What is the menopause, and do dogs have one?
The menopause is defined as the permanent end of an animal’s fertility cycle, in animals that undergo specific fertile periods based on the release of an egg from the ovary.
For most human women with normal reproductive systems, this fertility cycle is monthly, and results in a monthly menstrual cycle or period.
For pooches, however, the cycle is longer, and only occurs twice or even just once a year for some dogs. This is known as going into oestrus and unlike a woman’s period (which is the result of shedding the lining of the womb and an unfertilised egg after conception fails to occur) indicates their fertile window.
Because the reproductive cycle of humans and dogs are different in this regard, what happens later in life is different too.
Women undergo the menopause when their fertility cycles reaches its conclusion, usually when the woman in question reaches an age at which bearing young would not longer be viable for her.
This signals the end of menstrual periods, and a number of other physical and sometimes emotional changes too. The menopause can take months or even years to run its course; but it signals a definitive end to a woman’s fertility when it does.
Do dogs have a menopause?
No, dogs do not undergo a menopause like humans do. Whilst human women have a distinct end to their fertility as they get older and this is signalled by the menopause, the same is not true for unspayed female dogs.
A dog’s fertility drops off as she gets older – there is a distinct peak fertile window for dogs that occurs when they are fully adult but prior to the start of seniority, usually between the age of two and five or so, and beyond this top-end peak fertile age, the dog’s fertility begins to decline.
This means that her chances of conceiving young if mated drop off and continue to decline exponentially as she gets older, and also, the chances of the dog carrying a litter to term, producing a normal-sized litter and having healthy pups all drop too.
Unspayed female dogs will continue to have heat cycles for their entire lives, although as they age, these may become more and more erratic, uncommon and variable in nature, reflecting the dog’s declining fertility.
Pregnancies in older dogs are also risky for both dam and potential pups, and spaying removes these risks. It also helps to protect the dog against some forms of reproductive health issues too, such as ovarian cancer, which cannot develop in spayed dogs.