Key Insights
  • Umbilical disorders in foals include omphalitis, patent urachus, and umbilical hernias
  • Omphalitis is infection of the umbilicus, often linked to poor hygiene or low antibody transfer
  • Patent urachus occurs when the urinary channel fails to close, leading to urine leakage from the stump
  • Umbilical hernias form when abdominal tissue protrudes through an incompletely closed umbilical ring
  • Diagnosis may involve ultrasound, culture, and clinical exam to assess severity
  • Most foals have a good prognosis when treated promptly with medical or surgical care

Umbilical disorders in newborn foals can arise due to bacterial infection or improper closure of the umbilicus after birth.

The umbilical cord is the lifeline between the mare and the foal during gestation. Normally, this structure dries within a few days of birth and falls off in the following weeks, but complications can occur.

The three most common umbilical disorders in horses are omphalitis, patent urachus, and umbilical hernia. If not addressed promptly, these conditions can lead to serious health problems.

However, with timely and appropriate treatment, the overall prognosis for these conditions is generally favorable. Breeders must carefully monitor their foals for umbilical conditions, so that they can be treated promptly if they develop.

Umbilical Disorders in Foals

The umbilical cord is a vital link between the dam and foal, comprising blood vessels that transport nutrients and oxygen, and the urachus which transports waste products to and from the developing fetus.

After birth, the umbilical cord naturally detaches from the foal’s abdomen, leaving behind the umbilical stump. This tissue gradually dries out, shrinks, and eventually falls off on its own, typically within a few days to a few weeks.

The umbilicus, where the umbilical stump attaches to the foal’s body, then heals over time. [1] The major structures within the umbilicus are: [1]

  • Urachus (urinary component)
  • Umbilical vein
  • Two umbilical arteries

After separation of the umbilical cord, the structures within the umbilicus are no longer necessary for the foal and slowly grow smaller. [1] Eventually, the abdominal wall closes over the umbilical remnants, sealing them within the abdomen. [1]

However, the process of umbilical regression is not always successful, sometimes leading to infections or incomplete healing of the umbilicus.

Common Disorders

The most common umbilical disorders in horses include:

  • Omphalitis
  • Patent Urachus
  • Umbilical Hernias

Each of these disorders will be discussed in further detail below.

Omphalitis

Omphalitis refers to inflammation of the umbilicus, usually from a bacterial infection. [2] Approximately 0.2% of foals develop omphalitis. [1]

As an extension of the umbilical cord, the umbilicus connects directly to the foal’s liver, bladder, and vascular system. This makes infections of the umbilicus particularly serious for foals.

Any component of the umbilicus can become infected; however, it is most common in the urachus. [1] The urachus is a tube-like structure in fetal development that connects the urinary bladder to the umbilical cord, allowing for the drainage of urine from the fetus into the amniotic fluid.

Common diseases associated with omphalitis include: [1][3]

Any age of foals can develop omphalitis, but it is most common in foals under two months old. [1]

Risk Factors

The main risk factor for developing omphalitis is bacterial contamination of the umbilicus. [1] Bacteria that can cause omphalitis are normally found in the foal’s environment, including species such as Staphylococcus and E. coli. [1][4]

Foals born in unclean environments or those whose umbilical stumps are not properly cleaned have a high risk of developing omphalitis. [1]

Foals that experience failure of passive transfer also have an increased risk of omphalitis, as they do not get sufficient antibodies from their dam’s colostrum to protect against infection. [1] This is why all foals should have their antibody levels checked by 24 hours after birth.

