Owners often ask what “stage” their dog’s Cushing’s disease is in. Unlike some cancers, canine Cushing’s disease does not have an official, numbered staging system. It does, however, tend to progress in a recognizable way when it is not treated, and knowing that pattern can help you and your veterinarian stay ahead of it.
Early, Subtle Changes
In the beginning, the signs are easy to dismiss as ordinary ageing. You might notice your dog drinking a little more, asking for food more insistently, or seeming slightly less energetic. Because these changes are gradual, weeks or months can pass before an owner connects the dots. Catching the disease at this point — often through routine bloodwork that shows an elevated liver value — can make management smoother.
Established Disease
As excess cortisol continues, the more classic picture develops: markedly increased thirst and urination, a bigger appetite, a pot-bellied shape, symmetrical hair loss and thinning skin, panting, and reduced stamina. This is the stage at which most dogs are diagnosed, because the changes are now hard to ignore. Starting treatment here typically brings clear improvement over the following weeks and months.
Advanced or Complicated Disease
If Cushing’s disease goes untreated for a long time, the ongoing effect of high cortisol raises the risk of complications: persistent urinary tract infections, high blood pressure, muscle weakness, and a greater tendency to form blood clots. Some dogs go on to develop diabetes. In the small number of dogs with a large pituitary tumor, neurological signs such as disorientation or behavior changes can appear. These complications are exactly what timely treatment and monitoring aim to prevent.
Progression During Treatment
Once treatment begins, the goal shifts from “progression” to stability. Most dogs move into a well-controlled phase where the signs recede and quality of life improves. Doses may need occasional adjustment over the months and years, which is why periodic recheck testing is so important — it lets your vet catch drift in either direction, including cortisol dropping too low.
Why Early Action Helps
Because the disease tends to advance slowly, there is often a real window to intervene before complications set in. If you have noticed the early symptoms, an unhurried conversation with your veterinarian is worthwhile. For an authoritative overview of how the condition develops, see the Merck Veterinary Manual.