A dog first heat cycle begins sometimes between 6 and 8 months, though it's possible for a dog to get it's first heat cycle a little later. A heat cycle lasts 23 days on average, and it usually occurs twice a year.
A female dog can be spayed at any age, but will gain the most in health benefits if she's spayed before the onset of her first heat cycle. A female dog does not have a period of menopause as human women do. A dog can get pregnant at any age, though it's considered unhealthy to breed a female dog older than six years old. A female dog should not be bred before her second heat cycle, and then only after a veterinary exam gives her a clean bill of health, and she's current on all inoculations.
Virtually all breeds have two oestrus cycles each year. Initially, the vulva swells and within a day there is a clear discharge, which becomes tinged with blood the next day. This discharge increases in intensity and then slowly diminishes, ending after about ten days. During this time the female becomes more alert and urinates frequently, leaving signals of her impending willingness to mate. Ovulation takes place soon after the discharge has stopped. Only now will the female accept mating. Hormonal changes occur regardless of whether a female is pregnant, which is why there is no simple blood or urine tests to confirm impending motherhood.
The tallest dog is the Great Dane. The heaviest dog is the Saint Bernard. Both these distinctions are contested by near competators.
The heaviest breed of dog is Neapolitan Mastiff. The tallest breed of dog is the Irish Wolfhound. A popular breed, the Labrador, is actually a medium-sized dog.
The heaviest type of dog is the St Bernard. The biggest is the mastiff. The smallest is the chihuahua. the tallest is the Irish Wolfhound.
English mastiff, I think
1987 pounds
A very large dog, one of the heaviest.
NewFound land and the Masstieff
The Irish Wolfhound is the tallest breed of dog, but not the heaviest.
There are such things as "silent heats." These heat cycles do not present with bleeding (or minimal bleeding that the owner may miss). this is why it is important to know the schedule of your dogs cycles and observe her behavior and males reactions to her
The fattest dog in Britain is called Alfie the Labrador. At his heaviest, the dog weighed as much as Wayne Rooney.
If you are bleeding when a dog puts his teeth on you that means it bit you. If you aren't bleeding that means it nipped or mouthed you.
female dogs average heats are usually every 6 months but it can vary