Fertility Lecture by Angelika von Heimendahl BVMS (Berlin) dip ECAR MRCVS Oct. 2017
I recently attended an excellent seminar hosted by the Bearded Collie club, and presented by Berlin qualified veterinary surgeon, Angelika von Heimendahl , who holds a specialist certificate in reproduction. Angelika runs a reproduction specialist clinic near Cambridge. http://www.vetrepro.co.uk/ And she keeps Red Poll cattle on Cambridge commons.
She opened her talk with general wide-ranging comments, touching on what in her opinion is the ideal age to breed dogs- her rule of thumb being that both sire and dam should still be relatively youthful, with a combined age of no more than 10. Ideally, both still young. Failing that, an older female should be matched to younger male, and vice versa. Then she moved on to sizes of litters, pointing out that one or two only can be as much a nightmare for the dam as a huge litter. One over-sized puppy is almost always a disaster. And she added that in her opinion, a bitch’s first litter should never be after her fifth birthday.
She then went on a bit of a tirade against the anti-vaccination movement, arguing vehemently that the science of immunisation is sound, and that people should base their decisions on good, rigorous and well-established science rather than drawing their “facts” from “Dr. Google”. She continued by mentioning that she is concerned that in the very near future, antibiotics may be withdrawn entirely from veterinary practices to try and curb their over-use. (She pointed out that 50% of antibiotics world-wide are currently used for animals). This apparently followed on from the assumption that virus infections, caused by lack of immunity due to non-vaccination, will weaken the immune system and also open the dog to opportunistic bacterial infection. She is also very down on the use of a course of antibiotics as a “precautionary measure” on a bitch prior to mating. This is because it wipes out ALL of her bacterial ecosystem, good and bad, which effectively creates a microbial desert, and because of this, it in fact leaves her more prone to subsequently contracting dangerous opportunistic infections such as pseudomonas. She added that infection (e.g from an external pathogen) does not cause infertility in either dogs or bitches, which was an opinion that she was quite adamant about, although she didn’t go into detail. (I suspect that this bares closer investigation, as the formation of scar-tissue itself following a serious infection could no doubt interfere with fertility rates, such as in the case of a serious pyometra. A quick review of literature lists many possible infectious cause of sperm degradation, and there is also published research indicating that environmental toxins likewise can reduce it – see notes at the end- but that was not the main point of this discussion. )
She then went on to suggest that, when selecting breeding partners, one should check the fertility of the lines –especially the female line, where one wants to see good sized litters and few caesarean interventions- because this is largely an inherited trait. Breeding on from bitches with poor fertility, problematic labour and or bad maternal instinct is foolish. Similarly, male libido is a consideration, as is duration of fertility (as in years of viable stud duty), and there is in her view an element of heritability here too.
Prior to mating, bitches should be checked for strictures- just inside the vulva- and should also have an even / reasonable number of teats.
The primary cause of infertility in bitches is CEH, Cystic Endometrial Hyperplasia. 25% of five year old bitches will have this, and 75% of 7+ year olds. This condition is caused by heat cycles and the effect is cumulative. Each cycle inflames the uterus through the actions of progesterone, (regardless of whether there is a pregnancy or not), and this leads to increasing build-up of imperfections and cyst formation. There is a cumulative loss of fertility with each repetition, and a concurrent increase in infection risk (pyometra). Bitches will cycle throughout their lives, so this only gets worse with time.
Stud dog fertility should likewise be checked regularly. It is in general not connected to overall health, and will as a matter of course start to decline by mid-life, regardless of overall health. As a rule of thumb, small testicles relate to lower fertility, so bigger is better on this score. When evaluating sperm quality, one is looking for over 70% forward motility, along with greater than 60% correctly formed live sperm. Less than this is probably not worth considering. The morphology of the entire structure must be evaluated. Malformation most commonly relates to tail formation, which when wrong, results in lack of forward motility. They may also have malformation of the mid-section, which carries the energy source for the sperm.
