How Often Should I Treat My Dog or Cat for Fleas and Worms
Most pets need protection against fleas and worms throughout the year, but the exact schedule can vary depending on your pet’s age, lifestyle and the type of product used.
Some treatments are given monthly, while others last longer. Your vet can advise on the most appropriate parasite prevention plan for your pet.
Written by Gill Burkhill, Veterinary Surgeon, Animal Trust Vets CIC | Published April 2026 | Review date April 2029 | This advice is for UK pets only and is not a replacement for seeing a vet
Flea Prevention for Cats and Dogs
Most dogs and cats benefit from year‑round flea prevention. Flea treatments are often given monthly, although some products provide longer protection.
Even pets that spend most of their time indoors can still develop flea infestations. Fleas may be carried into the home on clothing, other pets or visiting animals, and once established they can quickly spread in carpets, bedding and furniture.
Regular flea control helps prevent skin irritation and allergic reactions. It also helps prevent tapeworm infections, as pets can become infected if they swallow fleas while grooming.
Worm Prevention for Cats and Dogs
Worming frequency depends on your pet’s age and lifestyle risk factors. Some pets may only need treatment every few months, while others benefit from more frequent protection. The most common worms affecting dogs and cats in the UK include roundworms and tapeworms. Dogs can also be affected by lungworm caused by Angiostrongylus vasorum.
Puppies and kittens
Young animals are more vulnerable to worm infections. Typical guidance includes:
Worming every 2–3 weeks until around 12 weeks of age
Then regular treatment until 6 months of age
Your vet will advise on the most appropriate schedule and products for your pet.
Adult dogs and cats
Adult pets are typically wormed every 1–3 months depending on their lifestyle and parasite risk. Pets that hunt, scavenge, or spend a lot of time outdoors may require more frequent treatment.
Factors That Affect Parasite Risk
Some pets have a higher risk of exposure to parasites than others. Factors that may increase risk include:
Outdoor access, particularly in areas with wildlife
Hunting behaviour, such as catching rodents or birds
Eating faeces or scavenging carcasses
Swallowing infected fleas, which can transmit tapeworms
Contact with other animals in kennels, catteries or dog parks
Raw feeding – feeding raw or undercooked meat may increase exposure to some parasites, so careful parasite prevention may be advised
Dogs may also become infected with lungworm by swallowing slugs or snails or encountering their slime in outdoor environments.
Signs Your Pet May Have Parasites
Signs of parasites can vary depending on the type involved, but may include:
Weight loss
Worms or worm segments in faeces
Scooting or irritation around the tail
Poor coat condition
Persistent coughing in dogs
If you notice any of these symptoms, it is best to speak to your vet.
Veterinary Advice on Parasite Prevention
Parasite control works best when it is tailored to your pet. Your vet can recommend the most suitable products and treatment schedule based on your pet’s age, health and lifestyle. Regular prevention helps protect your pet’s health and can also reduce the risk of some parasites that may occasionally affect people.