That old cat got you down, Fido? Got a headache you just can’t shake? Well, there’s a new generic painkiller made just for four-legged friends like you.

Portland, Maine-based Putney Inc. has introduced its first generic drug approved for pets by the U.S. Food and Drug Administration. The painkiller is a generic version of caprofen, whose branded version, Rimadyl, is owned by Pfizer Inc. It is a non-steroidal anti-inflammatory drug similar to ibuprofen that Putney bought from Northern Ireland’s Norbrook Laboratories Ltd. after it was approved.

It’s a first step toward the company’s goal of developing its own generic drugs for approval by the FDA’s Center for Veterinary Medicine. Fully 86 percent of drugs used for animals have no generic equivalent, so there is a huge potential market, company officials say.

Many of the patents on the drugs have long since expired, and an additional FDA review of a drug for use in pets is a relatively short pathway. For instance, it took three years to develop and gain approval for the painkiller marketed by Putney. Compare that with the 10 or more years it takes to develop a human drug from scratch.

Putney was launched in 2006, and has, until now, been marketing human drugs available to veterinarians, a very common practice. Company officials say they have 20 potential generic pet-drug targets of their own in the pipeline.

CEO Jean Hoffman said the eureka moment came after she adopted a black cat named Dude, who needed to take an expensive human thyroid medicine. “I thought, I can make this cheaper and easier to administer by making a pet version,” she said.

Will competitors bare their teeth?
But the big dogs who control the animal health market may not roll over and play dead for generic upstarts. Total sales of animal medicines was $19.2 billion in 2008, up 7.2 percent over sales the previous year, according to British research firm Vetnosis Ltd. Giants like Pfizer, Wyeth, Schering Plough and Merck all have big pieces of that pie. In fact, the impending mergers of Pfizer with Wyeth and Merck with Schering Plough have prompted the FDA to instruct the companies to divest some animal health assets to avoid having too much market share. These assets will likely be put to auction ­— and there is expected to be no shortage of bidders. Officials at drug makers including Sanofi Aventis, Eli Lilly and Bayer have all stated they are looking to expand their animal health offerings.

Since there are fewer companies chasing the generic pet medication market, the cost savings on a generic pet drug are likely to be around 20 percent, analysts say — rather than the 80 percent discount on prices of some prescription drugs for humans, which have been driven down by fierce competition. But veterinarians like Lisa Moses of Angell Memorial Hospital in Boston, say that they would welcome any relief for pet owners.

“There are people who have to put an animal down because they can’t afford the drugs. I know of one case of a dog with resistant pneumonia — the antibiotic cost $1,500. Who can afford that?” Moses said most of her patients’ owners do not have pet health insurance and that even those who do usually do not have a prescription drug benefit. Moses said more competition would be good for the field.

Maine is also home to another player in animal health: Westbrook-based IDEXX Laboratories Inc. is a diversified company with several divisions, most in veterinary products and services. The largest business unit is the companion-animal division, which booked revenue of $193.7 million for the quarter ending March 31, down from $202.8 million in the year-earlier period, before the recession took hold. IDEXX, in documents filed with the FDA, wrote that the dropoff in business was largely from “fewer patient visits to U.S. and European veterinary clinics, for routine screening, preventive care and elective procedures.”

But company officials predicted that business would rebound along with the economy.