Is Progesterone Testing for the Birds?


My usual way of breeding is to have female alpacas come to my farm and breed where I have control of the situation. Last year, for a variety of reasons some of my customers and I decided to bring my boys to their girls and do mobile breedings at their farm. I made several trips with my males to their farm last Spring, and we thought we had several pregnancies, but later their vet reported that the progesterone test results indicated that only one of the five were pregnant. (Three were maidens)

Well, we had to wait for my males to come back from their Summers away, and then we had the girls come over to our farm so we could be sure to get them pregnant this time. Two of them were very NON-receptive. Then it got really cold so we weren’t really breeding.

Then we didn’t want to give our customers January cria so we didn’t breed in February.

Then I started to notice something. Something alarming. to me.

One of these girls was huge. And her belly was dragging the ground.

Come to think of it, the other one who wouldn’t breed (the pretty rose grey one) was horribly spitty and kinda mean. She wouldn’t even let me into their shelter to put the food into their dishes without spitting green stuff all over me.

This got me thinking. Hard. I called my customer on the phone.

“The pretty rose grey one,” I said, “What was she like before she was bred?”

“Oh, she was the sweetest animal we had,” my friend gushed. “She would come and put her head in your lap before she was bred.”

Uh huh.

If it looks like a duck, walks like a duck, and quacks like a duck, it’s probably a duck.

Suspicious that the reason these two females are so big, so grumpy, and the reason they won’t BREED is because they are already pregnant, I called the vet’s office and begged for a quick appointment for an ultrasound for them.

In the meantime, I tried HARD not to think about them delivering a cria up in the front field while no one was there, but checked on them a lot to be sure it didn’t happen without us knowing. (I was kinda scared to know when they might be due…I’m heavy into denial)

Friday Dr. Stewart came by on his way home. I wish you had seen me wrestling that beautiful, extremely pregnant (*oh yes*) rose grey alpaca to get that ultrasound shot to prove without a shadow of a doubt, that, yes, there was a baby in there causing all this consternation!

Dr. Stewart is used to having a vet tech but he was on his way home and had to squeeze me in at the end of the day. I’m used to having a farm manager (or I used to be). But there was no one to help us or to (horrors for a blogger!) hold the camera.

So I will just have to describe it for you. The older one, whose belly is practically dragging the ground, was first. (I know to do easier first) I held her pretty strong and he was able to get a quick look. When the baby is this big you just need to see a rib or a head or a body part to know something is there.

The rose grey girl was like a bucking bronco. I could hold her for a few seconds. But as soon as he put the alcohol on her to use as the conductor (think the jelly they put on human pregnant bellies and how cold it is) she jumped around like crazy. I thought I was going to lose a limb. Had to shake it off several times, breathe and come back for more. I eventually had to tie her halter and we had to go for 3  Loooonnnnggggg seconds.

You know how professional bull riders have to ride for 8 seconds to get a score? We had to hold this beauty for 3 seconds for Dr. Stewart to get an ultrasound reading on her. When we did it, and he got a positive reading – it was the best feeling! I have a terrific bruise to show for it, and am proud as hell of it.

DSACAL144_3In the end – our friends are thrilled! They are getting two babies – SOON! When we looked at the breeding dates, both are due this month. They came to get them the next day so they can deliver at home.

Our story has a happy ending with these girls being ultrasounded and being diagnosed properly. In the past we have had alpacas misdiagnosed with false positives by progesterone testing when the alpaca had a retained CL (corpus luteum) and no pregnancy, costing the breeder a year of productivity.

Some breeders don’t have access to ultrasound machines. Do you rely on progesterone testing? Have you ever had a problem with it?

Leave us a comment and tell us your thoughts and experiences with progesterone testing for pregnancy diagnosis in alpacas.


  1. 100% accuracy with progesterone here….in 10 years……yes, I spit test, watch behavior etc….but Prog. is the one thing that tells me ‘yes’ or ‘no’!!

  2. Progesterone testing for us proved only the female was pregnant at the time of the blood draw. Some tend to slip early and you wait in comfort of a progesterone test for a while and find at ultrasound time there is no pregnancy. We try to test back with a male. Between that and some true personality change, there is usually no doubt that precious suprise is on the way. We have two due in the next week or so…not sure exactly when records lost in barn fire. But,the girls are “hanging low”. Nice story.

  3. Wow that is so crazy!! Glad we humans don’t get all cranky like that when pregnant… oh wait, we do! I probab;y acted like a bucking bronco a couple of times when I didn’t want to do something, LOL.

  4. 2 of our 3 pregnant girls had negative progesterone tests last year. When the tech was here to ultrasound the third girl, I had her check the 2 negatives and they were definitely pregnant. I’m not sure progesterone tests are worth the effort if I can’t trust the results.
    .-= Nancy ´s last blog ..Herdsires =-.

  5. I have been reading Katy’s blog for awhile, mostly as someone interested in what’s going on. I am a large animal veterinarian that works on cattle. My only alpaca and llama experience was while I was in veterinary school, which has been a few years ago, so I’m certainly not an expert on camelid husbandry. I will weigh in with a few thoughts for all on possibly why/how this happened.

    In using progresterone testing in cattle, the results are, well, variable. (Not unlike what we’ve seen here.) There are so many factors that go into the test. Sample amount, proper handling of the test, and quality of the lab doing the test. Then there is the fact that her progesterone being high or low may have NOTHING to do with her being pregnant. All animals “cycle” where they have varying levels of progesterone and estrogen. Being pregnant will change some of this, but the important part here is that progesterone (hormone required to maintain pregnancy) can be high without her being pregnant.

    Some of my cattle clients have tried progesterone testing only to get frustrated that they got inconclusive results or still found out their cow was the opposite of what the test told them to expect. I understand the appeal of this manner of testing. Large animal vets are hard to come by in some areas and the expense to have a vet come out may be more than some want or can afford to pay.

    I’ll share a couple of suggestions when it comes to using these tests:

    Ask the manufacturer what the false positive and false negative rate on these tests are. Any good testing company will know these numbers and should be able to give them to you. For example, a particular test has a false positive rate of approximately 10 percent, but the false negative rate is 0 percent. That tells me that if I get a negative, she’s truly negative, but if she’s positive, there could be a 10 percent chance she is a false positive, meaning she’s truly negative. Phew! Enough stats…

    I would also suggest using the progesterone test only when it’s for your knowledge, not necessarily making management decisions off of it. Based on what I’ve read here, people think it works, others haven’t had as good a luck. Would you want to buy or sell an alpaca based on progesterone testing? My gut says no. I suppose if you just want to know so you can decide not to go on vacation that month she might be due to deliver, then a progesterone test might be enough.

    Of course it’s always important to get good information from people who have experience. I’ve followed Katy’s blog for awhile and have found her to have good advice and stories for her readers.

    Now, back to the fun stuff. Where are those cute crias?
    .-= Kathy´s last blog ..Golden Boy – USD $75.00 =-.

  6. I had a cria born on July 10th to one girl that I had no idea was pregnant. Then I noticed my other maiden was acting strange. I was soooo certain and even had the farm manager tell me that he felt her belly. There was two times that he thought he felt the cria. Just got results this morning that her progesterone level is less than .2 and not pregnant. What the heck is going on?

  7. I hear you Jessica. Sometimes they do confuse us. Maidens in particular. I don’t use progesterone at all, just don’t find it a useful tool unless in conjunction with ultrasound. With technology the way it is today, I want to SEE that baby. Plus alpacas (other than maidens) are so good at spitting off to show their pregnancy status that I rarely need anything more than that with my experienced girls. Congrats on the surprise cria though!

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