Fecal shedding of Clostridioides difficile in calves in Sao Paulo state, Brazil.

OBJECTIVE: This study aimed to evaluate the fecal shedding of C. difficile in calves on farms in Sao Paulo State, Brazil. MATERIALS AND METHODS: Fecal samples (n = 300) were collected from diarrheic (n = 78) and nondiarrheic (n = 222) calves less than 60 days of age from 20 farms. Fecal samples were inoculated into enrichment broth supplemented with taurocholate and cultured under anaerobic conditions. Colonies suspected to be C. difficile were harvested for DNA extraction and then multiplex PCR for the detection of genes encoding toxins A and B and binary toxins. All toxigenic isolates were ribotyped and tested for antimicrobial susceptibility, and five selected strains were subjected to whole-genome sequencing to determine their sequence type. RESULTS AND DISCUSSION: C. difficile was isolated from 29.3 % (88/300) of the samples. All toxigenic isolates (17/88, 19.3 %) were classified as ribotypes RT046 (13/17-79.47 %, A+B+ CDT-) and RT126 (4/17 = 20.53 %, A+B+ CDT+). The sequenced strains from RT046 were classified as ST35 (Clade 1), while those from RT126 were classified as ST11 (Clade 5). No associations between the epidemiological factors in any of the groups and C. difficile isolation were observed. Most of the toxigenic isolates (16/17 = 94.41 %) were classified as multidrug-resistant. Calves can be an important source of toxigenic C. difficile strains, including multidrug-resistant isolates from ribotypes commonly observed in humans.

Effects of dietary copper and zinc hydroxychloride supplementation on bone development, skin quality and hematological parameters of broilers chickens.

This study was carried out to evaluate the effects of supplementation with different levels of copper (Cu) and zinc (Zn), using two mineral sources (sulphate and hydroxy forms), on the bone characteristics, skin strength/elasticity, and haematological parameters of broilers. A total of 1792 1-day-old male Cobb-500 broiler chickens were randomly distributed among eight dietary treatments, using Cu sulphate (CSM) or hydroxychloride (CHC), and Zn sulphate (ZSM) or hydroxychloride (ZHC). The dietary treatments were as follows: (1) low-CSM/high-ZSM, (2) high-CSM/high-ZSM, (3) low-CHC/low-ZHC, (4) low-CHC/medium-ZHC, (5) low-CHC/high-ZHC, (6) high-CHC/low-ZHC, (7) high-CHC/medium-ZHC, and (8) high-CHC/high-ZHC. On Day 42, blood samples were collected from one bird/pen to analyze the haematological parameters. Finally, two birds/pen were slaughtered, and the tibia and femur were collected to analyze the quality of bone and skin. The means were subjected to ANOVA and, when significant, compared by Tukey's test (p < 0.05) or Dunnett's (p < 0.05) test. The haematological parameters were not influenced by mineral supplementation. However, the inclusion of low ZHC enhanced the skin strength compared to high ZHC (p = 0.046). Furthermore, the bone mineral density of the tibia proximal epiphysis, tibia ash and tibia mineral content were positively improved with supplementation of low-CHC/medium-ZHC compared to high-CHC/medium-ZHC. This study demonstrated that hydroxy compounds are potential alternatives for replacing sulphate supplements in broiler diets. Moreover, among the Cu and Zn levels, the low CHC (15 mg/kg) and medium ZHC (100 mg/kg) improved bone development and skin integrity, suggesting that the combination of Cu and Zn can be a nutritional strategy to prevent the incidence of leg disorders in broilers.

Imiquimod treatment for Equus caballus papillomavirus infection in equine aural plaques.

BACKGROUND: Aural plaques are a dermatopathy associated with Equus caballus papillomavirus (EcPV). This disease affects horses of all ages, genders and breeds, and causes sensitivity of the ears. HYPOTHESIS/OBJECTIVES: The aim of this study was to evaluate the clinical efficacy of 5% imiquimod cream for the treatment of aural plaques and to compare the PCR detection of EcPV 3, 4, 5 and 6 before and after treatment. ANIMALS: Eight horses diagnosed with aural plaques (14 ears) were used. Three mares with unilateral aural plaques were used as untreated controls. METHODS: Imiquimod cream was applied every 48 h until complete resolution of the aural plaques was observed. Animals were evaluated clinically for 180 days after the end of treatment. PCR for detecting EcPV 3, 4, 5 and 6 was performed using aural plaque biopsies collected before and at 90 days after the end of treatment. RESULTS: Clinical resolution was observed in 93% of the treated ears. Imiquimod treatment promoted the clearance of EcPV in 71.4% of the treated ears. Clinical remission of the aural plaques and changes in EcPV DNA positivity between the first and second biopsies were not observed in the control group. In 75% of horses, sedation was required in order to carry out pretreatment cleaning. CONCLUSIONS: The results of this study support the hypothesis that 5% imiquimod cream may be used as an effective treatment for aural plaques in horses.

