NEW Protect your furbaby's laundry & wash their favorite items in style with our new Wash Bags! Learn More

Heat Cycle Abnormalities in Dogs

Female dogs can have heat cycle issues and it happens when you least expect it. These heat cycle abnormalities can be an irregular heat cycle in dogs or main dysfunctions occurring in a dog's heat cycle.

heat cycle abnormalities in dogs


Your dog will have her first heat cycle by the time she reaches puberty. On average, your dog will reach puberty when she's six months old but this actually differs from one breed to another. Smaller dog breeds go into heat earlier compared to bigger breeds. Bigger breeds may not come into their first heat until they're eighteen to two years old.


Dogs usually go into heat once every six months or twice every year, but this will differ from one breed to another (as mentioned above). Small breeds can go thrice a year and large breeds may only go into heat once a year.


When your female dog goes through a heat cycle, this is where she becomes receptive to a male for the possibility of mating, breeding and eventually pregnancy. Sometimes you may wonder why your dog has not yet come into heat. But actually, you may not realize that your dog has already cycled because she never exhibited the normal signs of a heat cycle like:

  • swelling of the vulva
  • sudden change of mood
  • sudden change of behavior like peeing and pooping in areas she knows she shouldn't
  • bloody discharge from the vulva
  • receptive to male dogs who are nearby

The following below are the situations that are possibly causing this abnormality in your dog's heat cycle.


Heat cycle abnormalities in dogs include the following:

Absent heat. Your dog missed a heat.

Silent Heat. Your dog goes through an undetectable heat cycle where you're not able to tell she's in heat because no visible heat signs are exhibited; but male dogs can still detect a female dog in silent heat and will still be open for mating.

Prolonged Heat. A heat lasting longer than the average heat cycle.

Split Heat. A heat that suddenly stops and then continues after some weeks.

Shortened Inter estrus Interval. Too short interval between heat cycles.

Prolonged Inter estrus Interval. Too long interval between heat cycles.

Premature Ovarian Failure. Your dog's ovarian functions weakens or stops at an early age.

These abnormalities are a cause of concern for most pet parents because abnormal cycling can lead to infertility in female dogs. Also if no pregnancy takes place for a number of heat cycles, the uterine lining begins to thicken until cysts are formed. The thickened lining then secretes fluids which is a very suitable environment for bacterial to grow and develop.


The treatment for heat cycle abnormalities in dogs can vary. Your veterinarian will rule out the possible causes of these and some of the possible causes can be:

  • Hypothyroidism
  • Ovarian hypoplasia - where your dog's ovaries do not fully reach sexual maturity resulting to not being able to produce the right amount of estrogen needed by the body
  • Ovarian Tumors
  • Malnutrition

Treatment can include hormonal medications through supplements and possible surgery for tumors and pyometra. You can use washable dog diapers as a way to cover up the incision site for your dog to prevent her from licking, scratching the area. Progesterone measurements and vaginal cytology are also needed to determine whether your female dog is cycling or not.

Abnormal heat cycles in dogs are more common than you think. But remember that there are always solutions regardless of the type of heat cycle abnormality your female dog is going through.

The Author:

Micka Virtudazo

Micka Virtudazo is a full-time content creator at Pet Parents who lives with thirteen adorable American Bullies and a Shih Tzu-Maltese mix named Gretel. She especially enjoys writing how-to articles as she feels through this she can connect to other pet parents on a more personal level.

Read More