FELINE PERCEPTION OF PAIN
I recently came across the misconception that cats do not feel pain. A philosopher and lecturer called Deitch believed and taught (quite wrongly) that cats feel no pain so they cannot be put in the same category as dogs, whom, he believed, do feel pain. This is a convenient conceit for scientists who use cats as research subjects (in both physical and psychological tests), but is factually incorrect and contradicts veterinary and behavioural studies.
The feline nervous system is very similar to the human nervous system. Cats have the same array of receptors on their skin and in their bodies and these receptors report on the cat's state of being, including pain. While some responses are the same as human reflex - for example the involuntary reaction of jerking a limb away from a painful stimulus - the fact that cats will avoid a similar painful stimulus in the future demonstrates that they do indeed feel pain. An animal unable to feel pain is unlikely to survive. While it important to understand that cats' perception of certain stimuli differs from our own perception of the same stimuli, it cannot be denied that cats feel pain.
Laboratory experiments have monitored the electrical signals in the brains of cats that are stressed or subjected to physical pain and have analysed the levels of various hormones in their blood. Changes in electrical signals and increases in those hormones strongly indicate that cats experience pain. Pain e.g. an electric shock has also been successfully used in Pavlovian style conditioning of cats, however cats are strongly demotivated by such training methods and generally refuse to co-operate further. Further information on these studies can be found at How Intelligent are Cats?
Cats react to pain in a different way to dogs. Dogs are pack animals and openly show their emotions to other pack members. A dog that is in physical or emotional pain can expect to be supported by other pack members. Cats do not have the pack animal mentality although they are not as solitary as once believed. A cat typically hides symptoms of pain. Showing signs of pain would bring it to the attention of rivals who could take advantage of its vulnerable condition. It has a better ability to produce endorphins (the body's own painkillers) and, if the pain is only moderate, this allows the cat to continue functioning. This is an important concern for veterinarians when assessing pain control treatment for sick or injured cats.
Flicking through a typical veterinary book ("Handbook of Feline Medicine" by Josephine Wills and Alice Wolf) results in several references about how to determine whether a cat is in pain e.g. abdominal pain, oral pain etc by observing symptoms such as posture, gait, reaction to palpation of the affected part. It also discusses pain relief, an important concern in post-operative care. Post-surgical pain relief is a subject that has previously received insufficient attention because cats are less expressive of pain and, therefore, it has been assumed that they are not in pain. Cats tend to be stoic creatures that prefer not to express their infirmities or discomfort so as not to attract adverse attention from competitors or predators.
Wills and Wolf note that pain in cats is indicated by the behavioural response (the cat tries to escape the stimulus or tries to bite the hand that is pinching it) rather than by the reflex response (e.g. a jerking limb if the toe is pinched). The fact that the cat reacts by aggression towards the person/object causing pain demonstrates that is has conscious perception of pain rather than displaying a simple reflex action. In unfamiliar surroundings, such as a the vet clinic, cats are likely to mask their discomfort as far as possible. Vets and vet nurses must therefore learn to read the cat's body language in order to assess the level of discomfort being experienced.
The following are excerpts relating to feline perception of physical and emotional pain.
(from "The Cat's Mind" by veterinarian Bruce Fogle)
[The] cat's body - and that includes the paws - is relatively insensitive to both low and high temperatures. What is painful to us is certainly not to cats. They will stand with their forepaws in hot frying-pans in order to eat the contents of your dinner. They will lie so close to fires that they singe their fur, And at the opposite extreme, they will walk on ice and sleep on snow with no apparent frostbite to their paws or skin. Pet owners often bring in their frying-pan thieves or their burnt-coated heat hogs for me to examine and it constantly amazes me that such injuries can happen without the cat apparently either noticing or caring. It amazes me because it's so difficult to understand that they have different touch sensations. We feel discomfort when our skin temperature reaches 112°F (44°C). Cats don't show signs of discomfort until their skin temperature reaches a dramatically high 126°F (52°C). This relative insensitivity to pain is possibly a consequence of the lack of heat receptors on the body, but also a result of the cat's superior pain-killing endorphin system.
The cat's nose also plays a part in eating, for, as well as scenting, it gauges the temperature of the food through the heat receptors that are located there. There are also touch and heat receptors on the tongue that assist the senses of smell and taste. The texture of food is just as important as its taste.
Of all the parts of the cat's body, the paws have the most sensitive and exquisite touch receptors. Using this tactile ability, cats will investigate the size, shape and texture of an object in much the same way as we do with our fingers. After a first gentle tap, a cat will then touch an object more firmly and will finally examine it with both forepaws and with the touch receptors on its nose.
(from "Feline Behavior: A Guide for Veterinarians" by Bonnie V Beaver, behaviorist)
Pain-induced Aggression. Pain effectively elicits defensive aggression, which frequently is seen when a cat's hair or tail is pulled or when its tail is stepped on. Continued application of pain eventually causes the cat to submit to the stimulus or try to escape it (Fox, M. W.: Aggression: Its adaptive and maladaptive significance in man and animals. In Fox, M. W., ed.: Abnormal Behavior in Animals, Philadelphia: W. B. Saunders Co., 1968.) . Early social play helps to teach the kitten what pain is as well as how much pain it can inflict on others. If slight oral pressure elicits a pain reaction from a littermate, then the kitten learns that this amount of oral pressure causes pain. Singly raised orphans are deprived of this learning experience. Those not getting several months to play with littermates also may not get the lesson of how not to bite hard.
Emotional pain is also felt by cats. Like dogs, cats will pine (sometimes to death) when a companion human or animal dies or departs. Many behaviourists are aware that cats can, and do, feel an emotion analogous to grief in humans. The symptoms include depression, withdrawal, loss of appetite, increased vocalisation and searching for the missing person. Levels of stress hormones in the blood may also be elevated, showing that there is a physiological response. Information on emotional responses in cats can be found atDo Cats Have Emotions?
Cats feel pain just as much as dogs do. However the more solitary feline social system means that cats tend to hide physical or emotional pain in order to mask vulnerability while dogs are more likely to display it to elicit sympathy from other pack members/human family. In a family situation, it is not unknown for some pet cats to develop a psychogenic (product of the emotions, not of the physical body) limp long after an injury has healed. This is because the individual cat has learned that in a pet-owning household it gets special care and attention when injured.