Last week the quiz show craze spread over the TV channels like the prize money showering on the shows' contestants. In seven days nearly $500,000 was paid out, or pledged against re-appearances, to an assortment of men, women, children and dogs as advertiser tried to outbid advertiser for an audience. As a result it has become difficult to get out of quiz show range at any hour of the day. Not counting the innumerable local shows there are now 21 question-and-answer contests on the three big networks - and seven of them are in action five days a week. On NBC, for instance, commencing at 11a.m. four one-half-hour quizzes follow one another. On Tuesday night there is only one hour in the period between 7:30 and 11 p.m. when the viewer need he out of sight or hearing of someone asking or answering a question -and being paid amply for doing so. In contrast to the impressive erudition of Columbia University Instructor Charles Van Doren and 11-year-old stock market statistician Leonard Ross, TV added a lucrative contest for talking dogs. The canines which could get out bi-syllabic words intelligibly on the early morning dog-talent search won $500 a word, with a $20,000 limit on canine loquacity. The 4-year-old terrier was the week's big winner there as he convinced the show's board of human judges that he was really speaking.