In cases where omphalitis is suspected, antibody levels should be checked again as part of their diagnostic work-up. [1]

Symptoms

The symptoms of omphalitis can vary depending on its severity, with some cases showing no outward indications of an infection in the umbilical area. [1]

The main signs of infection of the umbilicus include: [1]

  • Heat and pain when touching the umbilical area
  • Swelling or thickening of the umbilicus
  • Swelling of the skin around the umbilicus
  • Discharge from the umbilicus

Other systemic symptoms that are common in foals with omphalitis include: [2]

  • Fever
  • Lethargy
  • Poor appetite

Diagnosis

Ultrasound is the primary tool for diagnosing omphalitis. On an ultrasound of the umbilicus, areas of thickened, inflamed tissue and pockets of pus are visible, allowing for diagnosis. [1]

The veterinarian can also see the extent of the infection, including which structures are affected and how far the infection extends into the foal’s abdomen. [1]

Bacterial culture is another important component of diagnosis, as it allows identification of the causative bacteria and can guide antibiotic selection. [1][4] Ideally, both the umbilicus and the foal’s blood should be sampled, as blood testing can help identify whether the foal has developed septicemia (blood infection). [1]

Treatment

Treatment of omphalitis in foals can be either medical or surgical. Medical treatment is more common for mild cases of omphalitis, whereas surgical intervention is necessary for cases of sepsis or if a secondary infection elsewhere in the body is suspected.

Antibiotics

The veterinarian will typically choose an appropriate antibiotic based on the bacterial culture and sensitivity test performed on a sample from the umbilicus. [1][4][5] While they wait for culture and sensitivity results, broad-spectrum antibiotics can help get the infection under control.

Antibiotic treatment usually lasts two to three weeks or potentially more. [1][6] In some cases, the treatment protocol also includes topical disinfectants, such as iodine or chlorhexidine, to further reduce the bacterial population. [1][5]

Although treating omphalitis with medication avoids the risks of anesthesia or surgery, there is a chance the bacterial infection will spread to other locations before the antibiotics can control the infection. [1][2]

Surgical Intervention

Surgical intervention is usually performed if medical treatment fails, or if the foal has a severe and widespread infection. [5][7] Some veterinarians may prefer to treat surgically, rather than attempting medical treatment alone. [2]

The surgery aims to completely remove the umbilical remnants, extending from the skin surface to the bladder. [1][7] By doing so, the source of the infection is eliminated, allowing for the foal to recover. [5] Antibiotics are used to treat any remaining sites of infection not removed by the surgery. [1]

Post-operative complications are relatively common after omphalitis surgery, affecting between 14 – 30% of foals. [3][8] Possible complications include: [1]

  • Surgical site infections
  • Failure of the sutures (reopening of the surgical wound)
  • Development of an umbilical hernia

Prognosis

The prognosis of omphalitis is highly variable and depends on the extent of the infection. Most foals that are diagnosed early and receive prompt treatment have a good prognosis and recover without complications. [1][3][6]

Foals undergoing surgical intervention at an early stage, rather than relying solely on medical treatment, often show a more favorable prognosis. [3] In one study, foals that underwent surgery only after the failure of medical management had a poorer prognosis for survival. [3]

Foals that develop liver abscesses, septicemia, or infections in other locations have a poor prognosis. [3][7][8] Studies show that these foals have around a 30% chance of survival. [1]

Patent Urachus

A patent urachus is a urachus that fails to close, allowing urine from the bladder to leak out through the umbilicus. [1] In most cases, the urachus closes normally after birth, but then reopens due to infection. [1]

Risk Factors

Most cases of patent urachus result from omphalitis, with studies showing around 80% of foals with omphalitis have a patent urachus. [1] Around 21% of foals with septicemia also have a patent urachus. [1]

Other potential causes of a patent urachus include: [1]

  • Meconium impaction causing abdominal straining
  • Umbilical cord torsion causing an overdistended urachus in utero
  • Traumatic rupture of the umbilical cord preventing proper closure of the urachus

Symptoms

The most common symptom of a patent urachus is dribbling urine from the umbilicus. [1] In some foals, the dribbling is continuous, while in others it only occurs during normal urination. [1]

Other symptoms include: [1]

  • Continuously moist umbilical stump
  • Scalding and irritation of the skin around the umbilical stump
  • Straining to urinate
  • Enlarged or swollen umbilical stump
  • Pus leaking from the umbilical stump

Diagnosis

Most cases of patent urachus are diagnosed based on urine leaking from the umbilicus. Ultrasound can also help identify a patent urachus, by showing a fluid-filled structure within the umbilical stump that extends up to the bladder. [1]

Treatment

Treatment of a patent urachus depends on whether or not there is also omphalitis present. [1] Treatment for foals with omphalitis is described above.

