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Just like other animals, left intact, female dogs will undergo a heat cycle during which they are ready to mate with male dogs, but occasionally, you may stumble on a silent heat cycle in female dogs from time to time.

 What exactly is a silent heat cycle in female dogs? As the name implies, it's an abnormal heat cycle that may go unnoticed to even the most attentive dog owners. 

If your dog hasn't gone into heat for a very long time, there may be chances that your dog has undergone a silent heat. Knowing more about the silent heat in female dogs may be beneficial for you as a dog owner, especially if you want to breed your dog.

female heat silent

Difficult to Detect 

Female dogs tend to go in heat anywhere between every 6 and 12 months depending on breeds. It's therefore important for you to know what's normal for your breed.

For instance, small breeds go in heat every 6 months, while larger dogs may go into heat every 8 to 10 months and sometimes longer. Basenji or Tibetan Mastiffs tend to cycle once a year so there's nothing wrong if it takes that long for you to notice the first signs of heat in these dogs!

A silent heat in female dogs refers to the condition when a female dog is in heat but the condition cannot be detected. In other words, there are no outward signs.

Usually, during a normal heat cycle, female dogs will “flirt” with the male dog. In absence of a male dog, there are often other signs suggesting that the dog is in heat such as increased urine marking,the presence of discharge and localized swelling.

However, in the case of silent heat, these signs may not be evident at all. Female dogs may show signs of a silent heat at one cycle and resume to normal in the next, or they may always be prone to being silent in all their heats, explains Dr. Margaret V. Root Kustritz, a veterinarian specializing in animal reproduction in the book "The Dog Breeder's Guide to Successful Breeding and Health Management."

When a dog presents with a silent heat, there are two possibilities: it could be that the dog has failed to go in heat or it could simply be that the owner has failed to detect the signs, as it can happen with a female dog who is fastidiously clean and will lick away promptly any signs of discharge. The difference between the two can sometimes differentiate a dog in good health from a dog not in so good health.

A Sign of Trouble

From a medical standpoint, it's preferable that a dog owner missed the signs of a dog going in heat, than a dog not going into heat at all.

 Dog experts call the absence of dog heat a “skipped heat." This can happen when a dog is suffering from some underlying medical condition for example endocrine disorders such as low thyroid levels, Addison's disease or Cushing's disease.

 Sometimes, the presence of an ovarian cyst can affect the dog's heat cycle causing changes; therefore, this is something to consider getting checked out by the vet, explains veterinarian Dr. James. 

Therefore, if you suspect that your dog has skipped a heat cycle, it is always a good idea to have your dog see a veterinarian so that underlying medical disorders can be ruled out. Going to the vet will give you an idea whether your female dog is experiencing a silent heat or perhaps you're dealing with a skipped heat season.

Can a dog get pregnant during a silent heat? Female dogs that undergo silent heats are fertile, but it may be difficult for them to get pregnant, explains veterinarian Dr. Margaret V. Root Kustritz.

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A Couple of Strategies

dog silent heat

What if you are planning to breed your dog, and you need to rely on some hints so that you know when you should breed your dog? 

Two interesting strategies are suggested by veterinarian Dr. Dan Rice in the book "The Complete Book of Dog Breeding."

The first one consists of housing a compatible intact female dog known for having regular heat cycles with evident signs along with the dog prone to having a silent heat. 

The purpose of doing this is in hopes for the dog's heat cycles to synchronize as it often happens when female dogs are living together. 

There are therefore chances that once the guest dogs starts going in proestrus, the dog with a history of a silent heat cycle will go into proestrus too, but this time with more outward signs.

A better technique may involve housing an intact male dog for a long time, if feasible up to six months. Ideally, the male dog should be the one you are planning to mate your female dog with. Nobody is better at detecting a heat cycle than an intact male dog. Sooner than later hopefully, the two should mate and next thing you know, your silent heat dogs is having puppies!

And, if worse comes to worse, and you really have doubts whether your dog is in heat or not, you can always have your vet carry out a simple test that will tell you where in the heat cycle your dog exactly is.

Did you know? Toy breeds like Yorkies, may be prone to having a slightly different heat cycle compared to larger breeds. Their first heat might be barely noticeable compared to subsequent heats. If your toy breed dog has therefore gone into heat only at 1 year of age, it's likely that she had her first heat about 6 months ago but you missed it because it was silent, points out veterinarian Dr. Carla. 

"Some breeders will leave the male and female dogs together throughout the season and a number of matings will take place. This would obviously be the most natural way to handle things and the way most likely to get your (dog) pregnant." Dr. Scott Nimmo

Ruling Out the Obvious

And last but not least, it's important to rule out something that may sound obvious, but that is not. If you have opened your heart and home to a dog that has an unknown history and you were planning to breed her, consider that there may be chances that she wasn't intact to start with.

Sometimes, telling whether a dog was spayed or not can be quite a challenge, and even experienced people have a hard time. As the dog grows, the spay scar may become barely visible and difficult to notice, and people may assume the dog is therefore intact, when she is not.

So if you got a dog who has never had a heat, there are chances that you're not dealing with a silent heat, but rather a spayed dog!


  • The Complete Book of Dog Breeding, by Dan Rice
  • The Dog Breeder's Guide to Successful Breeding and Health Management, By Margaret V. Root Kustritz

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