Breeding a Ragdoll Cat

• The mutation is dominant, but its penetrance is incomplete. That means a cat can carry the mutation and never develop the disease.[7] Some cats with two copies never got sick, and about a fifth of them were still alive at around twelve years old.[8]
• Nobody agrees on how common the mutation is, so do not trust a single number. One small Vietnamese group came in at 8.8% carriers. A survey of 2,018 cats in the British Isles found about 27%, and a hospital referral group reached 33.9%.[9] The population you test changes the answer.
• The Governing Council of the Cat Fancy (GCCF, the main UK cat registry) has required the test since 24 February 2016 for every Ragdoll registered for breeding.[5] A vet must take the swab and check the cat’s microchip against its records. Cats with two copies, and then cats with one, lost their place on the active register during 2021.[5]
• That makes the GCCF stricter than the veterinary consensus. The American College of Veterinary Internal Medicine (ACVIM) writes the feline heart guidelines, and it still allows a carrier to be bred to a negative cat.[6] That option is open when the carrier has other qualities worth keeping. Check which rulebook your registry follows before you plan a mating.
• Never advertise a negative cat as "HCM free" or "clear of HCM". The GCCF bans the phrase, and the evidence supports the ban.[5][6] Say the cat tested negative for R820W, which is what the paperwork actually shows.

• Neonatal isoerythrolysis happens when a type B queen feeds kittens with type A or AB blood. The antibodies in her colostrum, the first milk she produces, attack them in the first days of life. Knowing both parents’ types tells you whether to plan for it.
• Watch out for a common mistake here. Type B is not the Ragdoll problem, and breeders who copy another breed’s advice get this backwards. Type B runs high in the Devon Rex, British Shorthair, Birman and Persian.[11] The Ragdoll’s oddity is the high AB rate, which is a different problem.
• Test the whole cattery for feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV), not just the cats you breed.[12] Retest a negative cat no sooner than 60 days later, because the first test can miss a recent infection. That includes a queen coming home from a stud.[12]
• Ragdolls are among the breeds at raised risk of feline infectious peritonitis (FIP), a usually fatal immune reaction to a common cat coronavirus. In that study purebred cats ran 1.3% against 0.35% for mixed breeds.[13] Susceptibility appears to be strongly inherited, so do not repeat a mating that produced kittens who died of FIP.[22]

• Ragdolls have among the longest pregnancies in that dataset, alongside Orientals and the Cornish Rex.[18] Count the days from the mating, and do not panic on day 66.
• Kitten survival looks good too. Deaths up to twelve weeks ran 7.4%, against a 13.81% average across breeds, and the difference was statistically significant.[17]
• Read those numbers with care. Dystocia, a birth that stalls and needs help, was measured across only 39 Ragdoll litters in one study, so treat the figures as encouraging rather than exact.[17]
• The queen’s age matters more than her breed. Cesareans were needed in under 6.5% of queens aged five or over, against 15% of queens under three.[17]

• Twelve weeks is not an arbitrary number. A kitten’s own immune system takes over at about that age, so the first vaccination has to come before then.[21] The rabies vaccine cannot be given until twelve weeks either.[21]
• If you use an outside stud, the stud owner gives you a certificate of mating when you collect your queen.[19] You need a copy of it to register the litter.[19]
• Place pet kittens on a spay or neuter contract. Breeding rights go only to cats you picked for a program, and to people you are willing to keep helping.

You can list the kittens on Petmeetly once they are old enough to leave.