Canine Spay

Spaying and neutering

Question: Dear Mike, I am a subscriber. Thanks again for being assessible on the web. I have two Shuhzi Chinese Doggies who are siblings. One is male, Chris, and one is female, Mui Mui. They are now six months old. My Vet recommend sterilization for both puppies. She said Chris will have bilateral orchidectomy. For Mui Mui, laparotomy with hysterectomy and bilateral salpingo-oophorectomy will be done. What is your opinion about this recommendation? My wife feel a bit uneasy to subject Mui Mui to such an apparently major operation. In addition, is there any trick or tip for looking after two puppies. They seems quite happy among themselves but not very friendly to us. I have anothe Shuhzi puppy previously, Ding Dong, who died of distemper, appeared quite differently. He enjoyed playing with us, and so do we. Look forward to hearing from you soon. Thanks. Regards, Ben

Ben- In the U.S., ovariohysterectomy (same surgery you are describing) is almost a "standard" recommendation for female dogs and cats. In some other countries, it is much less common, only being performed when there is an existing medical problem that requires it. These are the reasons that I can think of, for and against the surgery. When an ovariohysterectomy (OHE) is performed prior to the first heat period in a female dog, the risk of mammary cancer later in life is less than 1%. When OHE is performed between the first and second heat periods the risk is about 8% of mammary cancer later in life. Anytime after the second heat period the risk of mammary cancer in female dogs is about 25%, whether an OHE is performed later, or not. This is perhaps the strongest argument for spaying female dogs. The other major medical risk to female dogs that can be avoided by OHE is pyometra. This is infection of the uterus and it occurs in roughly 8% of female dogs sometime during their life time. In dogs uterine infections are a greater risk than in other species, due to the unusual way in which dogs have estrus cycles. The long interval between cycles with a closed cervix leads to severe infections developing with minimal clinical signs and so the condition often is life threatening at the time it is discovered. The disadvantages of spaying female dogs include a slight increase in aggressive tendencies in some females after OHE, an increased risk of urinary incontinence (usually treatable but may require life-long treatment), weight gain above what would occur with normal maturity in about 10% of dogs and the risk of the surgery itself. The surgical and anesthetic risk of death in a fairly large study done in Canada was reported to be about 1 in 500 for dogs in the study. For male dogs, the benefits of neutering (orchiectomy) are not quite as compelling, although it does decreased the risk of prostate hypertropy and infections pretty significantly and if the dog is going to be allowed out unsupervised it does help to keep the dog home and to avoid complications associated with seeking out females in heat, such as being hit by cars, shot by angry female dog owners (maybe only a U.S. problem?) and fighting with other suitors of the female in heat. Neutering makes urine marking less of a problem with many pet owners consider to be a major benefit, as well. There is about the same problem with weight gain, dogs neutered early may grow larger than they would have otherwise and there are surgical and anesthetic risks. Overall, I think that it is best to spay female dogs because it really seems to help them live longer. I think that neutering male dogs often provides a better life style for them and that in my practice area this benefit outweighs the risks. I hope this helps in your decision making. There is not an absolute right or wrong answer to the question of whether to spay and/or neuter pets but I think that the evidence favors going ahead with the spaying and neutering. Raising two puppies at the same time is both a good and a bad thing, too. It does give the puppies companionship when their owners can not be around and this can help a lot in avoiding behavioral problems such as separation anxiety. But it does seem to decrease the puppy's dependence on humans which can make them more distant and less willing to play with people or to share affection with them. All I know to do in this case is to make sure that you do provide the opportunity for affection and for play time and that you make it fun for the puppies so that they see a value in it. Over time, many dogs that have a companion dog they are highly dependent on will also develop similar affection for their owners. Mike Richards, DVM 4/3/2001

