworms you may notice.
- Scooting – when your dog drags their bottom across the ground to try to scratch it. Tapeworm segments irritate the skin around the anus and cause itchiness.
Tapeworms rarely cause significant illness in dogs.
Less common symptoms of tapeworm infection in dogs include:
- Weight loss
- Failure to grow in puppies
- Dull or shaggy coat
- Jaundice (associated with the more serious, but rarer, Echinococcus tapeworm)
It’s important to remember that many dogs infected with tapeworms may not show any symptoms.
How are Tapeworms Diagnosed in Dogs?
Diagnosis is generally made by seeing tapeworm segments in your dog’s feces or around its anus. Unlike other intestinal parasites, tapeworms are not usually diagnosed by microscopically analyzing the feces because these tests are not accurate for tapeworms. Some laboratories offer more specialized tests to diagnose tapeworms, but this is usually not required to make a diagnosis.
Treatment for Tapeworms in Dogs
A parasiticide medication called praziquantel treats tapeworm infections. Praziquantel comes in tablet form or is given as an injection underneath the skin. Side effects of praziquantel are rare in dogs but include vomiting, diarrhea, and decreased appetite. The injectable form can sting and cause temporary soreness at the injection site.
One dose of praziquantel is effective in treating a tapeworm infection, but depending on your dog’s case, your veterinarian may recommend repeating a dose of praziquantel in 3-4 weeks.
In recent years, there have been some reports of tapeworms developing resistance to praziquantel in North America. Praziquantel is still commonly used and highly effective, but few alternatives are currently available for treating the common tapeworms in dogs.
Preventing Tapeworms in Dogs
Because ingestion of an infected flea is necessary to cause common tapeworm infections in dogs, the most critical aspect of preventing tapeworm infections is to control fleas in your dog’s environment. Even with successful treatment with praziquantel, your dog can become reinfected with tapeworms if there are fleas in their environment. Many effective flea preventatives are available in different forms including oral tablets, topical medications, or a high-quality flea collar (Seresto). Discuss which flea preventative would work best for your dog with your veterinarian.
Not allowing your dog to roam and hunt unsupervised is also a method of preventing tapeworm infections acquired from ingesting rodents or rabbits.
Many common monthly heartworm preventatives, including Interceptor Plus, Sentinel Spectrum, and Iverheart Max, contain praziquantel to prevent tapeworm infections.
If you see tapeworm segments (white or yellow and about the size of a grain of rice) in your dog’s feces, on their bedding, or around their anus, your dog may have tapeworms. Your veterinarian can help you identify tapeworm segments if you are unsure.
A medication called praziquantel treats tapeworm infections in dogs. Treating the source of tapeworms, which are usually fleas, is also important in preventing reinfection with tapeworms in dogs.