After ejaculation, sperm will effectively “rest” within the uterus, awaiting the time when the eggs have become fertile, and they will then make their way up into the fallopian tubes, where conception actually takes place. While resting, they essentially bury themselves in the womb lining, and draw nutrients from it, which helps sustain them and accounts for the longevity of fresh healthy sperm after a successful mating. When departing for the fallopian tubes, they detach themselves in waves, rather than all at once, in order to increase the likelihood that some healthy viable set of them will arrive at the eggs at the optimal time, and the mechanism governing this is as yet unknown.
Timing is essential for optimum mating, and it is not necessary – if you get it right- to have multiple matings, such is the sheer volume of sperm he releases per ejaculation. A male takes two months to generate mature sperm, and although this generation is occurring all the time, it is possible to blow it all and for there to be a temporary reduction in fertility if- for example- you attempt to service multiple bitches in quick succession within a limited time frame, such as in the same week.
The best approach to correctly timing a mating is based on progesterone testing, and she is firmly of the belief that the colour strip tests are rubbish, and that one needs a proper progesterone blood test that produces numeric results. Go to a big established lab for best results, such as Idexx, because the machines are very expensive and need regular (ideally daily) calibration, and smaller outfits are unlikely to have the through-put to justify this.
One can also check the vaginal cells, looking for the tell-tale corn-flake shaped cells, but she uses this solely as back-up, not as primary determinate for mating .
Once the eggs are fertilised, they float freely for a couple of weeks before settling within the womb and implanting themselves there. This is followed by the establishment of the placenta, and it is only after this that the embryos are truly linked to the mother’s blood supply. Some experienced hands can feel the small- pea-sized bumps within the uterine horns at this stage, but keep in mind that the uterus is still very small, and the embryos within it are vulnerable, so it is much better to not grope around squeezing for them, but rather better to wait until after 4 weeks and get an ultrasound scan done.
She told us that reabsorption of embryos does occasionally occur, but much less frequently than assumed. After 40 days, reabsorption is not possible, due to skeletal formation, so only abortion occurs if the pregnancy fails at this stage. (She had more to say on this subject a bit further on). A bitch can open her cervix and expel one or more embryos that she is losing, then seal up and carry the remainder to term. This is essentially a partial abortion. For this reason, one should avoid going for a c-section prior to 55 days, regardless of what may be expelled, (unless of course the bitch’s own health is in danger). The remaining pups will not yet be viable and will not survive in the outside world due to premature lungs. Best let her seal up and attempt to carry them a further week until normal term.
Seasons:
Ovulation is at zero, and it takes 48 hours after the eggs are released for them to ripen to be able to become fertilised, so optimum fertility is 2 days after ovulation, but the eggs remain receptive for a further 3 days. After that, they deteriorate and the fertile period passes. So, at ovulation, allow 4 to 5 days for optimum breeding window. But this doesn’t mean that she will stand for this full period. Some bitches will only stand – if at all – for a VERY limited time. Others are complete tarts… Also, remember that the sperm can survive for several days in the reproductive tract, so an early mating (assuming a natural mating) can be just as effective as a more precisely timed one. With chilled and frozen semen it is another matter entirely. In these cases, the sperm do not remain viable for long once brought back to activity, maybe just hours rather than days as with fresh, so timing here is really vital for getting it right. Viability also diminishes when sperm is thawed, so chances of conception do drop when using anything other than fresh semen.
Mating timings:
Fresh, side by side or natural mating; Ovulation + 2 days. Or Ovulation +1 and +3 days, to be sure.
Frozen or chilled semen: ovulation + 3 days, or if doing two lots, Ovulation + 2 and +3 days.
She then outlined the types of artificial insemination available, which are briefly; 1- placing the semen directly into the vagina, 2- using a catheter (a long thin tube) and a small camera to place the sperm directly inside the cervix, (a specialised job), or 3- making a small incision on a bitch under general anaesthetic to place it directly into the uterus, called surgical insemination, and not allowed by the UK Kennel Club, but apparently rather common practice in the Greyhound Racing world.
