Dad has developed a problem eating. Could he have a dry mouth?

My Dad has been hospitalized for more than two months. He has no problem swallowing ice cream, canned fruit, soup, or liquids. Even something soft like baked fish or tuna or chicken salad is too much; he will chew and chew and need to spit it out. He has been on high doses of steroids and antibiotics. Could this be a side effect? If so, can it be reversed?