Dog Heat Cycle Calculator
Use this calculator to estimate when your female dog will come into heat again based on her last heat cycle.
About Dog Heat Cycles
What is a Dog Heat Cycle?
A dog heat cycle, also known as the estrous cycle, is the reproductive cycle of unspayed female dogs. It typically occurs every 6 months, though it can vary from 4 to 12 months depending on the dog’s breed, size, and individual characteristics.
Stages of the Heat Cycle
- Proestrus: Lasts 7-10 days. The vulva swells, and there’s bloody discharge. The dog attracts males but isn’t ready to mate.
- Estrus: Lasts 5-10 days. The discharge lightens, and the dog is fertile and receptive to mating.
- Diestrus: Lasts 60-90 days. The fertile period ends; if pregnant, this is when gestation occurs.
- Anestrus: Lasts 90-150 days. A resting phase with no reproductive activity.
Signs of Heat
- Swelling of the vulva
- Bloody or straw-colored discharge
- Increased urination
- Behavioral changes (e.g., restlessness, clinginess)
- Attraction to male dogs
How to Use the Calculator
- Enter the start date of your dog’s last heat cycle.
- Optionally, enter the average cycle length in months (e.g., 6) if known.
- Click “Calculate” to see the predicted date or range for the next heat cycle.
Note: This calculator provides an estimate. Heat cycles can vary widely. Consult your veterinarian for precise timing, especially for breeding.