Hello all,

I'm not a breeder, nor do I plan to be, but I've always been curious about this. What makes a successful mating, and does it always mean a pregnancy will result?

Just as humans can have fertility problems, do dogs suffer with this as well? Male and female?

Look forward to your replies.

A mating is not successful unless it ends in pregnancy Sorry couldn't resist

Seriously though, yes males and females can have fertility issues caused by a number of things. Will leave it to the more experienced, they will give a much more thorough answer

Any one got anything interesting to add?

I know some conditions can cause fertility problems in bitches, like hyperthyroidism giving irregular seasons and possibly non ovulation. Males can have sperm problems due to stress, maybe permanent but often will produceviable sperm after several months
There must be more experienced people than me here who would like to contribute

Yes, infertility problems do occur, the most recent and *famous* that I can think of, was the winner of a significant competition in 2009.

A successful mating, is one that has many aspects to it, a lot of planning and forethought.

Before any mating takes place, so much research needs to be done about the dogs involved, and what the aim is, that includes health testing, temperament, conformation and ability, and the strong consideration of what you are trying to improve upon. Both also need to be fit and healthy, or at least fit and healthy examples when in their prime, if we're talking about AI.

But, as so concisely posted already, the successful mating, then boils down to whether or not you end up with pups. And this of course, is down to timing, which premate tests can help with.

Thanks for your replies so far...sorry, I should have mentioned that I'm taking a distance learning course in Canine Studies. The topic I'm researching now is canine reproduction and my module project is about infertility.

I've always been curious about the whole breeding process anyway, but unless you either know a (responsible) breeder or have done lots of research into it, it can come as a surprise to discover just how much goes into the creation of a litter of pups.

Any other info on infertility would be appreciated.

About the first half of my initial question, which maybe should have been worded differently: can a successful mating occur without a tie?

Long post, apologies in advance... but this is kind of "my thing"

Infertility is not the only problem amongst a lot of dogs or breeds. There is also a lack of libido or just plainly refusing to mate.

Refusal to mate basically falls into 4 categories: psychological, physiological, nutritional and environmental.

Psychological Reasons: Has the dog been repeatedly told off for humping? Not only other dogs, but people, toys etc etc.... The dog will associate humping with punishment and eventually wil stop. Has the dog had a previous bad experience with a bitch? Has he mated/ or attempted to mate and been attacked? Is the dog very submissive? A low ranking dog (male) ie, bottom of the pack, sometimes will not mate. Dogs in the same house, occasionally will not mate especially as bitches are normally higher ranking.

Physiological Reasons: Pain is the greatest reason why libido is lacking, or simply why the dog won't mate. Dogs with back problems possibly won't mate due to pain. Often physiological and psychological reasons cross over. Even if the pain is corrected, the dog may associate mating with pain.

Nutritional Reasons: Certain medications, as with humans decreases libido. An unbalanced diet or a simple lack of nutrition or malnourishment (sp) will decrease libido. The body's stores will be used to keep the dog alive if supplies are low, not to reproduce.

Environmental reasons: Nutritional and environmental reasons often cross over also. An extreme example would be, the dogs simply cannot get to each other. Also, poor food supply would mean poor nutrition (hence the cross over) which can result in lack of libido. The height difference (although could be classed as physiological) is also a factor as to why a dog cannot mate.



Infertility/ Failure to conceive/ Failure to carry to full term.

The Stud:
Canine sperm is incredibly fragile. More fragile than human sperm but less fragile than bovine and equine sperm.

There are many reasons why a dogs sperm production will be halted/ affected in a negative way. The biggest and probably most common reasons why sperm production is altered is through malnourishment. The body's initial response when faced with starvation or inbalance diet, is to protect itself, to keep itself alive, reproducing goes to the back of this list of priorities. This type of infertility can sometimes be reversed if the nutritional element is fixed very quickly.

The next biggest cause is probably illness, in particular, fevers. The testicles are suspended in the scrotum so that they are further away from the body as sperm production requires a lower temperature than the body. If the dog becomes ill and has a fever the body may become too hot for sperm production and it will cease. The sperm already produced will die faster- the hotter the sperm is, the more energy it has and uses, causing it to run out faster and die. Also in order to penetrate the egg, the head of the sperm contains enzymes.

Enzymes become denatured at higher temperatures.... (search google for changes in tertiary structure of enzymes due to heat- should give you details as to why) basically chemical bonds in the tertiary (3rd) structure of the enzyme are altered by heat, changing its shape (the active site), meaning that the enzyme cannot "fit around" the substrate that needs breaking down... (google lock and key enzyme theory)... So basically, without these enzymes the sperm is unable to break through the "hostile" shell of the egg and there for fertilisation cannot take place.

