By Dr. Wendy Pearson

Canine Hyperadrenocorticism (aka ‘Cushings Disease’)

Hyperadrenocorticism (or “Cushings Disease”) is a disease that is frequently encountered as dogs age. It is characterized by over-production of corticosteroids, which are produced by the adrenal gland. Cushings is usually caused by tumours on the pituitary or adrenal glands (ie. spontaneous Cushings), or by chronic administration of corticosteroids such as prednisone (ie. iatrogenic Cushings). Of the spontaneously arising Cushings, tumours on the pituitary gland account for approximately 85% of cases. The tumour causes over-production of ACTH which stimulates the adrenal gland to produce corticosteroids and leads to the characteristic clinical signs of Cushings Disease, which include excessive drinking and urination, increased appetite, panting, sagging abdomen, skin infections and diabetes.

Treatment of spontaneous Cushings is usually achieved by surgical removal of the tumour (if it is an adrenal tumour) or drugs such as Lysodren (o'p'-DDD, which is a relative of DDT) or ketaconazole. Drug therapy is usually aimed at partially disabling the area of the adrenal gland which produces corticosteroids, thereby bringing blood levels of corticosteroids back down to normal. This is not without risk, as chronic Lysodren without attentive monitoring of blood corticosteroids can lead to Addison’s Disease (ie. ‘Hypoadrenocorticism), as well as more common adverse effects like inappetance, vomiting, diarrhea, lethargy and weakness. It is widely acknowledged that drug treatment of Cushings Disease is symptomatic therapy only, and does not increase life expectancy or modify progression of the disease. And given the broad spectrum of adverse effects, natural treatments are often sought in an effort to improve the quality of life for Cushings dogs.

There is very little scientific evidence for the efficacy or safety of herbs in treating Cushings Disease or adrenal gland dysfunction. What little research there is appears to be restricted to proprietary blends, most frequently Traditional Chinese Medicine. Theoretically, herbs which inhibit production of stress hormones (including cortisol and ACTH) should be of benefit to dogs with Cushings. Herbs with scientific evidence for a stress-hormone and/or anxiety lowering effect include Chasteberry (Vitex agnus castus), ginseng (Panax quinquefolium), and Magnolia bark (Magnolia officinalis). Supplementation with soy lecithin has also demonstrated an inhibitory effect on ACTH and cortisol.

Treatment of canine Cushings Disease should always be done in cooperation with your veterinarian. But integration of nutritional and herbal treatments with conventional veterinary care may be an effective strategy for blunting some of the unpleasant clinical signs of Cushings, and improving the quality of life for your Cushings dog.

References

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