Browsing tag: bitch spay

New study shows that spayed & neutered dogs live for longer and die of different diseases compared to entire dogs

It was just last month that I wrote a blog here about the pros and cons of the decision on whether or not to spay/castrate your dog. This seems to be an area which is coming under increasing scrutiny by researchers, perhaps because it is relatively easy to analyse stored data to discover differences between spayed/neutered and entire populations. After all, the contrast between two study groups doesn’t get much more black and white than that: spayed/neutered or entire.

In one of the most recent studies (published online in April 2013), the historical records of over 80,000 sterilized and reproductively intact dogs were examined from a database of dogs presented to North American veterinary teaching hospitals over a period between 1984 and 2004. The cause of death and the lifespan of each animal was noted. To make the data as “clean” and unbiased as possible, the researchers removed around half of the records. First, they took out all young dogs, and all those where the spay/neuter status had not been recorded. Then they took out all those dogs that had died from congenital disease (i.e. disease which the animal had been born with, which obviously could not be influenced by neutering). Finally, they removed all of those dogs where no specific cause of death could be categorised. This left them with 40,139 dogs for analysis of the relationship between the effect of spay/neuter on age and cause of death.

The findings of the study are fascinating, and if you have an interest in reading scientific papers, you should read the report in full yourself. For those who don’t wish to, there were two main findings.

First, spaying/neutering caused dogs to live significantly longer lives. Females lived for 26.3% longer if they were spayed, and the life expectancy of males was increased by 13.8% after castration.

Second, there was a striking effect of spaying/neutering on the cause of death. Spayed/neutered dogs were dramatically less likely to die of infectious disease, trauma, vascular disease and degenerative disease. In contrast, sterilized dogs died more commonly from neoplasia and immune-mediated disease. This difference was similar for both males and females.

So what does this mean for pet owners? The study results could be taken to be broadly supportive of spaying and neutering both males and females, if length of life is taken as the most important outcome. It also suggests that owners of spayed/neutered dogs should be aware of the fact that their pets will be more likely to suffer from neoplasia or immune-mediated disease, and it would make sense to discuss with their vet what sort of signs they should look out for, so that if these diseases do develop, they will be well briefed in advance.

I still stand by my recommendations in the previous blog: all pet owners should discuss spaying and neutering with their vet. It may not be the right decision for every pet, but on average, this study demonstrates that it’s the most likely choice to lead to a longer life for your much loved pet.

Was I wrong to castrate my young male dog? And is it wrong to spay young female dogs?

I knew I wasn’t going to breed from my Hungarian Viszla so I made the decision to have him neutered which I did at six months old. Since then I have been told by the breeding fraternity that neutering at such an early age is a factor in dogs getting bone cancer. I cannot bear that I may have done something in good faith that could affect my beloved dog’s future health. What is the truth?

This question from a VetHelpDirect reader is an increasingly common query from pet owners responding to internet rumours and discussions that are doing the rounds. As is often the case, the truth is complicated: we still do not know everything about the impact of spay/neutering, but we do know that there are pluses and minuses to having the operations done.

In the past, it was more-or-less universally agreed that early spay/neuter was the best choice for all dogs and cats. New information from recent studies means that this one-size-fits-all advice now needs to be modified. It seems that spay/neuter of some breeds of young dogs may increase the risk of some some types of cancer. At the same time, it should not be forgotten that the operation also reduces the risk of other (common) cancers. A balanced view now may be that the decision needs to be made for an individual, after considering all factors, rather than just saying “early neutering is always best”.

It does sound to me as in your case, with a Viszla, it was the correct decision. Early neutering is still strongly recommended for nearly all dogs as the best way to ensure that a dog is a good family pet. There are many behavioural advantages, such as stopping male dogs showing sexual behaviour, urine marking etc. And there are many health benefits too – reducing prostate disease, reducing certain types of cancer etc. And bone cancer is rare in Viszlas.

For female dogs, there are also many benefits from spaying. The operation eliminates the risk of unwanted pregnancy, dystocia and the physiological and behavioural changes associated with the six-monthly reproductive cycle. It eliminates the risk of pyometra, which occurs in 23% of intact females and kills approximately 1% of intact females. Mammary tumours are the most common malignant tumours in female dogs, and spaying before 2½ years of age greatly reduces the likelihood of this cancer.

