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Also known as: '''''Feline Neonatal Isoerythrolysis (FNI) — NI

Also known as: '''''Feline Neonatal Isoerythrolysis (FNI) — NI — Equine Neonatal Erythrolysis — ENI

==Description==

==Introduction==

Neonatal isoerythrolysis is a disease of humans and domestic animals and has been most commonly observed in newborn cats and horses. Rarely it has also been described in other species following [[:Category:Transfusion Medicine|blood transfusions]], [[Vaccines|vaccination]] or previous pregnancy. The disease is characterised by [[Immune Mediated Haemolytic Anaemia|immune-mediated haemolytic anaemia]] due to ingestion of maternal colostral antibody directed against surface antigens on neonatal red blood cells. This leads to a [[Type II Hypersensitivity|type II hypersensitivity]] reaction causing extravascular and intravascular haemolysis during the first few days of life.  

Neonatal isoerythrolysis is a disease of humans and domestic animals and has been most commonly observed in newborn cats and horses. Rarely it has also been described in other species following [[:Category:Transfusion Medicine|blood transfusions]], [[Vaccines|vaccination]] or previous pregnancy. The disease is characterised by [[Immune Mediated Haemolytic Anaemia|immune-mediated haemolytic anaemia]] due to ingestion of maternal colostral antibody directed against surface antigens on neonatal red blood cells. This leads to a [[Type II Hypersensitivity|type II hypersensitivity]] reaction causing extravascular and intravascular haemolysis during the first few days of life.  

==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.

===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. The newborn kittens ingest maternal colostrum containing anti-A antibodies leading to the clinical signs of FNI.

==Clinical signs==

==Clinical Signs==

===Horses===

===Horses===

Affected foals appear clinically normal at birth, and clinical signs develop from several hours up to a week after ingestion of colostrum. Foals with NI usually become progressively weak, lethargic and depressed and develop [[icterus]], tachycardia and tachypnoea. Although the signs are not pathognomonic for NI, a foal displaying '''haemoglobinuria and icterus''' born to a multiparous mare should be strongly suspected to have the disease. If the foal becomes severely hypoxic, seizures may occur. '''Neurological abnormalities''', such as somnolence or seizures, may also occur due to the phenomenon of '''kernicterus'''. Excessive amounts of unconjugated bilirubin are able to cross the blood-brain barrier in foals and lead to a bilirubin encphalopathy which can be permenent. '''Death''' usually occurs if NI is not diagnosed and treated promptly.

Affected foals appear clinically normal at birth, and clinical signs develop from several hours up to a week after ingestion of colostrum. Foals with NI usually become progressively weak, lethargic and depressed and develop [[icterus]], tachycardia and tachypnoea. Although the signs are not pathognomonic for NI, a foal displaying '''haemoglobinuria and icterus''' born to a multiparous mare should be strongly suspected to have the disease. If the foal becomes severely hypoxic, seizures may occur. '''Neurological abnormalities''', such as somnolence or seizures, may also occur due to the phenomenon of '''kernicterus'''. Excessive amounts of unconjugated bilirubin are able to cross the blood-brain barrier in foals and lead to a bilirubin encphalopathy which can be permenent. '''Death''' usually occurs if NI is not diagnosed and treated promptly.

A blood transfusion should be considered if the anaemia is severe (PCV less than 15%) or the foal is weak and shocked. The best donor of blood for transfusion is the dam, but this means that the serum containing the alloantibodies must be removed ('washing' of the red blood cells). This is achieved by mixing the mare's blood with saline and performing repeated centrifugation. If washed red blood cells from the mare are not available, blood from an acceptable blood-typed donor horse may be used.  

A blood transfusion should be considered if the anaemia is severe (PCV less than 15%) or the foal is weak and shocked. The best donor of blood for transfusion is the dam, but this means that the serum containing the alloantibodies must be removed ('washing' of the red blood cells). This is achieved by mixing the mare's blood with saline and performing repeated centrifugation. If washed red blood cells from the mare are not available, blood from an acceptable blood-typed donor horse may be used.  

Affected '''kittens''' should be removed from the queen for a period of 24 hours and fed milk replacer or fostered onto a lactating queen with blood type A. After this period, intestinal permeability to antibodies is greatly reduced and the kittens may be returned to the original queen. Supportive management of hypoglycaemia and hypothermia may be necessary. Severely affected kittens may require a blood transfusion, preferably with Oxyglobin if available. If this is not possible, washed type A blood is preferred. Intraosseous administration of blood is recommended due to the small size of the patient.  

Affected '''kittens''' should be removed from the queen for a period of 24 hours and fed milk replacer or fostered onto a lactating queen with blood type A. After this period, intestinal permeability to antibodies is greatly reduced and the kittens may be returned to the original queen. Supportive management of hypoglycaemia and hypothermia may be necessary. Severely affected kittens may require a blood transfusion, preferably with Oxyglobin if available. If this is not possible, washed type B blood is preferred. Intraosseous administration of blood is recommended due to the small size of the patient.  

==Prevention==

==Prevention==

The disease in horses is prevented by ensuring that mares are blood-typed before being mated. Mares who are negative for the blood antigens known for causing disease can be matched to stallions who are also negative. Similarly in cats, the disease is easily prevented if blood typing of cats is peformed prior to breeding.  

The disease in horses is prevented by ensuring that mares are blood-typed before being mated. Mares who are negative for the blood antigens known for causing disease can be matched to stallions who are also negative. Similarly in cats, the disease is easily prevented if blood typing of cats is peformed prior to breeding.  

==Literature Search==

[[File:CABI logo.jpg|left|90px]]

|flashcards = [[Equine Internal Medicine Q&A 09]]

 

|literature search = [http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=neonat*&occuring1=title&rowId=2&options2=AND&q2=%22isoerythrolysis%22&occuring2=title&rowId=3&options3=AND&q3=cats&occuring3=od&x=53&y=9&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all Neonatal Isoerythrolysis in cats publications]

 

[http://www.cabdirect.org/search.html?rowId=1&options1=AND&q1=neonat*&occuring1=title&rowId=2&options2=AND&q2=%22isoerythrolysis%22&occuring2=title&rowId=3&options3=AND&q3=cats&occuring3=od&x=53&y=9&publishedstart=yyyy&publishedend=yyyy&calendarInput=yyyy-mm-dd&la=any&it=any&show=all Neonatal Isoerythrolysis in cats publications]

[http://www.cabdirect.org/search.html?q=title%3A%28neonat*%29+AND+title%3A%28%22isoerythrolysis%22%29+AND+od%3A%28horses%29 Neonatal Isoerythrolysis in horses publications]

[http://www.cabdirect.org/search.html?q=title%3A%28neonat*%29+AND+title%3A%28%22isoerythrolysis%22%29+AND+od%3A%28horses%29 Neonatal Isoerythrolysis in horses publications]

==References==

==References==

Silvestre-Ferreira, A. C., Pastor, J. (2010) '''Feline Neonatal Isoerythrolysis and the Importance of Feline Blood Types''' ''Veterinary Medicine International Volume 2010''

Silvestre-Ferreira, A. C., Pastor, J. (2010) '''Feline Neonatal Isoerythrolysis and the Importance of Feline Blood Types''' ''Veterinary Medicine International Volume 2010''

[[Category:Materno-Fetal Immunity|E]]

[[Category:Materno-Fetal Immunity|E]]