Background: Salmonellosis is an important cause of diarrhea in horses with zoonotic implications. Diagnosis depends on the isolation of the agent through serial cultures or molecular techniques. The aim of this retrospective study was to describe the clinical, laboratory, and microbiological aspects of salmonellosis in horses presenting diarrhea referred to a veterinary teaching hospital. Materials, Methods & Results: Horses presenting signs of diarrhea treated between January 2009 and December 2019, from which Salmonella spp. were isolated from feces, were included in this study. Epidemiological data, clinical and laboratory findings (hematology, serum biochemistry, and blood gas analysis), and in vitro antimicrobial resistance profiles were analyzed. During this period, 78 of the admitted horses presented diarrhea, and Salmonella spp. were isolated from 28% (22/78) of them. Among these patients, 41% (9/22) were younger than 3 months, 27% (6/22) were between 6 and 12 months, 14% (3/22) were between 2 and 7 years, and 18% (4/22) were older than 9 years. Clinical signs included tachycardia, tachypnea, mucous membrane congestion and liquid feces. Clinicopathological tests revealed hyperfibrinogenemia, increased serum gamma-glutamyl transferase serum activity and metabolic acidosis. In addition to feces, Salmonella spp. were isolated from 10% (2/22) and 5% (1/22) of lung and intestinal tissues and blood, respectively, from horses that did not survive. The isolates were resistant to sulfamethoxazole/trimethoprim (4/20; 20%) and gentamicin (3/20; 15%), along with partially resistant strains (5/20; 25%) and strains resistant (2/20; 10%) to ceftiofur. The mortality rate in the study population was 59%. Discussion: The study highlights the severe impact of equine salmonellosis, particularly in cases complicated by septic shock, which contributed to a high mortality rate and limited the assessment of hospitalization duration and prognosis. The confirmed etiology of diarrhea was based on the isolation of Salmonella spp. through fecal, tissue, and blood cultures, with systemic dissemination evident in some cases. Serial fecal culture remains the diagnostic gold standard, although a single positive sample can suffice in horses with gastrointestinal symptoms. The antimicrobial resistance profile revealed significant resistance to sulfamethoxazole/trimethoprim, gentamicin, and ceftiofur. Notably, some isolates were partially sensitive (25%) or resistant (10%) to ceftiofur, reflecting concerns about the future efficacy of cephalosporins due to their widespread use in veterinary medicine. However, the absence of multidrug-resistant strains in this study contrasts with findings from other species and age groups, suggesting that antimicrobial use practices and regulatory differences may influence resistance patterns. Necropsy findings were consistent with equine salmonellosis and bacterial enterocolitis, indicating loss of intestinal barrier integrity, bacterial dissemination, and sepsis development. These findings underline the importance of early diagnosis, effective antimicrobial stewardship, and a better understanding of resistance mechanisms to improve outcomes in equine salmonellosis cases. This study confirms that salmonellosis is a prevalent cause of enterocolitis in horses and is responsible for a high mortality rate. We emphasize the importance of evaluating the antimicrobial susceptibility profile in all cases.

Infections with epidemic polymerase chain reaction ribotype (RT) 027 strains are characterized by higher mortality and morbidity and have caused outbreaks in North America and Europe. To date, RT027 isolates have not conclusively been shown in Brazil, although other clade 2 isolates have been identified. This case report discusses a 60-year-old patient, with medical history of colon adenocarcinoma, who developed a severe Clostridioides difficile infection (CDI) after chemotherapy, but showed a full recovery. The infection was caused by a C. difficile RT027 strain, demonstrating conclusively for the first time that this RT is present in Brazil. This case emphasizes the need for early CDI diagnosis of C. difficile in Brazilian hospitals for prompt treatment and notification.

BACKGROUND:Equine aural plaques are a benign form of auricular papillomatosis caused by equine papillomavirus. Despite the efficacy of 5% imiquimod cream, a marked local reaction is frequently observed during therapy, often requiring sedation before application. HYPOTHESIS/OBJECTIVES:The aim of this study was to evaluate the efficacy and potential adverse effects of 0.5% topical tretinoin in the treatment of equine aural plaques. We hypothesised that tretinoin would be effective, with fewer adverse effects compared to imiquimod. ANIMALS:The study included 10 horses of both sexes, aged between 7 months and 15 years, diagnosed with unilateral or bilateral aural plaques (totalling 17 ears). MATERIALS AND METHODS:This was a controlled clinical trial. Three horses underwent a pilot study, in which only one ear per animal was treated to allow for intra-animal comparison, while the remaining seven horses received treatment in both ears. Lesions were classified into three groups based on the percentage of the inner auricular surface affected. Treatment was performed with 0.5% topical tretinoin once daily until lesion stabilisation or resolution. Lesion characteristics, treatment response, adverse effects and recurrence were evaluated. RESULTS:Sixty-five percent of the ears exhibited an improvement of > 50% following treatment. On average, maximal lesion resolution occurred within 52.8 days (range 6-74 days). None of the horses exhibited severe sensitivity during the treatment period, allowing for ear manipulation throughout the study. CONCLUSIONS AND CLINICAL RELEVANCE:The topical application of 0.5% tretinoin cream proved to be an effective and safe treatment for equine aural plaques. Further studies with a larger sample size and long-term follow-up are recommended to optimise treatment protocols.

