Updated: Dec 9, 2021
Parasites in dogs take many forms, but they all have one thing in common: sooner or later their presence will almost always have an impact on your pet's health or comfort. They can cause anything from mild irritation to serious illness. To cover all of the parasites in detail would (and does) take up a book. So here is an overview of the most common parasites, how they work, and the problems they may cause. This will be a series of blog posts.
First, let’s define what a parasite is. It’s actually pretty simple. The Centers for Disease Control and Prevention sum it up:
“A parasite is an organism that lives on or in a host organism and gets its food from or at the expense of its host.”
According to the Companion Animal Parasite Council (CAPC), many dogs will be infected with parasites at some point in their life. The last things most dog owners want to think about are parasites. As a result, we tend to avoid learning the necessary information about internal dog parasites until it is too late! In this series, I plan on explaining what the parasites are, how they infect your pets, how to treat them, and the zoonotic (your pet giving you the parasite) concerns.
Tapeworms are ingested by your dog, via a host that is harboring a tapeworm egg. This is usually an adult flea. We know everyone dislikes fleas, and now you have one more reason to protect your pet from those pesky bugs. It will cause your dog to lose weight and have occasional diarrhea. You'll know if your dog's got them because you'll see segments of the worms around their anus, in their stool, or even on their bedding. The segments look like grains of rice. Your veterinarian will administer medication orally. The medication is highly effective. The best protection against tapeworms is to keep your dog free of fleas and away from dead animals and garbage.
What are Tapeworms?
Tapeworms are intestinal parasites. Along with roundworm, hookworm, and whipworm, this flat, segmented worm is found in dogs, cats, humans, and many other species around the world. The most common tapeworm species is Dipylidium Caninum. The medical term for a tapeworm infestation is Cestodiasis. If you’ve ever seen photos of tapeworms, your reaction was probably one of automatic revulsion. (Especially those alarming videos of tapeworms being removed from people. A woman in China had an eight-foot tapeworm taken out of her stomach!) Even though they’re disgusting to look at, it’s important to recognize the signs of parasites, so your dog can be treated before the worms do damage to his body. The good news is that treatment for tapeworms is very effective and simple.
How do Dogs Get Tapeworms?
There is a cycle through which dogs get tapeworms:
First, the dog will ingest a host that is harboring tapeworm eggs, most often an adult flea. There are a few ways a dog might ingest a flea, such as self-grooming, or grooming a canine or feline housemate. Other animals that are potential transmitters of eggs include birds, rabbits, and rodents, which even a well-fed dog, might scavenge for.
Once digested, the tapeworm eggs settle into your dog’s small intestine. There it will develop into an adult.
The adult tapeworm is made up of lots of small segments, each about the size of a grain of rice, called proglottids. Adult tapeworms usually measure anywhere from four to 28 inches in length.
As the tapeworm matures inside the dog’s gut, these segments break off and end up in the dog’s stool. Since these segments contain tapeworm eggs, the cycle will begin again, with a new host and most likely a new recipient.
How to tell if your Dog has Tapeworm
The Centers for Disease Control and Prevention (CDC) says the proglottid segments can sometimes be seen crawling near the anus or on the surface of the fresh waste. These eggs are released into the environment when the proglottid dries out. The dried proglottids can sometimes be seen stuck to your dog’s fur. Tapeworms are not usually harmful, and dogs rarely become ill as a result of an infestation, but weight loss may occur if he is heavily infected.
Diagnosis & Treatment
Have you ever wondered why we ask you to do the unpleasant task of collecting and bringing in a fecal sample for your pet's annual physical? The answer is: that’s how we test for worms. The test will find out if tapeworms are in the anal sac or in the feces of your dog. False negatives can occur, but the tapeworm test is reliable, and most results are conclusive. The prognosis for both animals and humans is very good post-treatment. A prescription drug called praziquantel is used to treat tapeworms, either orally or by injection, we prefer orally. The medication causes the tapeworm to dissolve within the intestine. The drug generally does not have adverse side effects. Other medications that are effective at removing tapeworms include chewable or granule medication that is sprinkled on food and tablets. There are also combination parasite medications that treat tapeworm, hookworm, roundworm, and whipworm in one. Dr. McMillen points out that it’s important to administer all of the prescribed medication to ensure that the tapeworms are completely gone from your dog’s body. If you only give half of the prescribed medication it's possible that not all the parasites will die; Resistance to the medication can also occur. And before using any over-the-counter medication on your own, consult with your veterinarian for proper diagnosis and treatment options. You wouldn't want to waste your money on a medication that wouldn't work to treat the parasite.
Can Tapeworms be passed on to humans?
Tapeworms can be transmitted to humans, but the risk of infestation is very low—you’d have to swallow an infected flea or, in the case of some species of parasites, via the accidental ingestion of feces that is carrying parasitic eggs. Children are most prone to this since they’re more likely to be outside playing in the grass, parks, and other areas where dog waste might be left.
Prevention of Tapeworms in dogs
The best way to avoid a tapeworm infestation is to keep your dog free of flea infestation. The surrounding environment must also be treated to prevent recurring infestations. The CDC recommends these steps to reduce the likelihood of tapeworm infestation:
Control fleas on your pet, and in their indoor and outdoor environments.
Have your veterinarian treat your pets promptly if they have tapeworms.
Clean up after your pet, especially in playgrounds and public parks. Bury the feces, or place it in a plastic bag and dispose of it in the trash.
Do not allow children to play in areas that are soiled with pet- or other animal feces.
Teach children to always wash their hands after playing with dogs and cats, and after playing outdoors.
Keep the dog away from dead animals and garbage.