Neutering and spaying has other beneficial effects on a society-wide basis: it prevents dogs from straying and dramatically reduces the problem of unwanted pups.

What about the negative aspects? A comprehensive review paper published in 2007 provides a detailed catalogue of the potential negative risks which seem to be more in some breeds and some cancers than others (e.g. more osteosarcoma in giant breeds like Newfoundlands and St Bernards). A more recent study on Golden Retrievers found an increased risk from other cancers and some joint diseases from early neutering but the study has been criticised by statisticians and other scientists as being potentially biased and not representative of the general population of dogs. It’s likely that other studies are in the pipeline, so it’s worth keeping an eye out for these in the coming years.

When reading these studies, it needs to be remembered that a big increase in the risk of a rare cancer may not be as significant to a pet as a small decrease in the risk of a common cancer. It is not easy for pet owners, unfamiliar with judging medical data, to assess these types of situations.
What should pet owners do? Refuse to spay/neuter their pet, then blame themselves when their male dog develops anal tumours or when mammary cancer affects their female dog? Or go ahead and spay/neuter, then beat themselves up when their pet develops osteosarcoma?

The best answer is that there is no perfect choice. The take home message is that you should not ignore the subject: all pet owners should discuss this with their vet. A decision should be made after addressing all of the issues above. Only in the fullness of time will you know whether it was the right or wrong choice.

The most important issue is that you carefully consider the various implications: at least then, regardless of the outcome, you will be able to look back and say ” I did my best to do the right thing”.

Neutering dogs – Bitch spay operation: a step by step guide

Deciding whether to spay

Spaying or neutering a female dog is not a small operation, so owners should think carefully about all the pros and cons before deciding.

The main advantages of spaying are preventing pregnancy, preventing infection of the uterus (pyometra), preventing ovarian or uterine cancer and reducing the likelihood of mammary (breast) cancer, all of which can be life-threatening. It also prevents the inconvenience of having a bitch in season with unwanted attention from male dogs.

The main disadvantages are major surgery with associated risks, an anaesthetic with associated risks and the increased likelihood of urinary incontinence in later life. Fortunately, the risks involved in anaesthesia and surgery are very small indeed compared with the risks of the other conditions which are prevented by spaying. Urinary incontinence in later life is a nuisance but not very common, and can usually be controlled by drugs.

There is no medical reason to let a bitch have one litter before spay, in fact some of the benefits like protection against mammary tumours, are lost if the operation is delayed. Unless an owner is committed to having a litter, with all the work and expense that can be involved, and the bitch is also suitable in temperament and free of any hereditary problems, then breeding should not be considered.

Tilly GrinSome people expect that their bitch will get fat after spay, but in fact this is entirely preventable with a healthy diet and proper exercise.

My own opinion is that most bitches should be spayed because of the health benefits. My boxer bitch Tilly was recently spayed.

Deciding when to spay

It is not a good idea to spay when a bitch is in season or about to come into season, because the blood vessels supplying the uterus and ovaries are all larger and this will increase the risks of surgery. The other time we try to avoid is the 8 weeks after a season, when a bitch may suffer from a hormonal imbalance called a false pregnancy. If this happens, she may be acting as if she is nursing pups and the operation at this time would cause such sudden changes in hormone levels that it would be unfair to her. Also if she was producing milk, the enlargement of the milk glands would make it more difficult for the spay wound to heal.

For all of these reasons, the time chosen to spay is usually either before the first season occurs, or 3-4 months after a season. A physical examination by the vet will determine whether a 5-6 month old bitch puppy is mature enough to spay before her first season.

Before the operation

As well as timing the operation carefully to reduce any risks, it is also important that the bitch is not overweight. Because this increases the difficulty of the operation, it may well be advised that an overweight bitch should lose weight before the operation.

Another important way of spotting avoidable risks is by taking a blood test before the anaesthetic. This could be done on the day of the operation or a few days earlier. This is used to check the liver and kidney function (both vital when dealing with anaesthetic drugs) and to rule out any unsuspected illnesses.