Hereditary myotonia in cats associated with a new homozygous missense variant p.Ala331Pro in the muscle chloride channel ClC-1.

Three-related cats were evaluated for a history of short-strided gait and temporary recumbency after startle. Neurological examination, electromyography (EMG), muscle biopsies, and a chloride voltage-gated channel 1 (CLCN1) molecular study were performed. Clinically, all 3 cats presented myotonia with warm-up phenomenon and myotonic discharges during EMG examination. Muscle biopsies showed normal muscle architecture and variation in the diameter of myofiber size with the presence of numerous hypertrophic fibers. The molecular study revealed a missense variant (c.991G>C, p.Ala331Pro) in exon 9 of the CLCN1 gene, responsible for the first chloride channel extracellular loop. This mutation was screened in 104 control phenotypically normal unrelated cats, and all were wildtype. The alanine at this position is conserved in ClC-1 (chloride channel protein 1) in different species, and 2 mutations at this amino acid position are associated with human myotonia. This is the third CLCN1 mutation described in the literature associated with hereditary myotonia in cats and the first in domestic animals located in an extracellular muscle ClC-1 loop.

A complex CLCN1 variant associated with hereditary myotonia in a mixed-breed dog.

Hereditary myotonia (HM) is characterized by delayed muscle relaxation after contraction as a result of a mutation in the CLCN1 gene. We describe here a complex CLCN1 variant in a mixed-breed dog with clinical and electromyographic signs of HM. Blood samples from the myotonic dog, as well as from his male littermate and parents, were analyzed via amplification of the 23 exons encoding CLCN1. After sequencing the CLCN1 gene, a complex variant was found in exon 6 c.[705T>G; 708del; 712_732del], resulting in a premature stop codon in exon 7 and a protein that was 717 amino acids shorter than the normal CLC protein. The myotonic dog was identified as homozygous recessive for the complex CLCN1 variant; its parents were heterozygous, and its male littermate was homozygous wild-type. Knowledge of the CLCN1 mutations responsible for the development of hereditary myotonia allows greater clarification of this condition.

Sequential Cerebrospinal Fluid Sampling in Horses: Comparison of Sampling Times and Two Different Collection Sites.

Analysis of the cerebrospinal fluid (CSF) is important as a complementary test in horses with neurologic diseases, and sequential analysis may provide information about the treatment response or evolution and quantitative measures of the CSF drug concentration during treatment. The aim of this study was to compare erythrocyte and nucleated cell counts and protein concentration in multiple CSF samples obtained sequentially from two different puncture sites in clinically healthy horses. Eight and 12 horses, with no evidence of neurologic disease, were subjected to CSF collection from the atlanto-occipital (AO) and C1-C2 spaces, respectively. Cytologic and chemical analyses were performed on the CSF obtained at five sampling times (T1, T2, T3, T4, and T5). Repeated measures models were used to compare the mean erythrocyte count, nucleated cell count, and total protein concentration between the AO and C1-C2 groups at each sampling time. C1-C2 CSF had a significantly higher total protein concentration at T1 and T4 than that of AO CSF. All total protein concentration values remained within the reference interval (<90 mg/dL) for all sampling times and groups. No statistical difference was present between results at T2, T3, T4, and T5 and at T1 in both groups for all analyses. In conclusion, five consecutive AO or C1-C2 CSF collections with at least a 7-d interval did not result in alterations in the CSF erythrocyte and nucleated cell counts and total protein concentrations and did not interfere with the CSF analysis results.

Production of Cytotoxic Antibodies After Intra-Articular Injection of Allogeneic Synovial Membrane Mesenchymal Stem Cells With and Without LPS Administration.