Sperm is produced in advance of needing it, it is stored until it is needed for about 6 weeks to 3 months. So any fever related infertility in the stud is often not noticed until a few weeks after the illness. Any sperm not used in this period is reabsorbed into the body, to put it simply. About 50% of the time this is not reversible, it depends how much of the enzymes have been denatured (enzymes are also used in the storing and production of the semen, denaturing cannot be reversed)

The next biggest cause is trauma/ growths to the testicles- sort of speaks for itself really- any structure that is damaged by trauma or growths that causes blockages or breaks in the tubes and micro tubes to prevent sperm leaving the epididamis (sp) into the sperm ducts will obviously cause a problem... if the sperm can't leave the body, it is irrelavent how much is produced. Also the destruction of certain cells will cause enzymes to be released. Enzymes aren't always helpful, occasionally they will chemically alter the steps involved in producing sperm. This type of problem causing infertility is very rarely reversible. Simpl

Hormonal issues also cause problems, lack of hormones and excess will cause sperm production to stop. Hormones trigger each step of sperm production.

All of the above things may not necessarily stop production, but may cause deformities in the sperm which make it impossible to fertilise from a DNA level- incorrect number of chromosomes, general mutations in DNA etc or in a physical way- no tails, poor motility etc.

Will do the bitch side of things in a minute...... will also talk about funcion of mating.... got guests now lol

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

Apologies, my units of measurement may change through the post.

The Bitch
Failure to Mate
The reasons a bitch won't mate are mentioned above; psychological, physiological, nutritional and environmental.


Failure to Conceive/ Carry to viability.
There are a numerous reasons why a bitch will fail to conceive/ fail to hold on to a pregnancy.
Unlike dogs, the gametes ( reproductive cells- males have sperm, females have ova [ovum for singular]) are present from birth in bitches. However, the issue with bitches is that they may not release those eggs. The reason for eggs not being released is almost entirely hormone related (off the top of my head I cannot think of any other reason why eggs wouldn't be released). The leutenising hormone is the "first domino" to trigger the releasing of the eggs. The eggs are released into the fallopian tubes, simultaneously, with this, the progesterone levels increase. Progesterone is the hormone that "holds on" to the pregnancy. At the point of ovulation, the progesterone level in the blood is approximately 5ng it continues to increase (approximately by 50-100% each day) until it reaches about 50ng about a week later then it begins to decrease gradually to about 4ng for the duration of the pregnancy. If the progesterone level during pregnancy drops below 4ng the puppies are either born (labour), aborted or absorbed, depending on the time of pregnancy.

Sometimes, the progesterone levels in the bitch will increase too quickly, the eggs are released, but then the progesterone drops too quickly and the pregnancy is lost or depending on definition of pregnancy (some say fertilisation, some say implantation), never occurs.

Sometimes, the progesterone level, for an unknown reason, never increases to the point that ovulation can occur. This is quite common and happens to most bitches that are entire, at one point or another (sods law says its bound to be the season you are planning on breeding them ). My theory is that the body is brought into season, but then circumstances change ie, environment temperature suddenly drops, shortage of nutrition, bacteria or virus is contracted and the body halts the season, by halting progesterone release and therefore egg release. So a bitch has a season, but fails to ovulate and therefore fails to conceive.

As with dogs, nutritional elements also play a part in failure to conceive. Malnutrition will often stop seasons. Explained in my previous posts.

There may also be physiological reasons why a bitch fails to conceive, polyps, hostile uterus etc.

To be continued....

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

The Mating
The first stage of ejaculation it the lubrication fluid to make penetration a smooth as possible for both male and female. There is sperm present within this ejaculant, but not rich with sperm. This is basically to wash out the urethra.

The second stage it the sperm rich formula. It happens when the dog performs an action like climbing the stairs. The majority of the sperm is expelled during this stage. (This is where if the mating is described as a slip, ends)

The third stage of ejaculation is the fluid based food which acts in 2 ways. Firstly it helps the sperm to swim up through the vagina and uterus of the bitch. It also acts as a food source for the sperm.

Sperm have the ability to live within the bitch for up to a week, until they are needed to ferlitize the ova (eggs). They attach onto the walls of the uterus where they feed from the nutrients within the seminal fluid, and remain dormant there for several days until the Leutenising Hormone surges, causing a release of the ova and the ripening of their shells. The sperm then release from the walls of the of the uterus and swim to fertilize the ova.

After all the thrusting stops the tie begins. The bulbus glands in the base of the penis swell. This locks within the circular muscle in the bitch's vagina and the dogs remain in the "locked" position. Often the dog lifts a back leg over the bitch's back and turns so that they are bum to bum, the penis locked in the vagina. This is the dangerous time of the mating. If the bitch panics (or the dog for that matter) they risk rupturing the genital tissue of both male and female parts, which in turn can cause them to bleed to death at the drop of a hat.

There are many reasons why it is believed the tie takes place but the main one leads back to the wild dogs. It is believed that the tie used to take place to prevent competitive males from mating with the bitch, and to give the inseminating male's sperm the greatest chance of fertilising the eggs and passing on his genes.

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

I'm judging by the lack of response on this thread that I've bored everyone to death

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SOMETIMES YOUR KNIGHT IN SHINING ARMOUR IS MERELY AN IDIOT WRAPPED IN TINFOIL

No, No...I am enjoying reading it.