Inflammation is the response of the body to an injury or infection. It actually helps the body fight off foreign invaders, such as bacteria. Classic signs of inflammation include redness, heat, pain, and swelling; loss of function can also indicate inflammation.
However, inflammation can sometimes become so severe that it has negative effects on the body. In these cases, anti-inflammatory drugs may be prescribed to help reduce or limit inflammation. Several different types of anti-inflammatory drugs are used in veterinary medicine, depending on the cause and severity of the inflammation.
Antihistamines selectively block specific histamine receptors in the body. One type, known as H1 antagonists, help reduce the itching and swelling associated with inflammation in certain skin disorders, and are also useful in the treatment of immediate hypersensitivity reactions, a type of allergy.
Corticosteroids are the most commonly used anti-inflammatory drugs. They can be highly effective in suppressing or preventing inflammation, but their effects also cause suppression of the immune response, which may increase the risk of infections.
Corticosteroids can be broken into 2 groups: mineralocorticoids and glucocorticoids. Mineralocorticoids are important in maintaining electrolyte (salt) balance. Glucocorticoids play significant roles in carbohydrate, protein, and lipid metabolism, the immune response, and the response to stress. Glucocorticoids can also affect fluid and electrolyte balance.
Glucocorticoids are commonly used to treat allergy and inflammation such as itching skin conditions and allergic lung and gastrointestinal diseases. In short-term allergic reactions or flea allergy dermatitis, these drugs can help relieve itching and limit self-trauma from scratching until the underlying cause is found. Glucocorticoids are also used in the management of chronic allergic bronchitis and feline asthma.
Nonsteroidal Anti-inflammatory Drugs
Nonsteroidal anti-inflammatory drugs (NSAIDs) have the potential to relieve pain and inflammation without the immunosuppressive and metabolic side effects that corticosteroids have. NSAIDs are often prescribed to treat musculoskeletal inflammation, osteoarthritis, pain following surgery, and laminitis and colic in horses.
There are many NSAIDs available for use in dogs, cats, and horses. Some, such as aspirin and acetaminophen are also used to treat pain in people. It is extremely important not to give these drugs to your pet unless directed by a veterinarian, however, as they can have serious adverse effects in certain species of animals. For example, cats have difficulty metabolizing aspirin and it stays in their system for much longer than in dogs, so it is rarely used in this species. Additionally, acetaminophen should never be used in cats.
There are certain compounds that have been identified as having a protective effect against inflammation and the degeneration of cartilage that occurs in some types of arthritis or tissue inflammation. Two of these compounds that are familiar to many people are chondroitin sulfate and hyaluronic acid, because they are also used to treat these conditions in people. Research is still ongoing as to the effectiveness and mode of action of these compounds, but it appears that they have few adverse effects.
Last full review/revision July 2011 by Philip T. Reeves, BVSc, PhD, FACVSc; Jörg M. Steiner, DrMedVet, PhD, DACVIM, DECVIM-CA; Dawn Merton Boothe, DVM, PhD, DACVIM, DACVCP; Maya M. Scott, BS, DVM; Ian Tizard, BVMS, PhD, DACVM; Jozef Vercruysse, DVM, DEVPC