Breeding policies vary between registries, but several permit controlled outcrossing to maintain genetic diversity within the breed. Approved outcrosses depend on the registry: The International Cat Association permits outcrossing to non-breed domestic longhair and shorthair cats, the Cat Fanciers' Association allows domestic longhair and shorthair outcrosses subject to its registration rules and timelines, When outcrossing to non-pedigree domestic cats, breeding guidance recommends selecting healthy cats of moderate type that closely match the desired LaPerm look and avoiding overly thick coats. This reflects the breed's origin in a population of non-pedigree cats and is described as a way to introduce fresh bloodlines (“
hybrid vigour”) into the gene pool. In the UK, registration rules can affect how kittens from outcross matings are recorded and shown. The GCCF breeding policy notes that the full register is reserved for LaPerms with three preceding generations of LaPerm-to-LaPerm breeding; cats with a domestic parent or grandparent are recorded on a reference register, and kittens become eligible for showing once the domestic cat is in the third generation (great-grandparent), with unknown ancestry pushed beyond the three-generation pedigree. However, in some countries, such as the UK, there can be legal complications to selling kittens from such matings as pedigrees because of the
Trades Description Act 1968, through which it has been established that the legal definition of a pedigree cat in the UK is normally one with a fully recorded three-generation pedigree. After outcrossing to a cat of unknown parentage, at least three generations must be bred to establish a full pedigree record. In
TICA outcrossing has mainly been with the
domestic short-haired cat and
domestic long-haired cat, although registration rules do allow other breeds to be used and bred down from towards the F3 generation, which is eligible for entry in TICA cat shows. In
Cat Fanciers' Association (CFA) breeders used the
Ocicat for two years, terminating on 1 May 2002; LaPerms registered during this period were permitted to have an Ocicat parent, and by extension, one or two Abyssinian grandparents, as the Abyssinian is an approved outcross of the Ocicat. Currently, CFA breeders may only use non-pedigree domestic cats, and after 2025, no outcrosses will be permitted in CFA. However, CFA accepts LaPerms for both breeding and showing with other breeds in their pedigrees if they are imported from another registry. The
GCCF has the most strict of the registration policies and only LaPerms with a full three-generation pedigree (i.e., parents, grandparents, and great-grandparents) of the only LaPerm to LaPerm breeding are permitted on the full register. Only LaPerms or cats from a list of approved breeds are permitted in the 4th and 5th generations. Cats with non-approved breeds anywhere within their five-generation pedigrees, particularly those with other rex genes, cannot be registered as LaPerms. In order not to cause any damaging restriction to the breed's
genepool, a supplementary register also exists for the registration of LaPerms bred as part of an outcross breeding program. LaPerms can only be registered on the supplementary register if, within their five-generation pedigrees, only LaPerms and cats from the approved outcross list are present. In the GCCF, this list comprises the
Somali/
Abyssinian, Asian/
Tiffanie/(European)
Burmese,
Ocicat and
Tonkinese. Domestic Shorthairs and Domestic Longhairs can be used in outcrossing, but certain restrictions apply, and the initial offspring are placed on the reference register and cannot be shown without first being assessed and approved by three judges. In other registries, the approved list (with some slight variations) is used for outcrossing, and cats of unknown parentage are not always permitted. In FIFe, which has its most active LaPerm breeders in Sweden and the Netherlands, outcrossing is done on a case-by-case basis. In antipodean countries, Somalis, Tiffanies, and Orientals have also been used, but Domestic Shorthairs and Domestic Longhairs are now the preferred choices of an outcross. ==Gallery==