Reasons to spay or not

Question: Dr. Richards. We recently adopted a Chihuahua who is about five pounds and will be five years old in October. We are considering having her spayed, but we are worried about the risks of sedation due to her size. I recently read in Dog Fancy that if a female isn't spayed by her second cycle that spaying will not prevent mammary tumors. So, why would we take the risk of having her sedated? Thanks..James

Answer: James- There are two medical reasons to spay female dogs. The first is the prevention of mammary tumors. Dog Fancy is right about this one. If a female dog is spayed before the first heat period, the later risk of mammary tumors is less than 1%. If she is spayed between the first and second heat periods the risk is about 8% and if she is spayed after the second heat period the risk is 25%, regardless of whether she is ever spayed, or not. The other major benefit of spaying is prevention of pyometra, which is the form of uterine infection most common in dogs. This is a life threatening condition when it occurs, due to the way that dogs have heat cycles at long intervals. About 8% of female dogs will develop pyometra during their life time. The signs of pyometra can be very subtle. Sometimes there is a vaginal discharge, in which case the pyometra is considered to be an "open" pyometra and requires attention quickly. In other cases, there is no discharge and the dog just seems ill. This is the really dangerous form of pyometra because dogs often develop severe infections before there is a clear sign of trouble. Most commonly there is an increase in drinking and urinating as the infection worsens and paying particular attention to this sign in intact female dogs is warranted. Spaying has some risks associated with it, especially the risk of an anesthetic problem. The rate of anesthetic related deaths in dog surgeries is estimated to be about 0.1% and the total anesthetic complication rate is a little over 0.2% (Journal of the American Animal Hospital Association, Jul/Aug'98, Dyson et. al.). There is a higher incidence of incontinence in spayed females and there is also a slightly increased tendency towards aggression. If you are very good at observing your pets and are pretty sure you will recognize subtle signs of illness and act on them by having your Chihuahua examine, then there may not be any advantage to spaying her now. If she did develop pyometra it would be best to spay her and the risk of the procedure would be increased but it can be done at that time. Mike Richards, DVM 2/10/2001

Spaying older dog

Question: Dear Dr. Mike, First I wanted to update you on my dog Penny who was limping. I brought her for x-rays and it turned out she has a small fracture in her right front leg. I guess it was the best news I could of had, seeing that it is only a temporary problem. My vet x-rayed her shoulders, etc. and found no signs of OCD. The problem is with my intact 10 year old Cairn Terrier, Shatzie. She has frequently had false pregnancies in the past, but always seemed to get over it rather quickly. This time however, she is acting really bizarre. She won't come out from under the table in the breakfast nook where we keep a large dog bed . She growls and snaps at Penny if she goes anywhere near her, she barely eats or drinks. This has been going on for about a week. Is she too old to have spayed and if I did would it make a difference? Is this something that gets worse with age? I am bringing her for her yearly check up in 2 weeks and I will talk with him about, as always your opinion is greatly appreciated. Sincerely, JoAnne

Answer: JoAnne- It would be no problem to spay Shatzie at this age. It would end the problems with false pregnancies except that if a dog is spayed during a false pregnancy there are anecdotal reports of a short term increase in false pregnancy signs (even stronger nesting/maternal aggression type behaviors) that may last a few days to a week or so. I can't recall a patient exhibiting these signs but that definitely doesn't mean it doesn't happen to some dogs. There are no major medical benefits to spaying at this age except a small decrease in the risk of uterine infection and the alleviation of the false pregnancy problems. Sometimes dogs that are in pain from things like spinal disc problems will exhibit behavior similar to what Shatzie is exhibiting but it doesn't sound that likely, especially with a previous history of this type of behavior with false pregnancies. Not that it seems likely but I have seen one patient with a sudden worsening of "false pregnancy" behaviors who was actually pregnant at eleven years of age. Just something to consider if there is any possible way a pregnancy could have occurred. Mike Richards, DVM 6/5/2000

