Ultrasonographic changes in fetal gastrointestinal motility during the last ten days before parturition in dogs

Prenatal Diagnosis of Canine and Feline Twins Using Ultrasound: A Retrospective Study

Prenatal diagnosis comprises a set of investigations, both instrumental and laboratory-based, which aim to monitor the health of the foetus during pregnancy, from the early stages of embryonic development to the moments preceding delivery. A growing interest is emerging for the preterm ultrasound morphological screening of embryos and foetuses, aimed at assessing the integrity and viability of the conceptus, as well as the early diagnosis of anomalies which can cause complications. This study is a retrospective study of the ultrasonographic findings of twins in the authors' clinical activity from 2016 to 2022. Only seven cases of monochorionic twins were recorded, out of the whole number of evaluations performed on 3120 foetuses, with a prevalence of 0.6% and 0.2% in feline and canine foetuses. All the twins had their own amniotic sac and umbilical cord but presented a single placenta and a single allantoic sac. Unfortunately, the three feline cases were not more recognizable at term. In the four canine cases, three were of opposite sex and then necessarily dizygotic. Twins may have an impact on the success of a pregnancy due to the risk of dystocia, as observed in some of the reported cases. Prenatal ultrasound allows early recognition of twins in dogs and cats.

Ultrasonography for the evaluation of pregnancy in the female canine

Ultrasonography can be used for canine pregnancy diagnosis, determination of gestational age, assessing foetal maturation and readiness for birth, monitoring high-risk pregnancies, assessing foetal distress, evaluating bitches in dystocia and foetal gender determination. As the quality and resolution of ultrasound machines have improved, the clinician's abilities to utilize ultrasound as an integral part of reproductive evaluation of all aspects of pregnancy have exponentially increased. This paper reviews the use of ultrasonography throughout pregnancy and the advances made in the interpretation of captured images.

Clinical use of the canine foetal kidney formula in dogs of different maternal sizes during the last ten days before parturition

Data concerning the use of the canine foetal kidney length (L) formula in the prediction of parturition timing are still lacking. In our study, we aimed to evaluate the accuracy of the L formula in predicting the parturition date during the last 10 days of pregnancy. Twenty-five clinically healthy pregnant bitches, aged 2-9 years and weighing 3.5-52.2 kg, were ultrasonographically monitored from -11 to 0 days before parturition (dbp). Kidney L was measured for the three most caudal foetuses, and the parturition day was estimated using the kidney formula, whose accuracy was calculated as the percentage of cases estimated (ranges of ± 1 or ± 2 days) on the actual parturition date. A K-proportions test was performed to identify differences in the accuracy among maternal sizes and the sex ratio of pups, and a two-proportions z-test was performed to identify differences between litter size classes (≤ 7 vs. > 7 pups) and time ranges (-11/-5 and -4/0 dbp). An accuracy of 35% within ± 2 days was found in the range of -11/-5 dbp and an accuracy of 30% within ± 2 days was found in the range of -4/0 dbp. The accuracy differed between small (53% ±1 day and 60% ±2 days) and large (10% within ± 1 and ± 2 days) bitches (P = 0.019 within ± 1 day, and P = 0.007 within ± 2 days). For small litter sizes, the accuracy was 38% within ± 1 day and 44% within ± 2 days, and for large litter sizes, it was 14% within ± 1 and ± 2 days. A threshold value was found between litter size classes within ± 2 days. The use of the L formula during the last ten days of pregnancy did not seem to warrant good accuracy in the prediction of parturition date. Further studies on different maternal sizes should be performed.