Allogeneic mesenchymal stem cells (MSC) are widely used in clinical routine due to the shorter expansion time and reliability of its quality. However, some recipients can produce alloantibodies that recognize MSCs and activate the immune system, resulting in cell death. Although antibody production was already described after MSC injection, no previous studies described the immune response after intra-articular MSC injection in acute synovitis. This study aimed to evaluate the influence of inflammation on immune response after single and repeated intra-articular injections of synovial membrane MSC (SMMSC). Horses were divided in three groups: control group (AUTO) received autologous synovial membrane MSCs; whereas group two (ALLO) received allogeneic SMMSCs and group three (ALLO LPS) was submitted to acute experimental synovitis 8 h before SMMSCs injection. The procedure was repeated for all groups for 28 days. Physical and lameness evaluations and synovial fluid analysis were performed. Sera from all animals were obtained before and every 7 days after each injection up to 4 weeks, to perform microcytotoxicity assays incubating donor SMMSCs with recipients' sera. The first injection caused a mild and transient synovitis in all groups, becoming more evident and longer in ALLO and ALLO LPS groups after the second injection. Microcytotoxicity assays revealed significant antibody production as soon as 7 days after SMMSC injection in ALLO and ALLO LPS groups, and cytotoxicity scores of both groups showed no differences at any time point, being equally different from AUTO group. Although inflammation is capable of inducing MHC expression in MSCs, which enhances immune recognition, cytotoxicity scores were equally high in ALLO and ALLO LPS groups, making it difficult to determine the potentiation effect of inflammation on antibody production. Our findings suggest that inflammation does not display a pivotal role in immune recognition on first allogeneic MSC injection. In a translational way, since specific antibodies were produced against MSCs, patients that need more than one MSC injection may benefit from a first allogeneic injection followed by subsequent autologous injections.

Aggrecan, IL-1ß, IL-6, and TNF-α profiles in the Articular Cartilage of Miniature Horses with Chondrodysplastic Dwarfism.

Dwarfism is a skeletal disorder that causes abnormal growth. In Miniature horses, dwarfism can occur as chondrodysplastic dwarfism, an autosomal recessive disorder associated with five mutations (D1, D2, D3*, D4 and c.6465A > T variant) in the aggrecan (ACAN) gene. The aim of this study was to evaluate the expression of aggrecan (at the gene and protein level) and specific cytokines (IL-1ß, IL-6, and TNF-α) in the articular cartilage of Miniature horses with chondrodysplastic dwarfism (D4/c.6465A > T genotype). Metatarsal bone samples from eight dwarf Miniature horses were collected for histopathological analysis, and articular cartilage was collected to detect and quantify aggrecan levels through Western blotting and determine the relative expression levels of ACAN, IL-1ß, IL-6, and TNF-α through qPCR. All affected animals presented chondrodysplasia-like lesions with disorganization of the chondrocyte layers and reduced the amount of an extracellular matrix. No significant difference in aggrecan expression levels in uncleaved samples from the dwarf and control groups (composed of phenotypically normal animals of similar age and breed (P = .7143)) was found using Western blotting. qPCR revealed that ACAN gene expression was higher in the affected animals than in normal animals (P = .0119). No significant difference in cytokine levels was detected between the groups. Mutant aggrecan may interfere with normal cellular function, leading to chondrodysplasia and the observed phenotypic findings.

Description of the D4/D4 genotype in Miniature horses with dwarfism.

Four causative mutations (D1, D2, D3*, and D4) of chondrodysplastic dwarfism have been described in the equine aggrecan (ACAN) gene. Homozygotes for one of these mutations and heterozygotes for any combination of these mutations exhibit the disproportionate dwarfism phenotype. However, no case description of homozygotes for D4 (D4/D4) has been reported in the literature, to our knowledge. We report 2 Miniature horses with the genotype D4/D4 in the ACAN gene. Clinically, the 2 dwarfs had a domed head that was large compared to the rest of the body, mandibular prognathism, and short and bowed limbs, mainly in the proximal region of the metatarsal bones. Radiographic examination revealed contour irregularities of the subchondral bone in the long bones and confirmed mandibular prognathism; histopathology revealed irregular chondrocyte organization. To determine the genotypes of the horses, we performed DNA extraction from white blood cells, PCR, and Sanger sequencing. Genotyping demonstrated that these 2 animals had the D4/D4 genotype in the ACAN gene. The D4/D4 dwarfs were clinically similar to animals with the other ACAN genotypes reported for this disease. Identification of heterozygous animals makes mating selection possible and is the most important control measure to minimize economic losses and casualties.

Evaluation of a new variant in the aggrecan gene potentially associated with chondrodysplastic dwarfism in Miniature horses.

