Sorry – this is getting silly. The by-law says you can’t keep an animal. You apply the ordinary meaning of the word.
If you have an animal residing at the property, either temporarily or permanently, you are breaching the by-law.
Jimmy has given the solution, you can waste a lot of time and effort splitting hairs, and putting the other owners offside. Or you can take the route suggested by Jimmy which, if the situation is as you say, is likely to be successful.