According to the New York Times:
[A]cross the country, veterinarians who care for the animals that provide the United States with food are in increasingly short supply.
For one, there is generally more money to be made caring for cats and dogs. And with fewer students from farm backgrounds, fewer gravitate to rural jobs, especially if a spouse needs work, too. Large-animal care can be tough, even dangerous — think of maneuvering in frigid weather around 1,000-pound cows in manure-filled pens. And more veterinarians are women, generally less inclined toward large animals.
Since 1990, the number of veterinarians focusing on large animals has dropped to fewer than 4,500 from nearly 6,000, according to the American Veterinary Medical Association, which said those doctors now made up less than 10 percent of private-practice veterinarians. A recent study predicted that by 2016, 4 out of every 100 food-animal veterinary jobs would go unfilled.