Before going to the surgery

Before any anaesthetic the patient should be starved for a number of hours, according to the instructions of the surgery. This prevents any problems with vomiting which could be dangerous. It is also a good idea to allow the dog enough exercise to empty the bladder and bowels. Apart from that, it is best to stick as closely as possible to the normal routines of the day so that the dog does not feel anxious.

Being admitted for surgery

On arrival at the surgery, you can expect to be seen by a vet or a veterinary nurse who will check that you understand the nature of the operation and will answer any questions you may have. They will ask you to read and to sign a consent form for the procedure and ask you to supply contact phone numbers. This is very important in case anything needs to be discussed with the owner before or during the operation.

Before the anaesthetic

Your bitch will be weighed to help calculate the dosages of drugs and given a physical examination including checking her heart. If a pre-anaesthetic blood test has not already been done, it will be done now and the results checked before proceeding. If any abnormalities are found, these will be discussed with the owner before deciding whether the operation goes ahead or not. One possible outcome is that extra precautions such as intravenous fluids may be given.

A pre-med, which is usually a combination of several drugs, will be given by injection. This begins to make the dog feel a bit sleepy and ensures that pain relief will be as effective as possible.

The anaesthetic

There are several ways in which this can be given, but the most common is by an injection into the vein of the front leg. The effects of the most commonly used drugs are very fast, but don’t last for very long, so a tube is placed into the windpipe to allow anaesthetic gas and oxygen to be given. The anaesthetic gas allows the right level of anaesthesia to be maintained safely for as long as necessary.

Various pieces of equipment will then be connected up to monitor the anaesthetic. This is a skilled job which would usually be carried out by a qualified veterinary nurse. Apart from the operating table, the instruments and the anaesthetic machine, a lot of specialised equipment will be on “stand by” in case it is needed.

The area where the surgical incision is to be made will be prepared by clipping and thorough cleaning to make it as close to sterile as possible. The site is usually in the middle of the tummy, but some vets prefer to use an incision through the side of the tummy.

The operation

While the bitch is being prepared for surgery as mentioned above, the surgeon will be “scrubbing up” and putting on sterile clothing (gown, gloves, hat & mask) just as in all television surgical drama programmes. The surgical instruments will have been sterilised in advance and are opened and laid out at the start of the operation.

The operation involves removal of the ovaries and uterus (ovario-hysterectomy). The surgeon carefully opens the abdomen by cutting through the various layers. The first ovary is located and its blood vessels are tied off before it can be cut free at one end, then this is repeated with the second ovary. It is a delicate and fiddly job, needing great care and attention. The main body of the womb or uterus is then tied off as well before the whole thing can be cut free and removed. After checking for any bleeding, the layers of the tummy can then be sewn closed again. A dressing might be applied to the wound. Further drugs may be given now as needed.

When the operation is finished, the gas anaesthetic is reduced and the bitch begins to wake up. She will be constantly monitored and the tube removed from her windpipe when she reaches the right level of wakefulness.

Recovery

Like humans, dogs are often a bit woozy as they come round, so she will be placed in a cage with soft warm bedding and kept under observation. Usually they will wake up uneventfully and then sleep it off for the rest of the day.

After-care

The bitch will not be allowed home until she is able to walk and is comfortable. Full instructions should be given by the surgery concerning after-care. The most important things would be to check the appearance of the wound, to prevent the bitch from licking it (with a plastic bucket-collar if necessary) and to limit her exercise by keeping her on the lead. Any concerns of any kind should be raised with the surgery.

Any medication supplied should be given according to the instructions. Pain relief can be given by tablets or liquid on the food. Antibiotics are not always needed, but may be supplied if there is a need for them.

Usually there will be stitches in the skin which need to be removed after about 10 days, but sometimes these are concealed under the surface and will dissolve by themselves.

tilly's wound with text

After a couple of weeks, if all goes according to plan, the bitch can be allowed to gradually increase her exercise levels. This is the stage that Tilly has now reached and she is thoroughly enjoying a good run again now that she is feeling back to normal.

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