Chondrodysplastic dwarfism in Miniature horses is an autosomal recessive disorder previously associated with four mutations (D1, D2, D3*, and D4) in the aggrecan (ACAN) gene. The aim of this study was to identify additional variants in the candidate ACAN gene associated with chondrodysplastic dwarfism in Miniature horses. Fifteen dwarf Miniature horses were found to possess only one of the dwarfism-causing variants, and two possessed none of the variants. The ACAN exons (EquCab3.0) of seven dwarf Miniature horses were sequenced. A missense SNP in coding exon 11 (g.95271115A > T, c.6465A > T-RefSeq XM_005602799.2), which resulted in the amino acid substitution p.Leu2155Phe (RefSeq XP_005602856.2), was initially associated with the dwarf phenotype. The variant was tested and found present in 14 dwarf foals as well as one parent of each, and both parents of a dwarf possessing two copies. Genetic testing of 347 phenotypically normal Miniature horses demonstrated that none had more than one of the dwarf alleles or c.6465A > T. However, a study of large breeds revealed the presence of c.6465A > T, which was present in homozygosis in two Mangalarga Marchador horses. We suggest that c.6465A > T as a marker of disequilibrium or complex interactions in the Miniature horse genome could contribute to the associated dwarfism.

[A survey on working satisfaction of nurses]. / La soddisfazione lavorativa dell'infermiere di assistenza domiciliare: un indagine conoscitiva.

A descriptive survey was performed in the home care service of Azienda ULSS 16 of Padova at a sample of nurses. The aim of this study was to identify working experience aspects which represent satisfaction or dissatisfaction factors. A questionnaire was administered to the 63 nurses of the service, in the same day. 53 nurses (84%) declare themselves satisfied or very satisfied for the way their job stimulates the development of new capabilities, the same for freedom of choice the way of working, while 43 (68%) are satisfied or very satisfied for profession in general. 55 (87%) state to be unsatisfied or not much satisfied for the relation between wages and responsibility, and 42 (67%) for career opportunity. Working satisfaction is mainly caused by the quality of the relation with patient and his family for 45 nurses (71%); this aspect also prevails satisfaction linked to the opportunity of working in autonomy (29, 46%).

Anemia hemolítica imunomediada primária em cães - Revisão de literatura / Primary immune-mediated hemolytic anemia in dogs - Literature review / Anemia hemolítica inmunomediada primaria en perros ­ Revisión de literatura

A anemia hemolítica imunomediada (AHIM) é o distúrbio imunológico de maior prevalência em cães. Caracteriza-se como uma hipersensibilidade do tipo II, que leva a destruição prematura de hemácias. Dentre as principais complicações, o estado de hipercoagulabilidade predispondo a coagulação intravascular disseminada e tromboembolismo pulmonar é a mais importante, sendo a causa de óbito em mais de 80% dos casos. O diagnóstico é realizado a partir da exclusão de outras causas para anemia e por meio da constatação de um ou mais desses sinais: anemia moderada a grave (hematócrito <25-35%), evidências de hemólise (hemoglobinemia, hemoglobinúria ou hiperbilirrubinemia) e presença de anticorpos na hemácia (caracterizado a partir da auto-aglutinação, esferocitose, teste de Coombs positivo ou citometria de fluxo). O tratamento é direcionado à supressão da resposta imune, sendo os corticosteroides e os imunossupressores, os fármacos de predileção.(AU)

Immune-mediated hemolytic anemia (IMHA) is the most prevalent immune disorder among dogs. It is characterized as type II hypersensitivity, leading to premature destruction of red blood cells. Among the main complications, hypercoagulability predisposing to disseminated intravascular coagulation and pulmonary thromboembolism is the most important, being the cause of death in more than 80% of the cases. The diagnosis is made by excluding other causes for anemia and the presence of one or more of these signs: moderate to severe anemia (hematocrit <25-35%), evidence of hemolysis (hemoglobinemia, hemoglobinuria or hyperbilirubinemia) and presence of antibodies in the erythrocyte (characterized by self-agglutination, spherocytosis, positive Coombs test, or flow cytometry). Treatment is directed to suppression of the immune response, with corticosteroids and immunosuppressants the drugs of predilection.(AU)

