''Christmas bazaar of the Association for the Protection of House Cats in Bonn Inc.,'' read the flyer in my mailbox.
The locale was the boathouse of the Plittersdorf Canoe Friends Inc., in the century-old brick schoolhouse just a few steps down the Rhine from me.
It seemed like an opportunity not to be missed.
As one might expect of a house-cats association, the place was littered with felines - not the living, purring variety, but marzipan, ceramic, and calendar versions. Other offerings included needlepoint, amateur oil paintings, cosmetics that do not depend on animal experimentation, and a bulletin board for lost cats. (''Gray tiger, about one year old. Friendly, trusting. Relatively large.'')
All the proceeds from the bazaar go to benefit Bonn cats, in categories neatly chalked on a blackboard. Among other services, the association offers counseling (1,694 instances in the first 11 months of 1982); neuterings, 865; and something called ''middleman'' services, 436.
Middleman work involves mostly finding homes for kittens, explains club treasurer Fritz Langner. Counseling, meanwhile, might include some judicious mediation between cat owners and bird-loving neighbors. The arbitration in cases of strife - sometimes in concert with the Bird Protection Association Inc. - has a gratifying resolution rate of 90 percent.
Advice can also entail passing on cat lore or legal niceties. For instance, 18th-century dramatist Gotthold Ephraim Lessing is said to have withheld every word of reproach when his cat shredded his just finished manuscript of the play ''Nathan the Wise'' into a thousand pieces. And legally citizens are entitled to tie up any cat that comes onto their property during nesting season - March 15 through August 15 - so long as they handle the animal decently and notify its owner to come pick it up.
In another program, club members feed stray cats. Here members take consistent responsibility for particular areas so that the strays get used to their caretakers. When familiarity has proceeded far enough for the feeder to approach the strays, these cats are bundled up for neutering and released afterward in their old precincts. Such efforts to keep the ''free living'' population down have had some results. There are thought to be only a manageable several thousand cats in the Bonn area.
The philosophy of the association revolves around the nature of the beast, explain Mr. Langner and the club's chairman, Kurt Fickentscher.
''A cat is complex. It's not like a turtle or a dog,'' they say. ''You have to figure out what the cat wishes or why it changes its habits. If it does things like ceasing to be clean, we often discover that the people it lives with have changed.''
The cat, adds Mr. Fickentscher, ''feels man as a partner on an equal level. That is the secret of the remarkable relation between man and this animal. A cat sees its owner as a kind of supercat.''
As Fickentscher explains in the October issue of the club magazine: ''Man is actually the social partner of the cat. As has long been known, friendship between a cat and the person(s) it is familiar with can become much more intimate, intensive, and durable than is possible between cats themselves. . . .
In a broader context the club does its bit of lobbying against the use of animals in medical and chemical experimentation. Fickentscher, a Bonn University pharmaceutical professor, is also a member of the World Society for the Protection of Animals and regularly testifies before the West German Parliament on questions of animal experimentation.
He wasn't very optimistic about progress so far in reducing the 90 million yearly tests in the United States and the 40 million each in West Germany, Britain, and France. He did have hopes, however, that alternative methods of testing that are now being proposed might catch on.
The Association for the Protection of House Cats in Bonn was founded in 1977 and has already spawned a few sister clubs in other parts of West Germany. It has also been officially recognized here as one of the charitable organizations to which donations can be made in lieu of traffic fines.