Re: I asked my vet about spaying on the left
Found this interesting article..... Doesn't really answer the left/right question....... I will ask Gary England when I see him next week (He's a proffessor in veterinary medicine & reproduction)
Spaying: What, When and How?
Spaying has been shown to reduce unwanted pregnancies, prevent pyometra and decrease the risk of mammary gland tumors in female dogs and cats. However, increased tendency to develop obesity, bone cancer, aggressiveness, sedentary behavior, and urinary incontinence may develop after spaying. The ideal spay would result in positive effects from spaying with the least risk of developing negative effects. It would also result in minimal pain and immediate postoperative complications. Controversy thus continues to surround the best time and method of spaying. Veterinarians in the United States should be aware of differing practices and the rationale for their use.
A major controversy is whether ovariohysterectomy or ovariectomy is the preferable surgery. The rationale for removing the uterus is that stump pyometra may develop if the uterus is not removed. The rationale for ovariectomy is that the surgery is less invasive and the risk of pyometra is minimal once the animal is no longer cycling. In several long term studies of dogs and cats under going ovariectomy, stump pyometra did not occur in any animal after surgery. Studies have also shown that there is no difference in the incidence of urinary incontinence after ovariectomy or ovaraiohysterectomy in the dog.
A second controversy surrounds whether or not a midline approach or a flank approach is preferable. The midline approach is the standard method taught in veterinary schools in the United States. The flank approach is routinely used to perform ovariectomy, with each ovary being approached through a small, muscle-separating approach. The flank approach is also used to perform ovariohysterectomy in feral cat neutering programs. One ovarian pedicle is ligated, the uterine horn is followed to the cervix, the uterus and uterine vessels are ligated and then the opposite uterine horn is is followed to the second ovary. The advantages of the midline approach are that it is technically easier to perform an ovariohysterectomy from this approach, the incision can be quickly opened if needed, and both sides of the reproductive tract are easily accessible from one approach. The advantage of the flank approach is that, in experienced hands, it allows ovariectomy or ovariohysterectomy to be performed through a very small lateral incision. The flank approach can be closed with a few buried sutures and has a minimal risk of dehiscence.
More recently, techniques for laprascopic ovariectomy and ovariohysterectomy have been described for the dog. Although the surgery is technically challenging, the advantage of performing a spay using minimally invasive surgery is that the dog experiences less postoperative pain and distress.
A third controversy surrounds the best time to perform a spay. This controversy has been widely discussed in the United States literature in regard to the issue of neutering at a very young age compared to the traditional age of 6-8 months. Initial studies of 2-300 dogs and cats followed for up to 4 years did not indicate physical or behavioral differences between early age spaying or traditional age spaying. A larger study of 983 dogs found that 12.9% of dogs spayed at < 3 months developed urinary incontinence, while only 5% dogs spayed at >3 months became incontinent. Other differences documented in early age neutered dogs compared to traditional age neutered dogs were an increased incidence of cystitis, hip dysplasia, noise phobias and sexual behaviors, and a decreased incidence of obesity, separation anxiety, escaping behaviors, and inappropriate elimination when frightened. In 859 cats, an increased incidence of shyness was found in early age neuters compared with traditional age neuters, whereas a decreased incidence of asthma, gingivitis and hyperactivity were found.
In Europe, the debate has centered on whether or not to spay before or after the first heat. The mammary carcinoma data would suggest that performing a spay before the first heat would result in the lowest chance of mammary cancer. The pyometra data would suggest that as long as a spay was performed in the first 4 years of life, pyometra is not likely. One study of 809 bitches showed no difference in urinary incontinence in animals spayed before or after the first heat at the 5% significance level, but a difference at the 10% level. Other studies have documented urinary incontinence in 9.7% of bitches spayed before the first heat compared to a 20% incidence in bitches spayed after the first heat. Even though the incidence of incontinence was lower in bitches spayed before the first heat, severity of the incontinence in these dogs was much worse than in dogs spayed after the first heat. The risk of obesity associated with spaying appears to be worse in sexually mature animals compared to immature animals.
More recently, studies in Rottweilers have shown that the risk of osteosarcoma is increased in spayed and neutered animals compared to intact animals. For each month that an animal remained intact, there was a 1.4% decrease in osteosarcoma risk. The overall incidence of osteosarcoma in the study population of 683 Rottweilers was 12.6% during the study period. Cruciate injury has also been shown to be more common in spayed and neutered dogs.
The question must be asked: is there a group of animals, particularly dogs, in which the risks of spaying may outweigh the benefits? The most likely candidates would be large breed dogs at increased risk for cruciate rupture, osteosarcoma, urinary incontinence and/or dominance aggression. Osteosarcoma may result in early death, while urinary incontinence and/or dominance aggression can result in a pet becoming unacceptable and at risk of euthanasia. Weighing the risks of these conditions may shift the balance of “spay to prevent mammary cancer and pyometra” to “don’t spay or delay spay to prevent severe urinary incontinence or biting”.
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