by Pat Rock
Newsflash: It’s not a perfect world.
In a perfect world all dog breeders would have access to and endless money to spend on a top repro vet. Newsflash: It’s not a perfect world. Many of us strive to breed dogs that conceive and whelp naturally, and don’t often need to seek the services of a specialist around whelping time. In the rare event that we do have an issue, it is important to be sure your attending vet is up to date on the use and misuse of pituitrin (oxytocin).
An excellent, one page article by Dr. Margaret V. Root Kustritz DVM.PhD, DACT that you might want to have handy was published on DVM360.com (URL: http://veterinarymedicine.dvm360.com/practical-matters-use-lower-doses-oxytocin-dystocia). Dosage recommendations are provided.
Here’s the gist of the problem:
During whelping the uterine horns contract to advance the puppies toward and through the cervix and vagina to the outside. The action of the involuntary muscle fibers in the uterine wall is akin to the way in which one of those miracle hoses contracts when the water is cut off. The dam aids in the expulsion of the puppy with contractions of the voluntary muscle of the abdomen and diaphragm.
Often there will be a prolonged pause during whelping, allowing the uterus to undergo some of the normal shrinking before actively contracting to push the next puppy or puppies toward the cervix. It is a judgement call to decide what is a normal pause in the process, and what constitutes dystocia (failure of whelping to proceed). This normal whelping pause must not be confused with active pushing with no progression caused by a large or malpositioned pup for which problem you generally don’t want to intervene with oxytocin injections. For hours long lack of labor contractions intervention with oxytocin injections may be helpful, or lead to a dead puppy.
Veterinarians in general practice may not be up to date on correct dosing of oxytocin. Following older guidelines a bitch with a retained puppy might be given a too large dose of oxytocin. The larger dose causes the uterine muscle to go into tetany (a prolonged strong contraction which can cause the placenta to separate, giving the puppy only a few minutes to make it to the outside and start breathing air. ) The smaller doses recommended in the above article can be used to encourage the uterus to shrivel up in a normal fashion.
If a bitch is confirmed by radiography to have undelivered pups, then small doses of oxytocin given at 20-30 minute intervals may result in vaginal birth. If the treatment does not work, then a caesarean section is indicated.
The trick is to know your bloodline and your individual dog. And copy the referenced article and take it with you on that middle-of-the-night trip to your vet.