Abstract The objective of this work was to estimate the frequency of favorable genotypes in the gene markers CAPN1 316, CAPN1 4751, CAPN3, and CAST c.2832 in Brazilian Brahman cattle. A total of 108 DNA samples from purebred Brahman cattle were analyzed to genotype the animals for each marker through polymerase chain reaction and direct Sanger sequencing. These samples were originated from 54 bulls and 54 cows used as semen and oocyte donors, respectively. The genotype frequencies, known to be associated with meat tenderness, were 48% AA in CAST and 14% GG in CAPN3. CAST has been used in the selection of animals with a meat tenderness phenotype across various cattle breeds, including Brahman cattle from other countries. The CC genotype, which is favorable in CAPN1 316 and CAPN1 4751, was not identified in the analyzed samples. The highest prevalence of the AA genotype in CAST observed in bulls and cows used in purebred breeding programs in Brazil indicates that this marker can be used to guide mating strategies in order to increase the frequency of this genotype and enhance meat tenderness.

Coragyps atratus desempeña un papel ecológico importante ya que participa en la descomposición de cadáveres y dispersión de nutrientes al mismo tiempo que actúa como centinela de sustancias potencialmente tóxicas y de agentes infecciosos en el ambiente. Pocos estudios han aislado e identificado miembros de la microbiota gastrointestinal de este animal, y la información disponible es limitada. El objetivo de este estudio fue realizar el aislamiento bacteriano bajo condiciones aeróbicas y anaeróbicas de hisopados cloacales de individuos de C. atratus. Se capturaron y muestrearon 38 individuos de vida libre, de los cuales se recuperaron 152 cepas bacterianas. Se identificaron 25 especies de bacterias, de las cuales 32% (8/25) fueron aeróbicas y 68% (17/25) anaeróbicas. El número promedio de especies bacterianas identificadas por buitre fue de 4.0 ± 1.4. De las cepas aeróbicas, Proteus mirabilis (32/38, 84%) y Escherichia coli (21/38, 55%) fueron las especies más frecuentemente aisladas. Para las cepas anaeróbicas, Paraclostridium bifermentans (16/38, 42%) y Paeniclostridium sordellii (15/38, 39%) fueron las especies más frecuentes. Se detectó un alto número de especies de Clostridia (81/152, 53%), incluyendo Clostridium perfringens, P. sordellii, C. tertium y C. paraputrificum, los cuales son agentes causales de diversas enfermedades en animales. Este estudio contribuye a la identificación de la microbiota bacteriana cloacal de C. atratus de vida libre. [Traducción de Luis Arroyo]

Diarrhea is a significant cause of morbidity and mortality in foals. Our hypothesis is that foals with diarrhea have a greater prevalence of ≥2 organisms causing coinfections. We investigated the major microorganisms associated with diarrhea in 200 foals up to 1-y-old (100 diarrheic and 100 non-diarrheic). Fecal samples were analyzed by real-time PCR (rtPCR) for the detection of Clostridioides difficile and toxin genes tcdA and tcdB, Clostridium perfringens (genotyping for toxin-encoding genes), Salmonella spp., Rhodococcus equi, Lawsonia intracellularis, Neorickettsia risticii, Enterococcus durans, Giardia duodenalis, and Cryptosporidium spp. Rotavirus A and coronavirus were detected using reverse-transcription rtPCR. Fecal bacterial culture was also performed for Clostridioides difficile and Clostridium perfringens, and isolates were submitted for the detection of toxin-encoding genes (conventional multiplex PCR). At least one enteric agent was detected by rtPCR in 85% and 70% of diarrheic and non-diarrheic foals, respectively. Co-detection was significantly more frequent in the diarrheic group (27 singly detected organisms vs. 58 co-detected organisms) than in the non-diarrheic group (37 singly detected organisms vs. 33 co-detected organisms; p = 0.008). Salmonella spp., C. difficile (and toxigenic C. difficile), and Cryptosporidium spp. were significantly associated with foal diarrhea. Our detection of multiple agents in diarrheic foals highlights the diagnostic complexity and potential interactions among agents in the multifactorial etiology of foal diarrhea.

