Transabdominal ultrasonographic evaluation of fetal well-being in the late-term mare and cow

Abstract

In the equine practice, attempts have been made to examine the fetus in the second and third trimester of pregnancy but all of the available methods have limitations. Until now, transabdominal ultrasonography has been regarded as the most informative examination. This method allows us to measure fetal heart rate, fetal activity as well as the quality and quantity of the fetal fluids. A modified biophysical profile for horses was used by several researchers in the USA from the 1990s as a gold standard. However, it is not sensitive enough and, in the authors' experience, professionals can face difficulties during its application (e.g. for measuring aortic diameter and fetal breathing movements). In cows, this method was first used for this purpose by a Canadian research group in 2007. They reported that transabdominal ultrasound was promising but showed low sensitivity in this species. The present studies show that birth weight cannot be predicted from fetal aortic diameter measurement in cows as suggested by other researchers. Transabdominal ultrasound needs special equipment (2-3.5 MHz convex transducer) and basic ultrasonographic knowledge; however, we suggest that in most cases it can be performed with the dam placed in a stock and without shaving the examination area. The method provides useful information within 30-40 minutes, enabling the examiner to determine whether or not the fetus is alive and to recognise placentitis or twins. This technique also allows measuring the combined thickness of the uteroplacental unit, and the authors' ongoing study showed higher normal values in Lipizzaner mares compared to values in other breeds. In conclusion, with the help of advanced techniques, simple and low-cost methods should be developed for the evaluation of the pregnant dam and its fetus to assess fetal viability in the veterinary practice.

Feto‐maternal heart rate ratio in pregnant bitches: effect of gestational age and maternal size

“…Among factors that affect FHR and FHR/MHR ratio, foetal movements should be considered. They have been deeply investigated in women and large animals (Baska‐Vincze, Baska, & Szenci, ; Dawes, Moulden, & Redman, ; Di Renzo, Copray, O'Herlihy, & Van Geijn, ), in which changes in FHR according to normal rates of movements have been described. Few information is available in dogs in which temporary accelerations of FHR may be associated with foetal movements (Davidson, ), but normal rates of foetal activity during different pregnancy periods have not yet been defined.…”

Monitoring of the mare during the perinatal period at the clinic and in the stable

“…This profile became the ‘gold standard’ for transabdominal ultrasonography for many years in the examination and treatment of pregnant mares in clinical practice (Baska‐Vincze et al . 2014). Transabdominal ultrasonography is truly a useful diagnostic tool, whereas transrectal palpation is not sensitive enough because only a small part of the fetus can be reached by hand (Reef et al .…”

“…Although improved diagnostic techniques are available in equine reproduction, the incidence of pregnancy loss is still high, varying between 10 and 15% during gestation (Bucca 2006; McCue and Ferris 2012; Baska‐Vincze et al . 2014).…”

Transabdominal ultrasonographic determination of pregnancy and fetal viability in buffalo cows

“…The most of studies were adopted the transrectal application of ultrasonography (6)(7)(8)(9)(10)(11)(12). A few and limited studies have adopted the transabdominal ultrasonography for evaluation of pregnancy in large ruminant (3,(13)(14)(15). While only one study was applicated the transabdominal ultrasonography for pregnancy diagnosis in buffaloes (16).…”