How often do cats and dogs need worming?

How do we know when we should be worming our dogs and cats in the UK?
There are so many different factors to consider and a range treatments available on the market. It can be hard to know where to start, especially for new pet parents!
You can walk into a general pet shop and buy worming medications with no guidance from a professional, stroll into a pet store and receive suggestions from an experienced salesperson, or visit veterinary practices for expert advice and prescription-only medications.
Many vet practices offer monthly health plans, including prescription flea and worm medications, strongly advising lungworm protection.
We've also seen the rise of monthly subscriptions from online companies supplying regular general medications, not including lungworm protection with non-prescription treatments.
So how do we know what to use, how often and which are the most effective for our pets?
Overuse of wormers can have a detrimental effect on the environment. There has been growing concerns regarding parasiticides reaching rivers via wastewater of homes or animals entering rivers.
Parasiticides can also be excreted through urine and faeces, causing them to absorb into the soil. There is a risk of drug resistance in worms and adverse effects in pets and even humans who handle the products.
There is also the financial cost to the pet owner to consider.
The British Veterinary Association actively encourage vets to use a risk assessment for the use of parasiticides. (Responsible use of parasiticides for cats and dogs | British Veterinary Association (bva.co.uk).
“Veterinary professionals should always take a risk-based approach to prescribing medicines, including parasiticides. They should avoid blanket treatment, and instead risk assess use of parasiticides for individual animals, taking into account animal, human and environmental health risks, in addition to lifestyle factors.”
Types of Worms found in the UK
Intestinal Worms
Roundworm | Toxocara species (spp) |
Tapeworm | Echinococcus granulosus and Echinococcus multilocularis, Dipylidium caninum and Taenia spp |
Hookworm | Ancylostoma and Uncinaria spp |
Whipworm | Trichuris vulpis |
Non Intestinal Worms
French heartworm/Lungworm | Angiostrongylus vasorum transmitted by ingestion of some species of slugs and snails by dogs. |
Heartworm | Dirofilaria immitis, Dirofilaria repens - Not endemic to UK, but found in parts of Europe, to bear in mind for dogs imported into the UK, or for UK pets that travel to Europe frequently. |
Alternatives to medications
Worm egg counts are used to determine if medication needs to be given. This method has been carried out for horses for years to establish whether a worming treatment is required.
Now stool screening is being encouraged for our dogs and cats. Regular faecal examinations are a good alternative in low-risk groups and can be used to figure out if parasite infections are present and if you should give medication.
Individual plans for our pets
The ESCCAP (Guidelines | GL1: Worm Control in Dogs and Cats | ESCCAP) split dogs into four groups (A-D) and cats into two groups (A and B) to determine how often worming medications are required.
For dogs in high endemic areas of the UK prone to eating in the garden or those who eat slugs and snails, we advise monthly preventative medication for lungworm (prescription only medication from your vet).
Group A - Dogs living indoors only or have access to outside with no contact with other dogs, parks, sandpits, snails and slugs, raw meat or prey animals. | Deworm 1-2 times a year against roundworms or carry out a faecal examination at a laboratory and treat as necessary. |
Group B - Dogs that go outdoors with contact with parks, sandpits, playgrounds and other dogs, but no access/eating of prey animals, raw meat or offal. | Deworm against roundworms 4 times a year or carry out a faecal examination at a laboratory and treat as necessary. |
Group C - Dogs as Group B but with access/eating of prey animals, raw meat and offal. | Deworming 4-12 times a year is recommended for roundworms and tapeworms depending on the risk analysis by a veterinary professional. |
Group D - Dogs living in fox tapeworm areas (Echinococcus Multiocularis), eats prey animals and goes out to hunt without supervision. | Deworming for tapeworms monthly and 4-12 times a year for roundworms depending on the risk analysis by veterinary professionals. |
Group A - Cats. Indoor cats, eating rodents unlikely with infection pressure being low. | Faecal examination is recommended 1-2 times a year or treatment for roundworms 1-2 times a year. |
Group B - Cats that are free to roam. Infection pressure with worm stages is high with rodents likely to be eaten. | The recommendation is to minimize the excretion of Toxocara and Taenia eggs carrying out a faecal examination at least 4 times a year or treatment for roundworms and tapeworms at least 4 times a year. |
Additional recommendation - Dogs and cats that share a home with children under 5 years or immunocompromised people. | Deworm against roundworms 12 times a year, or carry out a faecal examination at a laboratory and treat as necessary. |
Lifestyle and health factors to take into account
The ESCCAP discusses how often we should be worming our cats and dogs. Puppies, kittens and senior pets are at greater risk than healthy adults.