Oestrogen governs cycling of the uterus- sloughing-off and regenerating lining- but does not control fertility. LH (Luteinizing hormone) signals egg release, but is a very short event, and quite hard to catch in blood testing without really torturing the bitch with multiple blood draws. Progesterone governs fertility, and maintains pregnancy. Note, according to Angelika, Estrogen plays NO part in driving libido in a bitch, contrary to what another repro specialist once suggested to me. By the time the bitch is fertile, estrogen is gone.The only specific pregnancy detecting blood test is a test for Relaxin levels, she recommends after about 28 days.https://en.wikipedia.org/wiki/Relaxin https://vcahospitals.com/know-your-pet/pregnancy-testing-in-the-dog
Reabsorption:
She believes that this is often a myth or excuse for a failed conception, and that there are very few true cases of bitches reabsorbing puppies. Because of the function of progesterone, a bitch’s behaviour is the same, whether she is carrying puppies or not. Sometimes even going as far as producing milk. This is an evolutionary adaptation designed to give a pack of wild dogs readily available surrogate mothers should a litter lose its actual mother. She estimates that the true rate of reabsorption is probably no more than 5-10%. And certainly not whole litters. After 30 days, she said a bitch will more likely abort, not reabsorb, because the skeletons are forming by then, so they can’t be absorbed. They will be expelled instead, and owners may not notice as they are still quite small. Often, she may expel some and carry the rest on. Usually when breeders assume she absorbed them, she simply didn’t conceive and has had a phantom instead.
Birth:
Large litters are born a bit earlier, as it is the puppies that induce birth through the action of cortisone being released by them as they get stressed. Likewise, small litters may delay birth, or never stimulate the bitch enough to expel them easily, so are equally dangerous. Also, the last weeks are a time when the puppies’ rate of growth shoots up, so delayed puppies can be big puppies, and this too can be increasingly dangerous to the mother as they are much harder to expel.Stages one labour generally can last up until 36 hours. Beyond that, start to worry. Once the puppies begin to arrive, they should proceed at a rate of one every hour or so, with a gap of 2 to 3 hours being the point when you should start to worry. Likewise, if the dam is straining and contracting very hard for 30 minutes with no puppy emerging, there may be trouble, so intervention may be needed. Especially if dark green or worse- bright red fluid is also present. Dark green indicates placental detachment. Once that happens, the puppies are getting no fresh oxygen supply, so long delays can be fatal. All labour should be completed within 24 hours, (although many of us have known exceptions that produced perfectly viable puppies).Oxytocin may be used to help induce contractions, and it also brings down the milk. (Dr. Robert Hutchison says: never use it before at least one puppy has come naturally, or you can rupture the uterus. Never over-use it or you can “shrink-wrap” the puppies within the over-contacting uterus. ) The counterpart for oxytocin is adrenalin, so the bitch must be kept in a calm environment and stress-free as much as possible or else stress hormones may turn off the oxytocin. If things go wrong, a c-section must be done, and done fast, so one’s vet should be pre-notified that labour has begun, and kept in contact with during the process if things start to go wrong.
She estimates that less than 50% of vets are notifying the KC about performing c-sections, which is something they are requested to do so the KC can track how many an individual is having.She discourages the bitch from eating the afterbirth, she thinks there is no good reason for it, and that it will only cause her digestive upset and the squits. She was quite scathing about the advice that it may help stimulate the birth process, (as advocated in The Book of the Bitch), and dismissed that notion out of hand saying that it was a myth that eating placenta had any effect on milk flow, etc.She said that the overall rate of loss (still born, etc) is around 5%, but that in 12 breeds it is considerably higher, up to 40% in some, and this includes many giant breeds. This she thinks is due to large litter sizes and secondary uterine inertia. There are 3 breeds where losses can run as high as 80%, for example in Bulldogs…She then said that neonatal mortality overall is about 10 – 20% in the UK, but closer to only 7% in Norway. So, quite a difference.
