The author's Labrador, M, was diagnosed with Cushing's disease in its latter stages. Dr. Holcomb encourages owners to have their dogs checked annually to increase the chances of catching a problem before it gets too far along.

Departing from his usual Q&A format, Dr. Tom expands on last issue's tribute to a favorite duck dog…and offers some valuable insights, as well.

A black Labrador puppy, who became known as "M," came into my life in December of 1998.

She was a gift from Bob Mann, a client of mine. Over time she became a very good duck dog. Throughout her growing years and into her final year she continued to perfect her skills as a retriever, working with a tenacity of purpose that occasionally got her in trouble.

I remember one day, teal hunting on a favorite pond, when one of us dropped a bird that swam to the opposite shore. By the time I realized things were not going as expected I could only see M's rear sticking out of the bank. I took off around the pond and found her, by then with just her tail sticking out of a hole in the bank. I had to actually pull her out backwards. No duck but at least I got my dog back.

Last fall we had three great mallard hunts just as the ponds and marshes were freezing up.

The pond we hunted on is large, deep and surrounded by timber down to the water's edge. It was the only one in the area that had not frozen over, and needless to say, the ducks were using it like mad.

In one of our heated battles with incoming mallards someone wounded one that, unknown to us, coasted over the silt dam at the upper end of the pond and fell on the partly frozen water. Only M knew it was there and before I could get her stopped she was out on the thin ice making the retrieve. Fortunately, all went well and she got back without complications.

As I worried about the dangers of the thin ice I had no way of knowing that another much more serious problem was beginning inside her. Over the next several weeks I noted an increase in her water consumption. She had always been a big water drinker but she was now drinking four to six quarts of water per day, and normal for a dog her size would be about four to six cups daily.

I also started to note a thinning of her hair coat, loss of muscle mass and a pot-bellied appearance to her abdomen. M had always been a chow hound so I was slow to pick up on how ravenous her appetite had become.

It was at this point that I realized there was something seriously wrong with my dog. It was in her best interest for me to step aside as her veterinarian and let someone with more objectivity handle the diagnosis and treatment plan. I called in my young associate, Dr. Jennifer Hoffelmeyer, and told her what M's history and clinical signs were.

We agreed that I would become a client and she would take over diagnosis and treatment options. I would make the final decisions. I had never put myself in the position of being the client before. I had always tried to combine the two in caring for my pets. I later realized how conflicting that dual role can be.

After doing a complete physical exam, Dr. Hoffelmeyer obtained samples of blood and urine from M for a base profile. Fortunately we had the results of a blood profile that I had run in April 2008 as part of her annual physical. All values were well within normal range at that time.

Following completion of the in-house lab work Dr. Hoffelmeyer informed me that M had a high white blood count and that the differential white count showed a stress response or response to high levels of steroids. The serum chemistries showed high liver enzymes with especially high alkaline phosphatase. Her BUN was mildly elevated, indicating possible low grade kidney issues. Urinalysis confirmed mild urinary tract problems.