Laura:

Steroids and similar treatments are based on a number of factors that cannot be determine at a distance, or other than the prescribing vet:

a) Weight and age of the animal.
b) Purpose of the treatment - long-term or condition-specific.
c) Intended result - palliative or cure.
d) Tolerance of side-effects - what level of temporary or permanent side-effect is acceptable during or as a result of the treatment.

When our middle-male cat was getting over his blockage five years ago, he was treated with a 5-day course of steroids to reduce the inflamed urethra and bladder, including a very high first-dose, titrating down to a final low dose on the 5th day. But had he stayed on the first dose, he would not have lasted 10 days - it was that high. Our oldest dog (female Scottie, age 12) is on a very low maintenance dose of prednisone for her eyes, a tiny fraction of what the cat got, and she weighs 7 pounds more than he does (25 vs. 18 pounds). So, you get the picture.