Honestly, he became a lot like my husband.” Danny the Dachshund is 10 years old, has gained 5 pounds, loses his hair, has trouble sleeping all day and has to get up to pee at night. Stealing a look at the dozing man holding Danny in his plump lap, I got it.
“So he’s just an ‘old dog’, isn’t he, Dr. Ward?”
For a second, I didn’t know if she was referring to the spouse or the hot dog. I went with the latter.
What is Cushing’s disease?
As we say in medicine: “Age is not a disease.” I am more concerned about a hormonal disease that is quite common in Dachshunds called Cushing’s Disease.
Cushing’s disease, also known as Cushing’s Syndrome or hyperadrenocorticism (HAC), is a condition that produces an excess of the hormone cortisol. It is usually diagnosed in middle-aged and older Beagles, Boston Terriers, Boxers, Dachshunds, Miniature Schnauzers, and Poodles, although any breed can develop hyperhidrosis.
If I suspect a dog has hyperadrenocorticism, I would start with basic blood and urine tests. If the patient has elevated liver enzymes (especially very high ALP and slightly elevated ALT), high cholesterol, glucose and triglycerides, low urine specific gravity, urine glucose, protein or evidence of infection, then Cushing will at the top of the diagnostic list. .
Danny meets many of these screening criteria, which means it’s time for confirmatory tests. Cushing’s syndrome is caused by a benign tumor of the pituitary gland (estimated in 85% of cases), a malignancy of the adrenal gland (rare but more serious), or excessive steroid use (iatrogenic HAC).
Time to check
There are several tests to choose from, each with its own pros and cons. The first is the Urine Cortisol / Creatinine Ratio (UCCR). This test requires dog parents to collect two urine samples the first morning at home, usually two to three days after a potentially stressful event such as a vet visit, boarding, or brushing. hair. I use the UCCR as a convenient screening test whenever a patient cannot easily get to the clinic or if my index of suspicion is a bit low.
UCCR is very sensitive, which means that if a dog has a normal result, it is most likely not Cushing’s. Unfortunately, UCCR isn’t too specific, meaning a positive result may not be due to Cushing, requiring additional tests to confirm. Despite these limitations, UCCR is an excellent starting point for initial testing, especially in breeds at risk or those with early or mild symptoms.
The most common and arguably the most preferred evaluation for Cushing’s Syndrome in dogs is the Low-Dose Dexamethasone Suppression (LDDS) test. The main limitation of this test is that it requires eight hours in the clinic, and blood samples must be handled and prepared with care.
In the simplest terms, the patient was given a drug, dexamethasone, to suppress adrenal function, and blood cortisol levels were measured after 4 and 8 hours. Based on grades and elevations, a diagnosis is made. In about 70 to 80% of cases, this is the only test needed.
The ACTH response test is another classic Cushing test that involves the administration of the hormone ACTH and the measurement of exaggerated cortisol stimulation results. This is the gold standard test for diagnosing Cushing’s disease (i.e., steroid injections) and requires only one to two hours in the clinic. Compared to LDDS, it is less sensitive and is usually intended for special situations or as an add-on to LDDS. Some veterinarians prefer to start with an ACTH response test, especially in dogs that have been prescribed certain medications, especially steroids.
Endogenous ACTH and imaging (ultrasound, MRI, CT) are also excellent options for diagnosing or verifying Cushing’s disease in dogs, but are more complex and often more expensive.
Cushing’s Treatment
In Danny’s case we did an LDDS test and he was positive. As his symptoms worsened and affected his quality of life, not to mention the stress of peeing at 2am and the accidents that happened to his family, we decided to treatment determination.
I choose the newer trilostane (Vetoryl) over the classic mitotane (Lysodren) because I find it less likely to cause side effects and is easier to take once or twice daily with food. I instructed Danny’s owner to carefully monitor any potential side effects, including vomiting, diarrhea, listlessness, and not eating for 48 hours. Those signs could indicate an adverse event known as an Addisonian crisis, which requires immediate medical attention.
Danny underwent follow-up ACTH response testing at 14, 30 and 90 days to determine his dosage. Within a few months, his dog’s mother reported that his energy increased dramatically, drank and peeed less, lost weight (3 pounds!) and his fur started to grow back.
He has had very few side effects from the drug other than some movement disorders and a few loose stools. All in all, Danny the Dachshund is becoming more and more like his dog dad. That led to an unusual question from Danny’s dog’s mother: “Dr. Ward, would you mind giving my husband some of Danny’s medicine? ”
Cushing’s disease, also known as Cushing’s Syndrome or hyperadrenocorticism (HAC), is a condition that produces an excess of the hormone cortisol.
Keep a look out
The most common symptoms include:
- increased thirst and urination
- increased appetite and weight gain
- bloated belly (pot belly)
- weak
- comatose
- gasp
Many dogs with Cushing’s Syndrome will also have:
- Diabetes
- chronic skin infections
- underdeveloped hair resulting in thinning or balding areas, especially along the sides of the back and hips
- oily or greasy coat