For foals without omphalitis, a combination of topical disinfectants and antibiotics is used to prevent infection until the urachus closes on its own. [1] As the foal becomes more mobile, the abdominal muscles become stronger and eventually close off the urachus. [1]

Common topical disinfectants include dilute chlorhexidine or iodine. [9] Some veterinarians also use antibiotics such as penicillin or cephalosporins, which are eliminated in the urine, to help prevent infection. [6][9]

Some veterinarians advocate the use of cauterizing agents, such as silver nitrate, to encourage the urachus to close. [1] These products are applied daily to the umbilical stump. Use of these products can cause tissue death, which may predispose the foal to developing an umbilical infection. [6][9]

While waiting for the urachus to close, careful monitoring for signs of omphalitis is crucial so that the treatment protocol can be adjusted as necessary. [2]

Surgical intervention is recommended if the urachus does not close on its own within five to seven days. [1][9] Surgery aims to remove the urachus completely, from the umbilical stump to the bladder apex. [1]

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Umbilical Hernias

Umbilical hernias are common in horses, with around 0.5 – 2% of foals developing a hernia at the site of the umbilicus. [1]

Umbilical hernias result from incomplete closure of the umbilical ring after birth. As a result, abdominal tissue protrudes through a weakness or gap in the abdominal wall into the underlying skin. [1]

These hernias can contain any abdominal structures, but most contain adipose tissue (fat) from within the abdomen. [1]

Some more severe hernias contain loops of intestine, which may become incarcerated, or trapped, within the hernial sac. [1] Incarceration is an emergency, as the blood flow to the incarcerated intestine is lost, and the tissue begins to die.

Risk Factors

The main risk factors for developing umbilical hernias are: [1]

  • Female foals
  • Quarter Horse breed
  • Genetic predisposition
  • Omphalitis
  • Traumatic injury to the umbilical cord during delivery
  • Excessive abdominal pressure from straining to urinate or defecate
  • Caretakers manually breaking the umbilical cord after birth

Symptoms

The primary sign of an umbilical hernia is an enlarged umbilical area. Most umbilical hernias are soft and non-painful when touched. [1] Veterinary examination is recommended for any foal with abnormal swelling of the umbilicus.

Foals that have incarcerated intestinal loops often show symptoms of severe colic. Symptoms may include: [1]

  • Reduced appetite
  • Rapid breathing
  • Rapid heart rate
  • Swollen, firm umbilicus with pain on palpation

Diagnosis

A key objective in diagnosing umbilical hernias is to determine whether the hernia is reducible (can be manually pushed back into place) and to check for any signs of incarceration. [1]

To assess its reducibility, the veterinarian will palpate the hernia. During palpation, contents of a reducible hernia easily compress back into the abdomen. [1]

Additionally, by examining the hernia, the veterinarian can evaluate the size of the defect in the abdominal wall. [1]

Hernias that are non-reducible typically indicate that the tissue within the hernia is trapped or incarcerated. [1] Ultrasound examination of the umbilicus is necessary to determine which abdominal structures are involved and to make an appropriate treatment plan. [1]

Treatment

Treatment depends on the size and severity of the umbilical hernia, as well as the results of the initial veterinary assessment.

Daily Reduction

For small reducible hernias, treatment typically involves hand reduction on a daily basis. Hand reduction consists of pushing the contents of the hernia back into the abdomen with gentle external pressure.

As the foal grows, eventually the gap in the abdominal wall closes enough that the abdominal tissue remains in place. [1]

If the hernia has not resolved by the age of four to six months, then surgery is necessary to close the defect. [1]

Hernial Clamps

Hernial clamps grasp the skin on either side of the abdominal defect, pulling it tight to hold abdominal contents in place after the veterinarian manually reduces the hernia. [1] Most veterinarians limit the use of hernial clamps to small, reducible hernias with no signs of infection, as an alternative to daily reduction. [1]

While effective, hernial clamps are rarely used due to the chance of clamping unwanted tissue, which can lead to life threatening complications.