Seizures and spaying

Q: I have a 3 year old border collie who last December started having seizures - after having testing done it was determined she had an active case of ehrliciosis which was treated and she was immediately started on phenobarbitol. Also, immediately before her first seizure she had a Heartgard Plus tablet and also was put under anesthesia to have her hips OFA'd. My question is...I would like to have her spayed, however I don't want to do anything to cause problems with seizures...the neurologist doesn't want to try to wean her off the phenobarbitol for 6 months from her last seizure which was in February. So I won't know for quite a while if the seizures were brought on by the ehrliciosis or if it is epilepsy. Should I just wait awhile before having her spayed or are my worries about anethesia and seizures unfounded? Any insights you have have would be appreciated.

A: Sue- Sometimes I wonder if I have just been lucky and shouldn't base an answer on clinical experience but here goes: I have anesthetized A LOT of patients who have seizure disorders and a fair number of patients (at least 20 or more) who have seizure disorders and were on phenobarbital at the time of the anesthetic procedure. So far, I can not remember having an anesthetic crisis in one of these patients. We don't use barbituate induction agents anymore and have not had reactions to ketamine/valium induction and isoflurane maintenance. I know other combinations used by other vets successfully, too. So I think that it would be a good idea to go ahead and spay your dog if you wish to. There may even be some benefit since it reduces at least one major stress in her life (estral periods) that may (or may not) lower her seizure threshold. The only problem we have had is that we routinely use acepromazine as a preanesthetic agent and it can lower the seizure threshold. Not all vets believe this happens but I have twice given it to dogs with histories of seizure activity and had seizures occur within a couple of minutes of administering the acepromazine. So now I try really really hard to remember not to give it to patients with a history of seizures. Since it is part of our normal routine, we really do have to pay attention to make sure we don't give it to seizure prone patients. You might want to remind your vet's staff on the day you drop her off that she does have seizures. Since spaying is an elective procedure, you do have the option of waiting, as you point out. At her age (I am assuming she has been in heat at least twice) there is no particular benefit to spaying her before the next heat, except the small possibility that it might reduce the risk of seizures around the time of estrus. Hope this helps in your decision making. If this information leads to further questions, please send them. Mike Richards, DVM 4/17/99

When to spay

Q: We just got a lab puppy (7 weeks old), and we are wondering at what age is it safe to spay her. Also, any tricks for saving the lawn from yellow patches (2 dogs)??? Thanks. Curt

A: Curt- I think that the current research indicates it is pretty safe to spay puppies anytime after 4 months of age and it is likely that even younger spaying will not cause problems. I still like to wait until 6 months of age but only because it allows us to examine the puppy for retained baby teeth and remove these at the same time so that we don't end up anesthetizing a puppy twice in a short period of time. I have heard that adding d,l methionine to the dog's diet will reduce the urine burns in the grass but I am not sure this actually works. It is usually possible to train a puppy to use a certain area of the yard. If there is an area that isn't growing grass well anyway or has some other advantage like that it should be possible to train at least the younger puppy to use that area instead of the grass. Mike Richards, DVM

When to Spay

Q: Dear Dr. Mike, We have heard conflicting opinions on whether to spay our border collie before or after the heat. Can you give us your objective opinion on this? Thank you

A: I hope that you have not heard conflicting opinions from vets! It is pretty much universally agreed upon by vets that the best time to spay is BEFORE the first heat period. If a dog is spayed prior to the first heat, the odds of developing mammary cancer later in life are less than 1%. If spayed between the first and second heat periods the risk increases to about 8%. If spayed at any time after the second heat period, the risk of mammary cancer is about 25% in the dog (same as in an unspayed dog). There are no reasons not to spay prior to the first heat that I am aware of. A few dogs do develop incontinence from low estrogen levels after spaying but this does not appear to be affected much by the time the dog is spayed. Some dogs just develop this problem after spaying. With the obvious benefit of spaying before the first heat and the lack of any problems that have been proven to occur as the result of spaying early, there does not appear to be much reason for controversy to me. Mike Richards, DVM

Any correlation between incontinence and early spaying?

