Ultrasound pregnancy test
The results from an ultrasound scan pregnancy test depend largely upon the skill and experience of the operator and the quality of the machine used. However, the best can see pregnancies and fetal development 20 days post mating. A pregnant scan shows a dark area, which is the fluid-filled uterus, and the cria is seen as a brighter area inside this.
You can do scans yourself if you invest in the machinery, your vet can do them, and in some areas mobile sheep scanners can scan your alpacas for you.
Rectal scans are effective in picking early stages of pregnancy. Rectal is also used to investigate the state of the uterus and ovaries.
Exterior abdominal scans are effective from day 40 of pregnancy. We normally exterior scan females at 90 days of pregnancy because if we see a pregnancy then, it is likely to be retained for full-term.
Blood pregnancy test
Blood tests can be done to test for progesterone levels - which indicate pregnancy. These tests are around 5 dollars and we found to be fairly accurate. By drawing a small vile of blood and sending it into a laboratory such as M & M Laboratories, you can tell usually tell if an alpaca is pregnant within 20 and 60 day marks.
It is important that the labs/vet tell you the actual progesterone level (a number) and not just "pregnant/not pregnant".
A word to the wise
With experience and with knowledge of the individual behavior patterns of your alpacas, you can actually look at alpacas and tell whether they are pregnant or not. Hormonal change creates behavioral change. So a sweet friendly alpaca can become a grumpy one once she is pregnant, which is a mixed blessing. Maiden alpacas – first time moms– can be fairly pronounced. Especially if you know your alpacas’ personalities well, this can help you determine if she has conceived.
Note that between 15% - 18% of alpaca pregnancies do slip - or miscarry - in the first 90 days so be vigilant. Testing for pregnancy at the appropriate times will save you waiting and watching your prize female for 12 or 13 months and wondering why she is not producing the eagerly awaited cria.