Why won't my alpaca get pregnant?

Claire E Whitehead, recognised specialist vet in camelid health and production, outlines common reproductive problems and explains what you can do when your female isn’t getting pregnant.

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 specialist vet with camelid-specific reproduction experience is the quickest way to find out what is wrong and hopefully correct it. Your general practice vet is unlikely to have this expertise or the equipment

required to perform a proper examination. 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 pointless, it may also make things worse. As Einstein said, “insanity is doing the same thing over and over and expecting a different result.”

Common reproductive problems

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. Endometritis can be resolved with proper management.

With maiden females (that is, those that have not yet had a cria) you may sometimes see a female that appears very uncomfortable when being bred. There may be blood observed after breeding, and sometimes the male will not be able to get comfortable and gives up trying to breed that female. In these cases, the most common reason is that the female has a hymen that the male is unable to break down. Typically a male will easily be able to manage this, so I do not recommend interfering with females routinely to break down their hymens. I would normally only check for a persistent hymen after the above behaviour is observed because 95% of the time, it is not a concern. Some experienced breeders are able to evaluate for persistent hymen and break them down. However, if you are not confident I would not suggest doing this yourself until you have been shown how. With very small holes, you may get it wrong – there is another hidden opening in this area. The urethral opening is within about 1cm of the hymen and you would not want to accidentally open this. Not only would it be excruciatingly painful, but you could also do serious damage. There are other potential problems that may be found also. Where no hole is palpable, it could be that the anatomy of the vagina is not correct. In some cases, there is a complete wall – attempts to create a hole in this can lead to introducing infection into the uterine fluid that is accumulating on the other side. Correct differentiation of these problems is needed as some are fixable (and do not constitute a reason not to breed) and the female can subsequently be bred, while others mean that you cannot breed the female.

When females are bred and successfully ovulate, a corpus luteum forms that produces progesterone. This structure is responsible for maintenance of pregnancy but occasionally it will stick around in the absence of conception, and sometimes this occurs when there is inflammation in the uterus. In this case, it is termed a retained corpus luteum (CL). These can be seen on ultrasound (Figure 1). This is one reason why ultrasound confirmation of pregnancy is key. Behaviour testing with a male gives you a preliminary indication of pregnancy if a female spits off from 14 days onwards, but it doesn’t confirm pregnancy. About 15% of non-receptive females will not be pregnant. If you don’t confirm pregnancy by ultrasound, you could end up waiting for a birth that will never come and end up wasting potentially two years of breeding life. If you confirm pregnancy by ultrasound, you can be certain of the diagnosis. Females that are not pregnant can be rebred and this results in less wasted time with females open. It’s a good idea to also reconfirm pregnancy again at eight months, at which point you need to increase nutritional provision for females entering the last few months of pregnancy and any non-pregnant females can be allocated for early rebreeding in the Spring.

Figure 1: An ultrasound image showing a corpus luteum on the left ovary, adjacent to the tip of the uterine horn

A really important thing to remember is that if you have a female that is determinedly spitting off and you don’t think she’s pregnant, confirm the diagnosis first by ultrasound. This is best done by having your vet visualise the non-pregnant uterus on rectal ultrasound. It is much easier to miss a pregnancy on transabdominal ultrasound and be incorrect, but you cannot mistake a non-pregnant uterus. If a female is behaviourally non-receptive but not pregnant on ultrasound, we can give her hormones to cause luteolysis – that is, to make the CL go away. But clearly this will terminate any pregnancy.

Some of the problems that may be encountered in female alpacas are listed in the table and divided into those seen exclusively in maiden females and acquired problems (these may also be seen in maidens). These can usually be discovered by a thorough reproductive evaluation.

What can you do when a female isn’t getting pregnant?

We can do a breeding soundness evaluation. This will establish the underlying cause of the infertility and this may be resolved by the subsequent actions taken.

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 2 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 – and for good reason! Camelids are small compared with other large animals, such that rectal palpation or using rectal probes can be 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 the reproductive evaluation performed by a vet with camelid-specific expertise in reproduction, in much the same way that you would not ask your GP to do IVF. It is a specialist skill. 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. Referral is not required if they haven’t seen the case, but reports will be sent back to your vet so that they are aware of what has been done in case subsequent issues arise.

Please remember that just throwing antibiotics and hormones at an alpaca in the hope that something works is not good practice. For starters, it would be irresponsible use of antimicrobials. Secondly the medicines chosen may not be properly targeted at the problem that your female has. Thirdly, you can waste valuable time (and money).

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 in her lifetime 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 if you were to sell every one of those offspring 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. In addition, here we are also not considering the loss of potential future genetic advancement in terms of the progeny. 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 £200-£350 (current prices) depending on what diagnostics are required. It usually takes around one to two hours to complete and can usually be done as an outpatient procedure.

Case example

A seven year old female called Fine Design was presented for evaluation having failed to conceive for three years. She had been bred with two different males, had a course of antibiotics and later on had a series of non-diagnostic tests done at the regular vet’s including ultrasound, uterine culture and biopsies, costing around £450. When she came down to see me, I found that she had evidence of endometritis, collected a sample for culture from the uterus, performed a uterine flush under ultrasound guidance and gave antibiotics based on culture results once available. I also advised a specific controlled breeding protocol to improve her chances of conception when being bred. The owner was thrilled to let me know that she was pregnant to her first breeding following her visit to me – and even more ecstatic to let me know when she gave birth the following summer to a healthy female cria!

Although the owner travelled around six hours to come to see me, the cost of the consultation and treatment was only £370 +VAT.

AJ Bell, Florens Alpacas