How long does a dog bleed

The four phases of heat

Although the interval and duration of heat are quite different, the oestrus phase proceeds according to the same pattern in all bitches. The heat is divided into four phases.

Proestrus (pre-estrus):

The beginning of the proestrus can usually be determined quite precisely because it is associated with clearly visible changes in the bitch. The bitch's vulva swells and bloody vaginal discharge appears. This phase usually lasts nine days, but fluctuations between three and 17 days are not uncommon. The amount of bloody discharge also varies from dog to dog. While it is hardly noticeable in one bitch, other bitches bleed so badly that their owners have to fear red spots on upholstery and carpet. Another sign that the heat has started is the increased interest of the males, who suddenly hardly want to leave the bitch. Even if the bitch is not yet fertile at this point, she already gives off a very "seductive" smell. However, she usually reacts very bitchy and dismissive to the advances of her male admirers in this phase. She barks, evades or sometimes shows her teeth when a male becomes too pushy.

Oestrus (heat):

During the estrus phase of the oestrus, the bitch abandons her repulsive behavior - she suddenly appears open-minded and interested in the advances of the males. A clear sign that it is now "dangerous", because the bitch is now ready to mate and fertile. If a male dog approaches during this time, she willingly stops and turns her tail to the side. The phase, which also lasts an average of nine days, is therefore also called "stationary heat". During this time of standing heat, several ovulations take place. The vulva swells a little, the vaginal discharge becomes watery and sometimes slimy. If there is an act of cover in these days, the probability of fertilization is high.

Metestrus (after-estrus):

After about nine days of oestrus, the metestrus phase begins. The symptoms of heat, such as the swollen vulva and the watery discharge, gradually disappear. On the outside, there will soon be hardly any signs of heat, but inside hormones cause all sorts of changes in the bitch's body. Regardless of whether or not fertilization occurred, the corpuscles produce the hormone progesterone, which promotes the implantation and growth of the embryo in the uterus. Only after nine to twelve weeks are the corpuscles, which formed on the ovaries after ovulation, broken down again. The resulting drop in progesterone levels, in turn, boosts the hormone prolactin. The prolactin secretion stimulates milk production, which in some bitches leads to a false pregnancy.

Anestrus (resting phase):

After the weeks of strong hormonal changes, the sex hormones return to "normal". The progesterone remains at the same level, the estrogen level only shows slight fluctuations. This resting phase is called anestrus. It lasts for several weeks to months and ends with the onset of proestrus, the next heat. During this time the bitch shows no signs of heat and is not fertile.