The flank-incision method of spaying largely has been replaced by the trans-vaginal technique, which is faster, less labor-intensive, cheaper and safer. Using the trans-vaginal technique, a spayed heifer is back on full feed within 2-3 days, vs. 5-7 days with the surgical procedure, which also risks incision-site infections and scarring.
David Anderson, a Kansas State University DVM, says spaying isn’t without risk, particularly of hemorrhaging and other trauma, depending on the technique. Death loss in spaying heifers can be as high as 1%.
In earlier years, spaying was done with a flank incision, after which the surgeon removed the ovaries with spay shears or some other instrument. This method risks incision-site infections and scarring.
The trans-vaginal technique is faster, less labor-intensive, cheaper and safer. “Heifers bounce back in 2-3 days, whereas flank-spayed heifers might take 5-7 days to get back on full feed,” Anderson says.
Meyer, who began using the vaginal technique in 1983, says another disadvantage to flank spaying is that adhesions may develop. “Packers don’t like flank-spayed heifers because, when they pull the hides off, adhesions tear,” he says.
Anderson says there are two trans-vaginal techniques; both enter through the vagina into the abdomen to remove the ovaries. This can be done by hand, or with a Kimberling-Rupp spay tool that is inserted into the vagina, guided by a hand in the rectum (to locate the ovaries).
“There’s some risk of losing the ovary into the abdomen, which then may have access to blood supply from the omentum or mesentery and keep functioning. The Kimberling-Rupp instrument allows you to pull the ovary out, eliminating that possibility,” Anderson says.
The disadvantages of trans-vaginal spaying are the risks of puncturing the rectum, damaging the bladder or other trauma. “Proper training is important, but it’s a quick and economical way of spaying heifers. People who are good at it can do a heifer in two minutes,” he says.
Meyer says there’s always some chance of hemorrhaging. “Trace mineral deficiency [selenium or copper], or eating clover or moldy feed, may interfere with clotting,” he says.
Cleanliness is important. “You must keep things clean and disinfected. It’s also important to watch heifers closely for several days after spaying, and treat any that don’t feel well with antibiotics. Early intervention is crucial. Sometimes infections occur even if you’ve been meticulously careful and clean on the outside. A heifer might have vaginitis on the inside; the instrument may take it into the abdominal cavity,” Meyer says.
If a heifer is dull, off feed or feverish, he recommends a long-lasting antibiotic and Banamine® to reduce inflammation and help her feel better. “Usually there are no problems, but you have to treat one occasionally. It’s similar to castrating bulls; you need to watch them closely and deal with any problems,” he says.
In most instances, heifers are spayed after puberty. “We prefer them large enough to get a hand in the rectum and manipulate the ovaries, so we want heifers cycling. We can grasp the ovaries more easily,” Anderson says. Many people spay heifers in the spring of their yearling year, before pasture turnout. If they must be spayed younger, the flank technique is used.
“In the future, we may look at chemically sterilizing heifers,” Anderson says. “Vaccines are being developed for male castration, and we may eventually use something like this for heifers, thus eliminating the risks of surgery.”