Reproductive efficiency is vital in any livestock breeding business. Any period of time during which a reproductively sound female alpaca is not pregnant translates to a wasted investment. In an ideal world, a female alpaca is bred back 21 days after she gives birth and is pregnant for an average of 343 days. This gives an ideal interval between successive parturitions of approximately 364 days, or about one year. It is important to keep as close to this ideal as possible in order to have females giving birth during the ideal birthing months (Spring and Summer) or they will gradually slip back such that you are left with having to decide whether to breed a female in the Autumn or leave her until the following Spring, which wastes even more time.
Obviously, not every female will conceive every time: overall conception rates in alpacas are around 55%, so you have to expect some females will not become pregnant the first or even second time they are presented to the male. However, if a female is consistently repeating the same behaviour and not conceiving, there will be a reason for this. A breeding soundness evaluation (BSE) by a vet with camelid-specific reproduction experience is the quickest way to find out what is wrong. Endlessly repeating breedings or continuously presenting a non-receptive non-pregnant female to a male in the hope that things might change is not only wasting time (and money), it may also make things worse.
The most common acquired reproductive problem in alpacas is endometritis (inflammation/infection of the uterus). If this goes untreated, the inflammation can spread into the deeper layers of the uterine wall so that treatment may become impossible due to the development of fibrous tissue. Furthermore, because of the very invasive nature of copulation in alpacas with the male?s penis actually penetrating all the way through the cervix in order to deposit semen at the tip of the uterine horns, repetitive breeding can worsen the inflammation in the uterus and cervix and also add bacterial contamination into the uterine environment.
In the situation of a continually non-receptive non-pregnant alpaca, this is most likely due to the presence of a retained corpus luteum (CL). These can be seen on ultrasound (Figure 1). Failure to firstly recognise that the alpaca is not pregnant (although this is easily sorted through the use of ultrasonography in pregnancy diagnosis) and then not take appropriate steps to diagnose and treat a retained CL may result in a CL that ultimately will not respond to luteolytic drugs such as Estrumate (Intervet/ Schering-Plough Animal Health). In these chronic cases, unilateral removal of the affected ovary may resolve the problem but is clearly far from an optimal solution. Another point to make is to be careful when using luteolytics unless you know for sure that an animal is not pregnant by having ultrasound confirmation of a non-pregnant uterus. I once saw an alpaca in the US whose owner was really annoyed at having a continually non-receptive alpaca. The female had been given a 2 day course of Estrumate for a CL but was still non-receptive. On discovering that she was actually around 9 months pregnant, he was thrilled but also a little disgruntled at having been fooled! This female had been displaying perfectly consistent behaviour but no-one believed her and amazingly she had maintained her pregnancy despite a typically successful abortion protocol. A 2 day course of Estrumate causes abortion in 92.5% of pregnancies(1).
The sort of problems that may be encountered in female alpacas are listed in Tables 1 and 2 and divided into those seen in maiden females and acquired problems. These can usually be discovered by a thorough reproductive evaluation. This is not an exhaustive list.
Table 1. Reproductive Problems in Maiden Females
Persistent Hymen ? Females may exhibit discomfort at breeding +/- post-coital bloody vaginal discharge
? Easily identified and treated.
Immaturity Female not yet mature enough to be bred. Leave another 6 months.
(?Congenital? means ?present at birth?) ? Anatomical problems such as vulvar hypoplasia (vulvar opening not big enough), segmental aplasia of the vagina or uterus (a physical obstruction of either vagina or uterine horn), double cervix, uterus unicornis (only one uterine horn is present instead of two).
? Ovarian hypoplasia ? small inactive ovaries in an otherwise mature adult female. Usually the uterus is also undersized.
Table 2. Acquired Reproductive Problems
Problem Comments Treatment Options
Endometritis ? Usually ovulate (spit off at 7 days post-breeding) but don?t conceive (return to breeding at 14 days) ? this cycle keeps repeating itself
? May appear uncomfortable at breeding Treatable unless very chronic. Uterine flush and/or systemic antibiotics depending on the case.
