by Donald “Doc” Skinner
I enjoyed a recent article by Dr. Knopp on heartworms, but he diagnosis section needing some updating. Confirmation of the larval stage in a fresh blood sample does indicate the presence of adult filarial. However, the larval microfilaria immitis has to be differentiated from Dipetalonema reconditum, the adults of which do not reside in a heart chamber but elsewhere in the body. I once amputated a hind leg on a coonhound only to find the vessels of the back leg were occluded with Dipetalonema. The absence of microfilaria in a blood sample does not mean the dog does not have heartworms. Today many people use ivermectin, which can clear the blood of microfilaria but has absolutely no affect on the adult worms. An antibody test using the serum from the blood will show the presence of adult worms and is the only definitive test for heartworms.
While I am in the mood, let me say a few words about vaginal prolapse, a condition most of you have either seen or heard about. The vaginal tissue, especially the wall swells naturally during heat. An exaggerated swelling under the influence of estrogen brings about prolapse. The exact cause is not known since the estrogen level is normal and the female barring other complications is fertile. Prolapse when it occurs is most often seen in either the second or third heat and unless corrected, will return during subsequent heat cycles.
Vaginal prolapse occurs in three degrees based on size and severity. The first is an eversion of the vaginal wall without protrusion through the vulvar lips. This probably goes unnoticed by many Beaglers by may be felt when dilating a bitch for breeding.
The second type is prolapse of the cranial (towards the head) floor and wall through the vulvar lips appearing as a small shiny swelling.
The third and most obvious type is when the entire vaginal circumference protrudes looking like a doughnut. The urethral opening can usually be seen on the ventral (bottom) surface of the prolapse. Many times the prolapse will regress spontaneously about a week after ovulation, which corresponds to the time the estrogen level will drop. Since bitches may ovulate at different times in their heat, it follows that all prolapses will not regress at similar rates.
Nearly all bitches that have prolapse will do so again on their next heat unless corrective measures have been taken. Many times bitches can still be tied even with a prolapse and usually do not prolapse at whelping. Inducing ovulation by injection will usually cause regression of the prolapse in about one week. Care should be taken to keep the prolapse clean and lubricated. An E collar may have to be put on the bitch to stop her from traumatizing it.
Often the prolapse has to be surgically removed due either to trauma or size. One disadvantage to surgical removal is that the vagina becomes shorter and the stud if unable to tie must be held on. Replacement of the prolapse and containment with retention sutures has a fifty percent success rate.
Spaying will resolve the problem for sure but is not an acceptable alternative for a breeder although; breeding records of some families of dogs indicate it may be genetically transmitted.