Painkillers for cats

Vets prescribe painkillers to help your cat feel more comfortable after an injury, operation or a painful illness. The type of painkiller prescribed depends on the problem, as well as your cat’s age and general health. Human painkillers are not safe for cats.

Most cats will need painkillers (analgesics) at some point in their lives, especially as they get older. Sometimes treatment is for a short time, to help your pet recover from an injury or operation. Cats with arthritis may need painkillers every day to help them enjoy a happy active life. Side effects are common and depend on the medicine, but often include tummy upsets or sleepiness. Only use painkillers your vet prescribes.

What it’s for

What painkillers are available for cats and what are they for?

There are a number of different types of painkillers for cats. They act in different ways and the choice for your cat will depend on

  • Source of the pain.
  • Severity of pain.
  • How long treatment is needed.
  • Possible side effects and how likely they are in your cat (age, size, previous history).
  • Any other illnesses your cat has that might influence the effectiveness or risks of the painkiller.
  • Possible interactions with other medicines.
  • How easy it is to give the medicine to your cat.
  • Cost may be a consideration if there’s more than one suitable option.


How it works

Most commonly used painkillers for cats

Non-steroidal anti-inflammatories (NSAIDs)

The most commonly used painkillers are ‘’non-steroidal anti-inflammatory’ medicines or NSAIDs. As the name suggests, these painkillers act by reducing inflammation, so they act at the site of the problem.

For example:

  • Joints inflamed by sprains, twists, damaged cartilage or arthritis.
  • Wounds which become inflamed due to infection or lots of tissue damage
  • Where an operation has happened, such as tooth removal or neutering.
  • Skin and ears, where deep infections cause painful inflammation

Cost varies, depending on the type and dose of NSAID.

Opioid medicines

  • The opioid painkillers include morphine and related drugs.
  • Injections of opioids are used where a stronger painkiller is needed.
  • They may be used alongside NSAIDs.
  • May be used instead of NSAIDs when pain relief is needed and NSAIDs aren’t tolerated or aren’t safe.

Opioids act differently from NSAIDs. They act on the brain to reduce the feeling of pain rather than reducing inflammation. Their effects and side effects can vary between cats. An effective opioid for one cat may be ineffective or cause side effects in another.

Uses for opioids include:

  • Serious injuries like broken bones or road accidents
  • Before and during surgery to help recovery.
  • Additional or alternative pain relief when NSAIDs are no longer enough or aren’t tolerated by your cat
  • As part of a sedative treatment. Opioids have a ‘chilling out’ effect on patients

Opioids are strong medicines and are strictly regulated by Law. Some, like morphine and Fentanyl, will only be used in the vet clinic and their use is carefully recorded.

Monthly biological treatment – Frunevetmab

  • The newest form of painkiller works with your cat’s immune system.
  • Frunevetmab (Solensia) is an antibody.
  • It attacks the chemical messengers that tell nerves to signal pain.
  • This treatment is an injection given once a month by your vet.
  • Frunevetmab is safe for long-term use in cats.
  • Side effects may include irritation or redness at the injection site.

Alternative or additional painkillers for cats


  • Gabapentin is a human medicine used ‘off label ‘ as a painkiller for cats.
  • It’s actually used as an anti-seizure medicine in humans and cats.
  • It also acts on the brain and is often used as an additional pain relief for chronic pain or where other medicines aren’t tolerated.
  • Available as capsules, tablets or liquids to give with or without food

Used for:

  • Seizures
  • Chronic pain
  • Neuropathic pain: Pain due to nerve damage or irritation

Side effects include :

  • Poor appetite
  • Sleepiness
  • Loss of balance


  • Amantadine is a human medicine which is used ‘off-label’ for cats.
  • It acts by blocking the nerves which send pain signals to the brain.
  • Amantadine is generally used alongside NSAIDs or opioids to treat chronic or neuropathic pain
  • Amantadine is available as a syrup, capsule or tablet
  • It’s a very safe drug for cats.

Side effects aren’t common, but may include

Human painkillers for cats?

Never give human painkillers to your cat. Across-the-counter medicines you buy in supermarkets or pharmacies are dangerous for cats. They can cause serious illness, including

Can cats have paracetamol?