In addition, most veterinarians will only use clamps if the foal is anaesthetized and in dorsal recumbency, which adds another layer of difficulty and expense.

Abdominal Bandages

Some veterinarians use a large bandage wrapped around the foal’s abdomen to keep the hernia reduced. [1] However, the success rate of this procedure is poor, as the bandages are prone to slipping out of place. [1]

Surgical Closure

Some umbilical hernias require surgical treatment to correct the defect in the abdominal wall. There are two options for surgical closure: closed repair and open repair.

In closed repair, the veterinarian reduces the umbilical hernia and sutures the sides of the hernia together, holding the hernia in a reduced position. [1] The advantage of this method is that it avoids direct entry into the abdominal cavity, thereby reducing the risk of internal infection. [1][2]

Open repair is required for incarcerated or very large hernias. In this approach, the veterinarian opens the tissue covering the hernia and replaces the abdominal contents within the abdomen. [1] The veterinarian then sutures closed the abdominal wall to prevent recurrence of the hernia. [1]

Very large umbilical hernias may require the surgeon to place a mesh over the defect, rather than bringing the sides of the defect together. [1] This procedure is very complex, typically requiring a board-certified equine surgeon to perform the procedure. [1]

In cases involving intestinal incarceration, careful evaluation of the intestinal loops is necessary. The veterinarian may have to remove severely damaged segments of intestine before repairing the hernia. [1]

Prognosis

The overall prognosis of umbilical hernias is good, particularly when diagnosed early in the hernia’s development. [1]

However, surgical intervention carries its own set of risks. Surgical complications can include re-establishment of the hernia, surgical site infections, and scar tissue forming between abdominal organs. [1][2]

Frequently Asked Questions

Here are some frequently asked questions about umbilical disorders in foals:

Summary

  • Umbilical hernias, omphalitis, and patent urachus are the most common umbilical disorders in foals
  • The overall prognosis of these conditions is good with appropriate and prompt treatment
  • Careful and routine evaluation of the umbilicus is an important step in foal management
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References

  1. McKinnon. A. O. et al., Equine Reproduction. Wiley-Blackwell, 2010.
  2. Smith. M., Management of Umbilical Disorders in the Foal. In Practice. 2006. doi: 10.1136/inpract.28.5.280.
  3. Oreff. G. L. et al., Surgical Management and Long-Term Outcome of Umbilical Infection in 65 Foals (2010-2015). Veterinary Surgery. 2017. doi: 10.1111/vsu.12695.View Summary
  4. Rampacci. E. et al., Umbilical Infections in Foals: Microbiological Investigation and Management. Veterinary Record. 2017. doi: 10.1136/vr.103999. View Summary
  5. Elce. Y. A., Infections in the Equine Abdomen and Pelvis: Perirectal Abscesses, Umbilical Infections, and Peritonitis. Veterinary Clinics of North America: Equine Practice. 2006. doi: 10.1016/j.cveq.2006.04.002. View Summary
  6. Reed. S. M. et al., Equine internal medicine, 3rd ed. St. Louis, Mo: Saunders Elsevier, 2010.
  7. Bryant. J. E. and Gaughan. E. M., Abdominal Surgery in Neonatal Foals. Veterinary Clinics of North America: Equine Practice. 2005. doi: 10.1016/j.cveq.2005.04.011. View Summary
  8. Reig Codina. L. et al., Short-Term Outcome and Risk Factors for Post-Operative Complications Following Umbilical Resection in 82 Foals (2004–2016). Equine Veterinary Journal. 2019. doi: 10.1111/evj.13021.
  9. Mair. T., Urinary Incontinence and Urinary Tract Infections. Veterinary Clinics of North America: Equine Practice. 2022. doi: 10.1016/j.cveq.2021.11.006.