To Neuter Or Not Neuter Female Dogs

Spaying females and castrating males are the most common surgical procedures we routinely undertake. There are advantages and disadvantages to both procedures.

Spaying Females

‘Spaying’ is the surgical removal of the female reproductive organs. Historically, in the Anglo-Saxon world this has meant the removal of the two ovaries and the uterus – an ‘ovariohysterectomy’. When vets talk about spaying, in most circumstances we’re talking about an ‘ovariohysterectomy’.

Advantages Of Spaying

Reasons for spaying female dogs are both medical and social. Females can develop a variety of medical conditions – cancers and infections in particular – that are life threatening. Removing the source of female hormone early in life, specifically before two and a half years of age may reduce the risk of mammary tumours. A recent (June, 2012) review of over 10,000 research articles related to neutering and mammary tumours found flaws in most of the research papers making their conclusions unreliable. Spaying certainly eliminates the risk of womb infection. The result is that the spayed dog population (spayed before two and a half years of age) lives on average 18 months longer than the ‘intact’ female population.

(One exception is the Rottweiler breed. For reasons that simply aren’t understood, spaying a Rottweiler statistically increases her risk of developing a type of cancer called a sarcoma. This increased risk probably balances the life prolonging advantage of spaying so with Rotties your decision to spay is tipped more towards the social values of neutering.)

Spaying eliminates the female hormonal reproductive cycle. The spayed female doesn’t have to enter purdah twice a year and be denied the fun of walks in the park and activities with other dogs.

Disadvantages Of Spaying

In one out of every three or four dogs, spaying alters energy balance enough to lead to weight gain unless the energy level of the diet is reduced. When your dog is spayed we suggest reducing the quantity of her food anywhere from 10 to 20 per cent, or switching to a ‘neutered dog’ variety of food.

Coat length and texture are both associated with sex hormone. As a general rule, male sex hormone enhances hair growth so males are hairier than females. After neutering, a female’s male hormone (She produces male hormone in her adrenal gland.) may affect her coat, which can grow thicker and more luxurious. This has no bearing on pets but is a consideration for people who show their dogs.

In Golden Retrievers and Labrador Retrievers there is a statistical suggestion that spaying at under one year of age increases the risk of two types of cancer, lymphosarcoma and haemangiosarcoma. If you have either of these breeds and are considering neutering, please discuss timing in more detail with one of us.

Ovariectomy Is Less Invasive Procedure

Over 30 years ago, French vets switched from the ‘ovariohysterectomy’, removing the ovaries and uterus, to the ‘ovariectomy’, removing just the ovaries. This is a less invasive procedure. The incision is smaller and much less tissue – only the two relatively small ovaries – is removed. By the later 1990s all continental veterinary schools had switched to the ovariectomy as their first choice neutering procedure.

British vets worried that leaving the uterus intact would lead to increased womb infections later in life but Dutch vets have shown conclusively that this is not the case. In the absence of female hormone the uterus contacts down to a thin strand. Infection is only possible if female hormone drugs (progestogens) are given to the dog and there are virtually no medical reasons for this to be done. (Cervical cancer and uterine cancer are both very rare in dogs so leaving these organs intact does not increase cancer risk.)

In 2008, after discussing the European results with Professor Dick White, former head of surgery at Cambridge University’s vet school, we modified our procedures and now undertake the ovariectomy as the neutering procedure of choice. If, however, the uterus appears unhealthy, it is also removed and we perform the more extensive ovariohysterecomy.

The procedure itself is straight forward. On arrival at the clinic your dog is given a ‘pre-med’ consisting of a sedative and two forms of pain killer, one of which also has a sedative affect. During surgery a further pain killer is given. The incision is usually repaired with stitches under the skin (to reduce an interest in licking) and medical ‘superglue’ is added. A light dressing is then applied to cover the area and further reduce the risk of licking. She goes home later that day, together with non-steriod anti-inflammatory tablets or drops (pain killer) to give for several more days. Most dogs want to return to normal activity within three days but, of course, your dog should be restricted to lead exercise for a week after surgery.

Keyhole Surgery

‘Keyhole’ or ‘laparoscopic’ or ‘minimally invasive surgery’ is the normal for many human procedures (such as appendectomies or gall bladder removal) and is a procedure of choice for operations such as liver biopsy in dogs. However, because dogs don’t have interfering belly buttons, a canine ovariectomy can be carried out and spay them using the single incision midline approach.

When To Spay

We suggest that as long as the external female anatomy is normal or ‘adult’ that females are spayed when they are physically mature and before the first season. This perpetuates the existing personality and is medically the best time to spay. If however, your dog has either a small (infantile) vulva or if she has a condition called ‘juvenile vaginitis’ where she experiences an inflammation and discharge from her vulva, we recommended letting her have one season. This usually rectifies both of these problems.

If you have any questions about any of these procedures please telephone the clinic and speak with one of the nurses.