The school for cats / story and pictures by Esther Averill.

Enhanced descriptions from Syndetics:

Jenny Linsky, the famous little black cat of Greenwich Village, has never been to school before. When her master, Captain Tinker, sends her to a boarding school in the country to learn the special knowledge of cats--manners and cooperation--she is a little afraid, among strangers, and so far from home. As soon as she's settled in, taking off the red scarf that makes her feel brave, another student named Pickles, the Fire Cat, is upto his usual mischief, chasing smaller cats with his fire truck hook and ladder. When he chases Jenny, she runs away from school terrified.

Jenny soon realizes that the Captain would be disappointed if he found out she had left school. It's then that Jenny decides to stand up to Pickles. She returns to school and when Pickles next tries his tricks, he's surprised at the "new" Jenny. Pickles learns his manners and Jenny learns that not only can school be fun, but the friendships she makes there will last forever.