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UMBILICAL MASSES/HERNIAS IN CALVES
Overview of the Condition
The umbilicus in newborn calves consists of the urachus (a tube that attached the fetal bladder to the placental sac) and the remnants of the umbilical vessels that transported blood between the fetus and its mother. Normally, just after birth, these structures shrink until only tiny remnants remain within the abdomen (belly). If bacteria gain entry through the umbilicus, however, those remnants can become infected and require surgical removal. Additionally, if the area in the body wall through which these structures passed remains open, abdominal contents can protrude through the defect, resulting in an umbilical hernia. Umbilical hernias are the most common birth defect in calves and may be more common in the Holstein-Friesian breed.
Signs/Clinical Presentation
Calves with simple hernias may be completely asymptomatic (no clinical signs) except for the presence of a reducible umbilical hernia (where the hernia contents can be pushed back into the abdomen). Structures most commonly found within an umbilical hernia are the abomasum (the "true stomach" of the calf) and the omentum, a filmy membrane that provides blood supply and healing factors to abdominal organs. On examination, these structures can usually be pushed easily into the abdomen and the hernia ring palpated. In a very large or heavy animal it may be necessary to sedate the calf and put it in lateral or dorsal recumbency (on its side or back, respectively). By performing this maneuver it is very simple to palpate the hernia and associated structures.
A calf with an infection of umbilical remnants may have a fever, inappetence, and poor growth rate. If the urachus or umbilical arteries are involved, an astute owner might notice that the calf voids small amounts of urine frequently. The reason for this is that the urinary bladder is tied down to the umbilicus and never empties properly. A more worrisome condition is extension of infection to the remnants of the umbilical vein, which leads toward the liver. These calves may be more ill and less thrifty than other calves.
Differential Diagnoses
In order to determine whether the umbilical mass is a simple hernia or an infection, the calf is examined as mentioned by trying to reduce the hernia contents. In some instances it is possible to palpate an infected stalk within the hernia sac or around the umbilicus (Figure 1). If there is any doubt, the calf can be examined in lateral or dorsal recumbency under sedation to better palpate the umbilical structures. Ultrasound examination is extremely useful in determining whether there is any infection present and how extensive the reaction is. Some laboratory work such as white blood cell counts or fluid collection from the mass can also be useful for detecting infection.
Figure 1. An umbilical hernia (green arrows) in a calf with an ascending
infection to the urinary bladder. Note the small draining tract (red arrow).
Treatment Options
There are anecdotal reports of success treating simple umbilical hernias by applying a circumferential abdominal bandage. The idea is that by keeping the herniated contents reduced within the abdomen the hernia ring will close. Injection of irritating substances into or around the umbilical hernia to promote scar tissue formation should be avoided; this can spread infection and causes extensive tissue reaction, making surgery much more difficult.
Surgical treatment can occasionally be performed under sedation with local nerve blocks, but general anesthesia is ideal. The umbilicus and its associated structures are dissected free of the skin and body wall and any infected tissue is also removed. When the urachal infection extends all the way to the urinary bladder, a portion of the bladder wall may have to be removed as well (Figure 2).
Figure 2. In this calf, the infected urachal remnant extending to the bladder was surgically removed.
The urinary bladder has been oversewn (green arrows) with suture material to close the opening.
Aftercare
For calves undergoing simple hernia repair, antibiotics are often given only at the time of surgery. If the infection is more extensive, a 3 to 5 day course of antibiotics may be necessary. Non-steroidal anti-inflammatory drugs are useful for reducing pain but should be used cautiously since they can cause abomasal (stomach) ulcers if given too long. After surgery, the animal should be slowly reintroduced to feed and confined, to some extent, to prevent tension on the surgical repair.
Prevention and Prognosis
Prognosis is favorable for recovery, especially for simple hernias or minor infections. Calves that have infected umbilical vein remnants extending toward the liver may be at an increased risk of peritonitis (infection of the abdominal cavity). Occasionally a large abscess at the umbilicus must be drained before surgery can be considered (Figure 3).
Figure 3. This large abscess (green arrow) at the umbilicus had to
be lanced (cut open) and drained before it could be repaired surgically.
When to Seek Referral
Routine hernias can be done in the field, but those with extensive infection are best repaired by an experienced ACVS Veterinary Surgeon at a referral hospital where general anesthesia is available. Find an ACVS Veterinary Surgeon.
—Susan L. Fubini, DVM
Diplomate ACVS
Posted 8/21/2006
Updated 9/2/2009 by Dr. Fubini
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