Umbilical hernias are an anatomical defect where the muscles around the umbilical cord separate and portions of the bowel protrude from the abdominal cavity. There are several potential reasons why the abdominal body wall fails to heal properly following birth, including genetic defects, bacterial infections and environmental conditions of the neonatal piglet.
Umbilical hernias can cause increased low-value pigs at harvest and significantly reduce the profit potential of a barn. In addition, large hernias can increase mortality during the growing period.
The prevalence of umbilical hernias is estimated to be between 0.4 and 6.7% in commercial herds.
Umbilical Cord Management
Over the last few years, research has been conducted in an attempt to understand the significance of umbilical infections and pre-wean management strategies that may increase the likelihood of umbilical hernias in the finishing barn.
In 2009, staff at Carthage Veterinary Services (CVS) conducted a study of intensive management of the umbilical cord at birth and whether it could reduce umbilical and joint infections/swelling at weaning. In the study, 3,018 newborn piglets were randomly assigned to one of two groups.
In the intensive treatment group, within six hours of birth, pigs were given 5 mg injections of Ceftiofur Crystalline Free Acid (CCFA; Excede, Pfizer Animal Health); umbilical cords were tied off and sprayed with iodine.
The routine treatment group, serving as controls for the study, received no additional care on Day 1 but did receive 5 mg of CCFA at 3 days of age when routine processing was done for both groups. Piglets were identified within the litter by an ear notch.
Umbilical scores were assigned on a scale from 0 to 5 (see below; 0 = no signs of swelling or hernia; 3 = no hernia, no scab, but hard to the touch; 5 = hernia present). The umbilical scoring system was a collaborative effort by PIC and Bradley Wolter, chief operating officer at The Maschhoffs, Carlyle, IL. Pigs were evaluated for joint swelling between 17 and 19 days of age.
There was no difference in the mean umbilical scores or number of joint infections between the intensive and routine treatments. However, the intensive care treatment significantly reduced the prevalence of navel scores greater than or equal to 1 (13% vs. 10%) in the routine treatment group. The intensive care treatment at birth also reduced the amount of severe joint infections by 0.3%.
These data indicate that intensive treatment of navels in piglets at birth is not likely to result in a reduced rate of umbilical hernias or joint lameness in market pigs.
Umbilical Blood Clot Effects
In a follow-up study, CVS colleagues evaluated the role of the umbilical blood clot in navel infections. The objective was to determine if bacterial contamination of the umbilical clot in neonatal pigs resulted in increased umbilical hernias. In the 2010 study, 314 piglets from 100 sows were evaluated. Between 36 and 48 hours after birth, a culture was taken from inside the navel cord clot.
At 18 days of age, the umbilical stump was evaluated using the previously validated umbilical scoring system.
Laboratory tests showed 28% of pigs had a positive culture with 14 different species of bacteria identified. The most common isolates were E. coli (non-hemolytic), 13.7%; Staphylococcus hyicus, 12.4%; and, Enterococcus spp. (excluding E. faecalis), 7.3%.
The presence of any bacteria increased the risk of a higher umbilical score being more than or equal to 3. Each additional bacteria isolated (i.e., multiple bacteria were present) increased the risk by 49%. Isolated bacteria that appeared to be associated with a high umbilical score — greater than or equal to 3 — were S. dysglactiae spp, Strep suis, Enterococcus spp. and E coli. Pigs with bacteria in the naval stump were 10.5 times more likely to have arthritis at weaning.
These data suggest that navel infections may contribute to umbilical hernias in pigs but likely are not the sole cause. The study also showed that some bacteria are better predictors of umbilical swelling than others.
Overall, the studies demonstrate that the presence of bacteria in the umbilical cord can contribute to umbilical hernias in finishing pigs; however, further research conducted at Innovative Swine Solutions, Inc. has demonstrated that pigs with significant infections on the umbilical stump at weaning may not necessarily develop an umbilical hernia. Proper farrowing house hygiene continues to be essential.
Hernias are Costly
Market hogs with umbilical hernias are generally docked to 50% of value. Therefore, if 3% of pigs in a 1,200-head finishing barn are affected, assuming a 4% death loss per turn, 35 pigs would be sold as non-grade A pigs, fetching approximately $90/head vs. $180/head. When averaged across all pigs, the loss is $2.73/pig marketed. A portion of the death loss could be associated with severe umbilical hernias.
Laura L. Greiner is the director of swine research at Innovative Swine Solutions, LLC, Carthage, IL.