Colostrum:
Puppies must have colostrum in the first 6 hours after birth. Their guts progressively start to close to its large molecules after this time. Sucking does not mean they are getting milk. Puppies that suck and suck are not necessarily feeding well, in fact they may be starving. They should suckle for 10 to 15 minutes, then roll off and sleep, looking full and round. Lack of milk is a major cause of puppy loss. If there is no colostrum, blood may be drawn to be spun down in a centrifuge and fed to the puppies, which will stand in for colostrum and give them some immunity. If not the dam herself, it can be drawn from any other dog living in the same household instead, as they will share a common antibody signature. She was dismissive about the suggestion of drawing milk from the dam prior to a C-section, to ensure that, whatever the outcome, the puppies would have at least some colostrum from her. (This had been the practice of another German-trained vet when dealing with mid-delivery c-sections, brought about by secondary inertia, and still seems to me to be a rather clever idea.)
After birth, she said that puppies should NOT lose any weight, and if they do, there is a potential problem developing. So, weight at birth and regular weighing thereafter is a must for good post- natal practice. Any that do drop weight should be considered to be up to 4 times more vulnerable to developing serious issues and be at greater risk of death. Weight loss is a sign of low colostrum – e.g. not enough milk coming down. If a puppy is failing to gain, or worse dropping weight- a breeder should manage its feeding more closely. In other words, get it onto a good high-producing teat and make sure it gets a full belly and is not shoved off by a stronger sibling. Or supplement its feeding. Royal Canin now does an excellent colostrum replacement for dogs. She highly recommends it. This can be stored long term, so every breeder should have some.
Breeders lose more puppies in cold winter months than in warmer months, which underlines the necessity to keep things toasty warm! The biggest problem with cold puppies is that the motility of their digestive track reduces or even stops. They cannot digest anything and start to fade. Feeding them in this state is bad, as the milk ( or supplement) just sits there and goes sour. The puppy must be warmed carefully and gradually first, such as by placing against your skin inside a warm jumper. Only when they have returned to a correct temperature can the start to feed once more.
Again, the correct pattern of behaviour to look for in newborns is suckling for 10-15 minutes, then sleeping for two hours. Rinse and repeat. If they suckle longer or sleep less, it means they are not getting enough. An uneven litter also means that some are losing out on getting enough milk.
Final note: Best to avoid moving a bitch in the final trimester of her pregnancy, as she will not have built up a sufficient antibody profile for her new environment.As for the canine herpes jab, she was quite dismissive of it, for one main reason: Canine herpes is wide-spread and easily caught. Once a dog has been exposed, it has the antibodies. Therefore, the dam will likely have the antibodies if she has been out and about, so no need to supplement her. Likewise, no sense in re-vaccinating if she has had it for a previous litter. She claims that proven cases of puppies being lost to herpes are few and far between, and that it is a myth that this is a common cause of fading puppies.( I would recommend looking into this more closely )Footnotes and attachments:Study demonstrates rapid decline in male dog fertility, with potential link to environmental contaminants. Gary England et al.
https://www.nottingham.ac.uk/vet/news/2016/study-demonstrates-rapid-decline-in-male-dog-fertility-with-potential-link-to-environmental-contaminants.aspx
Ovulation is at zero, and it takes 48 hours after the eggs are released for them to ripen to be able to become fertilised, so optimum fertility is 2 days after ovulation, but the eggs remain receptive for a further 3 days. After that, they deteriorate and the fertile period passes. So, at ovulation, allow 4 to 5 days for optimum breeding window. But this doesn’t mean that she will stand for this full period. Some bitches will only stand – if at all – for a VERY limited time. Others are complete tarts… Also, remember that the sperm can survive for several days in the reproductive tract, so an early mating (assuming a natural mating) can be just as effective as a more precisely timed one. With chilled and frozen semen it is another matter entirely. In these cases, the sperm do not remain viable for long once brought back to activity, maybe just hours rather than days as with fresh, so timing here is really vital for getting it right. Viability also diminishes when sperm is thawed, so chances of conception do drop when using anything other than fresh semen.
