Steroids are used in dogs to treat inflammation and immune-related diseases, including allergic reactions, inflammation from arthritis and intestinal inflammation. Anti-inflammatory steroids called glucocorticords, a synthetic form of the hormone cortisol, are typically used. Generally prescribed orally, glucocorticords are started at a certain dose and slowly tapered down to lower doses until the steroid treatment can be stopped, as it can cause numerous side effects.
Short-Term Side Effects
Dogs on a glucocorticoid treatment program often have an increase in thirst and appetite. This side effect is usually followed by an increase in urination (and possible incontinence), stomach upset and weight gain. Steroids can also affect the dog's mood, making it irritable. Dogs also may become lethargic and begin panting incessantly. Steroids can also bring back a latent infection or tip pre-diabetic dogs into a diabetic state. Usually, diabetic symptoms and the other side effects diminish or resolve themselves once the steroid wears off.
Dogs that are given steroids continually over a period of months may develop more severe side effects such as Cushing's disease. The steroid triggers internal changes in the dog's body, resulting in an over-production of cortisol. Resultant symptoms/side effects include skin lesions that can form scabs over time or thin skin that is prone to red, angry patches. The dog may start to develop blackheads, lose hair and have poor ability to heal wounds.
Other Side Effects
Dogs that have been using steroids for four months or longer may become obese and lose muscle strength. Also, dogs who have had urinary infections in the past are 30 percent more likely to get these infections again. They may also develop Calcinosis cutis, hard plaques made of calcium that build up on diseased skin. The dog will also be prone to fungal infections in the nasal cavity and other opportunistic infections.
Dogs may develop adult onset demodectic mange with prolonged steroids. Demodectic mange is a mite infestion that usually occurs in puppies. Dogs over 2 years of age that get demodectic mange are diagnosed with adult onset demodectic mange. These dogs are usually immuno-compromised, are under prolonged steroid use or have Cushing's disease.