Many of the developmental anomalies observed in cloned animals are related to foetal and placental overgrowth, a phenomenon known as the 'large offspring syndrome' (LOS) in ruminants. It has been hypothesized that the epigenetic control of imprinted genes, that is, genes that are expressed in a parental-specific manner, is at the root of LOS. Our recent research has focused on understanding epigenetic alterations to imprinted genes that are associated with assisted reproductive technologies (ART), such as early embryo in vitro culture (IVC) and somatic cell nuclear transfer (SCNT) in cattle. We have sought and identified single nucleotide polymorphisms in Bos indicus DNA useful for the analysis of parental-specific alleles and their respective transcripts in tissues from hybrid embryos derived by crossing Bos indicus and Bos taurus cattle. By analysing differentially methylated regions (DMRs) of imprinted genes SNRPN, H19 and the IGF2R in cattle, we demonstrated that there is a generalized hypomethylation of the imprinted allele and the biallelic expression of embryos produced by SCNT when compared to the methylation patterns observed in vivo (artificially inseminated). Together, these results indicate that imprinting marks are erased during the reprogramming of the somatic cell nucleus during early development, indicating that such epigenetic anomalies may play a key role in mortality and morbidity of cloned animals.

Background: Numerous clinical abnormalities occur in cloned calves during the neonatal period. Objectives: Describe respiratory diseases affecting cloned calves. Animals: Twenty-five cloned Holstein calves. Methods: Retrospective clinical study of the cloned calves born at the Veterinary Teaching Hospital, Saint-Hyacinthe, QC. Results: Records of 31 cloned calves were reviewed. Twenty-five records were included. Four stillborn calves and 2 calves euthanized at birth were excluded. Twenty-two calves suffered from respiratory diseases. Nineteen calves received intranasal oxygen treatment (INO). They were tachypneic (78 breaths per minute) and 5 of them were hypoxemic (PaO 2 o 55 mmHg). Two of 19 calves remained hypoxemic despite INO. Thirteen calves were weaned from INO after a median of 70 hours and were discharged at a median of 5 days of age. Nine calves required ventilatory support: 3 from birth and 6 after INO. Five were successfully weaned from the ventilator after a median of 32 hours and were discharged at a median of 8 days of age. Three calves died and 1 was euthanized because of respiratory disease. Necropsy revealed atelectasis, pulmonary congestion, and alveolar damages.Conclusion and Clinical Importance: Respiratory disease occurs frequently in cloned calves. The most frequent abnormality is hypoxemia because of V/Q mismatch. It is possible to successfully support these calves by INO and mechanical ventilation.

ObjectiveTo describe how small animal anaesthesia is performed in French-speaking Eastern Canada, and the variations between practices, in particular based on practice type, veterinarian gender and experience. DesignObservational study, survey. Sample 156 respondents. ProcedureA questionnaire was designed to assess current small animal anaesthesia practices in French-speaking Eastern Canada, mainly in the province of Quebec. The questionnaire was available through SurveyMonkey, and consisted of four parts: demographic information about the veterinarians surveyed, evaluation and management of anaesthetic risk, anaesthesia procedure, monitoring and safety. Gender, year of graduation, and type of practice were tested as potential risk factors. Chi-square exact test was used to study relations between each risk factor, and the effect of the selected risk factor on each response of the survey. For ordinal data, the Cochran-Mantel-Haenszel test was used to maximize power. ResultsResponse rate over a period of 3 months was 20.85% (156 respondents). Overall, the way anaesthesia is performed by most respondents does not meet international guidelines, such as patient preparation and evaluation prior to anaesthesia, not using individualised protocols (for 41%), not obtaining intravenous access (12.4% use it for all their anaesthesia in cats, and 30.6% in dogs), lack of patient monitoring at certain intervals for 55% of the responses, PLOS ONE | https://doi.org/10.1371/journal.pone.

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Background: The neonatal period is associated with high morbidity and mortality in cloned calves. Objective: To describe morbidity and mortality in cloned calves from birth to 2 years of age. Animals: Thirty-one somatic cell-derived Holstein calves delivered at a veterinary teaching hospital. Methods: Medical files were retrospectively analyzed. Results: Four calves were stillborn. Five calves born alive had physical congenital defects. Twenty-three calves had an enlarged umbilical cord. Laboratory abnormalities included acidemia, respiratory acidosis, hyperlactatemia, anemia, stress leukogram, decreased total protein, albumin and globulins, and increased creatinine. Twenty-five calves survived the 1st hour of life. Among them, 11 stood without assistance within 6 hours of birth, 10 calves took longer than 6 hours to stand, and 4 never stood. Twenty-two calves suffered from anorexia. Twelve calves had complications arising from umbilical cord infections. Three calves developed idiopathic hyperthermia (>40°C). Eight calves suffered from gastrointestinal problems, including ruminal distension, abomasal ulcers, neonatal enteritis, intussusception, and abomasal displacement. Mortality between birth and 3 weeks of age was 32% (10/31). Causes of death and reasons for euthanasia included stillbirths, respiratory failure, and limb deformities. Mortality between 3 weeks and 2 years of age was 19% (4/21), with deaths in this group attributed to generalized peritonitis and complications arising from umbilical infections. Overall, mortality rate within 2 years of age was 14/31 (45%).Conclusion and Clinical Importance: Respiratory problems, limb deformities, and umbilical infections were the most common causes of morbidity and mortality in these cloned calves.