Mating timings:
Fresh, side by side or natural mating; Ovulation + 2 days. Or Ovulation +1 and +3 days, to be sure.
Frozen or chilled semen: ovulation + 3 days, or if doing two lots, Ovulation + 2 and +3 days.
She then outlined the types of artificial insemination available, which are briefly; 1- placing the semen directly into the vagina, 2- using a catheter (a long thin tube) and a small camera to place the sperm directly inside the cervix, (a specialised job), or 3- making a small incision on a bitch under general anaesthetic to place it directly into the uterus, called surgical insemination, and not allowed by the UK Kennel Club, but apparently rather common practice in the Greyhound Racing world.
Oestrogen governs cycling of the uterus- sloughing-off and regenerating lining- but does not control fertility. LH (Luteinizing hormone) signals egg release, but is a very short event, and quite hard to catch in blood testing without really torturing the bitch with multiple blood draws. Progesterone governs fertility, and maintains pregnancy. Note, according to Angelika, Estrogen plays NO part in driving libido in a bitch, contrary to what another repro specialist once suggested to me. By the time the bitch is fertile, estrogen is gone.The only specific pregnancy detecting blood test is a test for Relaxin levels, she recommends after about 28 days.https://en.wikipedia.org/wiki/Relaxin https://vcahospitals.com/know-your-pet/pregnancy-testing-in-the-dog
Reabsorption:
She believes that this is often a myth or excuse for a failed conception, and that there are very few true cases of bitches reabsorbing puppies. Because of the function of progesterone, a bitch’s behaviour is the same, whether she is carrying puppies or not. Sometimes even going as far as producing milk. This is an evolutionary adaptation designed to give a pack of wild dogs readily available surrogate mothers should a litter lose its actual mother. She estimates that the true rate of reabsorption is probably no more than 5-10%. And certainly not whole litters. After 30 days, she said a bitch will more likely abort, not reabsorb, because the skeletons are forming by then, so they can’t be absorbed. They will be expelled instead, and owners may not notice as they are still quite small. Often, she may expel some and carry the rest on. Usually when breeders assume she absorbed them, she simply didn’t conceive and has had a phantom instead.
Birth:
Large litters are born a bit earlier, as it is the puppies that induce birth through the action of cortisone being released by them as they get stressed. Likewise, small litters may delay birth, or never stimulate the bitch enough to expel them easily, so are equally dangerous. Also, the last weeks are a time when the puppies’ rate of growth shoots up, so delayed puppies can be big puppies, and this too can be increasingly dangerous to the mother as they are much harder to expel.Stages one labour generally can last up until 36 hours. Beyond that, start to worry. Once the puppies begin to arrive, they should proceed at a rate of one every hour or so, with a gap of 2 to 3 hours being the point when you should start to worry. Likewise, if the dam is straining and contracting very hard for 30 minutes with no puppy emerging, there may be trouble, so intervention may be needed. Especially if dark green or worse- bright red fluid is also present. Dark green indicates placental detachment. Once that happens, the puppies are getting no fresh oxygen supply, so long delays can be fatal. All labour should be completed within 24 hours, (although many of us have known exceptions that produced perfectly viable puppies).Oxytocin may be used to help induce contractions, and it also brings down the milk. (Dr. Robert Hutchison says: never use it before at least one puppy has come naturally, or you can rupture the uterus. Never over-use it or you can “shrink-wrap” the puppies within the over-contacting uterus. ) The counterpart for oxytocin is adrenalin, so the bitch must be kept in a calm environment and stress-free as much as possible or else stress hormones may turn off the oxytocin. If things go wrong, a c-section must be done, and done fast, so one’s vet should be pre-notified that labour has begun, and kept in contact with during the process if things start to go wrong.
