By Lauren Lamb, DVM
The umbilical stump (navel) is the remnant of the umbilical cord. The umbilical cord contains large vessels (umbilical artery and vein), which transport blood between the fetus and the placenta within the uterus. The umbilical cord also contains the urachus, which is a tube that is responsible for carrying urine from the foal’s bladder to a portion of the placenta. The umbilical cord will rupture one to two inches from the foal’s body wall when the mare stands after giving birth. Just prior to the umbilical cord rupturing, the blood flow within the umbilical artery and vein will stop. The umbilical remnant will contain the umbilical artery, vein and urachus.
The umbilical remnant, in a newborn foal (first few hours), will look like a moist string or worm hanging down from the foal’s belly button. Within 24 to 48 hours, the umbilical remnant should shrivel up and look like a dry twig or scab. The umbilical remnant should be dipped in dilute 1 percent iodine betadine three to four times within the first 24 hours of life. The iodine will help dry the umbilical remnant and prevent bacteria from traveling up the remnant and entering the foal’s body. The dried portion of the umbilical remnant should remain dry and eventually fall off as the foal ages. To help decrease the chances of an umbilical infection, always use exam gloves when palpating the umbilical remnant.
Clinical signs that a foal has an umbilical infection can vary depending on the location of the umbilical infection.
Foals with a local umbilical infection will have swelling around the umbilical remnant, purulent drainage (pus) from the remnant and pain and/or heat on palpation of the umbilical remnant. Signs of systemic infection include fever greater than 102 degrees Fahrenheit, diarrhea, increased respiratory effort and rate, depression, recumbency, decreased appetite/loss of suckle, colic, swollen and painful joints, along with general signs of a local infection mentioned above. Some foals with a local or systemic infection will start to dribble urine from the umbilicus. This urine is coming from the urachus, which is connected to the bladder, and has become patent following an infection of the umbilical remnant. Urine dribbling from the umbilical remnant can be seen when the foal urinates.
Systemic infection will occur when bacteria migrates up the umbilical remnant and enters the foal’s blood stream. When bacteria enter the blood stream, a foal’s joints and growth plates are at increased risk of becoming infected. This increased risk of infection is due to a unique blood flow at the foal’s growth plates and around the joints. Two factors that can increase the chance of a systemic infection include low IGG levels, also known as failure of passive transfer (lack of colostrum), and not dipping the umbilical remnant in 1 percent iodine.
Foals with an umbilical infection will also have an increase or decrease in the number of white blood cells, depending on how long the infection has been present. The Serum Amyloid A (SAA), which is a protein in the blood that is produced in response to infection or inflammation, will be increased. An ultrasound exam of the umbilical remnant can be used to definitely diagnosis an infection of the umbilical remnant and patent urachus. Pus can be seen within the umbilical artery and/or vein with an ultrasound exam.
Treatment options for an umbilical remnant infection consist of medical and/or surgical therapy. Depending on the overall health status of the foal and the type of infection (local vs systemic), your veterinarian will be able to recommend which option is best for your foal.
Read the April issue to learn more!