Silent Heat in Dogs: Symptoms, Causes & What to Do

If your female dog is unspayed and healthy, she will usually come into season once or twice a year. Understanding when your bitch is likely to be in heat is crucial to prevent unwanted litters or to plan breeding.

But what happens if you expect her season and it seems to never arrive? This could be a case of silent heat, also known as a “dry” heat, where your dog goes through the heat cycle without the usual signs like discharge or behavioural changes.

In this article, we'll explore how silent heat can be identified, its causes, breed variations, and what you should do to care responsibly for your dog during this time.

What Is Silent Heat in Dogs?

Silent heat means your female dog is experiencing a heat cycle but shows very subtle or no visible signs that usually indicate season. For example, there may be minimal vulval swelling, little or no discharge, and no clear change in behaviour.

While normal signs might be missing, male dogs nearby may still sense the scent and show interest, revealing your dog’s reproductive status indirectly.

Identifying the Lack of Typical Symptoms

Every bitch is unique in how she displays heat symptoms. Some may have clear behavioural changes like clinginess, restlessness, or increased urination, while others show almost no outward signs at all.

Even without obvious symptoms, silent heat doesn’t mean your dog is unhealthy; it may simply reflect her individual cycle expression. However, paying careful attention helps avoid confusion.

How Male Dogs React

One reliable way to suspect silent heat is observing male dogs’ behaviour. If local unneutered males suddenly pay unusual attention during walks or near your home, it’s a strong clue that your bitch might be in heat despite no visible signs.

Silent Heat vs Skipped Heat Cycle

It's important to distinguish silent heat from a skipped heat cycle where a bitch misses the season entirely. Missed cycles can occur due to medical conditions such as hypothyroidism, adrenal disorders, or significant weight loss.

If your dog misses a season and shows other symptoms like lethargy or weight changes, a vet visit is essential to rule out serious health issues.

Breed Differences in Heat Frequency

Most female dogs come into heat every six to seven months, but some breeds like the Tibetan Mastiff and Basenji typically have one season per year. Understanding your dog's breed norms helps set expectations and identify any deviations.

When to Get Veterinary Testing

If you suspect silent heat or skipped cycles, a vet can perform hormone tests, including progesterone levels, to confirm if your dog is in season. This can prevent unintended mating and guide breeding decisions responsibly.

Can You Induce a Season?

In breeding practice, housing an unspayed bitch with another in heat can sometimes induce a late or skipped heat, though this is not a guaranteed method and should only be considered under veterinary advice.

Promoting Responsible Ownership

Understanding silent heat improves your awareness as a pet owner and supports better reproductive health management. If not breeding, consider early spaying to prevent silent heats and reduce health risks like pyometra or mammary tumours.

Observe your dog’s health closely and consult your vet about reproductive cycle concerns.