Keesha presented for a Preventive Health Care Exam in the spring of 2008. Her owners felt that she was drinking a little more than previously and noted that she was having a very small amount of urinary incontinence. On physical exam she appeared to be a completely normal dog, and a urine sample was completely normal except that the urine specific gravity (a measure of concentration) while showing that Keesha’s kidneys were concentrating the urine, they were not concentrating it quite as much as we expected.
We ran a blood panel on Keesha and it was completely normal, there were no pointers or indications as to why her urine was slightly dilute so in discussion with her owners it was decided to monitor Keesha for any change over the coming months and recheck her if things worsened.
A couple of months later Keesha was back, she had started to have bigger urinary accidents: her owners described them as floods. We checked a morning urine sample and the USG was down to 1.015: barely more concentrated than her blood and a sign that something was not right. Since the urine was otherwise normal and her recent blood panel gave us no other clues, it was decided, in consultation with Keesha’s owners, to check to see if Keesha was actually able to concentrate her urine.
For this test, we check USG and also measure the concentration of the patients blood (her hematocrit) as a measure of the patient’s hydration status. We then withdraw water from the patient and under close supervision monitor hydration and urine concentration. A normal patient will start to concentrate their urine as soon as the blood starts to concentrate, limiting fluid loss and slowing the rate at which they become dehydrated. Keesha started the day at a USG of 1.015 (dilute) but by lunchtime her USG was 1.045 (concentrated).
This showed that Keesha was capable of concentrating her urine, but was not doing so. Limiting her water intake in should ensure she did not over- drink and so should ensure that she would produce smaller quantities of more concentrated urine. However, over the next few months we monitored Keesha’s USG and mostly, even with moderate water management her USG remained stubbornly low, so in early 2010 Keesha came back in for a recheck. We noticed immediately that her coat was not as good as it had previously been, and when we rechecked her bloods there were some change, slight increase in ALP and ALT, slightly increased blood sugar and a reduction in the number of the white blood cells called Eosinophils. These changes, along with her low USG and her coat changes suggested that Keesha might have a condition called Hyperadrenocorticism (Cushing’s Disease), where the adrenal glands produce too much of the hormone Cortisol.
We carried out the specific test For Cushing’s Disease and got a positive result. We discussed our findings with Keesha’s owners who decided that they would like to try a non-pharmaceutical treatment for Keesha that they had discovered online.
We kept in touch with Keesha and after a couple of months with no improvement in her coat, or her urine output, we started Keesha on a drug called Trilostane, which is one of the recommended therapies for Cushings Disease. However, even after several dose increases things had not improved for her. In fact they got worse. Her coat was getting much thinner, her thirst was getting worse and she was becoming ravenous, all signs of worsening Cushing’s.
In about 80% of Cushing’s patients the disease arises from a malfunction in the Pituitary Gland in the brain. These patients are usually easy to treat and do very well. In the other 20%, the condition arises from a tumour in one of the Adrenal Glands. These patients are harder to treat and ultimately have much poorer outcomes.
At this point we carried out an Abdominal Ultrasound to look at Keesha’s Adrenal Glands to see which type of disease Keesha had. To everyone’s relief Keesha had the Pituitary kind. There is another drug treatment for Cushing’s disease, which has a number of different names, Lysodren, Mitotane, OPDD. It is a specific chemotherapy agent which selectively destroys cells in the adrenal gland and reduces cortisol output. It is closely related to DDT, so you can guess why it was not our first choice treatment!
Keesha started treatment with Lysodren in November 2010, and by February 2011 after two upward dose adjustments her thirst was diminishing, but she was very itchy and her hair coat seemed worse not better. We performed skin biopsies and sent them off to a specialist dermopathologist. The results were interesting. The hairloss was attributed to all the old dead hair that had accumulated in Keesha’s coat falling out as the new hair was starting to grow. She also had signs of low grade allergic dermatitis which was probably been un masked as Keesha’s blood cortisol reduced with her treatment. We started bathing Keesha with a shampoo to soothe her skin, and over the next few months her coat slowly improved, her skin settled down, and her thirst and urine output were finally normal.
It was a long road to diagnosis and treatment, but Keesha triumphed over her disease, and thanks to the persistence and patience of her owners and her medical team is leading a normal life once more.
Keesha post treatment