Identifying and treating chronic pain in pets
#painsucks…..pass it on.
September is Animal Pain Awareness Month and we, along with other members of the International Veterinary Academy of Pain Management (IVAPM), want to help spread the word that living with chronic pain sucks for animals just as much as it does for humans. The good news is that there are more options now to treat chronic pain in pets than there ever have been before. But before we tackle treatment options, let’s dive in to how chronic pain develops and what makes it so difficult to treat.
Acute vs chronic pain
Acute pain is described as “Pain that follows some bodily injury, disappears with healing, and tends to be self-limiting.” (1) So is all pain bad? Acute pain actually serves a purpose and from an evolutionary perspective, contributes to our survival by signalling to the brain that there is a threat to the body, and as a result, causes the body to adapt in a way that will minimize any further damage until the area has healed. In contrast, chronic pain is defined as “Pain that lasts several weeks to months and persists beyond the expected healing time.” (1) Chronic pain serves no protective function, and over time results in a change to the nervous system that ultimately alters the brain’s perception of pain, long after the painful stimulus has subsided. The longer that pain exists, the more sensitive that the body becomes to it and the harder that it becomes to treat.
But before we can even think about how we treat chronic pain we first have to be able to recognize it, and since animals have evolved to mask their pain as a survival mechanism, this can often be a challenge for pet owners and even for veterinary professionals.
Identifying pain in our pets
So where do we start? Before there is a perceivable limp and hopefully long before the animal is vocalizing or whining due to pain, owners will often appreciate more subtle changes in their pet's behaviour at home.
There are several common behavioural changes that are frequently associated with early signs of chronic pain. These signs are often misinterpreted as common signs of aging, and although age may be a factor, it is not a disease and does not in and of itself cause pain. Keep an eye out for any of the following:
Decreased activity including a reluctance to go on walks or play.
Difficulty going up and down stairs.
Reluctance to jump up onto surfaces (particularly in cats).
Decreased appetite.
Overgrooming or licking a particular area.
Difficulty standing or getting up after lying down for an extended period.
In addition to monitoring for changes in behaviour, we often recommend that pet owners fill out a client-specific questionnaire to help highlight some of the areas where their pet may be struggling. These questionnaires are not only useful for identifying chronic pain in pets, but are also helpful for tracking the progression of disease or improvement with treatment. Below are links to some of our favourite client-specific questionnaires for use in dogs and cats.
For dogs:
Liverpool Osteoarthritis in Dogs (LOAD)
For cats:
Client Specific Outcome Measures for cats
The treatment of chronic pain
Treating chronic pain can be both extremely rewarding and extremely frustrating, for the patient, the owner and the veterinary team. There is no one size fits all solution and it is important that the treatment plan be tailored to each specific patient, since every pet may have a different threshold for pain and a different response to treatment. In addition to being specific to the patient, the treatment plan must additionally be frequently re-evaluated based on the patient’s changing disease state, other medical conditions and other medications. What works for one patient doesn’t always work for another, and sometimes there is some trial and error required to find the right combination of treatments to keep the patient comfortable and stable.
Pharmaceuticals
Although there has been a gradual shift among pet owners to more natural or holistic treatments, when it comes to pain management our best defence continues to be the non-steroidal anti-inflammatories. Let me say it again for the folks in the back. ANTI-INFLAMMATORIES CONTINUE TO BE THE MOST EFFECTIVE TOOL THAT WE HAVE IN OUR PAIN MANAGEMENT TOOLBOX. In pets with longstanding chronic pain or for those with underlying organ dysfunction, additional or alternative medications are often used to target different aspects of the pain pathway. In some cases this involves attacking the pain from systemic or whole body perspective, in other cases it involves providing targeted pain relief directly at the site of pain (ie joint injections).
Nutraceuticals and Disease Modifying Osteoarthritis Drugs (DMOADs)
Nutritional supplements have become extremely popular in the veterinary industry as an aid in the management of osteoarthritis in pets. It is important to realize that joint supplements will be most efficacious in the early stages of joint disease, before significant joint pathology and cartilage destruction occurs. One of our favourite nutraceuticals are the omega 3 fatty acids for their role in helping to control inflammation, however it is often underdosed - check with your veterinarian to ensure that your pet is receiving an appropriate dose for their weight. DMOADs are another group of products that help to maintain the health of the joint by slowing cartilage breakdown and decreasing joint inflammation. Like the nutraceuticals, DMOADs will be most beneficial early in the course of joint disease.
Physical Rehabilitation
Physical rehabilitation uses an integrative approach to comprehensively treat physical injuries, mobility impairments and promote functional mobility. Patients with reduced mobility or suffering from injuries often experience pain and stiffness, weakness and incoordination, and overall difficulty performing normal daily activities. Chronic biomechanical dysfunction can not only contribute to ongoing pain at the primary site of injury, but can also lead to secondary myofascial strain. In many patients this secondary compensatory dysfunction over time can be more painful than the initial injury and is often a major contributor to the patient’s overall pain. With the increasing availability of physical rehabilitation and many of the non-pharmaceutical modalities at our disposal, we have a multitude of additional options for reducing chronic pain from a physical medicine perspective, including:
Therapeutic exercises
Hydrotherapy
Manual therapies
Acupuncture
Therapeutic laser
Electrical stimulation
Extracorporeal shockwave therapy
Pulsed-electromagnetic magnetic therapy
Environmental and Lifestyle Modifications
Small changes to your pet’s environment and lifestyle can have big impacts on their comfort and mobility.
Weight loss
Even a small amount of weight loss can make a big impact on the strain that is placed on our pets’ joints. Body condition scoring is quick and easy for pet owners to do at home and should be done on a regular basis (check out this link for more on body condition scoring in dogs and this link for cats). If your dog or cat falls into the overweight or obese categories, talk to your veterinarian about how to implement a safe weight loss program for your pet.
Moderate activity
Moderate, controlled leash walking at your pet’s natural pace continues to be the best exercise that you can do with your pet. Keep in mind that for our smaller breeds that often means that we have to slow our pace down quite a bit to ensure that they are walking rather than trotting for the duration of the walk.
Non-slip surfaces
As arthritic animals age and lose muscle mass, they also lose balance and proprioception (the ability to know where their limbs are in space), which makes slips and falls much more common in older pets. Providing your pet with some added traction around their environment can go a long way in reducing the risk of muscle or joint injury. This can be facilitated either by covering the slippery floors with non-slip surfaces (yoga mats, carpets) or by providing traction by adding rubber or silicone grips to the pet’s nails.
Assistive devices
There are a number of options out there to help our arthritic pets get around more easily. From stairs and ramps to harnesses and wheelchairs, there is a solution for every stage of arthritis ranging from mild to more debilitative. Supportive beds, stairs and ramps are easy things for most owners to implement on their own; when it comes to specialized harnesses and wheelchairs it is best to enlist the help of a professional.
Although chronic pain is one of the most debilitating, variable and frustrating conditions that we treat in veterinary medicine, unfortunately it is also one of the most prevalent. The good news is that there continues to more and more advances and options in the field of pain management everyday, allowing us to help our pets and patients have the best quality of life possible.
Dr. Sarah
(1) Gaynor, JS. & Muir III, WW. Handbook of Veterinary Pain Management, Third Edition. Chapter 4: Definitions and Terms Describing Pain, pg 63. Elsevier Mosby Inc, 2015.