Multimodal Management in Arthritis

Arthritis is seen at different life stages in dogs and cats. In younger patients, specially large-breed dogs, it is a result of bad breeding practices resulting in larger joints getting affected (hip/elbow dysplasia). In older dogs and cats, it is the result of age-related degeneration, coupled with obesity, nutritional deficiencies and lack of exercise.

Whatever the cause, the symptoms range from stiffness, crepitus in joints, decreased mobility, reluctance to exercise, limited range of motion as well as pain of varying degrees. Hence pain management of arthritis becomes very important in older patients to improve quality of life. Finding successful treatments against canine osteoarthritis-related pain is challenging due to multimodal pain pathways. The pain associated with osteoarthritis is considered to be chronic, owing to both active inflammation and to a maladaptive component caused by signals sent to the brain. There is no one single drug that will manage (far less cure) arthritis, making a multimodal approach necessary. In order to understand multimodal approach to pain relief, we need to understand the origin of pain. Osteoarthritic pain has three different origins: inflammatory, nociceptive and neuropathic.
•    Inflammatory pain occurs due to joint inflammation caused by wear and tear or lack of lubricating fluid causing friction.
•    Nociceptive pain is a medical term used to describe the pain from physical damage or potential damage to the body.
•    Neuropathic pain is a medical term used to describe the pain that develops when the nervous system is damaged or not working properly due to disease or injury.

So how are these different types of pain addressed?
Inflammatory pain needs NSAIDs or non steroidal anti-inflammatory drugs. These drugs are generally safe, although they need to be given carefully under medical supervision since they have the potential to cause gastric irritation. They can also cause toxicity if the liver or kidneys are damaged, hence regular blood tests to monitor kidney and liver function are needed. Neuropathic pain is modulated via a blockade of calcium channels or increasing GABA receptors in the brain. Due to this mechanism of action, it can be used for pain management in dogs affected by osteoarthritis with minimal side effects, though owners should be warned about possible sedation when beginning administration. Nociceptive pain needs medicines or supplements acting on the central nervous system. Certain anti-anxiety medicines called tricyclic antidepressants as well as medical grade hemp oil (cannabis sativa) can be used.

Due to knowledge of these pain pathways, the healthcare market is flooded with several nutraceuticals. Supplements containing hemp oil, Boswellia extract, ginger/turmeric extracts, and extracts of a flower called acmella have shown promising results. However, pet parents should be careful in choosing the right products since the phytoactives in plant extracts work differently in humans and animals. Also the assumption that all plant products are safe should not be accepted as a thumb rule, since many plants are poisonous to dogs and cats. Lets discuss a few of these bioactives:

Cannabis sativa (hemp oil): For chronic arthritis or spondylosis, phytocomplex of sativa composed of molecules like terpene, flavonoids and phytocannabinoids is more effective than a single molecule. These molecules are extracted from the hemp plant after the psychogenic component, THC, is removed, making it safe for use.

Boswellia: Its purified extract, Boswellic acid, is thought to contribute to most of the herbal pharmacologic activities. Boswellic acid counteracts the effect of inflammatory mediators in the body, thus reducing inflammatory pain. Standard preparations of Boswellia show overall modest anti-inflammatory effects, which may ultimately lead to reduced efficacy. In an effort to improve its pharmacokinetic properties, Casperome, a lecithin-based formulation of Boswellia serrata extract was developed. This formulation is much more effective in the treatment of arthritis and spondylosis compared to standard extracts of Boswellia.

Ginger extracts: A recent formulation combining purified extracts (phytoactives) of ginger and acmella flower called Mitalgol, has shown good results. Mitalgol is formulated using a patented technology to optimise intestinal absorption and has a dual effect of down regulating inflammation and reducing oxidative damage to joints

Omega 3 fatty acid supplements also help reduce inflammation.