Cervical Scarring ? Can result from traumatic birthing (assisted or unassisted). Due to inadequate cervical dilation, or large cria
? Sometimes one ring of the cervix can be damaged but not the other such that pregnancies may still be carried No treatment
Persistent/Retained CL ? Typical history is a female that is continually non-receptive (and not pregnant!)
Endometrial Cysts ? Often single large cysts (see Figure 2)
? Prevent an embryo from implanting and developing Solitary cysts can be ruptured transcervically following identification.
Good prognosis for solitary cysts
Follicular Cysts These are cysts on the ovary arising from the follicles Hormonal therapy
Para-ovarian Cysts and Hydrosalpinx Infrequent. Laparoscopic resolution
Ovarian Tumours Rare. Teratomas and granulosa cell tumours have been reported. For unilateral tumours that haven?t spread, removal of the affected ovary may be curative.
So, when would I recommend investigation of reproductive failure? Assuming that presentation to the male takes place every 7 days:
1. Any female who breeds at every behaviour test
? Indicates failure to ovulate
? In a maiden, possibly immature reproductive tract or anatomical abnormality, or also recessive behaviour
? Allow 3 breedings and if still receptive at the 3rd or 4th week, wait 4 weeks and have a reproductive evaluation performed. It is advisable to wait these 4 weeks in case a pregnancy results from the latter breeding: additionally, the presence of semen in the uterus and/or the appearance of inflammation of the uterus on ultrasound or vaginal examination may make a proper evaluation impossible.
2. Any female who breeds and then spits off and repeats the cycle again
? Indicates ovulation is taking place, but conception is not occurring
? Classic history with endometritis since the uterine environment is not appropriate for implantation of the embryo
? Do not repeat this cycle more than 3 times without seeking advice from an experienced camelid vet proficient in reproductive techniques.
3. A female who is continually non-receptive over a 2-3 week period if behaviour-testing has been done regularly during this period.
? She should have been receptive at least once during a period of 2-3 weeks if spat off 3 times a week
? Possibly a retained CL or an unexpected pregnancy. In a maiden, could be a reproductive anomaly or indicate inexperience.
4. Any other situation where conception failure is occurring and you do not know the reason.
Other indications for a breeding soundness evaluation include:
1. Pre-purchase. In the equine world, no one will buy a horse without a ?vetting? to ensure that the horse is fit for its intended use. This is done pretty much regardless of value by individuals seeking to ensure that they are not going to be saddled (excuse the pun!) with a horse that will cost them money or not be able to perform its intended tasks. In the alpaca industry, most breeders sell alpacas with warranties of fertility since breeding is their ?intended use?. The problem with this is that sometimes disputes arise between buyer and seller when it may not be clear how or when a reproductive problem arose. This is particularly true for males where for example, disputes arise over fertility due to the presence of small testicles ? were they small before, or have they atrophied due to disease? And if disease such as heat stress caused it, when did this occur? If there is no paperwork attesting to that male?s status at the time of purchase, these disputes can be problematic. A pre-purchase reproductive evaluation may not be feasible for all alpacas bought and sold but may be worth considering for high value alpacas, or alpacas that are going to be exported when to return them may present significant obstacles.
2. Pre-breeding. A breeding soundness evaluation may be performed to ensure that a maiden has all the correct equipment that is of the correct size, with no congenital abnormalities, and to confirm that there is evidence of ovarian activity. In the US, some breeders insist on a pre-breeding check to ensure that a female has no evidence of reproductive problems (especially vaginal discharge that may indicate uterine infection) so as not to waste their time or that of the males, or potentially put their males at risk. This is usually a relatively quick examination and involves an ultrasound of the reproductive tract (via the rectum) and a vaginal examination.
3. Following a difficult or assisted birthing. A ?post-dystocia check? at 10-14 days post-partum is recommended for females who have had any sort of assisted delivery. This is because there may be problems that are easily addressed at this stage that may become difficult or impossible to resolve down the line. This is usually a much quicker evaluation than a full BSE. For example, these females are more likely to have uterine infections than females who experienced a normal delivery due to possible introduction of bacteria by human manipulations of a malpresented cria. At this point in time, a uterine flush with systemic antibiotic administration (using an antibiotic that is known to achieve good concentrations in the uterus) may resolve the issue with relatively little impact on the female?s subsequent fertility. If undiscovered, chronic endometritis may result and this may have a longer term impact on the female?s reproductive future. Also, if a female experienced vaginal tearing during a delivery, at this point, the vaginal wall may be trying to heal and may heal across the vaginal vault. If undiscovered, this will result in scar tissue formation and this will result in a female that cannot breed - and is entirely preventable by recognition and appropriate treatment at the appropriate time.