Bacterial infection of the equine central nervous system is rare. This report describes the clinical features, computed tomography (CT) findings, and postmortem results of a 3-month-old female Quarter Horse with an intracranial abscess. Clinical signs included seizures, depression, and bilateral blindness. CT imaging demonstrated a large space-occupying lesion in the left cerebral hemisphere, associated with a frontal bone fracture. Necropsy and histopathology confirmed the presence of an abscess secondary to head trauma. Bacterial culture identified Streptococcus equi subsp. zooepidemicus as the causative agent. Brain abscess should be considered a differential diagnosis in foals presenting with seizures and other acute neurological abnormalities.

ABSTRACT: Clostridioides difficile is an important enteropathogen in humans and multiple animal species. This study determined the fecal occurrence of C. difficile in hospitalized or healthy equids and ruminants at a veterinary teaching hospital. A total of 84 fecal samples from ruminants and equids and ten environmental swabs were collected. The samples were cultured under anaerobic conditions to isolate C. difficile. DNA was extracted from C. difficile colonies and subjected to multiplex PCR to identify toxin-coding genes. The isolates were ribotyped, with the toxigenic isolates and one selected non-toxigenic isolate submitted for whole-genome sequencing. C. difficile was isolated from 10/84 (12%) of the fecal samples, of which one bovine isolate was toxigenic (A+B+ CDT -), classified as RT 046/ST35/clade 1, and carried five antimicrobial resistance genes (ermB, tetA, tetB, tetM, and inuP). Although, the occurrence of toxigenic strains was low, the study identified isolates kept in the hospital environment, highlighting the need for preventive measures, especially due to the presence of numerous animals undergoing antimicrobial therapy.

Chlorfenapyr is a pesticide that interferes with mitochondrial function, leading to cell death and mortality. Although poisoning is primarily documented in humans and dogs, it can result in severe clinical signs, including sweating, respiratory distress, and neurological dysfunction. This report describes the clinical and laboratory findings of a horse with suspected accidental intoxication with chlorfenapyr. A 4-year-old Quarter Horse mare was referred to the veterinary hospital with signs of excessive sweating, hyperthermia, tachypnea, muscle fasciculation, and fearful facial expression. The clinical signs appeared a day after the paddock where the horse grazed was sprayed with chlorfenapyr for caterpillar control. Despite initial abnormalities in renal and liver profiles in the serum biochemistry analysis, the horse responded positively to supportive treatment with intravenous fluid therapy, sodium dipyrone (25mg/kg QID), and cold-water showers, showing improvement in clinical parameters, and was discharged without further complications.

Salmonella spp. are important pathogens of foals, causing clinical enterocolitis and sepsis. We characterized the resistance, virulence, and stress response genes in Salmonella isolates from foals with or without diarrhea. Salmonella isolates ( n = 23) recovered from fecal samples of 16 diarrheic and 7 non-diarrheic <1-y-old foals were subjected to whole-genome sequencing. The most common serovars detected in diarrheic foals were S. enterica subsp. enterica serovars Infantis and Minnesota. Multidrug resistance was observed in 9 of 23 isolates, with 8 of the 9 from diarrheic foals. All of the isolates contained at least 2 resistance genes, with most of the genes related to the multidrug efflux pump complex. Among the 9 isolates shown to be resistant to β-lactam antimicrobials, at least one antimicrobial resistance gene (ARG) related to the inactivation of these antimicrobials was observed ( bla TEM-1 , bla CMY-2 , bla CTX-M-8 ). Among the 7 isolates resistant to the quinolone class, 3 contained ARGs ( qnrB19, qnrB6). The occurrence of multidrug-resistant isolates, particularly among foals with diarrhea, and the zoonotic potential of Salmonella species, highlight the importance of implementing biosecurity measures on the studied farms.

Traumatic reticulopericarditis is a significant complication in cattle due to foreign body ingestion, which can penetrate the reticulum and pericardial sac, leading to inflammatory fluid accumulation. Due to the importance of this disease for animal health and production, this study aimed to describe the clinical, laboratory, and postmortem findings in cattle diagnosed with traumatic reticulopericarditis. Ten cattle were included based on postmortem confirmation of the condition. When available, the collected data included gender, age, period of evolution of signs until care, clinical signs, outcome, blood profile, serum biochemistry, cavitary effusion analysis, thoracic and/or abdominal ultrasound, and postmortem findings. The disease predominantly affected pregnant females in the final trimester. The main clinical manifestations were tachycardia, muffled heart sounds, dehydration, and recumbency. The primary laboratory findings included leukocytosis with neutrophilia, increased levels of the enzymes aspartate aminotransferase (AST) and creatine kinase (CK), hyperglobulinemia, hypoalbuminemia, hyperproteinemia, and a predominance of neutrophils in the cytological analysis of cavity effusions. Ultrasound proved to be a useful tool for detecting free fluid with fibrin in the thoracic and/or abdominal cavity. In this study, all animals died, and the definitive diagnosis was confirmed through postmortem examination. The prognosis is unfavorable, underscoring the importance of preventive measures to mitigate its impact on cattle well-being and production.

