Registering with Irish cat club

If your cousin gets a kitten or cat abroad, that cat may have a registration with the breed association in the country where it was bred. It may also be a pure tonkinese from a backyard breeder, meaning it won't have any papers at all. If it doesn't come with papers, you can't register it in Ireland. The tonkinese, as a siamese/burmese hybrid, is only recognised as a breed of its own in the last 10 years, which means you may need to be extra careful about its origins, as you may be getting an unpapered siamese/burmese cross as opposed to a tonkinese of tonkinese parentage.

A pedigree is a record of the animal's heritage - parents, grandparents, great grandparents, so on. Even if your cat is an excellent example of the breed, you can't get a registration if you have no pedigree illustrating where the cat comes from. However unless you want to either show or breed the cat, a pedigree isn't vital - it's more important for your cousin to ensure the cat comes from an ethical breeder who does right by their cats. (There appear to be more of these in the world of cat fancy than there is in the world of puppy-mills and back yard -oodle breeders.)

If the cat has a registration and papers in its country of origin, give the Irish cat registration body a call and ask them what they need to accept the pedigree of the cat. It's not unusual - a lot of ethical breeders will import stock from abroad to dilute their lines so they're not inbreeding, so there are plenty of pedigree kittens doing the rounds in first world countries whose parents are from different places.

Do you specifically want a tonkinese, or are you just attracted to the nature of the oriental types? While I completely defend your right to an ethically produced purebred animal, as the owner of four oriental crosses I can tell you that the siamese / burmese type seems to win out in personality, even if not in appearance.

My two first generation oriental crosses are a blue burmese cross and a siamese cross (who's come out a green-eyed silver tabby with a siamese body shape). I was defrosting the dog's raw dinner in the sink recently, a 750g bag of raw meaty bones and a chunk of liver. The siamese cross got into the sink, dragged out the bag of dogfood, hauled it down the house into the cat room and chewed the end off the bag before pulling it about the place - which considering liver bleeds as it defrosts, means I came home to a 6" wide swash of blood across the carpet in the cat's room - I nearly had a heart attack when I saw it!

So yeah, if you can grab a cross from a shelter you'll have the same trouble fun.