The U.S. Food and Drug Administration has announced the approval of the first drug developed specifically for the treatment of cancer in dogs, The Oregonian reports.

The drug, Palladia, is manufactured by Pfizer Animal Health. It is approved to treat mast-cell tumors in dogs, a type of cancer responsible for about 20 percent of canine skin tumors, according to the FDA.

While mast-cell tumors are often small, they can be a serious form of cancer in dogs. Some of these tumors are easily removed without further problems, while others can lead to life-threatening disease.

All cancer drugs now used in veterinary medicine originally were developed for use in humans and are not approved for use in animals by the FDA, although since 1994 it has been legal to prescribe certain drugs intended for humans to animals, the paper said.

Palladia works in two ways: by killing tumor cells and by cutting off the blood supply to the tumor. In a clinical trial, Palladia shrank tumors significantly, compared with a placebo.

The most common side effects associated with Palladia are diarrhea, decrease or loss of appetite, lameness and weight loss, the paper said.

Photo of dog courtesy of Repoort on Flickr.