VET’S DIARY: To spay or not to spay

THERE is a whole raft of reasons why it is a good idea to neuter young bitches and these fall into the categories of behavioural and medical, writes Dominic Plumley.

The operation, known as spaying, involves the removal of the dog’s uterus and ovaries, requiring surgical entry into the abdominal cavity; a procedure that is not entirely without risk but is routine in young healthy animals.

The obvious reason for doing the op is to prevent unwanted pregnancies. This ties in with removing the behavioural changes associated with some bitches during oestrus (also referred to as season or heat); which can be anything from being a little grumpy to being over amorous and consequently over the wall to find a mate. Inevitably, in multi-dog households, these twice-yearly fluctuations in temperament can have a significant impact on normal harmony.

In addition, a hormonal quirk in dogs means that some individuals suffer from pseudo-pregnancy. The interaction of oestrogen and progesterone results in physiological changes in the body consistent with pregnancy even if no insemination has occurred.

At about the time that a normal gestation would be complete (about two months after their heat) the bitch starts to produce milk and exhibits innate behaviour associated with giving birth – nesting for example – and they will often adopt a toy as a surrogate pup.

One of the major medical benefits of early neutering is the massive influence on the reduction in incidence of mammary tumours later in the animal’s life. For a really significant effect the procedure should be performed within the first year of life and often before the bitch has had her first season. Bitches spayed at this stage may be as much as 90 per cent less likely to develop mammary tumours than those that are not, with mammary cancer very common in older entire animals.

This week we were reminded twice in the same day of another medical benefit of early neutering. Both dogs were late middle-aged entire bitches that had been showing their age over the last month or two and then suddenly became very ill.

The tell-tale thick and smelly vaginal discharge that had also just started in both dogs was on its own just about diagnostic of the problem – pyometritis or infection of the womb.

Over the life of the bitch – the uterus goes through many hormonal cycles and as the organ becomes older these changes can be more dramatic until an irreversible inflammatory vicious circle develops. The uterus swells and fills with pus – effectively becoming a large abscess within the abdominal cavity. This in turn releases toxins into the blood stream causing the dog to become rapidly very ill – often off their food but very thirsty and also vomiting. If un-treated – and occasionally even when treated – these cases are rapidly fatal the dog’s body overwhelmed by toxic shock.

Thankfully, in both cases blood tests revealed no damage to the kidneys and intravenous fluid therapy followed by emergency ovario-hysterectomy soon had them back on their feet.

As is often the way with pyometritis, both dogs were dramatically better following their surgery than they had been for several months. This reflects the insidious nature of the changes that can occur to the uterus – the inflammatory process slowly brewing until melt down occurs.

Sometimes the cervix will open – resulting in the discharge seen in our two fortunate pooches, though it can remain closed with uterine rupture an added complication if the problem is not addressed quickly.

Of course – we can’t spay all bitches early as there wouldn’t be any to breed and have puppies – but for any animals not intended for the family way – early neutering is the thing to do.