Dog In Heat

dogs heat cycle induced dog discoveries

A dog in heat, also known as estrus, is a natural part of a female dog’s reproductive cycle. It’s a period of hormonal changes and physical signs that indicate she is fertile and receptive to mating. Understanding the stages and signs of heat is crucial for responsible dog ownership, whether you plan to breed your dog or prevent unwanted pregnancies.

The estrus cycle typically begins around six months of age for smaller breeds, but larger breeds might not experience their first heat until they are a year or even two years old. The cycle repeats roughly every six to twelve months, although this can vary between individual dogs.

The canine estrus cycle consists of four distinct stages:

Proestrus: This is the beginning stage, lasting approximately 7-10 days. The vulva will become swollen, and a bloody discharge will be present. Male dogs will be attracted to her, but she will typically reject their advances. Hormonally, estrogen levels are rising.
Estrus: This is the actual heat stage, lasting roughly 5-10 days. The bloody discharge may lighten to a pinkish or straw color, or it might even disappear entirely. The vulva remains swollen. More importantly, the female dog will now be receptive to male dogs. She may even actively seek out males and display flirtatious behavior, such as flagging her tail to the side. Ovulation occurs during this stage.
Diestrus: Regardless of whether or not she mated, the dog enters diestrus, lasting approximately 60-90 days. Progesterone levels are high during this period. If she is pregnant, this is when the pregnancy progresses. If she is not pregnant, her body will go through a false pregnancy (pseudopregnancy) in some cases. The vulva gradually returns to its normal size, and the discharge ceases.
Anestrus: This is the period of reproductive inactivity. It lasts for several months, varying significantly between dogs. Her body is essentially “resting” before the cycle begins again.

Recognizing the signs of heat is critical for preventing unwanted pregnancies. These signs include:

Swollen vulva
Bloody or pinkish discharge
Increased urination
Excessive licking of the genital area
Changes in appetite
Restlessness or nervousness
Flirtatious behavior towards male dogs, such as flagging the tail
Increased attention from male dogs

Managing a dog in heat requires vigilance. Keep her strictly confined to your property, preferably indoors. Supervise her closely during walks and avoid areas frequented by other dogs, particularly intact males. Even a brief moment of inattention can result in a pregnancy. If you have male dogs in the household, keep them completely separated to prevent accidental mating. Dog diapers can help manage the discharge and keep your home clean.

Spaying your dog is the only foolproof way to prevent heat cycles and unwanted pregnancies. It also offers several health benefits, including reducing the risk of mammary cancer and uterine infections. Discuss the best age for spaying with your veterinarian.