How often should I deworm my adult dog?

Adult dogs should only be dewormed if it has been established that your dog has worms or if you strongly suspect it.

Symptoms that the dog may have worms

  • Diarrhoea
  • Weight loss
  • Dry or dull coat
  • Vomiting
  • Cough

Adult worms can sometimes be seen in your dogs faeces or vomit, but usually worms must be diagnosed via the detection of eggs in the faeces.


Try to only deworm against the type of worm your dog has to reduce the risk of resistance in the parasites. Weigh your dog before you go to the pet store to buy dewormers because the dose it should have depends on how much it weighs. If your female dog has had puppies, both she and the puppies must be dewormed with a suitable agent and at suitable intervals. Feel free to ask for advice from the pet store or your veterinarian regarding which preparation is best to use.

Various dewormers for dogs

There are both prescription and over-the-counter dewormers for dogs available. Some tablets and pastes should only be given once, others more than once. If you have difficulty getting medicine into your dog orally, a prescription spot-on preparation that is dripped onto the skin can be an alternative. Consult a veterinarian or a pharmacy to get help finding the preparation that suits your dog best.

Deworming of puppies

The breeder will usually deworm the puppies routinely before you get your puppy home. Puppies are dewormed against roundworms and depending on which preparation you have chosen to use, the number of dewormings and when the last de-worming is done can differ slightly. Check with your breeder that your puppy has received all doses, or if you need to give the last dose yourself.

Deworming in connection with travel

There may be rules depending on where you are travelling from or to regarding worming your dog.

Stool test/strain test

If you are unsure whether your dog needs to be dewormed, you can consult a veterinarian. You can also buy a kit intended for taking your dogs stool samples. The sample is sent to a laboratory that analyses it to discover if your dog has worms and what kind of worm it is.

Transmission routes

Puppies can be infected by worms already in the foetal stage but also through the milk during the first weeks of life. That is why puppies are regularly dewormed their first time in life.

Adult dogs are most often infected through something they eat, such as infected small rodents, or by ingesting worm eggs from their surroundings.

What are the most common intestinal parasites in dogs?

The most common intestinal parasites in dogs are roundworms, tapeworms, hookworms, coccidia, Giardia and lungworms. 

Frequently asked questions about deworming