page_title: Neonatal isoerythrolysis
section_title: Clinical signs and testing
hierarchical_section_title: Neonatal isoerythrolysis / Neonatal isoerythrolysis in foals / Clinical signs and testing
caption_attribution_description: English: Eye and buccal mucosae of the mule foal of this pic with anaemia and icterus. Walon: Siblareyès finès peas des ouy et del boke do moultea del foto cial
context_page_description: Neonatal isoerythrolysis, also known as hemolytic icterus or hemolytic anemia, is a disease most commonly seen in kittens and foals, but has also been reported in puppies. It occurs when the mother has antibodies against the blood type of the newborn.
context_section_description: Foals present normally at birth, but over the following 12–72 hours weaken, become depressed, and have a decreased suckle response. Signs typical of hemolytic anemia occur, including tachycardia (increased heart rate), tachypnea (increased respiratory rate), dyspnea, pale mucosa which becomes icteric by 24–48 hours of age, and occasionally hemoglobinuria. In more severe cases, seizures may occur secondary to cerebral hypoxia. Laboratory findings will show a decreased packed cell volume (PCV) that is usually less than 20%, an increased bilirubin, especially unconjugated bilirubin, and occult blood in the urine.
  A definitive diagnosis can only be made if alloantibodies are discovered in the mare's serum or colostrum and are shown to be against the foal's red blood cells. Such tests include crossmatching the mare's serum to washed red blood cells of the foal, which is added to exogenous complement, and is positive if hemolysis occurs. A direct Coombs test may also be used, but does have a high rate of false negatives. Crossmatching using saline agglutination does run the risk of false negatives, since some alloantibodies only produce lysis rather than agglutination. Currently, screening tests of colostrum for use in the field have not been found to be accurate.
  The severity of clinical signs and their speed of onset is determined by the dose of alloantibodies taken in by the foal and their potency. Alloantibodies against the Aa blood group are especially potent, and usually produce more severe signs than other alloantibodies when an equivalent dose is absorbed. Mares with multiple exposures to a blood group antigen also produce a greater amount of alloantibodies and therefore the foal receives a larger dose.
caption: Icteric mucous membranes seen in a mule foal with NI.
exif: {"Image Make": "Panasonic", "Image Model": "SDR-H20", "Image Orientation": "Horizontal (normal)", "Image XResolution": "72", "Image YResolution": "72", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "Ver.1.00", "Image DateTime": "2010:04:19 11:31:08", "Image YCbCrPositioning": "Co-sited", "Image ExifOffset": "200", "Thumbnail Compression": "JPEG (old-style)", "Thumbnail Orientation": "Horizontal (normal)", "Thumbnail XResolution": "72", "Thumbnail YResolution": "72", "Thumbnail ResolutionUnit": "Pixels/Inch", "Thumbnail JPEGInterchangeFormat": "576", "Thumbnail JPEGInterchangeFormatLength": "11532", "Thumbnail YCbCrPositioning": "Co-sited", "EXIF ExifVersion": "0220", "EXIF DateTimeOriginal": "2010:04:19 11:31:08", "EXIF DateTimeDigitized": "2010:04:19 11:31:08", "EXIF ComponentsConfiguration": "YCbCr", "EXIF CompressedBitsPerPixel": "112181/28800", "EXIF Flash": "No flash function", "EXIF FlashPixVersion": "0100", "EXIF ColorSpace": "sRGB", "EXIF ExifImageWidth": "640", "EXIF ExifImageLength": "360", "Interoperability InteroperabilityIndex": "R98", "Interoperability InteroperabilityVersion": "[48, 49, 48, 48]", "EXIF InteroperabilityOffset": "424", "EXIF ExposureMode": "Auto Exposure", "EXIF WhiteBalance": "Auto", "EXIF SceneCaptureType": "Standard"}