Worms in dogs and puppies are very common, and whilst they might be a concern to owners, they do not usually have serious consequences and are easy to treat.

Our guide contains expert advice from qualified and registered veterinary nurses to help you choose the best course of action for your pet and help answer your question – does my dog have worms and how do I prevent and treat them?
Symptoms of worms & common causes of worms

Symptoms and presenting signs

  • Sickness
  • Diarrhoea
  • Pot belly in puppies
  • Weight loss
  • Poor coat quality
  • Weakness
  • Loss of energy
  • Sore bottom
  • Coughing (lungworm)
  • Wheezing (lungworm)
  • Shortness of breath (lungworm)

Worms in dogs are very common, with the most frequently seen intestinal types being roundworms and tapeworms. Worms can be picked up in a variety of ways.

Common causes


  • Swallowing larvae from mother’s milk
  • Eating dead animals or killing animals outside and eating them
  • Having fleas and swallowing them whilst grooming
  • Picking up worms or larvae from faeces whilst outside
  • Contact with or swallowing slugs or snails (lungworm)

Tapeworms are transmitted to dogs by fleas. Immature fleas (larvae) ingest the worm eggs and infection is passed on to a dog when it swallows an infected flea. This is one of the reasons why it’s important to treat your dog for fleas as well as for worms.

Roundworm larvae start by infecting a dog’s intestinal tract, but they can burrow their way into other tissues and organs. As toxocara canis larvae mature, they will move onto the lungs to develop and then then up to the airway before being coughed up and swallowed again, returning to the intestine to complete their lifecycle. Toxascaris leonina do not move around the body and have a far simpler lifecycle.

  • Worms in older dogs

Adult dogs can get worms from other infected animals, scavenging dead animals which might carry worms or infected parasites such as fleas, or from eating the larvae or eggs of worms outside, for instance by eating grass.

  • Worms in younger dogs

Puppies can inherit infection from their mother, as well as from ingesting larvae in their mother’s milk

Triage of worms in dogs and puppies

As noted above, the types of worms found in dogs can be wide ranging.

At PetGP our UK based veterinary nurses follow strict guidelines laid out by our veterinary director and ask a series of questions that determine the relative seriousness of your pet’s condition.


This process will hopefully rule out the more serious cases (which must be dealt with by a vet) and leads to advice on what you should do next for your pet. If appropriate, our experienced and knowledgeable veterinary nurses will give advice relevant to your pet’s condition based on your answers.

  • Our UK based Registered Veterinary Nurses will ask you several questions designed to assess (triage) the condition
  • You will need to be with the dog as we will ask you to check a few things while you are on the phone to us
  • We will ask if you how long the dog has had the symptoms for
  • We will ask if you have seen any obvious evidence of worms

Call us at PetGP on 0333 332 7883or visit https://pet-gp.co.uk/ if you are unsure or worried and our expert nurses will advise you on what to do next. If the situation does not merit a trip to the vet, we will give advice for managing the situation at home.

If the situation is more serious we will advise that you contact your vet.
Diagnosis of worms by your vet

Your vet will give your dog a thorough examination and take a full history from you.

Most healthy animals will not show any symptoms of worm infection. Puppies with a heavy worm burden may be sick and this may contain roundworms. In severe cases they may have a pot belly due to the sheer number of worms. Worms are sometimes seen in faeces or around the dog’s bottom – tapeworms resemble flat grains of rice and can sometimes be seen moving around this area. There are two species of roundworm which can affect dogs, toxocara canis and toxascaris leonin. Both are long, white and spaghetti-like in appearance and they absorb nutrients from the infected dog. If you have found any worms it’s very helpful for the vet to see them so they can identify the type.

More serious cases in canines can produce signs of worms such as weight loss, poor coat, weakness, excessive hunger, loss of energy and diarrhoea and sickness. A dog with worms may eat more than usual, but still lose weight and where the diarrhoea is severe it can cause the dog’s bottom to become sore. If a dog has a bad reaction to the worms and there is diarrhoea or sickness, simple foods such as rice with chicken or white fish can help to settle the stomach, and fresh water should always be provided, but the most important thing is to use a worming treatment to get rid of the infestation.

The specific symptoms of lungworm include coughing, shortness of breath, wheezing, open-mouthed breathing, lethargy and exercise intolerance, reduction in appetite and fever. Lungworm can be extremely serious – It can cause haemorrhages in the lungs, liver, intestine, eyes and spinal cord but also just about anywhere in the body. If left untreated, it can be fatal in severe cases. Lungworm can be treated with spot-on treatments or tablets, which should be prescribed by your vet to ensure that an appropriate product is used.

If your dog has shown any of these symptoms they should be reported to your vet, and your information together with the vet’s clinical examination will be vital in making sure the correct treatment is given.

Treatment of worms

The treatment of the condition will depend partly on the vet’s diagnosis, but worming should be done regularly regardless of symptoms as a preventive measure.

