How long is a dog fertile when they are in heat?

Question

Okay, I asked this yesterday, and got 2 answers but 5 stars from people who didn't answer... So I think many people are curious! Let's try the day crowd.....

No, I am not breeding any animal.... Just curious.

Rabbits can conceive while they are already pregnant, and then give birth to a litter of full-term babies AND the other babies that were just barely conceived at the same time.... They usually die though because they are under-developed.

Since I know dogs can have pups from 2 different fathers, I was wondering what the window of fertility is for them- isn't it the whole second week of heat? So they could conceive babies 6 or 7 days apart?

(My brother breeds show rabbits, no this hasn't happened to him- he makes sure the buck stays with the doe for only a short time to make sure this doesn't happen..... Somehow dog breeding came to my mind and I was just curious!)

ADD from yesterday-- so are the runts and the ones that die shortly after birth the ones that were conceived last if this is true with dogs?

Answer 1

i believe its every 6 months 10 days in and 10 days out

Answer 2

Here's how their estrus (heat) cycle goes

Proestrus : the dog starts bleeding from the v***a and develops progressive swelling to the uterus: lasts 5- 9 days on average. Ovulation usually occurs towards the end of proestrus. The female becomes attractive to males.

Estrus: the bleeding diminishes but the v***a remains swollen. The dog is receptive to males at this time. Two days after ovulation, the egg can be fertilized by sperm. Estrus usually last 6-12 days.

Diestrus: the dog comes out of heat and v***a begins to return to normal. If the dog is pregnant, the egg implants at this time and pregnancy begins.

So to answer your question... they can be fertilized anytime from the being to the end of ovulation and it can be multiple times as long as its in that time frame..so they could get fertilized one day and then again the next day.

Answer 3

Okay.....yes, they can have many different fathers.  Had Great Dane, bted her 3x, she only had 3 puppies, then one day my son brought up a brand new puppy when the others were 4 days old.

So I would say that  she conceived from 2 different breedings.  

When is a dog in season. Actually  a male of the canine species is a dog, a female is a *****.  So the season starts w/swelling of the v***a...this will last about 3 wks...the swelling.

Then after about 7-8 days bleeding will start and continue for about 7 days...it is when the bleeding stops that she will ovulate.   She will bite a male's head off if he tries to breed her when she is not ovulating.  Usually there are  2-3 breeding a day apart as long as she will accept the male.

If the puppies are all born at the same time, they I would assume they are from one breeding, no matter what the size of them.   If she has a few,  then 4-5 days later has another, then  I would  think there were 2 sires.  

Been breeding for 40 yrs but there are some things we just won't know, unless we do DNA, just speculate.

Runts are usually considered the result of a very small ancestor....could be a grparent,  gr grandparent....just like in humans.

Answer 4

Uuuum,,,,,,I think my brain just broke...lol

Answer 5

It`s about a week that they are in "Standing heat", during their heat cycle..

Some dogs only come into season once a year, others twice.

Good luck and God bless

Answer 6

Okay - So I know close to zero about dog reproduction- however I will make my best guesses based on human anatomy. In order for a rabbit (or dog) to have two completely seperate litters the female would have to ovulate twice - that means her ovaries would have to release eggs twice during her one cycle. I don't know if this is possible in dogs or not. It is not possible in human - they can release more than one egg at a time but onces the egg(s) are released they are not going to release again in the same cycle. In order for humans to get pregnant, they build up the lining of the uterus and then release the egg(s) and then become fertile. You can only fertilize the number of eggs that are released. I would guess that if not all eggs are fertilized by the first male, the a second male could come in a fertilized the rest OR two sperm could enter the same egg - again don't know if this is possible in dogs but the later is not in humans for sure (one sperm per egg. period. no exceptions.). Finally, runts are caused by a lack of blood flow and nutrients to that developing pup - which has a lot to do with the position in the uterus and the health of the mother. I don't know if time of fertilization actually affects which pups get the 'best' positions. So basically I related it as much as I could to what I know about human reproduction and  hopefully at least gave you some starting points for questions to search on the internet to find out if it is possible. I will keep watching to see if anyone who actually knows the answers to these questions posts. GREAT QUESTION :)

Edit: Leslie it sounds like to me a pup just got 'stuck' in the mother or didn't come out with the rest of the litter. In humans that doesn't happen because we have the technology to know how many babies are inside and make sure they all come out at once. From you description, it sounds more like a straggler who wanted to stay in the womb a few more days versus 'another litter'.

Edit 2: I also just read that rabbits can have two litter at once because they have two lobes that lead to the uterus and each one can 'house' a litter. So you might want to find out if dogs have a similar situation.