  • Paracetamol is a human painkiller.
  • It is extremely poisonous to cats
  • Vets will sometimes prescribe Paracetamol ‘off-label’ for dogs. Never for cats!

Directions for use

What are the directions for use of painkillers in cats?

Only give your cat painkillers as your vet prescribes.

All painkillers are ‘prescription only’’

  • This means a vet has to check your cat to decide which medicine is most likely to be effective and safe

Vets may advise a blood test for your cat before they start painkillers.

  • This is to check for liver and kidney problems. Blood tests are very important for older cats or those likely to have long courses of painkillers

Always give painkillers at the dose and times prescribed.

  • Giving too much risks dangerous side effects.

Take your cat for regular check ups.

  • Cats on long-term medicine need to see a vet regularly for check-ups.
  • This is required by law.
  • But it’s to make sure your cat is well and still on the most effective and safest treatment for their health condition(s).

Some specific directions for particular groups of painkillers


NSAIDS (meloxicam, robenacoxib) are available as injections and tablets or liquids. Vets may start treatment with an injection, followed by oral medicine at home.

  • NSAIDs are usually given by mouth once or twice daily, depending on the type
  • Give with or immediately after feeding to reduce stomach irritation
  • If your cat goes off their food or develops a tummy upset, stop giving the medicine and call your vet as soon as possible

NSAIDs reduce inflammation. Inflammation causes pain and loss of function. But inflammation is also an important part of the healing process. So although your cat needs painkillers to make them comfortable and to limit “loss of function”, we also need to support the recovery process.

This may mean:

  • Strict rest for cats with sprains strains or muscle injuries to prevent more damage
  • Strict rest after an operation, or as directed by your vet. This means no jumping on to high surfaces or chasing toys.
  • Keeping wounds clean. Use a cone collar or body vest if necessary to prevent licking.

Opioid medicines

Opioids are available as injections, and less frequently, given as tablets, liquid or special patches that give the medicine through the skin.

  • The effect is unpredictable even at low doses
  • Your cat may take a few days to get used to the medicine
  • Give the first dose at home when you’ll be around to keep an eye on them. Protect them from injury due to stumbles or falls if the medicine makes them wobbly.

Side effects

What are the most likely side effects of painkillers for cats?

Side effects of painkillers are quite common. Different cats will respond differently to different medicines. This applies to both the effects and the side effects. But side effects are more likely for any cat when the medicine is given incorrectly.

Contact your vet if you cat is showing side effects of taking painkillers.


Side effects can include:

  • Vomiting and diarrhoea
  • Loss of appetite
  • Kidney damage
  • Stomach ulcers: vomiting blood, passing black tarry poo. This is an emergency and your cat should be seen by a vet immediately.

All breeds of cats are equally susceptible to side effects of NSAIDs, but accidental overdose is more likely in young kittens and old cats

Give NSAIDs with food to reduce the risks of side effects.

There are many different NSAIDs licensed for cats in the UK. The newer ones tend to be more ‘selective’ in the way they act to reduce the risk of harmful side effects.

Opioid painkillers

Side effects of opioid medicines include:

  • Sleepiness
  • Wobbly gait and tremors
  • Euphoria, agitation, restlessness
  • Drooling
  • Vomiting and reduced appetite
  • Constipation

All injectable painkillers

  • Irritation or infection at the injection site
  • Small risk of infection


What happens if

When should my cat not take certain painkillers?

NSAIDs are only used very carefully or avoided if your cat:

  • Has problems with blood clotting
  • Has liver disease, kidney disease or heart disease
  • Has a history of stomach ulcers
  • Has suffered a bad reaction to the same medicine in the past.
  • Is pregnant
  • Is a kitten under 6 weeks old.

Opioid medicines may worsen symptoms of confusion and unsteady gait

Talk to a vet as soon as possible if you think your cat is suffering severe side effects from medication.

Joii can help with advice on:

  • How to give medicines safely
  • Recognising side effects and reducing the risk where possible
  • Caring for wounds
  • Managing exercise for a cat with arthritis or recovering from surgery
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