Worms can be a common problem for dogs, and, without preventive treatment, most will catch them at some point throughout their life.
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What are worms?
Worms are parasites that live inside the body and are caught when a dog accidentally eats their eggs or larvae.
What different types of worms do dogs get?
There are many types of worm that can affect dogs in the UK, the most common are:
Roundworm
Roundworm are the most common type of worm and probably look most like people expect worms to. They are white, can grow up to 15cm long, and look like spaghetti or noodles. It’s rare to see them, unless a dog is very heavily infested.
Roundworm ‘Toxocara canis’ can also rarely infect humans and cause an illness called ‘Toxocariasis’ – this is especially risky for children.
Tapeworm
Tapeworm are very long worms that attach themselves to the wall of the gut. They look like flat ribbons made up of lots of little segments and can grow up to 50cm long! If your dog has tapeworms, you might see worm segments (which look like grains of rice) crawling around their bottom.
They rarely cause serious illness in adult dogs, but can be more serious for puppies. Although it’s rare, certain types of dog tapeworm can cause disease in humans called ‘Echinococcosis’.
Lungworm
Lungworm is a parasite that can cause severe illness and even death. Dogs catch lungworm by eating infected slugs and snails, which often happens by accident whilst eating grass or drinking outside.
Despite its name, it actually travels around the whole body and can cause breathing difficulties, heart failure, seizures, bleeding disorders, and even death. It’s important and easy to prevent lungworm by making sure your dog’s normal de-worming regime also includes lungworm protection.
Less common are threadworm and whipworm - these are both relatively rare in the UK.
How do dogs catch worms?
Many puppies catch roundworm from their mother in the womb (so are born with them), or through their mother’s milk. Adult dogs catch roundworm most commonly by eating soil and poo contaminated with microscopic worm eggs passed by other dogs.
Dogs most commonly become infected with tapeworm by eating fleas (usually during grooming), so flea control is an important part of preventing these worms. They can also catch them by eating raw meat, rats and mice, or the carcasses of other animals such as sheep.
Symptoms of worms in dogs
Most of the time, adult dogs who have round or tapeworms will not have any symptoms at all. Problems are more commonly seen in puppies.
Roundworm symptoms
- Weight loss
- Diarrhoea
- Vomiting
- Poor growth in puppies
- Pot-belly and bloating (most common in puppies)
- Life-threatening blockage of the intestines (severe cases)
Tapeworm symptoms
- Scooting or excessively licking anus (bottom)
- Weight loss
- Itchy skin due to concurrent fleas
Lungworm symptoms
The symptoms of lungworm can be difficult to spot because they are often very vague and varied. They tend to vary depending on how many worms your dog has inside them and which organs they reach. Common lungworm symptoms can include:
- Coughing
- Breathing problems (fast, heavy, noisy)
- Weight loss
- Unexplained bruising and bleeding
- Seizures
- Collapse and shock
- Blindness
How to find the best dog dewormer for your dog
1. Ask your vets which worms to treat your dog for and how frequently - this will depend on their age, lifestyle and where they live in the UK.
2. Buy a prescription wormer that is effective against all the worms you need to treat. Prescription wormers can only be bought from a vet, or an online pharmacy (using a prescription from your vet), but are generally more reliable than non-prescription products. There are currently no lungworm preventives or treatments available without a prescription.
3. If for any reason you aren’t able to buy a prescription wormer, and need to use a non-prescription wormer, choose one carefully because they vary a lot.
4. There are two main types of non-prescription worming products: ‘NFA-VPS’ products and ‘off the shelf’ products.
- ‘NFA-VPS’ products can only be sold by a specially qualified person who will ask you some questions about your dog (this could be a pharmacist or a specially qualified shop assistant). You can also buy NFA-VPS products online by filling out a form that will be checked by someone before they send the product. ‘NFA-VPS’ products tend to more dependable than ‘off the shelf’ products.
- Off the shelf’ products can be bought without speaking to anyone, or answering any questions about your dog, for example in a supermarket. Products you can buy without a prescription are not veterinary licenced and often contain less effective ingredients.
Home remedies for worms are very unlikely to work – it’s always best to use a treatment with proven ingredients.
The treatment or preventive options for worms depend on whether you’ve got a puppy or an adult dog:
When should puppies be wormed?
Worming puppies is essential for the first few months of their life and should be done regularly.
As a general rule, their treatment should start at around three weeks old and be repeated every two - three weeks until they are 16 weeks old. However, check this with your vet because each product has its own treatment frequency guidelines.
Make sure to use a worming treatment suitable for your puppy’s age and weight as they grow.
How often should adult dogs be wormed?
It’s not possible to stop your dog picking up worms completely, but you can prevent any problems developing by worming them regularly - every one to three months is usually enough.
More frequent worming may be necessary if your dog scavenges or hunts a lot.
Remember to protect your dog against lungworm as well as intestinal (gut) worms.
What to expect after treating your dog for worms?
It’s likely that you won’t see anything after treating your dog for worms - unless they had a particularly heavy infestation, in which case you may see dead worms in their poo. Contact your vet if your dog seems unwell or has diarrhoea after a worming tablet.
Can you do faecal worm egg counts for dogs?
Regular testing of dogs’ poop for worm eggs can sometimes be done as an alternative to preventive treatment.
However, unlike in horses, the worms that dogs carry will only shed their eggs intermittently, meaning that not every poop passed will contain them, so this approach may not be suitable for dogs who are at high risk of infection. Speak to your vet about whether regular fecal testing could be suitable for your dog.
Can dogs get worms from other animals, like your cat?
If you have other pets, such as another dog or a cat, then it is possible that they could get worms, too, if your dog has them. You should make sure you treat all animals in your house for worms regularly.
Do not use cat worm treatments on dogs and vice versa. Your vet will be able to provide the appropriate treatment for each pet in your home.
Can humans catch worms from dogs?
It’s very rare for humans to catch worms from a dog, but it does occasionally happen. It’s most common in young children who have been playing in areas where dogs have toileted, such as areas in your garden or local parks. If you have small children, it is very important to deworm your dog regularly.
It’s also important for all dog owners to always pick up their dog’s poop and dispose of it correctly – It takes time for worm eggs to become infective after being passed, so clearing poo quickly will help to reduce environmental contamination.
If your dog has worms, there is a chance there could be worm eggs around your home, as the eggs can survive in the environment for a long time. Get your dog treated as soon as possible to make sure they are clear of worms.
Thoroughly clean all of your dog’s bedding, and favourite spots, such as blankets or sheets they may have touched. You may also want to steam clean flooring at home to kill off any remaining eggs.