Parasite control is often referred to as a “parasite vaccine”. It is worth correcting that: parasites are not prevented by a vaccine. They are prevented and treated by antiparasitic medication given at intervals, because the protection wears off and reinfection is always possible.

Internal parasites

Roundworms. The most common intestinal worm in dogs. Puppies are very frequently infected from their mother, before birth and through her milk, which is why puppies are wormed from a very young age and repeatedly. A heavy burden produces a pot bellied puppy with a dull coat, vomiting and diarrhoea.

Roundworm larvae can infect people, particularly young children, and in rare cases migrate to the eye. This is the main reason regular worming matters in households with children, and the reason for picking up after your dog.

Tapeworms. Usually acquired by swallowing an infected flea while grooming, or from raw meat and offal. Rice grain segments may be seen around the anus or in bedding. Treating tapeworm without treating fleas lets it return.

Hookworms and whipworms, causing diarrhoea and in heavy burdens anaemia.

Echinococcus, a tapeworm of real public health importance in Türkiye, acquired by dogs eating raw offal from sheep and other livestock, and capable of causing serious cystic disease in people. Do not feed raw offal, and worm dogs with access to livestock areas on the schedule we advise.

Giardia, a protozoan causing persistent diarrhoea, particularly in puppies and in dogs drinking from standing water.

External parasites

Fleas. The most common skin parasite and a leading cause of allergic skin disease. The adults on the dog are a small fraction of the population; eggs, larvae and pupae are in the carpet, the bedding and the car.

Ticks. Picked up in grass and scrub. They transmit disease, so prompt removal matters. Use a proper tick hook and twist rather than pull, and never use a lit match, alcohol or petroleum jelly, all of which make the tick regurgitate.

Mange mites, sarcoptic and demodectic, covered in their own article.

Ear mites, causing dark crumbly discharge, head shaking and scratching.

Lice, uncommon and usually in neglected or weakened animals.

How often

There is no single schedule. It depends on:

Whether the dog scavenges or hunts
Access to livestock areas and to standing water
Whether there are children or immunocompromised people in the household
Other animals in the home
Season and region, though in heated homes fleas persist year round

We set the interval for your dog rather than applying a default.

Doing it properly

Weigh the dog and dose to its actual weight; underdosing is a common reason treatment appears to fail. Treat every animal in the household on the same schedule. When treating fleas, wash bedding hot and vacuum thoroughly, including the car. Keep to the interval, because a late treatment leaves a gap.

One warning

Never use a dog product on a cat. Spot on treatments for dogs containing permethrin cause tremors, seizures and death in cats. If you have both, keep the treated dog away from the cat until the application has dried.