Most people are familiar with the term “cortisone” which is really an old fashioned word for “cortisol,” the hormone produced by the adrenal cortex in times of stress. In higher doses, cortisol has potent anti-inflammatory properties making it a very useful medication. Because of this property, cortisol has been synthetically improved so as to provide an entire family of “glucocorticoid” hormones which include such familiar medications as:

• Prednisone and Prednisolone
   
• Dexamethasone (Azium^®)
   
• Trimacinolone (Vetalog^®)
   
• Methylprednisolone (Medrol^®)

These  medications last longer than natural cortisol and are stronger. In fact, there are so many therapeutic steroids that a doctor may choose the strength as well as duration of activity.

THERE HAS NEVER BEEN A CLASS OF DRUG
THAT HAS MORE APPLICATION IN DISEASE TREATMENT
THAN THE GLUCOCORTICOID CLASS.

INDEED, THIS GROUP IS RIVALLED ONLY
BY ANTIBIOTICS IN LIVES SAVED.

Side effects from the  glucocorticoid group are numerous and can be classified into those seen with short term use and those seen in long term use.

SHORT TERM SIDE EFFECTS

The pet on glucocorticoids is likely to experience the following:

• Increased hunger
   
• Increased thirst (and possibly urinary incontinence if there is inadequate access to an area for appropriate urination).
   
• Panting (dogs)
   
• General loss of energy
   
• Recrudescence of latent infection

Further, pre-diabetic animals may be “tipped over” into  a diabetic state with steroid use.  Often in these cases, the diabetes resolves once the steroid wears off. Sensitive individuals may experience upset stomach which can be serious.

Should the above issues become problematic, generally adjusting to a lower dose of medication will solve the problem. The goal with glucocorticoids is always to find the lowest dose of medication that is still effective. Sometimes changing to another steroid solves the problem.

LONG TERM SIDE EFFECTS

There are many conditions which require long term suppression of the immune system. Glucocorticoid doses generally include an “anti-inflammatory” dose which is lower and an “immune suppressive” dose which is higher, though with long enough term use, lower doses will become immune suppressive.  When steroid use stretches out for more than four months, a new set of side effects (in addition to those listed above) becomes of concern:

• Latent Urinary Tract Infections in up to 30% of patients
  Monitoring for these is necessary with periodic urine cultures.  The patient will not have the usual symptoms of urinary infection as the steroid will suppress the inflammation associated with the infection. Culture may be the only way to detect the infection.
   
• Development of Thin Skin, Blackheads, and Poor Ability to Heal Wounds or Grow Hair
   
• Development of Obesity and Muscle Weakness
   
• Hard Plaques of Diseased Skin called “Calcinosis cutis”
  These plaques actually represent the deposition of calcium in the skin.
  
  
  
• Development of Opportunistic Infections
  Fungal infections of the nasal cavity and development of adult onset Demodectic Mange have been classically described with immune suppression from chronic steroid use.
   
• Development of Diabetes Mellitus
  Animals on glucocorticoids will drink and urinate excessively but a rapid weight loss is a big clue that something new may have developed and some additional blood work should be performed.

The animal on long term high doses of glucocorticoids may well develop Cushing’s Syndrome, which is largely described by the list of symptoms above. This may be unavoidable but is certainly undesirable and in many cases, an additional medication can be added to the regimen to “spare” the amount of steroid needed to control the disease being treated.

THE MORAL OF THE STORY

Glucocorticoid hormones are not “bad” and it is not inherently “bad” to use them.  They should be respected and not over-used. Pet owners should be aware of steroid side effects and that it is usually possible to alter the regimen to minimize side effects.

• Do not use glucocorticoids on a daily basis except when your Veterinarian specifically tells you to.
  
  Life-threatening immune-mediated diseases often require daily steroid use. Most steroid protocols require daily use at first only.  If using steroids to control itchy skin or for musculoskeletal pain, it is very important to use at least an every other day schedule. If you feel  your pet is not comfortable except with daily steroid use, the regimen will need to be altered and your veterinarian should be informed.
   
• Do not stock large quantities of glucocorticoids at home.
  
  It may seem frustrating to have to get multiple refills when it may be less expensive to buy in bulk but your veterinarian will need to periodically check in with you about how you are using your medication and will likely not allow for large quantities “to go” so as to be sure to keep in contact with you and to prevent over-use.

At our hospital, no more than 4 months of every other day steroid use is prescribed annually without a consultation to review the therapy and consider alternatives. Animals that require long term use of steroids are monitored with quarterly urine cultures and annual blood panels/check ups.  If your pet appears to require steroids more than four months out of the year and you have not received a specific monitoring schedule, ask your vet for a recommendation and plan ahead for monitoring tests.