Q: Dr. Mike Is there any correlation between incontinence and early spaying? Is it less likely for a bitch to develop incontinence if she is allowed to go through one heat? Thank you

A: I do not know of a really good study of early spay procedures (less than 6 months of age) and later incontinence incidence so the best I can really say is that I don't know. I believe that the incidence of incontinence in dogs spayed after 6 months of age has been studied and there was not a statistically higher incidence of incontinence ultimately in spayed bitches --- but the onset of the symptom was younger compared to unspayed dogs. I don't think that waiting through one heat period would make a big difference but have no proof for that belief. There are known advantages to spaying prior to the first heat period, including a reduction in the rate of mammary cancer from about 8% in dogs who went through one heat to less than 1% in dogs who were spayed prior to the first heat. I wish I could give you more solid information but I can't. Mike Richards, DVM

Spayed, but still in heat

Q: Dear Dr. I AM VERY CONCERNED ABOUT MY FEMALE DOG(A PUREBRED BEAGLE). SHE IS DUE TO HAVE PUPPIES NEXT WEEK.wHEN I GOT THIS DOG A YEAR AGO I DID NOT KNOW IT'S PAST SO I TOOK HER TO A VET .HE TOLD ME THAT THIS DOG WAS FOR SURE FIXED(SPAYED) BECAUSE OF THE SMALL SURGERY SCAR SHE HAS ON HER BELLY . SO WHEN SHE BECAME IN HEAT A WHILE BACK I LET MY NEIGHBOUR'S DOG BEING A DASCHOUND BREED HER IN THINKING SHE COULD NOT GET PREGNANT . WHEN I TOLD MY FRIENDS SHE WAS PREGNANT THEY SAID IT COULD BE VERY DANGEROUS IF SHE IS PREGNANT IN THE OVARIES .THEY WORRY BECAUSE SHE WAS SUPPOSE TO BE SPAYED . IS IT POSSIBLE FOR HER TO CARRY THIS PREGNANCY THIS FAR(SHE IS ON HER EIGHT WEEK)AND BE PREGNANT IN HER OVARIES ? I WOULD BE SO HAPPY IF YOU COULD GIVE ME ANY SYMPTOMS OF DOGS BEING PREGNANT IN THE OVARIES. I BROUHT HER TO MY VET ON JANUARY 6, AND TOLD HER ABOUT MY WORRIES .SHE DID NOT DO TO MUCH IN TESTS TO PROVE TO ME THAT MY DOG WILL HAVE PUPPIES SUCCESSFULLY. YOURS TRULY.

A: It is unfortunate, but dogs can have scars for reasons other than being spayed, such as cesarean section, bladder surgery or tumors. So it is possible that your dog wasn't spayed since she came in heat. In this case, she may very well be pregnant. Your vet should be able to X-ray her to determine if puppies are present if she is due on the 23rd. Puppy skeletons calcify at around 45 days of gestation and are visible on X-rays after that. It is also possible that the dog was spayed but a small part of the ovary was left inside. Normally, in a spay procedure both ovaries and the uterus are removed. Once in a while there is ovarian tissue in odd places due to congenital problems or inefficient removal of the ovary, leading to later estrus (heat). In these cases the dog can not become pregnant. If this is the case, it is a good idea to have the section of ovary removed because there is a small possibility of complications such as infections of the small remaining portion of the uterus. It is best to attempt this surgery during the signs of heat because the remaining ovarian tissue is most visible then. The last possibility is that your dog was not in heat but had signs of estrus for other reasons, such as cystitis (bladder infection) causing similar signs. This seems less likely since you appear certain that the dogs mated but it has to be considered. The most likely scenario is that a small piece of ovarian tissue is still present in your dog. X-rays might give you a lot of relief right now, though -- and allow you to prepare if she is pregnant. Mike Richards, DVM

Last edited 12/05/02