NEONATAL ISOERYTHROLYSIS IN KITTENS
(Photo Credit: Julian Ortega via Wikimedia Commons)
IMAGINE THIS TRAGIC SCENARIO:
A mother cat in a cattery carries her litter normally and gives birth to a healthy litter of kittens. She cleans them, nurses them, cares for them but within a few days they have all weakened and died. This may happen litter after litter with the cattery breeder wondering what keeps going wrong. While there are many reasons why newborn kittens might not survive, in this hypothetical the kitten loss is predictable and preventable. We are describing "Neonatal Isoerythrolysis."
A mother cat carries her litter normally and gives birth to a healthy litter of kittens. She cleans them, nurses them, cares for them but within a few days they have all weakened and died. This may happen litter after litter with the cattery breeder wondering what went wrong. While there are many reasons why newborn kittens might not survive, this particular condition is preventable.
Neonatal isoerythrolysis is a tragedy among breeders of kittens and is often written off as infectious disease, genetic defects, or simply natural selection. In fact, it is simply a matter of mismatched blood typing.
WHAT IS COLOSTRUM?
Colostrum is special milk produced by the mother of any mammal species for the first 12-24 hours or so. The first day of life is extra special for baby mammals as this is the time when the mother gives a copy of her own immunity to her young. The milk produced in this period is rich with all the antibodies the mother has to give: vaccination generated antibodies, antibodies from exposure to all sorts of proteins she has experienced or infections she has survived, and, of course, antibodies against the “wrong” blood type.
The infant’s intestine is in a sensitive time during this period. The antibodies delivered in the mother’s colostrum are not digested like regular proteins; instead, they are absorbed intact and provide the basis for the baby’s protection against infectious disease until the baby’s immune system is mature enough to make its own antibodies. After the first day of life, the intestine achieves what is called “closure” and no more such absorption takes place. Any proteins that enter the GI tract are broken down as nutrients.
The type B mother cat is giving a great big dose of anti-A antibodies right into her kittens with her colostrum and the babies are absorbing it into their bodies. The antibodies destroy the kittens’ developing red blood cells, they get pale, perhaps even jaundiced. They get weaker and weaker and then they die, poisoned by their own mother’s milk.
PREVENTION AND SAVING THE LITTER
As with human Rh disease, the first step in prevention is awareness. If one is going to breed purebred cats, have their blood types tested before they are bred. This can be done at the vet’s office with a test kit and can often be done “while you wait.” Ideally, a type B mother cat would only be bred to a type B tomcat.
So what do we do about the kittens already on the way? The key to survival is to keep the kittens from drinking their mother’s colostrum. As soon as they are born, they must be removed from the mother cat and either nursed by another mother cat or bottle-fed (see our page on Orphan Kitten Care for full instructions). They can be returned to their real mother after her colostrum production is over. This ought to be 12-18 hours but keep them away for a full day just to be sure. Regular mother’s milk produced after this time is not a hazard as the antibodies will be digested by the babies. During that first 24 hour period, the kittens may nurse on a Type A mother cat or can be bottled or tube fed.
As for the immunity lost by giving up colostrum, there is a next best thing: a plasma transfusion. Feline plasma of the correct blood type can be given to the kittens by injection. This blood product will contain many protective antibodies and none of the harmful ones. It is not as good as type matched colostrum, but is fairly available in most animal blood banks.
Feline blood typing can be performed by most animal hospitals. If a litter of kittens is planned, see your veterinarian about at least typing the mother cat so that one can plan ahead for complications. Neonatal Isoerythrolysis is a preventable syndrome but only if it is anticipated.
Page last updated: 6/25/2013