Controlling Colitis in Dogs with Sulfasalazine

Sulfasalazine is a drug used to treat colitis in dogs. Colitis is when a dog's large intestine becomes inflamed and painful.

Colitis in Dogs Explained

Colitis is a general term used for a variety of gastrointestinal conditions that can affect a dog's large intestine (colon): inflammatory bowel disease (IBD), spastic bowel syndrome (SBS) and acute colitis (AC). A dog can acquire colitis if he's anxiety-prone or has environmental causes of stress.

A dog affected with colitis will typically be constipated, have diarrhea, nausea and may even lose weight. Any dog can develop this condition, but Boxers are notoriously known for being more susceptible to having colitis.

Colitis is not a particularly dangerous medical condition, but can become life-threatening if left untreated. Veterinarians will typically treat colitis in dogs with antibiotics if the illness is caused by bacterial agents. If caused by parasites, a deworming or anti-parasitic medication will be prescribed. A popular drug for the treatment of colitis in dogs is sulfasalazine.

Controlling Colitis in Dogs with Sulfasalazine

Sulfasalazine, a sulfa drug, is prescribed to dogs to help control bowel inflammation. It's made by combining sulfapyridine (an antibiotic) to salicylic acid. The ingredients in the medicine remain bonded as they travel through a dog's large intestine to the colon. The bacteria within the colon separate the ingredients and the antibiotic is absorbed as the salicylic acid coats and helps ease inflammation within the bowel.

Sulfasalazine comes in tablet-form and is usually administered three times per day for a period of three weeks or less.

Side Effects of Sulfasalazine

The most reported side effect of sulfasalazine is dry eye, as a dog taking this medicine won't produce as many tears. This reaction typically occurs in dogs that have been taking sulfasalazine for an extended period of time. Signs of dry eye in a dog taking sulfasalazine are noticeable eye irritations and squinting. These side effects usually go away after the use of the medicine has discontinued. 

Other side effects have also been reported, but are rare. Inflammation throughout the body can occur while a dog is taking sulfasalazine for colitis, including inflammation of the kidneys, eyes, muscles and joints. A fever may accompany this inflammation. A rash could also develop in response to the treatment and will go away when the dog no longer takes sulfasalazine. In some extreme cases, dogs taking sulfasalazine for colitis have developed liver failure or hepatitis. Signs of a failed liver include nausea and jaundice, which can be noticed when the whites of a dog's eyes and gums turn a shade of yellow. The composition of a dog's bloods cells could change in proportion, a condition called blood dyscrasias. This change in blood cells can weaken a dog's immune system. The sulfa component of sulfasalazine can also cause a dog to lose red and white blood cells along with platelets. Make sure your vet is aware of all the medications the dog is taking, to make sure no dangerous drug interactions occur.

When a dog is suffering with colitis, the use of sulfasalazine can help ease the inflammation that accompanies it.