Pregnancy loss is a common complaint in camelid practice. The general approach to diagnosis is similar to that in other species. However, camelids have several unique features of placentation and pregnancy Reproduction of Llamas and Alpacas Relative to body size, the nonpregnant reproductive tract of camelids is relatively small. Uterine morphology is similar to that of a mare, with relatively short horns and uterine body. The... read more . In nearly all pregnancies, the fetal horn is the left uterine horn, and the placenta is epitheliochorial, microcotyledonary diffuse (such as in the horse), but the allantochorion adheres to the amniotic sac.
Noninfectious causes of abortion include fetal or placental abnormalities (twinning, umbilical cord torsion, severe deformities, chromosomal abnormalities and placental insufficiency, uterine torsion), luteal insufficiency (hypoluteidism), environmental stressors (severe disease process; long, stressful trip; heat stress), or iatrogenic causes (administration of prostaglandin F2alpha, corticosteroids, 8-way vaccines). Recurrent loss due to luteal insufficiency has been associated with obesity and possibly hypothyroidism. Presence of large avillous areas suggest placental insufficiency. Twin conceptions are not rare, and most are reduced to a singleton or lost by day 45. Abortion of twins is generally seen between 5 and 9 months of pregnancy.
On a herd basis, severe losses may be seen with nutritional deficiencies (selenium, vitamin A, iodine), or toxicosis (copper Copper Poisoning in Animals Acute and chronic copper poisoning may occur in most animal species, although susceptibility varies markedly between species. Chronic poisoning is more common and is characterized by low morbidity... read more , iodine). Lactating and very young maiden females may have an increased incidence of embryo and fetal losses.
Bacterial Causes of Abortion in Camelids
The most commonly diagnosed infectious causes of pregnancy losses are chlamydiosis Overview of Chlamydiosis Bacteria of the order Chlamydiales are ubiquitous, obligate intracellular gram-negative bacteria. Within the host cell, they replicate via a unique developmental cycle competing with the host... read more and brucellosis Brucellosis in Large Animals (in some parts of the world). Chlamydophila spp have been identified as a cause of abortion and birth of weak crias in llamas. C abortus has been associated with infertility and ovarian hydrobursitis in camels.
Brucellosis (Brucella abortus and B melitensis) is a common cause of abortion in camelids in some areas of the world.
Other reported bacterial causes of abortion in camelids include leptospirosis (Leptospira interrogans serogroups Icterohaemorrhagiae and Ballum), listeriosis (Listeria monocytogenes), and campylobacteriosis (Campylobacter fetus fetus). Coxiellosis (Coxiella burnetii) abortion is suspected to occur but has not been diagnosed definitively.
Nonspecific bacterial infections (Escherichia coli, Streptococcus equi zooepidemicus) are often isolated from cases of abortion that were due to placentitis.
Fungal Causes of Abortion in Camelids
Sporadic cases of abortion due to Encephalitozoon cuniculi and Aspergillus spp have been reported.
Protozoal Causes of Abortion in Camelids
Reported protozoal causes of abortion in camelids include toxoplasmosis Toxoplasmosis (Toxoplasma gondii), neosporosis Neosporosis in Animals Neosporosis is a disease caused by infection with protozoal parasites in the genus Neospora, most often N caninum but also N hughesi in horses. The most commonly observed... read more (Neospora caninum), and sarcocystosis Sarcocystosis in Animals Sarcocystosis is an intracellular protozoan infection that is generally asymptomatic but can cause mild gastrointestinal signs, including diarrhea, in cattle, sheep, pigs, horses, dogs, cats... read more (Sarcocystis aucheniae and S cruzi). Trichomoniasis Trichomoniasis (Tritrichomonas foetus) has been isolated from camels, but there is no strong evidence it is involved in abortion.
Viral Causes of Abortion in Camelids
Viral causes of abortion are dominated by bovine viral diarrhea virus Intestinal Diseases in Cattle Determination of the cause of intestinal disease in cattle is based on clinical, epidemiologic, and laboratory findings. Nonspecific therapy includes oral and parenteral fluid therapy to restore... read more (BVDV). However, abortions due to equine herpesvirus 1 Equine Herpesvirus Infection Equine herpesvirus 1 (EHV-1) and equine herpesvirus 4 (EHV-4) comprise two antigenically distinct groups of viruses previously referred to as subtypes 1 and 2 of EHV-1. Both viruses are ubiquitous... read more , equine arteritis virus Equine Viral Arteritis , and bluetongue virus Bluetongue have been reported. The most common BVDV serotype that affects alpacas and llamas is noncytopathic BVDV-1b. Abortion may occur at any stage of gestation, or a weak, persistently infected cria may be born prematurely. The birth of a persistently infected animal can have significant effects on a herd of animals. Diagnosis of BVDV infection is based on virus isolation from fetal blood, fetal tissues (lymph nodes), and placenta. Immunohistochemistry may be performed on formalin-fixed tissues. PCR on whole blood samples is commonly used to screen newborn crias.