Dog Flatworms

" Dog flatworms are  internal parasites which infest the gastrointestinal tract or lower respiratory tract. Flatworms may be either flukes (any flat parasite) or tapeworms. Hepatic (liver), intestinal and lung flukes have been identified as dog flatworms, while different genus of tapeworms can infest dogs. Intestinal flatworms can primarily cause enteritis (Inflammation of the intestinal tract); hepatic or liver flukes on the other hand can cause fibrosis (hardening of the tissue) in the liver and gall bladder; while lung flukes can cause deep coughs in dogs. Tapeworms can cause severe itching around the anus, vomiting and weakness. Diagnosis is usually based on laboratory confirmation; as most  cases go unnoticed clinically. Treatment can be completed with anti–helmintics, preferably Praziquantel."

Types of Dog Flatworms:

Tapeworms and flukes can both be termed as dog flatworms, even though both belong to different classes, due to their morphology (the branch of biology that deals with the form and structure of organisms), as tapeworms are segmented and appear as a true “worm”, while flukes on the other hand are non segmented platyhelmenthes, flat as a “plate”.

dog flatworms
Dog Flatworms
Pictures of Dog Tapeworms
Source: CDC Dr. Mae Melvin

Flukes: Intestinal, hepatic (liver) and lung flukes are three different types which can infest dogs. However, the clinical importance of each type is not very important. Hunting and outdoor dogs are more susceptible to picking up a worm problem.

Nanophyteus salmincola, Alaria canis and Heterobilharzia Americana are three different types or species of intestinal flukes, both of which are seen in domesticated and wild dogs. These range between 0.5–1.0 mm in size.

Snails and fish can transmit intestinal flukes. Dogs fed raw fish or food containing fish products are more susceptible. Intestinal flukes become embedded in the intestinal wall and cause mild to severe enteritis (intestinal inflammation). Diarrhea with blood in it occurs in severe cases.

Hepatic Flukes; Opisthorchis viverrini and Metorchis albidus are two species of hepatic flukes; which can cause fibrosis and thickening of the walls in the bile duct, gall bladder and liver. These may range between 5–9 mm in size and appear elongated.

Hepatic (liver) flukes can cause hepatic fibrosis, but only if the worms stay for a long period of time in the liver, gall bladder or bile duct. M. albidus is also called a “2 minute fluke”, as they cause notable clinical (diseased) conditions in dogs for a short period of time.

Fibrosis can eventually develop into carcinoma (cancer, an invasive malignant tumor) of the infested part of the body, weakness,progressive loss of body condition, coma and eventually death depending on the severity of the fibrosis and the pathogenesis (development) of the carcinomas.

Lung Flukes; Paragonimus kellicoti and P. westermani are two species which reside in the lungs of dogs, in the form of cysts. Adult flukes are approximately 14 mm (1/2 inch) in length and 7 mm in width. Crabs, snails and crayfish can act as intermediate hosts the eggs of lung flukes. Clinically, chronic and deep cough is noted, while intolerance, labored breathing, lethargy and progressive weakness are associated with lung incompetency (problems). >

Tapeworms are the other form of dog flatworm. These have segmented but flat bodies, and can infest dogs by attaching themselves against the intestinal wall and by releasing segments into the feces. Rice like segments can cause severe itching and irritation at and around the anus. Diarrhea, vomiting and weight loss can also occur. Different species of tapeworms such as Dipylidium, Taenia, Echinococcus, Diphyllobothrium and Mesocestoides can infest both companion and wild dogs.

Diagnosis of Dog Flatworms:

As, two different kinds of dog flatworms i.e. flukes and tapeworms can infest dogs, in most cases, both types usually go unnoticed. Clinically it is not possible to precisely diagnose dog flatworms. Laboratory examination of the feces for the presence of eggs and/or segments of flukes or tapeworms is usually an effective way to confirm the presence of the worms.

In the case of lungworms, x-rays may help in making a diagnosis. Eggs and elongated flukes are visible in high resolution X–Rays.

Treatment of Dog Flatworms:


Hepatic flukes should be treated with Fenbendazole at a dose rate of 200mg/kg B.W (by weight)orally for at least 3 days. Praziquantel as an alternative, can be administered at a rate of 100mg/Kg B.W orally given in single doses.

For intestinal flukes, praziquantel should be administered as an injection, at a dose rate of 10–30 mg/Kg B.W, single dose administered through SC (subcutaneously, under the skin) or IM (intramuscular) route. Fenbendazole can be used orally as an alternative at a dose rate of 50 mg/Kg B.W for at least 14 consecutive days.

Bithional is an effective option for lung flukes, if administered daily for a one-week period. Praziquantel can eliminate lung flukes, if administered at a dose rate of 25 mg/kg B.W for three consecutive days, orally.


Praziquantel is the drug of choice for dog flatworms and it can effectively eliminate dog tapeworms as well if administered at a dose rate of 7.5 mg/Kg B.W, orally for at least 2 consecutive days.

Dose rates may vary depending on a dog's age, weight and breed.  The only FDA approved over the counter product available for Tapeworms (contains Praziquantel) is Trade Winds Praziquantel Canine Tape Worm Tabs

Homeopathic Preventative for Flatworms and other Parasites

While not a cure, there is a homeopathic supplement available that can help the body naturally expel parasites such as worms. The product, Parasite Dr. Capsules, contains well known ingredients such as Wormwood, Coves, Neem (natural dewormer),and Herb of Grace.  For dogs that are continually exposed to the risk of worms, this might be a helpful approach.

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