Prednisolone is often recommended as an alternative to prednisone in animals in which the former provides superior bioavailability. In horses, prednisolone is indicated for the treatment of Recurrent Airway Obstruction (RAO). 

Although prednisone and prednisolone are different drugs, they are often considered bioequivalent, as most species rapidly convert prednisone to prednisolone in the liver. Horses, cats, and animals with compromised hepatic function may not efficiently absorb or convert prednisone to prednisolone, however.1 Since prednisone does not appear to be absorbed well after oral administration in horses, prednisolone is indicated in this species.

RAO in the Horse

Recurrent airway obstruction (RAO) is a very common allergic respiratory disease of horses characterized by varying levels of respiratory difficulty. Episodes of airway obstruction are seen when susceptible horses are exposed to common allergens. Most horses exhibit clinical signs when stabled, bedded on straw, and fed hay, whereas elimination of these inciting factors tends to result in a decrease or elimination of clinical signs.2

Two different forms of RAO are recognized in the horse: the barn-associated type seen in stalled horses that are fed hay, and summer pasture-associated obstructive pulmonary disease which is more commonly seen in horses living on pasture in the Southeastern United States.3 

The most common signs of RAO are chronic cough, nasal discharge, exercise intolerance, and respiratory difficulty. The classic “heave line” that is sometimes seen along the bottom edge of the ribs in horses with RAO is the result of hypertrophy of the abdominal muscles, which assist in breathing and become overdeveloped from excess work. Severely affected horses may also exhibit weight loss, anorexia, and exercise intolerance.3

Where to buy Prednisolone 

Prednisolone is available in the U.S. through pharmaceutical manufacturers and through veterinary custom compounding companies. 

This product carries numerous potential drug interactions. Please consult your veterinarian prior to beginning any treatment regimen.

FOR RX ONLY: A valid prescription from a licensed veterinarian is required for dispensing this medication.

2Merck Veterinary Manual.

3aaep.org.