For roundworms, Toxocara can be passed on to puppies and kittens via the milk of the mother. If there is a flea infestation, Dipylidium Infection (tapeworm) can occur due to pets ingesting fleas during grooming.
Roaming dogs in a shared environment (kennels, shelters, breeders) and working and hunting dogs will be at greater risk of acquiring parasites.
Nutrition also has an impact on parasite infections.
Dogs and cats with access to rodents, slugs or snails, raw fish or meat without appropriate heating or freezing to kill eggs/larvae, and carcasses have an increased risk of parasite infections.
Finally, location and travel should always be considered. Do you travel with your pet on holiday to different countries or areas where certain parasites are endemic?
If so, appropriate treatment is recommended. Also, pets imported from endemic countries should receive treatment soon after arriving in the UK.
Environmental control of parasite transmission
For parasites that can be passed on via faeces, pet parents need to minimise the risk of infection to other animals and humans.
The safe disposal of faeces should be done daily and not flushed down the toilet or composted for edible crops. Poo disposal bins and bags are encouraged for dogs, and you should always keep them on a lead in urban areas.
Never allow your dogs into children's play areas and cover sandpits at all times when not in use to avoid contamination. Desiccation and UV light are detrimental to worm eggs, so sunlight and drying out of areas can assist in reducing contamination levels.
It is more difficult to know where cats are defecating so further care on worm control should be taken. Eggs can lay dormant in the soil for years so in contaminated areas soil should be removed and concreted if necessary.
Protecting ourselves
For years we have been warned of the risk of certain transmissions to humans from our pets. One of the main concerns is Toxocara (roundworms). Accidental oral ingestion of eggs or eating undercooked meat containing larvae can result in an infection.
The Toxocara can migrate within the body. If larvae become blocked in the eye, brain or nerve tract during migration, serious health problems can occur.
Echinococcus granulosis and Multilocularis (tapeworm) live in the small intestine of dogs and move into the environment via faeces.
Pigs and sheep or rodents then act as intermediate hosts ingesting them from the environment, which develop into hydatid cysts passing back to dogs from eating raw offal or infected rodents.
Eggs can be passed to humans via faeces, through direct contact with dogs or contaminated food. Both infections result in the formation of hydatid cysts, usually in the liver or lung of humans, and if left untreated, can have fatal consequences.
Tips to prevent worms:
- Practice good personal hygiene. Wash hands after handling your pet and before eating food.
- Minimise exposure to children and educate them with regards to good personal hygiene.
- Wear gloves whilst gardening.
- Wash fruit and vegetables before eating.
- Regularly treat pets for worms or faecal testing.
- Clean up and dispose of pet faeces responsibly.
- Groom dogs regularly to reduce risk of worm egg contamination.
- Special care should be taken with pets and risks for immunocompromised people, the elderly, diabetics. Other people at risk are pregnant women, babies and toddlers, as well as people at occupational risk such as farmers, kennel workers, and hunters.
If you have anymore questions regarding parasites, you can video call a registered vet nurse for free with Buddy.
Our nurses will walk you through the types of parasite treatment available and develop a unique plan specifically for your pet. Taking into account lifestyle and different factors.