Losses arising from abortion are distressing for owner and animal alike and are a financial set back. Well planned breeding programmes can be severely disrupted with knock-on effects for the genetic development of herds and breeders marketing initiatives. Ahmed Tibary, DMV, PhD, Dipl. ACT, of the Veterinary Teaching Hospital, College of Veterinary Medicine, Washington State University, outlines some of the causes and consequences associated with this problem.
Pregnancy loss is the second most common complaint in alpaca infertility in my practice. There is no epidemiological data on the extent of this problem. However based on records in the theriogenology service at the Veterinary Teaching Hospital, Washington State University, 7–12% of all pregnancies will be lost during the 11–12 month gestational course. From a clinical point of view, pregnancy losses can be divided into three categories; early embryonic death; early fetal loss and late fetal losses.
Diagnosis of the cause of pregnancy loss is one of the most challenging aspects of infertility work up. It requires the services of a veterinarian with a good background in theriogenology (a veterinary speciality dealing with infertility, obstetrics and neonatal problems), and an excellent diagnostic laboratory support. The objective of the present article is to discuss the causes, diagnostic approach and possible therapy for pregnancy loss in alpacas.
Defining the problem: The importance of pregnancy diagnosis
When discussing or working up a case of pregnancy loss it is important to define the precise problem in terms of whether this is an individual female problem or a herd problem, when does the loss occur and what are the historical data of importance that happened before observation of the pregnancy loss. Talking about pregnancy loss suggests that a female has been diagnosed pregnant at a first examination and is found open at a subsequent examination. Therefore, of utmost importance in defining the problem is what method is used to diagnose pregnancy in the first place.
Pregnancy can be diagnosed by a variety of methods and is most commonly based on female behaviour, hormone assays and ultrasonographic examination of the uterus and its content.
I consider ultrasonography to be the gold standard method for any examination for pregnancy
I consider ultrasonography to be the gold standard method for any examination for pregnancy. For a well-trained person, ultrasonography carries a very high accuracy (100%) starting at 12 days post-breeding (Figure 1) when done trans-rectally and starting at 45 days (Figure 2) and up to 5 months when done trans-abdominally (Figure 3). Transabdominal ultrasonography for pregnancy evaluation beyond 5 months is possible and highly accurate but requires shaving a large area of the abdominal wall to allow better visualisation because the fetus is very deep in the abdomen. Ultrasonography offers the veterinarian the clinical means not only to establish a diagnosis of pregnancy but also evaluate normalcy of the pregnancy with respect of cervical tone, placental health, fetal well-being and fetal number (twins).