How often does a cat really NEED to be wormed?

Treating your cat for worms is an important part of preventative healthcare, part of taking a proactive approach where possible to keep your pet in optimum health and prevent disease or illness. Worms are extremely common, and cats can become infected in various ways. Every cat requires a worming protocol, but how often they need worming depends on factors such as age, life stage and lifestyle. 

Why do I need to worm my cat?

A worm burden can lead to a range of symptoms including; weight loss, a dull coat, lowered immunity, gastrointestinal issues such as vomiting or diarrhoea, a pot-bellied appearance, an itchy bottom and/or lethargy.

More obvious signs include tapeworm segments that resemble grains of white rice, which may be seen in your cat’s bedding or around the anus and tail. Sometimes worms can even be seen in faeces or vomit. While worms don’t usually cause serious health problems in adult cats, kittens are more at risk from complications. A heavy worm burden in a kitten can result in anaemia, intestinal obstruction or gastrointestinal upset leading to dehydration, these complications can be fatal.

However, it’s not always easy to tell if your cat has worms, sometimes there aren’t any notable symptoms – but regular worming is still important even if there aren’t any signs or you’re not sure if your cat has worms. Some worms are zoonotic, meaning they can be transmitted to humans. This makes a regular worming protocol important not only to keep your cat in good health but also to protect everyone in the household from toxocariasis, particularly young children who are not usually the most fastidious handwashers! Outdoor cats can also spread worm eggs into the local environment through their faeces, contaminating gardens, sandpits, or children’s play areas. 

It’s also important to remember that wormers may have impacts on the environment – although so far most of the research has been into flea treatments, it does suggest that we shouldn’t worm more often than necessary.

What worms are my cat at risk from?

In the UK the main worms that commonly infect our feline friends are some types of Roundworms and Tapeworms. A basic understanding about them and how they spread can help determine a worming frequency to protect your cat.

Roundworms:

Roundworms are very common, these spaghetti-like worms grow up to around 10cm in length and are usually cream or slightly pink in appearance. Sometimes you might see them in your cat’s vomit or faeces but usually there are no symptoms. The main roundworms seen in UK cats are Toxocara cati and Toxascaris leonina.  

Microscopic roundworm eggs are passed in the faeces of an infected animal and these hardy eggs can live in the environment for up to a year so are still viable even after the original faeces have disintegrated. Your cat might then pick these eggs up on their paws and coats and ingest them whilst grooming, they can also pick up worms from eating infected prey such as birds and rodents. 

Tapeworms:

Tapeworms are long, flat worms made of many segments; it’s these tiny white segments that are sometimes seen around the anus or on bedding. Sometimes cats can vomit up long sections of tapeworm. Tapeworms have a more complex lifecycle because they require an intermediate host before they can infect a cat. They are also species-specific meaning that certain species of tapeworms can only mature in certain animals or definitive hosts; dogs are at risk from more tapeworm species than cats. In the UK, cats are mainly susceptible to: 

Dipylidium caninum - The intermediate host for this tapeworm is the flea (and sometimes lice) so your cat becomes infected when they ingest infected fleas during grooming. This is why regular flea treatment is needed alongside worm treatment.

Taenia taeniaeformis - rodents are the intermediate host for this tapeworm who pick up the infection by ingesting tapeworm eggs from contaminated environments. Outdoor cats and hunters are therefore at higher risk.

How does life-stage and lifestyle effect the worming frequency of my cat?

Unlike treatments for ectoparasites (external parasites such as fleas and ticks) that can provide protection and prevention for several weeks or longer, worming treatments usually only kill the worms present in your cat at the time of treatment. They do not generally offer ongoing protection, meaning your cat can become re-infected almost immediately after being treated.

Your cat’s life stage and lifestyle play an important role in determining how often they should be wormed as some cats will have a higher risk than others. When the lifecycle of the worm itself is also considered, the prepatent period refers to the time between an animal getting infected up until the parasite becomes detectable in the host (your cat). The patent period begins once the parasite is detectable and is infectious meaning that worms can be transmitted from the host (your cat) to others. The aim of a worming protocol is to treat your cat during the prepatent period i.e. before the worms start producing eggs and your cat begins shedding them — thereby breaking the cycle and preventing infection/re-infection.