A Breeding Soundness Evaluation typically involves an initial interpretation of history, physical findings and evaluation of the reproductive tract itself. The reproductive examination should include inspection of the external genitalia, ultrasonographic evaluation of the entire reproductive tract including the ovaries, each uterine horn, the uterine body, cervix and vagina as well as a vaginal examination. Figure 3 shows a female alpaca having a BSE in a custom-made alpaca chute. Depending on the individual, a culture from the uterus may be indicated, or flushing of the uterus under ultrasound guidance so that you can ensure first of all that the flush is in the uterus and secondly observe any filling defects that might help achieve a diagnosis (eg endometrial cysts or segmental aplasia of the uterus). Flushing of the uterus may also be therapeutic in some cases. Other diagnostic tests may also be recommended based on the findings of the initial examination: these may include hormone analysis, biopsy or endoscopy of the uterus.
Many vets are not comfortable with the use of rectal ultrasound ? for good reason! Camelids are small compared with other large animals, and have much more friable rectums than cows, making rectal palpation or the use of rectal probes a potentially hazardous activity, particularly if adequate restraint is not achieved. Furthermore, vets may not be familiar with the camelid-specific reproductive anatomy and physiology in order to assist them in making a diagnosis. It takes time to develop these skills and to be able to recognise what is abnormal and differentiate it from the normal. Camelids are different from other domestic species with respect to reproductive anatomy and physiology and findings that may be normal in a cow for example may be highly abnormal in an alpaca. Additionally, for a thorough evaluation of the reproductive tract, it is necessary to have the right equipment. Some ultrasounds are fine for pregnancy diagnosis but not good for the detailed imaging required for reproductive evaluations; having the right tools for vaginal examination can also make life very much easier. For these reasons, it is important to have a BSE performed by a vet with camelid-specific expertise in reproduction. Therefore, if you have an alpaca with reproductive failure, and your vet is not happy performing a BSE or has taken the evaluation as far as they are comfortable doing without success, they may suggest referral. If not, you may also ask for referral to a vet with this experience.
If you are still not convinced that reproductive evaluation is worth it, consider a possible cost-benefit analysis. Let?s say that you have a female alpaca worth £5000. Consider that she may have 10 crias for example and, on average, 50% of those cria should be female and 50% male. If we make the assumption that each female cria is worth the same as the dam, and assume that the males will be pet quality since only the best males should be used for breeding (the going rate for a gelding alpaca is around £500), then your potential sales from offspring from this female could total around £27,500, with the average value per offspring of £2,750. So, if that female loses a year of breeding, which may have been prevented by proceeding with a timely reproductive evaluation, you?ve effectively lost £2,750. This analysis does not take into consideration the amount spent on managing and feeding a non-pregnant alpaca, vaccinating her, and neither does it consider the time costs of the individuals (and males) that are trying to get her bred. To give you an idea of the cost of the BSE, at my clinic a typical full evaluation involving rectal ultrasound of the reproductive tract and vaginal examination +/- culture +/- uterine flush may cost from £160-250 (current prices) depending on what diagnostics are required. It usually takes around 1-2 hours to complete and can usually be done as an outpatient procedure.
I am always happy to provide advice to vets about reproductive complaints as well as other problems with your alpacas and, in addition, I am willing to take referrals for reproductive evaluation of alpacas. I can be contacted at the Camelid Medicine and Reproduction Referral Service, Camelid & Farm Animal Hospital, at The Royal Veterinary College on 01707 666297. The Hospital is based near Hatfield in Hertfordshire, just north of the M25.
1. Smith BB, Timm KI, Reed PJ, et al: Use of cloprostenol as an abortifacient in the llama (Lama glama). Theriogenology 54:497, 2000