Worms in dogs

Worms in dogs

A dog with a pot-belly, an out-of-condition, skinny puppy or even a perfectly healthy looking animal – all these pets can be suffering from intestinal worms.

The most common types of intestinal worms found in both dogs and cats include roundworms, hookworms, whipworms and tapeworms. Symptoms can vary depending on whether the affected pet is a cat or dog, what kind of worm they have contracted, as well as how extensive the infestation is. Sometimes, there are few or no symptoms – which makes preventative treatment the best course of action.


Roundworms can be hard to detect as they can lay dormant, appearing in times of stress or during a host’s pregnancy, when they activate to infest the dog's offspring in the uterus. Larvae can also be transferred to nursing puppies through feeding. Roundworm eggs are eliminated in the faeces and vomit. They have a hard shell, which allows them to exist in the environment for years, until, if they are ingested, they infest other dogs as well as cats. Symptoms include lethargy, coughing, vomiting, abdominal swelling and pain, weight loss, and dead roundworms (which look like short spaghetti) in the stool.


Whipworms shed relatively fewer eggs, making them difficult to detect in the stool, even when examined by a vet. Occasionally, adult whipworms appear in the faeces – they are small and threadlike, with one larger end. Symptoms include chronic weight loss, diarrhoea and mucus in the stool.


Hookworms are the most dangerous of the intestinal worms. Like roundworms, dogs can become infected in the uterus, through nursing, through the skin or by ingesting eggs in the environment. The hookworms feed on the blood of the host by attaching to the intestinal lining. They produce a substance that prevents blood clotting, and can cause anaemia when they move from place to place, leaving bleeding wounds. Symptoms include a poor appetite, unhealthy appearance, pale nostrils, lip and ear linings, and possibly dark stools, diarrhoea and constipation.


The transmission of tapeworms is usually through dogs and cats hunting and eating birds and rodents that have tapeworms or fleas, or from the ingestion of fleas through grooming. So, to prevent tapeworms, it's important that you're diligent with flea treatment. Fleas act as an intermediary host for the tapeworm, eating the tapeworm eggs when in the larval stage. Then, during grooming or in response to a flea bite, the tapeworm-infected flea can be ingested by your dog, and the tapeworm’s life cycle is completed. Tapeworms grow to 10-15cm in length, and are made up of segments, which can break off – this is usually how their presence is discovered. The segments look like grains of rice and may be present in the stool or area around the anus. Infected pets will also display symptoms of an itchy behind – scratching or biting at the area, or ‘scooting’.

Treatment and Prevention

Use an all wormer (such as Aristopet™ All Wormer tablets for canines) and follow the instructions on the pack. If you think your dog has tapeworm, you’ll also need to treat for fleas. As worms can be spread to humans, you’ll want to make sure that you take preventative measures as well. For your canine companion use a wormer regularly (usually every three months), and practice good stool hygiene – remove dog faeces from your garden regularly and always have a poo bag handy when out with your dog. If you also have a cat, make sure litter boxes are cleared regularly. Flea prevention is also important, and children should be encouraged to wash their hands thoroughly after handling pets.