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Pain is defined as an unpleasant sensory and emotional experience associated with actual or potential tissue damage. It is not well understood either in humans or other animals. Since it is complex and cannot be measured directly, pain is very subjective. I'm sure you can think of two people who might undergo the same unpleasant experience, but each will have a different description of the pain. We assume that as each person interprets pain differently, each individual animal also experiences pain differently. Animals cannot communicate with us verbally, making it especially difficult to identify, classify and quantify their pain. Yet the anatomic and chemical pathways of pain and its perception are probably similar in all animals. Therefore we work with the premise that conditions that are painful to a human are also painful to animals, such as our rabbits.

Attitudes are changing about pain

Because rabbits can't talk to us, caregivers and veterinarians have traditionally relied on the observation of pain induced behaviors to decide when it is time to intervene. We have used pain to indicate that there is an underlying problem, and in the past, the approach was to correct the problem and assume that the pain would then resolve. The current thinking is that we want to be sensitive to the subtle signs of pain, because the treatment of pain itself can aid healing. It is not only rabbit owners and veterinarians who are changing their attitudes. Human infants are similar to rabbits in many ways, because they also communicate in ways that can be obscure and challenging for parents and doctors to understand. Both pediatric and veterinary medicine are learning that subtle changes in behavior may be the only indication that an animal or child in discomfort. The study of pain has been very active in both human and veterinary medicine over the past 10-15 years.

Veterinary medicine is asking questions such as 1) how can we recognize signs of pain in our patients 2) what types of benefits are associated with adequate pain control 3) how can we differentiate pain from anxiety 4) what types of drugs are effective in alleviating pain 5) how do different types of animals respond to different treatments.

How can we recognize pain in rabbits?

When working with rabbits the presence of pain must be inferred by the observation of change from normal behavior. A normal rabbit is bright, alert, active, inquisitive, has a smooth coat and good body condition. Pain may be evident as a limp or a change in gait, withdrawal or protection of an injured part, awkward or abnormal postures, licking, rubbing or scratching at an area or decreased food and water intake. Rabbits are unique from most of the other companion animals, because they are adapted as a prey species, an animal that normally needs to hide any handicap in order to escape predation. Signs of pain may be subtle such as a change in respiration, reluctance to move, apprehension, sudden aggression, inability to rest or sleep normally, or a worried or anxious expression. A rabbit with abdominal pain or sore feet may lie stretched out or sit in a hunched position. Grinding of the teeth is a sign of severe pain. It is unusual for rabbits to vocalize but when they experience sudden pain or anxiety they may give a high pitched squeal, quite unnerving to any person hearing it. Very often the presence of pain in rabbits is under diagnosed by both caregivers and veterinarians, and when it is recognized it is often underestimated. It is very difficult to differentiate pain from anxiety in rabbits, especially since they are often combined and may be manifested by similar changes in behavior. It may be simplified by a basic acceptance that rabbits will be anxious whenever they are placed in an unfamiliar environment.

Is it useful for an animal to feel pain?

It used to be thought that pain was a protective mechanism that helped animals decrease their activity and thereby decrease any damage to an injured body part or surgical site. However, this same adaptation can be detrimental when a rabbit is under veterinary care. Current medical thinking has tried to understand and minimize the detrimental effects of pain. Pain is stressful and can prolong recovery. Rabbits will often stop eating when they are painful or frightened and a change in gastrointestinal motility can be very harmful to a rabbit. Therefore treatment should be directed at decreasing pain and anxiety.

What benefits are associated with pain control?

We still have a long way to go in both evaluating pain in rabbits and effectively managing it for their benefit. Human medicine has tried to document the benefits of pain control. Most of the veterinary studies have looked at dogs and cats because these are the most common animals brought to veterinary practices. Some of these benefits include improved breathing functions, decreasing stress responses surrounding surgery, decreased length of hospitalization, faster recovery to normal mobility, improved rates of healing and even decreasing the spread of cancer after surgery. Almost all studies show people and animals return to normal eating and drinking habits sooner when given relief from pain. Therefore prevention, early recognition and aggressive management of pain and anxiety should be essential to veterinary care of rabbits. Rabbit owners are justified to request support from their veterinarian on this issue. It is a good idea to assume that any invasive surgery can potentially be painful for a rabbit. Rabbits tend to return to eating and recover faster following spay and neutering surgeries when provided a narcotic to relieve pain during the surgery and for 12­18 hours following the surgery.

What can we do to reduce pain?

