What is a bitch’s season?
If you own a bitch (female dog) then provided she has not been spayed she will come into season on a fairly regular basis through her life. This is commonly known as ‘being on heat’ and is something that owners of all dogs need to be aware of. It is only while the bitch is in season that she can get pregnant and owners need to beaware of the cycle to avoid unwanted pregnancies. Similarly breeders need to be aware of the season to ensure mating at that time. Bitches do not have a menopause in the way humans do and they will come into season throughout their entire lives, although they will be less fertile.
What is being in season?
A bitch’s season is so do with her oestrus cycle which is the regular changes that occur in her reproductive cycle due to hormone level changes. There are various stages of the cycle and these are known as pro-oestrus, oestrus, metoestrus, dioestrus and anoestrus.
The season is from the start of pro-oestrus to the start of dioestrus and as a general rule this will take around three weeks. At the start of pro-oestus her levels of oestrogen will rise in anticipation of the release of her eggs and her uterus will start to swell. There will be physical and behavioural changes that will include
- She will likely urinate more and this is a way for her to leave a message for male dogs to let them know she is in season.
- She may become more outgoing and flirtatious as she attempts to attract suitors although at this stage she will not let them mount her. She may stand with her hind quarters towards the dog and move her tail to one side to allow the dog to better see and smell that she is nearing her most fertile time.
- Physically her vulva will swell and become a more red/pink colour.
- She will start to bleed or spot and this is more noticeable in some bitches than others. Some are so good at keeping themselves clean that it is barely noticeable.
This stage of the cycle will last an average of 9-10 days but this varies from bitch to bitch and across breeds.
The next stage of the cycle oestrus coincides with ovulation and the release of her eggs and over the next 5 or so days she will allow herself to be mounted. Physically her vulva will become even more swollen and a straw coloured discharge will often be seen.
Metoestrus follows and during this phase things start to return to normal in the bitch, she will be less exciteable, her vulva will start to return to its usual size and colouring and discharges will stop. She will not allow mating and her body starts to produce progesterone that will line her uterus in readiness for pregnancy.
Dioestrus is the final stage and progersterone is still being produced. In non pregnant bitches the high levels of this hormone can lead to phantom pregnancies.
Anoestus is the much longer period between the seasons until oestrus starts again.
When and how often do bitches come into season?
This again varies from bitch to bitch and across breeds but generally the first season will be around the age of 9 months and thereafter every six to nine months. The presence of other bitches in season or male dogs can make a bitch come into season sooner and groups of bitches housed together may well end up with their seasons synchronising so thaey happen close to each other.
For those that wish to breed it is recommended to wait until the bitch is at least a year old to allow for her development and maturity to reach the right level. Mating should therefore not take place during her first season.
What do owners of bitches need to be aware of?
Bitches in season are pretty much irresistible to male dogs and they will be able to detect the scent of a bitch in heat from a considerable distance and will want/try to get to her. Sensible precautions must be taken by the owners of bitches in season to avoid pregnancy. During the period when she will allow mating it may be wise not to take her out for walks but to provide exercise in the garden or house. If there is a male dog living in the house they need to be strictly seperated. If taking her out for a walk it is sensible to keep her on a lead at all times and to go to quiet places where there are unlikely to be other dogs. During the stage of the cycle where the bitch is bleeding/spotting or discharging the straw coloured fluid, surfaces should be thoroughly cleansed and good hygiene practiced eg. Using a new floor cloth each time, wearing gloves and washing hands.
Spaying – the advantages
Unless you intend to breed from your bitch it is recommended that they are spayed. There is debate as to when this should happen and we would say it needs to be after 6 months of age and in some breeds it is better to wait until after their first season. The best advice is to consult your vet who will give you guidance. Advantages of spaying are that they are less prone to certain cancers, will not accidentally become pregnant and won’t suffer from a potentially fatal uterine infection known as a pyometra.