She estimates that less than 50% of vets are notifying the KC about performing c-sections, which is something they are requested to do so the KC can track how many an individual is having.She discourages the bitch from eating the afterbirth, she thinks there is no good reason for it, and that it will only cause her digestive upset and the squits. She was quite scathing about the advice that it may help stimulate the birth process, (as advocated in The Book of the Bitch), and dismissed that notion out of hand saying that it was a myth that eating placenta had any effect on milk flow, etc.She said that the overall rate of loss (still born, etc) is around 5%, but that in 12 breeds it is considerably higher, up to 40% in some, and this includes many giant breeds. This she thinks is due to large litter sizes and secondary uterine inertia. There are 3 breeds where losses can run as high as 80%, for example in Bulldogs…She then said that neonatal mortality overall is about 10 – 20% in the UK, but closer to only 7% in Norway. So, quite a difference.
Colostrum:
Puppies must have colostrum in the first 6 hours after birth. Their guts progressively start to close to its large molecules after this time. Sucking does not mean they are getting milk. Puppies that suck and suck are not necessarily feeding well, in fact they may be starving. They should suckle for 10 to 15 minutes, then roll off and sleep, looking full and round. Lack of milk is a major cause of puppy loss. If there is no colostrum, blood may be drawn to be spun down in a centrifuge and fed to the puppies, which will stand in for colostrum and give them some immunity. If not the dam herself, it can be drawn from any other dog living in the same household instead, as they will share a common antibody signature. She was dismissive about the suggestion of drawing milk from the dam prior to a C-section, to ensure that, whatever the outcome, the puppies would have at least some colostrum from her. (This had been the practice of another German-trained vet when dealing with mid-delivery c-sections, brought about by secondary inertia, and still seems to me to be a rather clever idea.)
After birth, she said that puppies should NOT lose any weight, and if they do, there is a potential problem developing. So, weight at birth and regular weighing thereafter is a must for good post- natal practice. Any that do drop weight should be considered to be up to 4 times more vulnerable to developing serious issues and be at greater risk of death. Weight loss is a sign of low colostrum – e.g. not enough milk coming down. If a puppy is failing to gain, or worse dropping weight- a breeder should manage its feeding more closely. In other words, get it onto a good high-producing teat and make sure it gets a full belly and is not shoved off by a stronger sibling. Or supplement its feeding. Royal Canin now does an excellent colostrum replacement for dogs. She highly recommends it. This can be stored long term, so every breeder should have some.
Breeders lose more puppies in cold winter months than in warmer months, which underlines the necessity to keep things toasty warm! The biggest problem with cold puppies is that the motility of their digestive track reduces or even stops. They cannot digest anything and start to fade. Feeding them in this state is bad, as the milk ( or supplement) just sits there and goes sour. The puppy must be warmed carefully and gradually first, such as by placing against your skin inside a warm jumper. Only when they have returned to a correct temperature can the start to feed once more.
Again, the correct pattern of behaviour to look for in newborns is suckling for 10-15 minutes, then sleeping for two hours. Rinse and repeat. If they suckle longer or sleep less, it means they are not getting enough. An uneven litter also means that some are losing out on getting enough milk.
Final note: Best to avoid moving a bitch in the final trimester of her pregnancy, as she will not have built up a sufficient antibody profile for her new environment.As for the canine herpes jab, she was quite dismissive of it, for one main reason: Canine herpes is wide-spread and easily caught. Once a dog has been exposed, it has the antibodies. Therefore, the dam will likely have the antibodies if she has been out and about, so no need to supplement her. Likewise, no sense in re-vaccinating if she has had it for a previous litter. She claims that proven cases of puppies being lost to herpes are few and far between, and that it is a myth that this is a common cause of fading puppies.( I would recommend looking into this more closely )Footnotes and attachments:Study demonstrates rapid decline in male dog fertility, with potential link to environmental contaminants. Gary England et al.
https://www.nottingham.ac.uk/vet/news/2016/study-demonstrates-rapid-decline-in-male-dog-fertility-with-potential-link-to-environmental-contaminants.aspx
Acquired Infertility in Male Dogs with Normal Libido
- Cristina Gobello , DMV , DECAR ,
- Yanina Corrada , MV
