Pain management in veterinary rehabilitation

The veterinary profession is slowly coming to the realization that treating pain is a fundamental part of practicing good medicine. Research and clinical experience have debunked outdated assumptions about the biology of animal pain, and the number of treatment options and their efficacy continues to increase. There is growing concern in our society for the ethical and compassionate care of animals, and pet owners are routinely seeking out practices that provide comprehensive and humane care.

Home care: Make sure your pain-management protocols take into account the fact that animals can experience postoperative pain days or possibly weeks after a procedure - even those rehabilitating from elective surgeries. (PHOTO: SARAH M. GOLONKA/GETTY IMAGES)

Adding pain management to a practice is not difficult or time-consuming, and profit margins on drugs and services can be significant. Indeed, pain management provides one of those rare convergences of benefits for the patient, satisfaction for the client and economic health for the practice.

Busting the myths about animals and pain

For a long time, misunderstandings about the way animals experience pain devalued the concept of pain management in the veterinary community.

Myth 1: Animals do not feel pain like people do. In fact, the basic anatomy, physiology and biochemistry of pain are remarkably similar in animals and people.

Myth 2: Pain benefits an animal by limiting its activity. Pain may actually make it more difficult to control an animal's activity because unmanaged pain can trigger a stress response, including increased arousal and other changes detrimental to healing.

Myth 3: Elective surgical procedures do not require "take-home medication." Acute pain is most intense during the first 24 to 72 hours after surgery, but pain often persists for days or even weeks after the patient returns home. Postoperative pain is not determined by whether the surgical procedure is elective or not.

Myth 4: Animals tolerate pain better than people do. Human and animal pain thresholds are about the same. Animals, however, will instinctually hide the signs of pain so potential predators do not see them as easy prey. This behavior is true even in pets.

Myth 5: Pain relief "masks" physiologic signs of patient decline. In cases in which pain management is effective, patients are less likely to experience detrimental tachycardia, hypotension and other stress-induced abnormalities. Blood pressure, heart rate and partial pressure of carbon dioxide and oxygen will all still change and can be monitored for evidence of patient decline.

Myth 6: Analgesics are toxic and can cause adverse events. When used appropriately, many analgesics are considered safe and effective for pain management. As is the case with any medication, it is the responsibility of the veterinarian to weigh the risks and benefits and make the appropriate recommendation for each patient.

Myth 7: Pet owners won't pay for pain control. The reality is that the vast majority of pet owners see their animals as members of the family. They are sensitive to their pets' comfort and well-being and are likely to pay for what they perceive as compassionate care.

The multimodal approach to veterinary pain management

Many medications available to treat pain in animals are considered safe and effective, including both analgesic and anesthetic drugs. These drugs can be used preemptively or perioperatively to head off pain. They can target existing pain and help manage chronic conditions. In patients with more severe pain, several drugs targeting different pain pathways can be used in combination to provide relief.

Evidence suggests that combining drug therapies with the therapeutic modalities used in human physical therapy can significantly improve outcomes for patients. An accurate diagnosis is critical to developing a therapeutic plan that doesn't just rely on the old standbys: rest and NSAIDs. Hot and cold therapies, electrical stimulation, laser therapy and therapeutic ultrasonography can all be used to help control pain in animals. Ideally, these modalities should be performed by a certified rehabilitation professional with the training and hands-on experience to ensure that they are used properly. The various modalities are described below:

• Heat therapy is generally used to reduce pain from arthritis, trigger points and muscle spasms. Heat creates vasodilation, leading to increased local circulation, a decrease in pain, relaxed muscle tone, reduced muscle spasm, an increase in tissue extensibility and cellular metabolism and improved local tissue oxygenation. Heat can be applied with hot packs, infrared light, hydrotherapy and therapeutic ultrasound.

• Cold therapy creates analgesia by decreasing nerve conduction velocity. It is commonly used in the acute period after injury or surgery. Cold can be applied via ice bath, ice massage, ice pack, vapocoolant gel or circulating ice compression units.

• Electrotherapy works to control pain at many levels, affecting both sensory and motor nerves. Transcutaneous electrical nerve stimulation (TENS) creates an overload of interneurons that limits the ability of sensory nerves to transmit pain signals to the brain. TENS is used immediately postoperatively and during therapy to help a patient work through a painful treatment. Neuromuscular electrical stimulation (NMES) rehabilitates muscles by stimulating the motor nerve that causes the muscles to contract. NMES can be used to help prevent muscle atrophy, increase local blood circulation and maintain or increase joint mobility.

• Low-level laser treatment also can be used for pain management. The physiological effects include accelerated cell division via mitochondrial stimulation, increased leukocyte phagocytosis, stimulation of fibroblast production, enhanced synthesis of ATP and angiogenesis.

• Therapeutic ultrasonography provides pain relief by creating deep local heating, an increase in blood flow and breakdown of scar tissue. This modality can be used in veterinary rehabilitation to treat a number of conditions, including joint swelling, muscle spasms, strain lesions and bicipital tenosynovitis.

A multimodal approach to pain management can also include dietary modifications, exercise therapies, acupuncture and nutraceuticals. Many resources are available to veterinary professionals interested in learning more about the principles and applications of multimodal pain management, including the International Veterinary Academy of Pain Management (IVAPM). The IVAPM is dedicated to promoting, advancing and enhancing pain management in animals. Membership is inexpensive, especially if multiple members of a practice join. Visit their Web site at www.IVAPM.org.

Conclusion

The successful veterinary team recognizes the need to combine meticulous diagnosis methods with a multimodal approach to therapeutics, keeping pain management a top priority at all times. Today's clients expect their veterinarians to provide appropriate pain management for their pets. Gone are the days when pain therapy would be offered as an option for patients going home from the hospital. Pain is now being addressed with preemptive approaches, new drugs, alternative routes of administration and a focus on diagnostic techniques that allow veterinarians to provide better — and more humane — care.

Dr. Van Dyke is the founder and CEO of the Canine Rehabilitation Institute in Wellington, Fla., with locations in Fort Collins, Colo., and Annapolis Junction, Md.