Liza Dillon, age 10, of Flushing, New York, for her question:

Is there such a thing as a retarded dog?

Some dogs are extra bright and seem able to learn fast with no trouble at all. Others are less bright and slower to learn. No two dogs are alike and it stands to reason that some are smarter than others. Once in awhile, we meet a dog who seems to be very backward indeed. When you call him, he just sits there grinning and thumping his tail. He seems unable to learn the simplest lesson and he refuses to obey the simplest command. This fellow really may be backward or retarded. However, there may be other reasons for his failure to learn.

He may not hear too well. If this is so, a dog doctor may be able to help him. You may be teaching him the wrong way. If this is so,the problem is solved when both you and your pet attend a few classes at an animal obedience school. Even if your dog really is retarded, tie may be able to learn the few simple things necessary to make it possible to live with him. However, you will need extra.time and patience to train a slow learner. Let's hope that he has other qualities such as affection and loyalty to make up for his not being a genius of the dog world.