The Dog's Heat Cycle Explained
A pie chart example of the dog's heat cycle
A dog's heat cycle may appear to be something quite difficult to understand. Unlike other species, the heat cycle of canines does not seem to follow any logic such as following a specific seasonality or temperature change. Rather, it just occurs regardless if it is the dead of the winter of the dog days of summer.
Many times the dog's heat cycle, better known as estrous cycle, seems to be quite unpredictable. The first heat generally occurs around six months in small, medium dogs and around 12-18 months in larger breed dogs. However, It is not unheard of some giant dog breeds going into heat at around 30 months of age.
Phases of the Dog's Heat Cycle
The cycle is divided in four distinct phases.
This is when the dog's reproductive tissues swell and appear puffy. A bloody discharge will take place as the female carefully licks herself quite often in order to keep herself clean. Loss of appetite and irritability are not very uncommon. Male dogs may be interested in the female but she will not be interested as of yet. This phase generally lasts seven to ten days.
This is phase is also known by breeders as ''standing heat'' because this phase is actually when the female dog will stand still for the male to breed. Gradually the bloody discharge seen in proestrus will be replaced by a pink or straw colored discharge signaling this important phase. This phase generally lasts six to ten days.
This phase concludes the mating process, as most females at this point will no longer be interested in males. Males however, may still stick around. This phase if the dog has been impregnated lasts generally from the end of the estrus until the birth of the puppies, averaging therefore 60 days. If the dog has not been impregnated, the diestrus phase will not be any different from the anaestrus stage.
This is the longest phase of a dog's heat cycle, indeed it ranges from 100-150 days. It appears to be a quiet time for the dog's reproductive organs, however, the dog's pituitary gland an ovaries are in reality getting ready for the next proestrus cycle.
- Split Heat
In this case, the dog's heat is interrupted and then continued at a later time. Basically a female dog will exhibit signs of pro-estrus with the typical bleeding but then once estrus approaches the symptoms disappear for some time.
- Induced Estrus
It appears that in some cases, the presence of a female in heat may awaken the heat cycle as well in other females.
- Silent Heats
In this case, the heat is silent, meaning that there are hardly any outward signs suggesting that the heat has occurred.
How Often does a Dog come into Heat then?
Most dogs generally go into heat every six months or better said, twice a year. However, Basenji's and wolf hybris tend to go only once a year.
So at What Age Can a Dog be Bred?
Professional breeders know that dogs should never be bred on their first heat cycle. Rather, the second or the third are much preferable because the dog is more mature and makes a better mother. Of course, only top breeding quality dogs should be bred to decrease the pet over populataion problem.
While males seem to have no problem breeding with the female in heat, females on the other hand may be selective at times.
-Multi Sired Pups
If the female dog is allowed to escape she may breed with various males, often causing what is known as ''multi sired litter'' where there are puppies from different fathers.
The complete book of Dog Breeding Dan Rice DVM
Questions & Answers
Will a female dog continue to bleed if she is pregnant?
No, it is not normal for a female dog who is guaranteed to be pregnant to be bleeding. Bleeding in a pregnant dog can be a sign of a miscarriage, and therefore a veterinary exam would be needed for the investigation. In some cases, the bleeding may stem from other causes such as trauma or maybe the blood is coming from the urinary tract, as it is common with urinary tract infections. Bleeding disorders may also be a cause, as it happens with exposure to rat poison.
In an intact (not spayed) female dog who is NOT pregnant, bleeding can be worrisome, considering that this may be a sign of Pyometra. Pyometra is a uterine infection which often starts within 3-4 weeks following the heat cycle.
Will a female dog bleed/spot after heat?
A normal heat cycle in dogs typically lasts an average of 7 to 14 days. If a female dog's bleeding goes on longer than that, then it is worthy of wondering whether something's going on.
At times, some dogs may develop ovarian cysts, and these may cause irregularities in a dog's heat cycle.
Even more worrisome, bleeding after a heat can be indicative of Pyometra, a uterine infection which may turn life threatening if treatment is not sought in time. Affected dogs though are normally quite ill.
Other possibilities include the presence of a growth or tumor in the uterus that is bleeding. If the dog has been bred or accidentally mated, bleeding after a cycle may also be indicative of a miscarriage.
If a dog is bleeding/spotting after a heat cycle, it would, therefore, be important having her examined by a vet. The vet may wish to rule out serious disorders and perhaps run some blood tests to evaluate the dog's hormone levels.
When will my female dog go into heat after having puppies seventeen weeks ago?
Usually, most dogs tend to go into heat every six to seven months. There can be individual variances with some dogs going into heat as early as four months, or as late as every twelve months.
What is a dog's gestation period?
The gestation period of a dog is approximately 63 days.