Cortisone For Dogs with Atopy
By Dr. Jeff LaCroix
"You're not going to use cortisone, are you?", "Cortisone is bad for the
kidneys, isn't it?", "Won't cortisone damage the liver?" These are only
a small sample of the questions presented when I inform a client that
the use of a glucocorticoid (also referred to as corticosteroids) may be
part of the treatment for a pet's medical condition.
Fifteen or twenty years ago, I could avoid some of these
questions by not using the word "cortisone" and using, instead, the less
offensive and less recognized word "steroid". Steroids are now widely
known as drugs abused by athletes and bodybuilders, so this ruse is no
longer effective. I've tried "glucocorticoid", but the client invariably
sees through this and knows I mean "cortisone".
If you haven't guessed by now, this will be the other
side of the story - a defense of the use of cortisone in the treatment
of medical conditions in the dog, especially allergy.
First, what is "cortisone"? Adrenal corticosteroids are
produced by the adrenal glands. They are often simply called steroid
hormones. Although the mammalian adrenal gland produces numerous
steroids, only a few have significant biological activity. The
significant hormones are classified into 3 groups: glucocorticoids,
mineralocorticoids and androgens. They may be thought of as the sugar,
salt and sex hormones, respectively.
It is the glucocorticoids that are most often used
therapeutically in both human and veterinary medicine. Glucocorticoids
can affect the body in many ways. The suppression of hypersensitivity
and the anti-inflammatory properties of glucocorticoids are utilized in
the treatment of allergy, or more specifically, Atopy.
These beneficial effects must be balanced against other
effects that occur to some degree with all glucocorticoids, both natural
and synthetic. These include, but are not limited to, increased glucose
production, facilitation of free water excretion, the loss of both
potassium and sodium, protein wasting, and the general suppression of
the immune mechanism (especially at higher doses).
I'm sure some of you are already thinking "All these
side effects just to reap the anti-inflammatory and hypersensitivity
moderating benefits?" I haven't yet mentioned the most serious side
effect of prolonged steroid use - the suppression of the natural
function of the dog's own adrenal gland.
So why are we going to use glucocorticoids to treat
Atopy? The answer is because nothing else works as well or as
Yes, some dogs can be helped with hypoallergenic diets,
i.e. those with novel proteins or proteins of altered molecular size.
However, few cases of Atopy are complicated by food allergies, because
with Atopy, the majority of allergens are inhaled.
For the most part, chemicals other than antihistamines
mediate allergies in dogs. Thus, antihistamines are of limited value
unless the sedation they produce as a side effect is considered
beneficial. The antihistamine hydroxyzine may be an exception, and may
have some direct beneficial effect, in addition to decreasing the amount
of glucocorticoid necessary if both are used together. Vitamin E may
also have this same cortisone-sparing effect to some degree.
Recently, essential fatty acids in various forms and
combinations have been found to have a beneficial effect in modifying
the immune response in allergic states.
Finally, topical treatments, such as oatmeal shampoos
and rinses, can be helpful and soothing, but their duration is
short-lived. The same is true for "leave-on" shampoos containing both
hydrocortisone and antihistamines.
So, when you're faced with an atopic dog who has not
been helped through allergy testing and desensitization, and is unable
to be managed by dietary manipulation, antihistamines, fatty acids,
shampoos and rinses, and if you are unwilling to move to a mountain top
in Arizona for the sake of your dog's health, what are you going to do?
Back to the point of this article, which is the rational
use of corticosteroids to manage the allergic dog. In many cases, this
will be the only way to control the condition and assure some level of
comfort for the dog.
What do we do to attain the beneficial effects of
glucocorticoids without harming the patient?
Most of the significant side effects occur with long
term, higher and steady doses. With the exception of increased urination
and thirst, nearly all side effects can be avoided by using an
appropriate product and dose.
I mentioned previously that the most serious long-term
side effect is the suppression of the dog's own adrenal gland. This
occurs through a "feedback" mechanism. The pituitary gland (master gland
at the base of the brain) can't tell one glucocorticoid from another.
Thus, when cortisone is constantly delivered in the form of a pill or
injection, the pituitary gland no longer feels the necessity to tell the
adrenal glands to make more hormones. It stops producing the messenger
ACTH (adrenocorticotropic hormone), and the adrenal glands respond by
ceasing production. The resulting adrenal atrophy can potentially be a
problem if cortisone therapy is suddenly stopped, or if working adrenal
glands are required for other metabolic functions.
Obviously, one way to minimize the side effects is to
use the lowest dose possible. The simultaneous use of essential fatty
acids and hydroxyzine may be helpful in making this low dose more
Secondly, it's necessary to use the right product. Depo
injections (long lasting injections) with products such as depomedrol
have no place in the management of the allergic dog. Unintended
overdosing can happen easily, and, if so, the side effects will persist
for the duration of the drug (several weeks). Also, adrenal suppression
is most likely with this form of therapy.
Other shorter acting injections may have a place, but
only for their immediate effect as a loading dose.
Oral forms of glucocorticoids are the safest and most
effective for the long-term management of the allergic patient, because
dose and duration of activity can be easily controlled. The products
available include hydrocortisone (the natural hormone), prednisone,
prednisolone, triamcinolone, dexamethasone and flumethasone. The
duration of action of hydrocortisone is less than 12 hours. Prednisone,
prednisolone and triamcinolone are of intermediate duration, lasting 12
to 18 hours. Dexamethasone and flumethasone are long acting, lasting 36
to 72 hours.
In most cases, the duration of action with
hydrocortisone is too short to be effective. The long duration of
dexamethasone and flumethasone makes adrenal suppression more likely to
Drug levels are most easily controlled with prednisone,
prednisolone or triamcinolone. Additionally, if it is possible to
control the pruritus (itching) with a dose administered on alternate
days, significant side effects (especially adrenal suppression) are
unlikely to occur.
Alternate day therapy described above is always the goal
in long term management of the allergic patient - although it is not
With long-term steroid therapy, it is wise to monitor
liver function and electrolyte levels (especially potassium) at regular
There is as yet no "cure" for Atopy. Management is
through avoidance, desensitization or medication. In the real world,
avoidance is usually impossible, and desensitization has inconsistent
results. Thus, most cases will be managed medically. Done properly, the
dog can be made much more comfortable, and serious side effects can be
avoided nearly 100% of the time.