Worms in cats and dogs: Our MKVG Guide

Cats and dogs can pick up a range of worms including nematodes, cestodes and trematodes in Europe – lets break them down into their generic names.

Intestinal worms

Roundworms
Tapeworms
Hookworms
Whipworm

Non-intestinal worms

Heartworm
Subcutaneous worms
French heartworm
Lungworms
Eye worms

Roundworms (Toxocara canis & Toxocara Cati)

Toxocara canis is a large intestinal nematode that can measure up to 15cm in length and affect dogs. The feline equivalent, Toxocara cati, can measure up to 10 cm in length. Roundworm can affect animals of any age, from puppies and kittens to older cats and dogs. These nematodes are also zoonotic, meaning that the infection can be transferred on to a human from our pets.

Adult worms will inhabit the small intestine and lay eggs that will be excreted in the animal’s faeces – eggs can survive in the environment for years once they are passed. Cats and dogs can become infected via contact with eggs in the environment, or as a result of consuming meat or prey infected with roundworms. Puppies and kittens can also be infected through their mother’s milk when they feed.

Adult animals are unlikely to experience clinical signs if infested with roundworms. Infection of puppies and young animals can lead serious illness if untreated.

Tapeworms (Echinococcus granulosus, Echinococcus multilocularis, Taenia and Dipylidium caninum)

Echinococcus granulosus is a small cestode that lives in the small intestine of dogs and some other canids, including foxes. Echinococcus multilocularis is another small cestode that lives in the small intestine of foxes, dogs and (rarely) in cats. Both these tapeworms can also infect hosts such as sheep, pigs and mice. Dipylidium caninum is a common parasite throughout Europe. The flea or chewing dog louse acts as the intermediate host within the life cycle, with dogs and cats commonly infected following ingestion of these insects as they groom.

Adult tapeworm develops in the small intestine of dogs and cats. This tapeworm is zoonotic and can also infect humans if ingested, although this is rare. It is rare that symptoms of this tapeworm are seen – most commonly owners will see white segments resembling white rice grains in their pet’s faeces or on the coat around the anus.

Taenia spp. can infect dogs, cats and foxes following ingestion of intermediate hosts, and again is commonly be seen in Europe. Intermediate hosts can include sheep, cattle, rodents or rabbits. Infections of these tapeworms do not generally result in clinical signs, however mature mobile segments may be seen around your pets’ anus or in their fur. You might also notice your pet rubbing their bottom along the floor more often.

Heartworm (Dirofilaria immitis)

This is a threadlike worm which lives in the pulmonary arteries of the heart in dogs and cats. They are commonly seen in Southern or South East Europe, so preventative measures are particularly important for animals who travel. This also helps minimise chances of the disease coming back to Great Britain.

Mosquitos are involved in the life cycle of Dirofilaria immitis, passing infection on as they feed from the host. Infections can be severe and potentially fatal, however low worm burdens can be asymptomatic. Where numbers increase, symptoms may include weakness, dyspnoea, and coughing.

French Heartworm (Angiostrongylus vasorum)

Angiostrongylus vasorum is a nematode, and is often referred to a Fox Lungworm. Dogs become infected through ingestion of intermediate hosts such as slugs and snails, or from food infected with slime from those slugs and snails. If ingested, female worms will begin to produce eggs that hatch rapidly, and the larvae will penetrate the lungs via blood circulation. Larvae are coughed up or swallowed passing through faeces of infected animals, or move as adult worms to the liver and into the pulmonary arteries of an infected animal.

Clinical signs can be variable, but can include coughing, dyspnoea, gastrointestinal symptoms, or bleeding disorders such as melaena or prolonged bleeding. Some cases can be fatal.

Hookworms (Ancylostoma spp.)

Ancylostoma caninum (in dogs) and Ancylostoma tubaeforme (in cats)are small nematodes that can be identified by their large mouth piece, commonly known as hookworm.

Adult worms will live in the small intestine and their life cycle will happen there. The adult worms lay eggs, which will pass in the faeces and over a period of two to three weeks mature into adults in the environment. Hookworms are most commonly transmitted via milk from the mum to the puppies.

Common signs can include weight loss and diarrhoea, while severe burdens may cause anaemia.

Whipworm (Trichuris vulpis)

Whipworm is a nematode that affects the large intestine. Whipworm eggs are passed in the faeces of infected dogs, which then developed to larvae within one to two months depending on the environmental conditions. Larvae can survive in the environment for years and infected dogs can continue to shed eggs for up to a year. Heavy burdens may result in diarrhoea or mucousy faeces.

Our team at your independent veterinary practice, Milton Keynes Veterinary Group, are always happy to support you to provide the best parasitic plan for your pet. Additionally, we also have our Healthy Pet Care plan which provides all the required parasitic control to prevent these parasites.