That said, if these ingredients change, or if the relative amounts of the ingredients on the food label are different from what the dog is used to, the flora in the GI tract may experience a sudden shift, where one particular species of bacteria may "overgrow" another,leading to GI upset.

What's the best way to introduce a new food? Gradually. Do it over a 3 week period to allow the GI flora to "compensate". Here's a sample schedule:

Week 1: Mix 25% new ration with 75% old ration

Week 2: Mix 50% new ration with 50% old ration

Week 3: Mix 75% new ration with 25% old ration

Week 4: 100% new ration

In most cases, this gradual change-over will spare your dog any GI upset caused by the food switch.

Two weeks ago, we touched on the trend toward an increasing veterinary student debt load as one reason that the cost of pet health care keeps going up. Here's a second trend:

Trend 2: The Increase In The Number of Corporate-Owned Veterinary Practices

When I opened up my first veterinary practice in 1987, all veterinary practices were privately owned. However, beginning in the late nineties, a number of practices began to coalesce into large, multi-group corporations that have since gobbled up hundreds of other practices or opened new ones across the country. While you gain the advantage of procedural uniformity and expectancy when you visit one of these "corporate" practices, you also get that same uniformity, plus a high degree of inflexibility, when it comes to pricing. Which means that a pet owner in Texas may be paying the same prices as a pet owner in California, where veterinary fees are among the highest in the country.

While this is by no means the "rule", it's still a concern. The other concern is loss of veterinarian discretion. As a private practice owner, I have the option of lowering a particular fee or eliminating it altogether in special circumstances. Veterinarians employed by corporations usually lack such discretion. I know. I've done relief work at a few of these corporate practices over the years.

Don't get me wrong. I'm not knocking the quality of medicine that these corporate practices provide. In most cases, it's excellent. But they can be pricey. And the centralized computers connected to the home office rarely, if at all, allow for price adjustments. Good for the bottom line, but bad for that pet owner who finds himself/herself in a difficult financial situation.