Roundworms in dogs

Roundworms are the most common parasitic worm affecting dogs in the UK and they’re picked up remarkably easily by our pets. In fact, almost all dogs will become infected with roundworm at some stage in their lives although they're most common and most serious in puppies. This parasite can also affect you and your family so it’s important to know what you´re up against.

The problem is – you might not know your dog has them!

What are roundworms?

Roundworms are one of the most common types of worm found in dogs. Living in the dog's small intestine, a roundworm looks like a piece of spaghetti – long, white, and cylindrical, with both ends tapering to a point. These worms can affect any breed of dog, at any age, though they are most common in puppies.

How do dogs get roundworms?

Almost all puppies are born already infected, as the parasite can pass across the placenta from the bitch to her unborn pups, and roundworms can also be transmitted via the mother’s milk.

Adult dogs are easily infected too, via:

their environment - roundworm eggs are passed out in the faeces of infected dogs and, depending on the worm burden in the dog, a single gram of dog poo may contain thousands of eggs!
These eggs can survive in the soil for several years and can reinfect your dog or other dogs if swallowed. Once swallowed the eggs develop into worms in the dog’s intestines. This is why it is so important to pick up dog poo wherever you are – in gardens, parks and even in the countryside. Unfortunately it is almost impossible to pick up every trace of poo every time
hunting or scavenging - if a dog eats a rodent, bird and other small animal that's been infected with the larval stages of either round and tapeworms, they can then become infected. Feeding raw meat or some types of raw diet can also transmit both round or tapeworms.

The signs of roundworms

Adult dogs often won’t show signs of a roundworm infection but diarrhoea and vomiting do occur in some cases.

However, roundworms can be extremely serious in puppies and in severe cases where puppies are affected by large numbers of worms, they can even be fatal. Key signs to look out for:

vomiting and diarrhoea: puppies may sometimes vomit up whole worms, or pass them out in their stool - diarrhoea is a common sign.
poor growth and poor condition: puppies with roundworms often show signs of poor growth and may be small for their age; they can also have a pot belly and their coat may be dull and in poor condition.
coughing: the larval stage of the roundworm parasite migrates through the lungs in very young puppies and this can lead to pneumonia and a cough.

If you see any of the above symptoms, it’s important to consult your vet as they can also be indications of other health issues that may need to be dealt with.

Risks of roundworms to humans

It is actually possible for people to also become infected with roundworms if we accidentally swallow roundworm eggs. Usually our immune system will step in and tackle the problem but in some cases, the larvae of the parasite migrate within our bodies. If the larvae end up in the eye (a condition called ocular larva migrans), it can lead to blindness. This condition, called toxocariasis, is rare but is obviously extremely serious when it does occur and is one of the reasons why it’s so important to regularly treat your dog for worms.

How do you treat roundworms in dogs?

Fortunately, worming treatments that can kill roundworms in dogs and puppies are available. Speak with your vet for advice on which wormer will suit your pet best and how often it should be used.

Other measures to reduce the risks

Good hygiene is important, too: wash your hands after playing with your dog and before mealtimes, and clean your dog’s bedding, blankets and food bowls regularly. It's also really important to make sure all your pets are treated regularly for fleas and worms.