When is a dog no longer able to breed?

A female dog typically reaches reproductive maturity between 6 to 12 months of age, but her ability to breed effectively can decline as she ages. Most female dogs can breed until around 5 to 6 years old, while some may be able to conceive up to 8 years, though the risks to maternal and puppy health increase. Male dogs can remain fertile well into their senior years, often until around 10 years old, although sperm quality may decrease as they age. It's essential to consider the health and wellbeing of both the dog and potential offspring when deciding to breed.