Symptoms of Cushings Disease

[Wylie's Mom]

Symptoms of Cushings:

Some dogs with Cushing’s disease show the classic symptoms, while others show only a few vague symptoms. The classic symptoms are:

- Polyuria/polydipsia (PU/PD)- This is excess urinating and excess drinking of water. It is one of the first signs of the disease, and usually precedes the other symptoms by a significant period of time. Several other important diseases cause these symptoms also, notably liver disease, kidney disease pyometra, and diabetes mellitus (sugar diabetes).

- Pot bellied abdomen to the point a dog might look pregnant. It is due to hepatomegaly and abdominal muscle weakness (the mechanism of which was described above in the physiology section).

- Thin skin and usually symmetrical hair loss along the trunk. The hair might grow in lighter in color or lose its luster. It might not grow in well at all. Calcium deposits under the skin, called calcinosis cutis, occur on occasion. Secondary skin infections called pyoderma are common also. The skin might also be hyperpigmented.

- Muscle wasting over the head, shoulders, thighs, and pelvis.

- Polyphagia- excess appetite. This is often interpreted by clients as being healthy, since most people think of a sick pet as not eating well. In this case your pet is over-eating, which is consistent with Cushing’s.

- Other occasional symptoms include:

-Pruritis (itchy skin)- due to secondary bacterial, fungal, or parasitic infections of the skin
-Recurrent infections of skin, ears, eyes
-Panting- due to affects on the lungs or the respiratory center in the brain
-Obesity
-Anorexia (poor appetite)
-Straining to urinate or blood in urine due to urinary tract infection or bladder stone
-Weakness
-Depression
-Aggression
-Lethargy
-Corneal plaques
-Irregular heat cycles in female dogs
-Testicular atrophy in males and clitoral enlargement in females
-Emesis (vomiting) due to pancreatitis
-Ataxia (incoordination), blindness, circling, and seizures due to a large pituitary tumor or spread of a malignant adrenal tumor
-Lameness due to a ruptured cruciate ligament
-Intra-abdominal bleeding near the kidneys (retroperitoneal space) resulting in anemia, weakness, and abdominal pain

Info on difference btwn ACTH and LDDS Cushings tests:

ACTH stimulation is a good screening test in the first instance and is the test of choice for diagnosing iatrogenic Cushing’s and monitoring anti-adrenal therapy. It has a lower false positive rate than the low-dose dexamethasone suppression test but a significant false negative rate. It will reliably diagnose about 85% of PDH cases but only 50% of ADH cases. It is quick and simple to perform and is less affected by stress and non-adrenal illness. The initial values are useful as a reference to monitor effectiveness of treatment.

Low-dose Dexamethasone screening test is more sensitive than the ACTH stimulation test in confirming HAC. Diagnostic sensitivity is almost perfect (>95%) meaning that false negative results very seldom occur giving us tremendous confidence in a negative test result. Unfortunately, false positive results are common especially when there is concurrent non-adrenal illness or other sources of stress. Positive results of the low-dose dexamethasone test should be regarded with suspicion in dogs known to have significant non-adrenal illness. Ideally, the test should be postponed until any identified non-adrenal illnesses have been resolved or stabilised.