DMRT3 Allele Frequencies in Batida- and Picada-Gaited Donkeys and Mules in Brazil.

In Brazil, the production of mules with a comfortable gait primarily involves the breeding of marching saddle mules. This is achieved by crossing gaited Pêga donkeys with horses from the Mangalarga Marchador and Campolina breeds. The DMRT3:g.22999655C>A SNP is implicated in regulating gait phenotypes observed in various horse breeds, including the batida (CC) and picada (CA) gaits found in these horse breeds. We aimed to determine if genotypes influenced gait type in 159 mules and 203 donkeys genotyped for the DMRT3 SNP by PCR-RFLP analysis. About 47% of mules had the CC-genotype, while 53% had the CA-genotype. Donkeys predominantly had the CC-genotype (97%), and none had AA. Both CC- and CA-genotypes were evenly distributed among mules with the batida or picada gaits. In donkeys, the CC-genotype frequencies were consistent regardless of gait type. However, the CA-genotype was more common in picada-gaited donkeys than in batida-gaited donkeys. The prevalence of CA mules and the rare presence of the non-reference allele in donkeys align with previous findings in Mangalarga Marchador and Campolina horses. This suggests that the non-reference allele likely originated from the mares involved in donkey crosses. Our results also imply that factors beyond this variant, such as other genes and polymorphisms, influence gait traits in equids.

Clinical and Therapeutic Aspects of Brazilian Native Bothrops Envenomation in Nine Horses.

In this retrospective study, clinical records of nine horses with a diagnosis of Bothrops envenomation were investigated. The accidents were classified as severe (5/9), moderate (2/9), or mild (2/9) according to the adapted bothropic snakebite severity score (BSSS). All snakebites were on the head region. The main clinical signs were local edema, blood coagulation disorders, and respiratory distress. The whole-blood clotting time (WBCT) was prolonged in all horses, and five horses presented with uncoagulable blood. All horses received specific snake antivenom according to the BSSS (six vials for severe, four vials for moderate, and two vials for mild accidents), and emergency tracheotomy was required in six horses because of respiratory distress. One horse died after eight days of hospitalization, whereas the others were discharged after nine days of hospitalization. The BSSS plus the WBCT were useful in determining the prognosis and the amount and frequency of antivenom therapy. Snakebite accidents are emergency cases; therefore, rapid and efficient therapeutic intervention will reflect positively on the prognosis.

Canine POMC deletion (P187fs) allele frequency in Labrador Retrievers in Brazil / Frequência de alelos mutados (P187fs) no POMC de cães Labrador Retriever no Brasil

The Labrador Retriever is among the main breeds with the greatest predisposition to obesity. Several factors, especially the interrelationships between food management, exercise and social factors; influence the likelihood of a dog becoming obese. Furthermore, genetic factors are also responsible for obesity in dogs, and in Labrador Retriever, a frameshift mutation (P187fs) in pro-opiomelanocortin (POMC) gene is strongly associated with obesity. There is no knowledge of studies that have previously evaluated the prevalence of the canine POMC deletion (P187fs) in Brazilian Labrador Retriever. Therefore, the objective of this study was to investigate this mutation in Labrador Retriever dogs in Brazil. Of the 108 Labrador Retrievers that were assessed in this study, 59 were from a previous study, composed by animals assisted in a veterinary hospital with unknown lineage, and 49 were from a prospective study, composed of 19 pet and 30 assistance/rescue Labrador Retriever dogs. The obesity risk and appetite questionnaire were applied, with some modifications, to tutors of the animals used in the prospective study. Fragments of the DNA, containing the mutation, were amplified by PCR and submitted to direct gene sequencing. The allele frequency of the mutation was 21.3% and was out of Hardy-Weinberg equilibrium (P<0.05). Using only the data of animals with known lineage, the presence of the mutated allele was higher in the Assistance/rescue Group than Pet Group (P<0.01), furthermore, the allele frequencies observed in Assistance Group (31.7%) was out of Hardy-Weinberg equilibrium (P<0.05), while that in the Pet Group (18.4%) was in equilibrium (P>0.05). Although the mutation has increased the food-motivation in the assistance/rescue dogs, other variables, especially frequent exercising, favored that these animals maintained the ideal body weight (body condition score = 5). In summary, the Hardy-Weinberg disequilibrium observed in the allele distribution of the deletion POMC_P187fs in this study, independently of the Labrador Retriever group assessed, suggesting the possibility of positive selection of the mutated allele, which may lead to the maintenance of this deleterious allele in the studied population.(AU)

O Labrador Retriever é uma das principais raças caninas com maior predisposição à obesidade. Vários fatores, especialmente as interrelações entre a alimentação, exercício e fatores sociais, influenciam a probabilidade de um cão se tornar obeso. Além disso, fatores genéticos são também responsáveis pela obesidade em cães, e no Labrador Retriever a mutação "frameshift" P187fs no gene pró-opiomelanocortina (POMC) está fortemente associada à obesidade. Não existem estudos prévios de prevalência da deleção P187fs no gene POMC em cães Labrador Retriever no Brasil. Portanto, o objetivo deste estudo foi investigar esta mutação em cães da raça Labrador Retriever no Brasil. Dos 108 Labradores Retrievers avaliados neste estudo, 59 eram de um estudo retrospectivo (composto por animais atendido no hospital veterinário e sem linhagem conhecida) e 49 eram de um estudo prospectivo (composto por 19 cães pet e 30 cães de assistência/resgate). Um questionário de risco de obesidade modificado foi aplicado nos tutores dos animais usados no estudo prospectivo. Fragmentos de DNA, contendo a mutação, foram amplificados por PCR e submetidos ao sequenciamento gênico direto. A frequência alélica da mutação foi de 21,3% e estava fora do equilíbrio de Hardy-Weinberg (P<0,05). Usando somente os dados dos animais de linhagem conhecida, a presença do alelo mutado foi maior no Grupo de cães de Assistência/resgate que no Grupo de Pets (P<0,01), além disso, as frequências alélicas nos Grupos de Assistência/resgate (31,7%) e no de pets (18,4%) estavam fora e em equilíbrio de Hardy-Weinberg (P<0,05), respectivamente. Embora a mutação tenha aumentado a motivação pelo alimento em cães Labrador Retriever do Grupo de Assistência/resgate, outras variáveis, especialmente o frequente exercício, favoreceu a manutenção o peso corporal ideal (peso corporal = 5). Em resumo, o desequilíbrio de Hardy-Weinberg observado na distribuição do alelo POMC_P187fs observado neste estudo, independentemente do grupo de Labrador Retriever avaliado, sugere a possibilidade de uma seleção positiva para o alelo mutado, o qual poderá levar a manutenção desse alelo deletério nesta população.(AU)