Dogs in Heat and the Estrus Cycle
Do female dogs have periods? Well, yes, but they are a part of what is properly called an estrus cycle. You may have also heard of a dog as being “in heat” or “in season” during this time, and the estrus cycle is sometimes called a “heat cycle.”
The first estrus cycle for dogs happens when the animal reaches puberty at around six months of age, though that number may vary between breeds and individual dogs. Smaller breeds tend to reach maturity earlier, while larger dogs might take more than a year to have their first heat.
The cycle often happens twice per year. The American Kennel Club (AKC) writes that some smaller breeds can go into heat up to four times per year, and extra-large dogs, such as St. Bernards or Great Danes, may only experience it every eighteen months. When a dog enters the cycle, it lasts for two to three weeks, though the actual amount of time differs for each individual dog. During this time, the vulva becomes red and swollen, a pink or clear discharge leaks out, and your dog will likely seem jittery and alert, notes the AKC.
Discharge also varies quite a lot and is not pure blood, notes PetWave. Some dogs may leave spots on the floor or dog bed, while for others the discharge will be barely noticeable. The cycle often starts with a heavier reddish discharge in the beginning, which fades to a yellow, pink, or watery spotting later on. Cleanup can be exasperating, and Canine Journal has even reviewed some doggy diapers for pups in heat. If you use diapers make sure to change them frequently and keep the skin clean and dry. Heavy bleeding or bleeding outside of a heat cycle is not normal. If your dog experiences it, you should call your veterinarian immediately.
While dogs are bleeding, they also urinate more frequently, says Daily Puppy. Some dogs will mark areas of their house or outdoors with their strong-smelling urine, known to attract their male counterparts and alert them of their mating status.
Since all of these symptoms can be startling or uncomfortable, some dogs can become grouchy or fretful while in heat. Pethelpful recommends showing your dog a little extra love and attention during this time. Keep an eye on her appetite and give her frequent baths to clean up any discharge. You should also be careful to keep her away from any male dogs who might turn aggressive and make sure she is securely on a leash or behind a fence when shes outside.
If you adopted a dog that wasnt spayed, this whole bleeding experience will probably be new for you. Make a list of any questions you have and visit your veterinarian to learn about how to best care for a dog in heat. If you arent sure what questions to ask your vet, here are a few to get you started:
Why Bleeding From the Vagina Occurs in Dogs
There are a few reasons why your dog may be bleeding from her vagina (vulva). Blood in the urine may indicate a urinary tract infection but differs from blood that passes from the vulva and is usually present within a voided urine sample.
Estrus Cycles
Unspayed females will go through two to three estrus cycles annually, also known as going into heat. A heat cycle lasts two to three weeks and begins as spot bleeding from the vulva. Your dog’s vulva will also become swollen, and she may urinate more often than normal. Her excessive urination is meant to attract male dogs. Estrus cycles are not a medical condition but a natural reproductive cycle in dogs.
Pyometra
Pyometra is a medical condition that may arise during or, more typically, after, an estrus cycle and is an infection in the uterus. Pyometra is a serious, life-threatening condition that requires immediate medical treatment. As your dog’s hormones change during her heat cycles white blood cells, which prevent infection, are not permitted into the uterus. The uterine lining will grow in anticipation of pregnancy. However, if pregnancy does not occur within several consecutive heat cycles, cysts can start to grow within the thickened tissue and create an ideal environment for bacterial growth. Without the white blood cells present to combat the bacterial growth, your dog can develop a uterine infection.
Miscarriage
Your dog may become pregnant during her estrus cycle, and after a few weeks, her body may abort the pregnancy due to a number of reasons. Miscarriages will often result in excessive bleeding from the vagina where your dog may pass the placenta and other tissues.
Vaginal Inflammation
If your spayed female is experiencing vaginal discharge that contains blood, she may be suffering from vaginal inflammation or vaginitis. Additional symptoms of vaginitis include frequent urination or difficulty urinating. Your dog may also lick her vulvar area more frequently and scoot her bottom across the floor. Vaginitis is usually caused by an infection or foreign body and can affect any female at any age although prepubescent and older dogs appear more predisposed.
Vaginal Tumors
Unspayed females are more likely to develop vaginal tumors as they age. Most vaginal tumors are benign, or non-cancerous and can cause vulvar bleeding as well as blood in the urine, vaginal odor, and difficulty giving birth.
Prevention of Bleeding From the Vagina
Many of the medical conditions associated with bleeding from the vagina can be prevented by spaying your dog. Spaying your dog will also end future estrus cycles and prevents contribution to the dog overpopulation. Pyometra results from hormone changes associated with consecutive estrus cycles not resulting in pregnancy. The treatment for pyometra is usually an ovariohysterectomy (spay), but this can be a complicated surgical procedure when your dog is fighting a bacterial infection.
Bacteria can also grow in the urinary tract and infect your dog. Giving her access to clean water and the opportunity to eliminate her waste frequently will help prevent bacterial infections that might lead to vaginal inflammation.
Unfortunately, you may not be always able to prevent tumors from growing in your dog’s vagina, but early spaying can significantly reduce the risk of developing tumor growths and cancer later in life. Transmissable Venereal Tumors (TVTs) can be spread via sexual contact with an infected male. This type of cancer usually responds well to chemotherapy.
Dog Periods: When your dog is in heat and bleeding
There comes a time in the life of an intact female dog when theyâre ready to breed. This period is called being in heat. The stage of heat, also called estrus or season, has distinct physical and behavioral signs.Â
Many of the estrus factors, such as frequency, length of time, and severity, are dependent on your dogâs age and breed. Your dog may have symptoms that are particular to them.Â
Keep a leash handy, because your dog may have to urinate more when sheâs in heat. You may also observe that her vulva is large, red, or swollen with some bleeding or blood-tinted discharge.Â
Your dog will only bleed for around half of the total cycle, usually 7 to 10 days. Generally, bigger dogs bleed more than smaller dogs, but it varies between dogs. Some dogs bleed very little. If your dog prides themselves on their appearance and grooms themselves regularly, you probably wont find much blood spotting around the house.Â
Even though your dog will bleed, she isnt in pain during heat. However, being in heat can make your dog uncomfortable and fidgety. If her symptoms seem to be causing her pain, consult your vet.Â
Smaller dogs can go into heat as soon as they are 4-months old. Larger breeds may not first go into heat until they are 18 to 24 months old. On average, the first heat begins at around 6 months of age.Â
Even though they are old enough to get pregnant, your young dogâs eggs arenât yet fully matured. Waiting until after the second estrus cycle will promote a healthy pregnancy.