Veterinarians, who have traditionally derived about a fifth of their gross income from pet medicines, face ever-new rivals scrambling for a piece of this business in which dog and cat owners may pay markups of 100 to 300 percent on prescription drugs.

It has been years since the entry of mail-order veterinary pharmacies, which have since morphed into online merchants like Wisconsin-based Foster & Smith. But in 2010, Target launched its PetRX pilot program in more than 100 stores in Georgia, North Carolina, Georgia and Minnesota, and other retailers are getting into the business.

"Internet pharmacies are not our real competition, but rather the local discount pharmacies," Tennessee veterinarian Ronald Whitford said in an article written for others in the profession last year. "Anytime you cannot dispense with at least a 30 percent markup you lose! And even then it is not worth the time and effort."

But 30 percent is an excellent profit margin for high-volume chain retailers.

Target's PetRX is now in 670 stores in 25 states, including Texas, spokeswomen Erin Medsen said.

"The program has been really well-received," Medsen said, noting that Target pharmacists can add flavors like chicken, tuna and roast beef to make liquid medicines more palatable to Rover or Princess. All Target locations with pharmacies not in the program can still dispense drugs for people and pets, she added.

Walgreens has been filling such scrips since at least 2009, when it sold 400,000 in 10 months, according to VIN News Service, which covers the veterinary medicine industry. A spokeswoman said pets can be enrolled in the chain's family prescription plan, but stores mostly carry crossover drugs suitable for people and some pets.

In the past year, Kroger stores quietly rolled out their own pet med program in North Texas and across the country, frequently undercutting veterinarians' prices, particularly on drugs in its $4 generic program like common antibiotics for animals and people.

Read the complete story at star-telegram.com