Pain is only one of many stress factors that sick rabbits must face. Sick rabbits need to cope with their disease or injury in addition to stressful changes that come with the problem. A sick rabbit usually has to leave his familiar surroundings and travel to the veterinary hospital, a strange environment with threatening noises and smells. He may also be separated from his human and/or rabbit friends. The veterinarian (usually a stranger to the rabbit ) palpates, pokes and moves painful parts of the rabbits body. The doctor may need to restrain him and take blood or perform other diagnostic procedures. We need to try to see it from the rabbit's perspective. We can reduce frightening and/or painful aspects of a procedure by petting the rabbit, speaking in soft tones, using good nursing practices and providing a home and hospital environment that is conducive to rest. Rabbits respond better and may recover faster if returned to their familiar home environment as soon as possible. It is a strongly held belief by many rabbit owners that rabbits are comforted by being with a familiar companion rabbit whenever possible. However, caregivers must also listen to the veterinarian's decision because there are occasions that warrant keeping the rabbit alone for observation.

What is analgesia?

Analgesia literally means absence of pain sensation. The realistic use of analgesia tries to relieve pain and discomfort through the use of medication. There is not one drug that abolishes pain without complete anesthesia or loss of consciousness. Unfortunately, not all medications work exactly the same in every animal or human. This makes it difficult for the veterinarian to determine how effective or even how long a treatment may be effective in an individual. Treatment may involve many different levels of providing comfort.

What types of medication can control pain?

When a rabbit needs to be hospitalized, the veterinarian may choose to give medication to reduce anxiety, such as diazepam (Valium). Rabbits require high dosages of this type of drug and may appear quite drowsy, yet when they are moved or examined, they become very alert. Your veterinarian will assess your rabbit and his disorder prior to prescribing any medication. There are no drugs developed specifically for rabbits, but many analgesics have been evaluated for rabbits, and dosages are available. There are several different categories of medication to control pain, and these will be briefly described:

1) Local anesthetics such as lidocaine, provide excellent analgesia provided that the local block is given over the entire surgical area. Veterinarians use local anesthetics for minor surgical procedures such as skin biopsies, or they can be used in the immediate period following surgery as a supplement to general analgesia.

2) Non-steroidal anti-inflammatory drugs (NSAIDS), such as aspirin or Carprofen, are able to decrease swelling and inflammation. The potency of different NSAIDS vary with each drug, dose and type of pain. Rabbits require high dosages of aspirin but it can be a very effective analgesic. It can be administered at home but should onl be used under veterinary supervision. NSAIDS cannot be given for very long time periods because they have side effects on the gastrointestinal tract and the kidneys.

3) Alfa-2-Agonists, such as xylazine, are powerful analgesics especially for the treatment of abdominal organ pain. But these drugs also produce deep sedation and depression of the heart rate and blood pressure. Therefore this type of drug is not used very often for relief of pain after surgery although it can be used as part of the surgical anesthesia drug combination.

4)Narcotics include a diverse group of drugs in the opiod family. A common example of an opiod drug used for rabbits is butorphanol. Opiods are the most effective analgesics for the treatment of pain but there are well known side effects and disadvantages. Veterinarians often use narcotics for rabbits just prior or during surgery and immediately following surgery. Some opiods are controlled by the Federal Drug Administration and can be difficult for veterinarians to prescribe for home use. I have been testing the use of a narcotic patch that can be applied to the skin and left in place at home for 3-4 days. Because it does not need to be injected, it may be a good alternative to most other forms of narcotics. Your veterinarian should be able to recommend an appropriate plan to alleviate your rabbit's pain once a diagnosis has been made. Do not try to develop your own home remedies for pain relief. Each medication has side effects that could be very dangerous for your rabbit. Caregivers can do a number of things to minimize their rabbits discomfort such as careful handling of the sick rabbit, prompt communication with your veterinarian, gentle nursing care and rest to improve his comfort, access to food and water and a palatable diet to keep the rabbit eating. It is important to prevent changes in the gastrointestinal motility especially when the rabbit is already stressed by disease.

References

Baumans, V., Brain, P.F.; Brugere, H.; Clausing, P.; Jeneskog, T. and Perretta, G. 1994. Pain and distress in laboratory rodents and lagomorphs: Report of the Federation of European Laboratory Animal Science Associations (FELASA) Working Group on Pain and Distress accepted by the FELASA Board of Management. Laboratory Animals. 28: 97-112.

Eisele, P.H. 1997. Analgesia in small animals. Veterinary Proceedings. 11:796-799.

Eisele, P.H. 1997. Signs of pain in small mammals. Veterinary Proceedings. 11: 795 -796.

Hansen, B.D. 1994 Therapeutics in practice: analgesic therapy. The Compendium. July : 868-875.

Hellebrekers, L.J. Treatment of perioperative pain in dogs, cats and rabbits. Surgery.

Liles, J.H. and Flecknell, P.A. 1992. The use of non-steroidal anti-inflammatory drugs for the relief of pain in laboratory rodnets and rabbits. Laboratory Animals. 26: 241-255.

Sackman, J.E. 1991. Pain. Part II. Control of pain in animals. The Compendium. 13: 181-192.

Short, C.E. and Van Poznak,A. (ed) Animal Pain. 1992. Churchill Livingstone, N.Y.