When Navel Dipping, Gentler is Better
Modern Horse Breeding, February 1995.
Strong iodine is not the solution to umbilical
health. Dipping the umbilical stump of a newborn foal is a routine management
procedure on breeding farms. Yet some managers have long observed that stronger
solutions sometimes seem to do more harm than good. Now, research from the
University of California-Davis School of Veterinary Medicine has confirmed that
when it comes to navel dipping, gentler is better.
A team of researchers compared dipping the navel
stump in four common bactericidal solutions: 2% iodine, 7% iodine, 1%
povidone-iodine solution and 0.5% chlorhexidine solution. The dipping was done
immediately after birth and again six to eight hours later. A fifth group of
control foals was not treated with any solution.
The researchers looked carefully at the various
solutions' abilities to reduce the type and number of bacteria which typically
colonize the umbilicus. They viewed the area with ultrasound to examine the way
in which the umbilical vessels regressed and whether they were beginning to
abscess. In addition, they followed the progress of separation and atrophy of
the umbilical stump and compared that process with the development of
complications which may have arisen due to invasion of bacteria.
The results indicated that 7% iodine, while
extremely effective in eliminating bacteria, did its job all too well. The
strong tincture opened the door for infection due to rapid drying out of the
stump, sloughing of adjacent tissue, and development of a long tail, giving
bacteria a free ride into the bloodstream and opening the door to abscessing,
systemic infection, and navel ill. Instead, the more gentle solution of
chlorhexidine, diluted with water in one-to-four solution, proved equally
effective in controlling bacteria but without the undesirable side effects.
The results of the study were presented by John
Madigan, DVM, at the Sixth International Symposium on Equine Reproduction in