Everyone makes mistakes. That includes pet owners who like to think of themselves as diligent.

Yesterday Denise, Buster, and I were driving home after a couple of days in Tahoe. We pulled over to run a quick errand. Since the weather was cool and there was no chance of overheating, we left Buster in the car while we took care of the chore.

On the way back to the car, I had a painful revelation. We had left Buster unattended with our leftover dinner from the night before. We assumed that our Black Lab had devoured some juicy BBQ chicken in our absence.

Buster, it turned out, either didn’t smell the chicken (which seems implausible) or wasn’t hungry — which seems impossible for a Labrador Retriever, especially when BBQ chicken is involved. For reasons that only Buster knows, he didn’t touch the leftovers.

Our near miss reminded me of a similar story from several years ago that had a different outcome.

Buddy was a friendly and easy-going Pit Bull who bore an uncanny resemblance to his owner. Both were affable and stocky. Both sported short gray hair. And both, it turns out, liked burritos.

Buddy’s owner didn’t know about his dog’s penchant for Mexican food until they went to San Francisco’s Mission District to pick up a super burrito with carne asada. On his way home he stopped at the post office. He was out of the car for no more than one minute. The burrito was left on the dashboard. The owner assumed that Buddy, a none-too-limber dog, would not be able to reach the meal.

When the owner returned to the car, the burrito was gone. There was no trace of it — or the bag and aluminum foil that wrapped it. Buddy sat placidly in the backseat as if nothing had happened. He didn’t even lick his chops.

Later that night at home, the aluminum foil reappeared. Chunks of it erupted from Buddy’s hind end along with copious diarrhea that soon covered the owner’s floor and walls. Buddy began to vomit and became dangerously dehydrated.

When I saw Buddy in the morning, he was suffering from a raging case of pancreatitis. Pancreatitis occurs when the pancreas, an organ that helps to digest food, becomes inflamed. In dogs, this happens most often after consuming a large quantity of very fatty food — such as a carne asada super burrito.

It took a few days of treatment before Buddy was back on his feet. The owner assumed that all would be well as long as he swore off burritos.

However, the pancreas does more than help digest food. It also secretes the hormones that control blood sugar. Buddy’s pancreas had been so severely damaged by the incident that it could no longer perform this function and he developed diabetes.

Buddy was a big dog, which meant that he required large quantities of expensive insulin. It also took several months to get the diabetes regulated. And, like many diabetic dogs, Buddy’s insulin requirements often changed. He required frequent blood tests and dosage adjustments.

Diabetes predisposes dogs to cataracts and blindness. Before long, Buddy developed severe cataracts in both eyes. His owner took him to a veterinary ophthalmologist for cataract surgery — twice.

Buddy ultimately lived out a long and comfortable life. But that was one very expensive burrito.

For the sake of your dog and your wallet, I strongly recommend that you never leave food unattended with your dog.