Forms of treatment that can be managed at home could involve:-

  • Tablets
  • Powders
  • Chews
  • Pastes
  • Spot-on treatments

Prevention of worms

You need to worm your dog regularly even if you haven’t seen any symptoms of worms, to kill the worms that are present and prevent reinfection.
Exercising good hygiene precautions is very important, particularly with children, who should be taught not to share food plates with the dog and to wash their hands after stroking or playing with him or her. Provided you worm your dog regularly, and clean up faeces after your dog, any risks should be kept to a minumum. If you have children it is also a good idea to fence off a separate part of the garden where they can play but where your dog is not allowed in.

If you need further advice, why not visit us at PetGP.

or telephone the PetGP nurse on 0333 332 7883

Frequently asked questions about worms in dogs
Does my dog have worms?

Dogs do not always show symptoms of worms, but if you notice any signs such as eating more than usual, poor coat quality, sickness or diarrhoea, or you see any worms in your dog’s faeces or around their bottom, then you will know that they have worms.

Why do dogs get worms?

Dogs can pick up worms from a variety of sources, from their mother’s milk as puppies, from eating dead animals or prey when outside, from having fleas which carry worm larvae, and in the case of lungworm, from contact with slugs or snails.

What causes worms in dogs?

Worms in dogs are picked up in lots of different ways, as mentioned above, but it doesn’t mean that your dog is unhealthy or has bad habits!  Don’t forget, treatment for worms is usually very straightforward, and prevention is often better than cure.

Can you catch worms from dogs?

It is possible to catch worms from your dog, the commonest being roundworm and one particular type of tapeworm. This is why it’s very important to exercise good hygiene after petting your dog and to make sure that he or she is wormed regularly to prevent infestation.

There is also a risk from toxocara, which may be found in faeces if not picked up by the dog’s owner. The toxocara canis eggs are ingested accidentally by someone – they won’t develop into adult worms, but will nevertheless become larvae that may travel around the body to the lungs, liver, and sometimes the eyes, where they can cause impaired or even complete loss of vision.
What do dog worms look like?
Tapeworms look like flattened grains of rice joined together. You may see segments of tapeworm around your dog’s bottom – they break off and can sometimes be seen moving outside the dog’s body.

Roundworms resemble spaghetti with tapered ends and are long and often curled around. You may see these in vomit, particularly in puppies.
How do you treat worms in dogs?
Some of the tablets, powders and pastes can be given in dog food or treats, others may need to be given directly into the mouth, again you will need to follow instructions. Your vet or a veterinary nurse at your practice may be able to administer a worming treatment for you if you are not confident of doing it effectively. Some wormers are not recommended for certain breeds of dog, and so the advice of your vet in helping you select the right product can be very helpful.

How do I tell if my dog has worms?

Any of the symptoms already mentioned, including excessive hunger, vomiting and diarrhoea, poor coat quality, finding live worms, or sometimes your dog may scoot along on his or her bottom.
How to worm a dog
Worming should be carried out regularly, following the instructions given by a vet or on the pack if supplied elsewhere. Treatments range from tablets, powders, pastes or chews to spot-on treatments applied to the back of the neck between the shoulder blades. It’s important to treat your dog for worms according to the manufacturer’s or your vet’s instructions to help prevent infestations and to kill the worms that are already there.

Some of the tablets, powders and pastes can be given in dog food or treats, others may need to be given directly into the mouth, again you will need to follow instructions. Your vet or a veterinary nurse at your practice may be able to administer a worming treatment for you if you are not confident of doing it effectively. Some wormers are not recommended for certain breeds of dog, and so the advice of your vet in helping you select the right product can be very helpful.

My dog is showing symptoms of worms.
If you notice any symptoms of worms in dogs or you have seen worms in your dog’s faeces or vomit, you can call us at PetGP to discuss the symptoms on 0333 332 7883.

My dog is coughing and seems very tired after exercise.

Another type of worms in dogs that is on the increase in the UK is lungworm, which dogs can catch from coming into contact with slugs, snails or frogs – some dogs may have a habit of picking up and sometimes swallowing them. Parasites within infected slugs and snails that are eaten by a dog develop into adult worms, which live in the heart and arteries of the lungs; larvae that are passed out in the dog’s faeces are eaten by other slugs and snails and so the cycle continues.

If you notice your dog is coughing or wheezing and is lethargic and easily tired, it’s vital to contact your vet as these may be symptoms of lungworm or another serious illness.
What other types of worms might be dog be at risk of catching?

Hookworms are not common in the UK but they are found in Europe. They are short, blood sucking parasites with teeth. They can be fatal in young puppies, due to the amount of nutrients they can extract from the dog.  Hookworms have a very similar lifecycle to the toxocara canis roundworm, moving about the body and into the lungs to mature before returning to the intestine.