So the worming frequency is determined by the likelihood or risk of infection alongside the lifecycle of the worm. ESCCAP (European Scientific Counsel Companion Animal Parasites) publish guidance on parasite control in pets

Kittens

Roundworm (Toxocara cati) larvae migrate to the mammary glands of lactating queens and are then transmitted to kittens via the milk. The prepatent period for this worm species is at least 4 weeks therefore ESCCAP recommend that kittens should be wormed for the first time at 3 weeks and then every 2 weeks until after weaning to make sure all worms are killed before reaching the patent period. After weaning, monthly worming should be continued until 6 months of age especially if the kittens are likely to pick up worms from the environment. 

Adult cats

For the purposes of worm protocols we will consider cats who have reached sexual maturity i.e. over 6 months in this age group. 

The worming frequency of your adult cat depends on their lifestyle. Remember that regular worm treatment is needed alongside regular treatment for fleas due to the lifecycle of the tapeworm. ESCAPP place adult cats into risk categories: Group A and Group B

Group A – Indoor Cats

Indoor cats can still become infected with worms either by eggs carried into the house on shoes, from other pets or from fleas. ESCCAP recommends worming 1-2 times a year, or faecal examination can be carried out to determine if treatment is necessary. However, ESCCAP go onto say that if an animal’s individual risk of infection cannot be clearly assessed, the cat should be dewormed or faeces examined at least 4 times a year and that 1-3 dewormings per year may not be enough.

Bear in mind that in multi-cat households if one cat has worms the others can be infected easily so they should all be wormed at the same time. This is why it’s most often recommended to worm pet cats at least 4 times per year.

Group B – Cats free to roam 

Cats with unrestricted access to outdoors and who come into contact with other cats are at risk from picking up worms either through eggs in the environment, fleas or through hunting. The recommended worming period for these cats is 4-12 times per year. Worming every 3 months is not necessarily often enough to prevent a patent infection so for known hunters and cats who roam widely and freely monthly worming is recommended.

It’s also recommended that cats living in homes with young children under the age of 6 years, immunocompromised individuals or elderly people are wormed monthly.

Pregnant and lactating queens

ESCAPP recommend that pregnant queens are treated with a suitable wormer at approximately 7 days before parturition (giving birth) to prevent lactogenic (in the milk) transmission of Toxocara cati to the kittens. They should be treated again, at the same time as the kittens receive their first treatment (3 weeks after delivery).

Travelling cats

If your cat is going abroad with you speak to your Vet about parasite control, depending on the country you are travelling to your cat may be at risk from different parasites than those in the UK.

Which wormer should I use for my cat?

There are many different cat worming products on the market but they are not all equal in their efficacy. Wormers can be purchased from supermarkets or online stores, there are even herbal or “natural” wormers available to buy. The wormer must be suitable for the age and weight of your cat, some worming products should not be used on kittens and correct dosing is essential for safety and to make sure that the treatment works. Never use a dog wormer even if your terrier or toy breed is the same size as your cat! Some worming products also treat fleas and other parasites, and some of these are potentially lethal to cats. It can be tricky to choose the right wormer. Your Veterinary team really can offer you the best advice on which wormer will suit your cat.  

Prescription wormers available from your vet along with some NFA-VPS worming products dispensed by an SQP (suitably qualified person) or pharmacist often contain the most effective, proven ingredients.

If your cat turns into a tiger the moment medication is involved or is a master at avoiding tablets no matter how you try and disguise them in food don’t despair! There are also spot-on worm treatments available; again speak with your veterinary team about the options available to suit your cat. The ISFM have some useful advice on medicating your cat here.

Conclusion

Hopefully you now have a basic understanding of why your cat needs worming as well as how often they need to be wormed. Parasitology is a big topic and you can learn more in the linked webpages and related articles. If you’re still not sure about worming, your veterinary team is the best source of advice tailored to your cats’ individual needs.

Although faecal testing for worms is one option to determine if treatment is needed, the expense of this compared to the cost and safety of worm treatments mean that a regular worming programme is the usual course of action for most cats. It’s easy to lose track of when your cat was last wormed and when they are due so it’s useful to mark on a calendar or set a reminder so you don’t forget to treat your cat for worms (and fleas!)