La anemia hemolítica inmunomediada (AHIM) es el disturbio inmunológico con mayor prevalencia en perros. Es definido como una hipersensibilidad tipo II, que lleva a destrucción prematura de hematíes. Dentro de las principales complicaciones, el estado de hipercoagulabilidad que predispone a coagulación intravascular diseminada y tromboembolismo pulmonar es el más importante, siendo la causa de muerte en más de 80% de los casos. El diagnóstico se realiza excluyendo otras causas de anemia y confirmando una o más de las siguientes alteraciones: anemia moderada a grave (hematocrito <25-35%), evidencias de hemolisis (hemoglobinemia, hemoglobinuria o hiperbilirrubinemia) y presencia de anticuerpos en hematíes (caracterizado a partir de autoaglutinación, esferocitosis, test de Coombs positivo o citometría de flujo). El tratamiento se basa en la supresión de la respuesta inmune, siendo los cortico esteroides y los inmunosupresores los fármacos de elección.(AU)

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)

Use of PCR to estimate the prevalence of Equus caballus papillomavirus in aural plaques in horses.

Aural plaques occur on the skin of the medial surface of the pinnae of horses. In this study the presence of Equus caballus papillomavirus (EcPV)-3 and -4 DNA was assessed in 45 such plaques using a 'touchdown' PCR. Papillomaviruses (PVs) were detected in 62.3% (28/45) of samples: EcPV-3 and -4 DNA in 8.89% (4/45) and 37.78% (17/45) of samples, respectively, with 15.56% (7/45) of samples exhibiting co-infection. Viral DNA was not detected in 37.78% (17/45) of samples, suggesting the possible existence of other equine PVs. Neither EcPV-3 nor -4 were detected in negative control skin. This study is the first to evaluate the prevalence of these two viruses in equine aural plaques.

Ocorrência do SNP c.767G>T no gene DNM1responsável pelo colapso induzido pelo exercício em cães da raça Labrador Retriever no estado de São Paulo / Occurrence of DNM1 SNP c.767G>T responsible for exercise-induced collapse in Labrador Retriever in the Sao Paulo state

O colapso induzido pelo exercício (EIC) é considerado uma síndrome autossômica recessiva que afeta principalmente cães da raça Labrador Retriever. A doença é caracterizada por fraqueza muscular e colapso após exercício intenso. Usualmente, ocorre recuperação clínica após o episódio, mas alguns animais podem vir a óbito. Os sinais clínicos são decorrentes do polimorfismo de base única (SNP) c.767G>T no gene Dynamin 1 (DNM1). O objetivo deste trabalho foi determinar a ocorrência deste SNP em 321 cães da raça Labrador Retriever do Estado de São Paulo. Primers específicos para a amplificação de todo o exon 6 do gene DNM1 foram usados nas PCRs utilizando DNA a partir de amostras de sangue ou swab bucal, a avaliação final foi realizada com sequenciamento direto dos produtos da PCR. Dentre os 321 animais estudados, 3,4 % (11/321) eram homozigotos para o SNP c.767G>T no gene DNM1 e 24,6% (79/321) eram heterozigotos. Somente um dos 11 animais homozigotos apresentavam sinais clínicos compatíveis com a EIC. Este é o primeiro estudo sobre a ocorrência deste SNP no Brasil e considerando que quase 25% dos animais estudados eram heterozigotos, a genotipagem dos animais para este SNP pode ser importante antes dos acasalamentos para cães desta raça. A EIC deve ser considerada nos diagnósticos diferenciais de enfermidades neuromusculares em cães da raça Labrador Retriever.

The exercise-induced collapse (EIC) is considered an autosomal recessive syndrome that mainly affects Labrador Retriever dogs. The disease is characterized by muscle weakness and collapse after intense exercise. Recovery usually occurs after exercise but some animals may die. The clinical signs occurs due to the single-nucleotide polymorphism (SNP) c.767G>T in Dynamin 1 (DNM1) gene. The aim of this study was to evaluate the occurrence of this SNP in 321 Labrador Retriever dogs from São Paulo state. Specific primers for amplification of the entire exon 6 of the DNM1 gene were used in a PCR performed with DNA from blood or buccal swab samples, direct sequencing was performed for the final evaluation. Among 321 animals studied, 3.4% (11/321) of animals were homozygous for the DNM1 SNP (c.767G>T) and 24.6% (79/321) were heterozygous. Only one of the 11 homozygous animals in this study had previous clinical signs compatible with this disease. This is the first study that evaluated the occurrence of DNM1 SNP (c.767G>T) gene in Brazil and considering that almost 25% of the studied animals were heterozygous, the routinely evaluation of this SNP may be important before this breed mating The EIC should be include in the differential diagnosis of neuromuscular diseases in Labrador Retriever dogs.