Many dog owners wonder how long a dog can be in heat for. A female dog’s heat cycle is complex and will often start from the age of six months old and will continue for the rest of her life.
Female dogs will normally go into "heat" or oestrus twice a year. The age at which their cycles begin as well as the duration of the cycle varies greatly depending on the physical characteristics of the dog. If you are planning to breed your dog in the future, it is important for you to learn about her reproductive cycle. A dog in season has a very narrow breeding time! Likewise, if you don’t want to breed your dog, you might want to consider spaying her. In this pet parent guide, you will find important information regarding this topic!
When does the oestrus cycle begin?
Dogs can go into heat as early as four months old in smaller breeds. Generally, though, the average is around six months old. Some giant breeds may take more time. Indeed, some may go into their first heat after 18 months of age (sometimes after 2 years). Most vets are strongly against breeding a young female dog during her first and second cycle. According to research, the dog hasn’t reached full maturity at that stage. Breeding her regardless could be dangerous for her and her puppies’ health.
How long is a dog in season?
The length of a dog's season is usually between 2-4 weeks. Early in the cycle, female dogs are not receptive to male dogs. Nevertheless, there may be exceptions, since some cases have reported that female dogs in season have been receptive throughout the entire cycle.
Usually, your dog is most fertile period about nine days after she goes into heat. This is a period of time in which the vulva has reduced to its normal size and bleeding has stopped. Fertility lasts for about five days.
Stages of the heat cycle
There are four important stages of the heat cycle:
- Proestrus: in this stage, the vulva begins to swell and there is bloody discharge. Males begin to feel attracted to females, but females will not accept them yet. She may, however, start to act very clingy with her owners.
Length: 4-20 days.
- Oestrus: its primary sign is the swollen vulva. It can be accompanied by a yellowish and watery vaginal discharge. Females will willingly accept a male during this phase, in fact, they may even seek them out! A way to reliably know whether a female is ready to mate is to run your hand down her back and over her rump. Dogs who are in heat move their tail to one side when you do this (an instinctual behaviour known as ‘flagging’, done so that the tail doesn’t impede entry by a male). Mating occurs during this phase.
Length: 5-13 days.
- Diestrus: this is the name given to the period of time that passes after mating. It is during this stage that pregnancy occurs, if the mating was successful. On the other hand, false pregnancies and infections of the uterus can be quite common during this phase for unspayed females who have not mated.
Length: 60-90 days.
- Anoestrus: this last stage is mainly a period of inactivity between oestrus phases. A female dog cannot get pregnant during this phase.
Length: 2-3 months.
Does this process occur for the rest of a dog’s life?
Once oestrus begins, it can initially take a while for the cycle to become regular. Usually, it can take up to 18 months until their cycle becomes regular. Once it does, your dog should be in heat around once every six months, although, once again, this can vary greatly between individuals. Owners should keep tabs on their dog’s cycles so that they can prepare for them properly.
Unlike humans, female dogs experience oestrus throughout their whole lives, but the time between cycles will get longer, making them more sporadic. However, unspayed females will still be able to get pregnant at any point in their lives.
There is a level of controversy here because, with the exception of breeders, a lot of pet owners choose to spay their female dogs before their first heat. Some experts believe this reduces the risk of mammary cancer and other conditions, while others think that this procedure has harmful long-time effects on their bodies. It is important that you have a conversation early on with your vet to discuss pros and cons and make an informed decision about spaying.
Precautions when dealing with a dog in heat
Dogs can get pregnant during their first heat cycle, but this is not advisable because complications for the mother and the puppies can arise.
Lately, many dog owners are supporting the decision of spaying their dogs before the first heat. This eliminates the risk of breast cancer, accidental pregnancy and reproductive diseases later on in life. Nonetheless, recent studies seem to suggest that early spaying and neutering may have some adverse effects on a dog’s health later on in life. Early neutering is a complex issue which needs to be discussed properly before your dog’s first season.
If you have a dog in season, you'll need to be prepared for it. Fortunately, it only happens twice a year. With this guide, you now know what to expect when you are expecting.