How can pain be recognised and monitored in cats?

Due to the unique nature of and often subtle changes in feline body language, recognising pain in cats can be a challenge for their owners. Being able to identify changes in behaviour is essential in determining if a cat is in pain and, if so, ensuring that they receive timely treatment. Ongoing monitoring of cats who are experiencing pain is also crucial in making sure they consistently receive appropriate pain management that is adapted to their level of pain and is aimed at keeping them comfortable. For cats who are in pain, whether they are on a path to recovery or need a lifelong pain management plan, detecting changes in their behaviour and frequently monitoring their pain levels will be essential in providing them with appropriate pain relief and optimal welfare support.

One way to improve the quality of life and welfare of cats who are experiencing pain is to provide effective pain relief as soon as signs of pain are detected. To properly treat and manage pain, it’s imperative to be familiar with the cat’s normal and abnormal behaviours as well as know what certain behaviour and changes in behaviour could mean.

The onset of pain can be sudden (acute) or slow (chronic) and may range from mild to severe. Pain may last for days, weeks or more and can be debilitating and emotionally distressing. There are many reasons that could cause a cat to be in pain. Acute pain generally appears suddenly and usually does not last very long with the appropriate treatment, while chronic pain lasts more than three months and is either persistent or intermittent. Below are a few examples of common situations and conditions that can result in a cat showing signs of pain:

• Acute pain: surgery, trauma or injury, infections, digestive and urinary problems
• Chronic pain: degenerative joint disease (arthritis), chronic kidney disease
• Both: cancer, nerve disorders or damage, spinal disc disease

Note: Many conditions can begin with acute pain and later become chronically painful.

Recent advances in feline health and welfare research have led to the development of new and more efficient ways of identifying signs of pain in cats, which could otherwise be overlooked. Newly available strategies aid owners and veterinary professionals to better recognise and monitor cats who are in pain and can also assist owners to know when they should seek veterinary advice [1].

Common signs of pain

Owners of cats who show one or more of the following signs, which are indicative of pain, should promptly seek veterinary advice:

• Changes in vocalisation (e.g., meowing, hissing, growling, or purring)
• Signs of aggression, especially if the cat is usually friendly (e.g., growling, ears pinned back)
• Changes in activity level or posture (e.g., restless, hiding, limping, trembling, arched back)
• Changes in daily behaviours (e.g., appetite, sleeping, drinking, grooming, litterbox use)

Cats who are in pain may have heighted sensitivity to being touched, picked up, approached or interacted with. Additional care and caution should be used, as interactions that were previously painless might unintentionally cause the cat additional pain, to which they may respond by biting or scratching. In this situation, if the cat must be handled, owners who are concerned that their cat might react to being handled may consider using a soft, clean towel or blanket to reduce the risk of injury to themselves or their pet.

Changes in facial expressions

Together with other behavioural signs, changes in facial expressions can also help to identify pain. A new tool called the Feline Grimace Scale (FGS), allows owners to quickly and reliably assess acute pain in their cat [2]. The method relies on observing the cat undisturbed for 30 seconds and then scoring changes in the following five facial features:

• Ear position
• Squinting of eyes
• Muzzle tension (or tightening)
• Whisker position
• Head position

For cats who are suspected to be in pain, this tool assesses these facial features, or ‘action units’, to which each are given a score according to how apparent they appear:

• Absent (score = 0)
• Mild to moderately present (score = 1)
• Obviously present (score = 2)

Once the five facial features are individually scored, the final scores of each are added together. A cat who receives a score of 0 out of 10 would be considered to have no observable signs of pain. In contrast, the maximum score that can be given is 10 out of 10, which would suggest a cat who is in severe pain. Any cat who is scored as 4 or more out of 10 should undergo a veterinary examination so that appropriate pain relief can be given as soon as possible, and suitable investigation and treatment can be performed.

Before using the FGS tool, owners should read the online training manual and other helpful infographics that are provided for free on the official FGS website. With the proper knowledge, this tool allows cat owners to differentiate between painful and non-painful signs, monitor for changes in level of pain, and provide timely and effective pain relief under veterinary supervision to improve their cat’s overall welfare.

There is now a Feline Grimace Scale phone app that people can use to help them assess acute pain in their cats based on changes in facial expressions. This quick and easy-to-use tool underwent rigorous scientific validation and it was shown to be valid and reliable for the evaluation of pain in cats with different medical and surgical conditions, using both image- or real-time evaluation. More information and a link to the app can be found on the official FGS website.

Monitoring pain in cats

The frequency and timing of monitoring cats who are in pain will vary depending on the cause of pain as well as on the veterinary treatment plan. When using the FGS tool, cats who are scored below 4 out of 10 should be monitored at least one to five times throughout the day. If signs of pain continue, then seek veterinary advice. For cats receiving pain relief, increased frequency and timing will likely be needed to ensure that the medication being used is effective.

Useful resources

Veterinary professionals from several organisations have also recently developed other guides to aid in recognising pain in cats, which can be used by cat owners to know when they should seek veterinary advice. Below are additional resources available to help cat owners understand signs of pain in their pets:

• How do I know if my cat is in pain? | AAFP’s Cat Friendly Homes
• How to tell if your cat is in pain | AAHA’s Pain Management Resources
• What does my cat’s body language mean? | RSPCA UK’s Understanding Cat Behaviour