Worms are little wrigglers that are more than just a nuisance. They can kill pups and make adult dogs really unwell. Dog owners need to be particularly aware of the danger of worms and how to prevent them.

Dogs can become infected with four different types of worms, namely hookworms, roundworms, tapeworms and whip-worms. There are several different varieties in each type. In northern Australia, the hookworm is a major disease risk.

Dogs can become infected with four different types of worms.

How do you know if your dog has worms?

Regretfully, you may not know your dog has worms until it is sick. In puppies, a worm infection can cause a life threatening condition to develop quickly.  Contrary to common belief, it is not common to see worms in a dog’s or puppy’s droppings under normal circumstances. Under a heavy load, a roundworm may be passed, and but this indicates a significant problem.


With hookworms in young pups you are likely to see soft tar-like faeces that develop into diarrhea, usually with blood staining. The blood loss in puppies can be extreme and a serious anemia is a common, fatal side effect. Hookworms are quite small so it is not common to see hookworms in the animal’s droppings after proper treatment.


Roundworms are a big worm, measuring up to 18cm in length. They are a particular problem in puppies as they are spread to them while they are in the mother’s uterus. Thus, pups can be born with a roundworm infestation.

Roundworms cause diarrhea, sometimes with blood staining, and can commonly cause a blockage of the bowel due to their large size. Affected puppies have a ‘pot-bellied’ appearance and a rough coat. Such puppies are often ‘poor doers’.

After treatment, it is common so see several of these large roundworms in the animal’s droppings.

Roundworms cause diarrhea, and can commonly cause a blockage of the bowel due to their large size.


Tapeworms are a common problem in dogs. Surprisingly, although they are quite big – up to half a meter long, they cause only mild disease. They are one, but not the only, cause of ‘scooting’ behaviour of dogs. This unusual behaviour is where a dog rubs its bottom along the ground. The irritation is due to the emergence of tapeworm segments from the dog’s anus. The segments are easy to identify. They are the size of a rice grain and are quite active. They will wriggle visibly and can be seen with the naked eye on the dog’s droppings or on its fur around its bottom. By continually ‘scooting’, a dog will occasionally cause a lot of self-inflicted irritation around the skin of its anus.

A rare tapeworm, the Spirometra worm, is contracted by dogs and cats eating insects, grubs and other animals.


The last worm, the Whip-worm, is a medium size worm that affects the lower bowel of dogs. It again causes diarrhea which characteristically contains mucus and often some fresh blood.

So what do you need to do if you think your pup has worms?

Worms can be eliminated with common worming medications that are available from your veterinarian or pet shop. Be sure to choose a medication that will treat all four worms that your pup can be affected by. However, if your pup is already unwell, it may need other medication to control any diarrhea that is present and to build up reserves of, for instance, iron that may be depleted from continual blood loss. For advice on this, you should consult your veterinarian.  Your vet’s advice should certainly be sought if your pup is weak and lethargic or if it is vomiting and you suspect is has a worm infestation.

Preventing worm infestations

Preventing worm infestations is a very important matter. Puppies under three months of age, should be wormed every two weeks from two weeks of age onward. There are various  worming suspensions that are ideal for puppies of this young age.

Once the pup reaches three months of age is it advisable to worm it every month until it is six months old and thereafter it should be wormed every three months.

Many owners place their dogs onto a monthly heart worm medication that also contains an intestinal worming medication. This is a good idea and the dog is wormed for the common worms every month. However, you need to be certain that the monthly product you are using does treat all worm species that can be present.

If you are using a monthly product to control heart worm and intestinal worms, it is still important you use an all-wormer tablet at least once every six months and many vets advise an all-wormer is used every three months.

There are so many alternatives when using worming preparations for your dogs and cats to to ensure you are getting it right, consult with your veterinarian.

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Dr Cam Day

Dr Cam Day

Vet Behavioralist

Dr Cam Day is a Veterinarian consulting full-time in pet behaviour in South-East Queensland, Australia.