Senior Dogs and Cushing’s Disease
I have a Schnauzer, Pongo, who is 7 or 8 years old. He is a rescue dog, therefore his age is a guesstimate. He was diagnosed with Cushing's Disease a year ago and is on Lysodren 500 mg three times a week. He is also checked every six weeks with a loading dose and follow-up blood work. Pongo still pants and drinks excessive amounts of water. Of course, he has the pot belly, eats a premium dry food (a handful for breakfast and dinner), and goes on a daily walk with me after sun down.
Any Information you have would be great as I'm just trying to learn as much as I can about this disease.
Thank you so much,
Read Dr. Sherry Weaver’s Advice
You have described the classic symptoms of Cushing’s disease: pot belly, increased appetite, panting, and excessive water intake and urination. The disease is extremely common in middle-aged and older dogs. In a situation like yours, with proper diagnosis and ongoing treatment, the symptoms should be controllable.
I would first ask your vet if you could regulate the hormone levels any more tightly. There are ranges of acceptable values on the follow-up lab results, so there may be some leeway in the medication dose.
Since a common side effect of Cushing’s is bladder or kidney infections, make sure your vet has done a urinalysis recently. Sometimes these infections don’t show up well on a urinalysis, so a urine culture would also be a reasonable way to rule this out.
When your vets are checking your dog's cortisol levels, they should also periodically evaluate kidney and liver enzymes, electrolytes, and blood glucose in order to rule out the secondary problems associated with Cushing’s diseases. Diabetes is not an uncommon secondary to Cushing’s, and symptoms can look very much like the Cushing’s itself.
Finally, if there is no more room in the dose regimen and the blood work is completely normal, it is time to evaluate the abdomen separately. In older dogs, Cushing's can happen concurrently with other illnesses such as intestinal or heart disease and cancers. For patients who don’t respond appropriately to Lysodren but normalize their blood levels, I recommend an abdominal ultrasound. Often if the liver enzymes are elevated (which can be caused by Cushing’s), I will even do a needle biopsy of the liver to rule out other reasons for liver insufficiency.
Taken separately, each of the symptoms of Cushing’s can mean many things. When a dog’s symptoms do not go away with appropriate treatment, we should take a step back and start to look at each symptom separately to see if we can find the missing puzzle piece that makes it all make sense.