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→Feline Neonatal Isoerythrolysis
==Pathogenesis==
==Pathogenesis==
===Equine Neonatal Isoerythrolysis===
===Equine Neonatal Isoerythrolysis===
In foals, the condition results when a foal inherits red blood cell antigens (which the dam does not have) from its sire. The Aa and Qa antigens are most strongly antigenic and exposure of the mare to these antigens during a previous pregnancy or whole blood transfusion leads to the mare producing alloantibodies to the foal's red blood cells. At birth the foal ingests large numbers of red blood cell antibodies in the colostrum, leading to severe haemolytic disease. During pregnancy however, the foal is unaffected because blood and antibodies are unable to cross the placenta. First foals are rarely affected, as a sensitization reaction (usually during an earlier pregnancy) is usually required.
In foals, the condition results when a foal inherits red blood cell antigens (which the dam does not have) from its sire. The Aa and Qa antigens are most strongly antigenic and exposure of the mare to these antigens during a previous pregnancy or whole blood transfusion leads to the mare producing alloantibodies to the foal's red blood cells. At birth the foal ingests large numbers of red blood cell antibodies in the colostrum, leading to severe haemolytic disease. During pregnancy however, the foal is unaffected because blood and antibodies are unable to cross the placenta. First foals are rarely affected, as a sensitization reaction (usually during an earlier pregnancy) is usually required.
The disease most often affects foals of multiparous dams since sensitisation usually occurs late in gestation, or during parturition of an incompatible foal. A primaparous mare can produce a foal with NI if she has received a prior, sensitising blood transfusion or developed placental abnormalities early in gestation, which allowed leakage of foetal RBCs into her circulation. References: [[/en.wikivet.net/NationWide Laboratories|NationWide]]
===Feline Neonatal Isoerythrolysis===
===Feline Neonatal Isoerythrolysis===
[[Blood Groups - Cat|Cats have three main blood types]], type A, type B and type AB. Worldwide, the most common blood type in cats is type A and type A is dominant over type B. Queens with type B blood have high levels of naturally occurring alloantibodies to type A blood. Feline neonatal isoerythrolysis (FNI) develops when type B blood mothers mate with type A tomcats producing kittens with type A/B blood. The newborn kittens ingest maternal colostrum containing anti-A antibodies leading to the clinical signs of FNI.
[[Blood Groups - Cat|Cats have three main blood types]], type A, type B and type AB. Worldwide, the most common blood type in cats is type A and type A is dominant over type B. Queens with type B blood have high levels of naturally occurring alloantibodies to type A blood. Feline neonatal isoerythrolysis (FNI) develops when type B blood mothers mate with type A tomcats producing kittens with type A/B blood.
Most non pedigree cats are type A, however, in pedigree cats there is a higher incidence of type B, particularly in the British Shorthair. All type B adult cats naturally have high titres of anti-A antibodies (alloantibodies). If a type A male mates with type B female, the type A kittens receive maternal anti-A antibodies in the colostrum. Kittens which appear healthy at birth, fade due to haemolysis with icterus, haemoglobinuria and severe anaemia. Some may die in shock. Some cases are less severe with mild anaemia, these kittens may recover. References: [[/en.wikivet.net/NationWide Laboratories|NationWide Laboratories]]
==Clinical Signs==
==Clinical Signs==