Worms in the digestive tract of our pets

Intestinal worms are classified into two main groups: cestodes, or flatworms, and nematodes, which are round.

Flatworms

Dypilidium caninum is the most common cestode in dogs and cats. Infestation occurs when a flea carrying the parasite in its larval stage is ingested (by licking or biting the coat). This larva then develops in the small intestine of the final host, to become a flatworm several tens of centimetres long. It consists of a kind of head, called a scolex, which has four suckers and a retractable rostrum with hooks, as well as a chain of rings containing the eggs. These rings are detached one by one and eliminated through the anus. These are generally quite easily recognisable at the anal margin, in the form of melon seeds, or even grains of rice if they have dried out. Although these are relatively harmless, they are annoying for infested animals as they cause anal pruritus. Your dog or cat, if it is a carrier, may bite its hindquarters or “do the sledge sign”.

Taenia taeniformis is the second most common flatworm in cats, after Dypilidium caninum. It mainly affects hunting animals as the intermediate host is the mouse. In the adult stage, this worm is not less than 60 cm long. Taenia saginata, unduly called tapeworm, can measure up to 15 metres! It is strictly specific to humans, and therefore cannot infest our four-legged friends.

Roundworms

Toxocara has several species. T. canis, also known as the “dog roundworm”, is the most common parasite of this species, and is found all over the world. This white worm lives in the anterior part of the small intestine and measures 9 to 17 cm. It is found in balls, and these balls usually look like spaghetti! Puppies are frequently infested. When it affects humans, T. canis migrates to other organs. T. leonina is somewhat smaller, affects cats and dogs, and does not migrate outside the digestive tract. T. cati, on the other hand, mainly infests cats and is only 5 to 10 cm long.

How can I protect my pet ?

A dewormer is a medicine that fights intestinal parasites and worms. This medicine is not remanent, which means that it is only active at the time it is taken. Regular and systematic deworming, even if there are no symptoms of parasitism, helps to protect the dog or cat from an early age and to avoid human contamination. Talk to your vet about it.

For more information:

ESCCAP (European Scientific Counsel Companion Animal Parasites) is an independent, non-profit association that writes and disseminates recommendations for the treatment and prevention of the major internal and external parasites of pets: intestinal worms and advice on deworming.