Exploring the Feline Grimace Scale

Pain in Cats

Exploring the Feline Grimace Scale by Natalie Hunt (BAppSc - VT)

Whether animals feel pain like humans do has been long debated within the scientific and philosophical fields. The following has been refuted:

• Animals do not experience pain.
• Pain may be experienced, but not in a way that is detrimental to wellbeing or warrants treatment.
• Signs of pain are too subjective.
• Pain is good as it limits activity, and therefore further injury.
• Analgesia is bad because it has limiting side effects and increases the inability to assess and accurately monitor patients.

Cats themselves are masters of deception. In nature, pain and weakness make you a target for predators and therefore cats are experts at masking their vulnerabilities.

Unfortunately, due to their unique behaviours, it is now understood that cats are frequently neglected or overlooked when it comes to adequate analgesia.

Ultimately, pain is not only what you feel, but also how it makes you feel.

Classic signs of pain include, but not limited to:

• Hiding in the back of a cage
• Limitations of movement, or not wanting to respond to stimulus.
• Dull mentation
• Inability to rest or sleep.
• Tense in abdomen or around site of injury/illness
• Hunched
• Abnormal behaviours, including vocalisation.
• Changes in vital signs, including but not limited to increase in heart rate, and respiration
• rate, pyrexia, increase in blood pressure.
• Trembling or shivering
• Inappetence

The most common pain scales used include the following:

• UNESP – botucatu multidimensional composite pain scale for assessing post-operative pain
• in cats (Score …/30)
• Glasgow Feline composite measure pain scale (CMPS – Feline); (Score …/20)
• Colorado State University Veterinary Medical Centre – Feline Acute Pain Scale (Score …/4)

The Feline Grimace scale (FGS) is a tool that utilises facial expressions in cats to determine if they are experiencing pain or discomfort.

How to use FGS:

1. Observe the cat undisturbed for 30 seconds
2. Each action unit (AU) is to be scored individually with the corresponding numbers (AU = ear position, orbital tightening, muzzle tension, whiskers change, and head position)
   • ‘0’ = absent
   • ‘1’ = moderately present
   • ‘2’ = obviously present
3. The maximum score for the FGS is 10, and if the score noted is of 4 or higher, a veterinarian should be notified that analgesia may be required. It is then important to continue to reassess the patient.

General challenges in the clinical assessment of feline acute pain:

• Unique personalities and behaviours
• Individual response to analgesia
• White coat syndrome
• Inappropriate handling
• Lack of training and education if feline pain recognition
• Other factors that need to be explored further including behavioural changes after drug administration.