BackgroundIn horses, systemic calcinosis is a rare syndrome characterised by muscle lesion associated with the mineralisation of large muscle groups or other organs, in the absence of an alternative cause for the calcification, such as toxic, enzootic or metabolic. Molecular and histopathological aspects of the disease are still poorly elucidated.ObjectivesTo describe the epidemiological, pathological and molecular aspects of systemic calcinosis in a convenience sample of six horses submitted to necropsy in the Southern and Midwestern regions of Brazil.Study designRetrospective exploratory study.MethodsPost-mortem necropsy records of six horses with a cause of death compatible with systemic calcinosis, were reviewed followed by histopathology, immunohistochemistry, microbiology and molecular investigation.ResultsThe affected horses were all Quarter Horses with a mean age of 16.8 months, and an average disease course of 15.5 days. Muscle necrosis and mononuclear infiltration were observed in all animals in association with mineral deposition variably affecting the muscle tissue and/or other organs such as heart, lung and kidney. All tested animals (5/6) showed positive PCR results for the E321G MYH1 gene variant, which encodes the heavy chain of fast-contracting skeletal muscle myosin and is associated with myopathy. Three horses demonstrated positive immunostaining for Streptococcus equi, which is a known trigger for immune responses.Main limitationsThe study was limited by the small sample size, molecular evaluation was not completed in one animal due to technical limitations, lack of pre-mortem evaluation of calcium metabolism and lack of accurate descriptions in the necropsy reports of involvement of each muscle individually.ConclusionsIn horses, systemic calcinosis syndrome causes immune-mediated muscle lesions in association with calcification of organs and tissues, varying greatly among animals. The E321G MYH1 variant was present in all horses tested for the variant and could be involved in the pathophysiology of systemic calcinosis.

The association between aural plaques, Equus caballus papillomavirus (EcPV), and the different breeds of horses and risk factors is poorly described. The objective of this study was to determine the clinical prevalence of aural plaques in Mangalarga Marchador (MM) and Quarter Horse (QH) horses in Brazil, to evaluate the association of this prevalence with some risk factors, and to detect the presence of EcPV DNA (types 1–10) in aural plaques biopsies. A total of 400 MM and 425 QH horses, were clinically evaluated. For each horse, an identification form was completed, containing information on breeding, sex, age, presence, and classification of aural plaque lesions, presence of ectoparasites, management type, ear clipping performed, and sensitivity to ear palpation. Biopsies of the lesions were taken from 30 horses and assessed for the presence of EcPV DNA using PCR. Among the MM and QH horses evaluated, 41.5

Brain abscesses in ruminants often arise from primary infection foci, leading to an unfavorable prognosis for affected animals. This highlights the need for comprehensive studies on brain abscesses across different ruminant species. We retrospectively investigated medical records of epidemiological, clinical, neuroimaging, anatomopathological, and bacteriological findings in six ruminants (three goats, two cows, and one sheep) diagnosed with brain abscesses. All animals studied were female. Apathy (50%), compulsive walking (33%), decreased facial sensitivity (33%), head pressing (33%), seizures (33%), semicomatous mental status (33%), strabismus (33%), unilateral blindness (33%), and circling (33%) represented the most common neurologic signs. Leukocytosis and neutrophilia were the main findings in the hematological evaluation. Cerebrospinal fluid (CSF) analysis revealed predominant hyperproteinorrachia and pleocytosis. In three cases, computed tomography or magnetic resonance imaging were used, enabling the identification of typical abscess lesions, which were subsequently confirmed during postmortem examination. Microbiological culture of the abscess samples and/or CSF revealed bacterial coinfections in most cases. Advanced imaging examinations, combined with CSF analysis, can aid in diagnosis, although confirmation typically relies on postmortem evaluation and isolation of the causative agent. This study contributes to clinicopathological aspects, neuroimages, and bacteriological diagnosis of brain abscesses in domestic ruminants.

Background: Congenital myotonia is a genetic neuromuscular disorder characterized by delayed relaxation of the musculature following a strong contraction. Variants in the skeletal muscle chloride channel 1 gene (CLCN1) have been linked to this disorder across several species. The CLCN1_c.1775A>C, an autosomal recessive variant, was identified as a potential causative factor for congenital myotonia in New Forest Pony. While the CLCN1_c.1775A>C variant has been studied in different breeds of horses, it remains unexplored in Brazilian Quarter Horses. Therefore, this study aimed to assess the prevalence of the CLCN1_c.1775A>C variant among Brazilian Quarter Horses across various disciplines. Materials, Methods & Results: In this study, 96 DNA samples were obtained from athletic Brazilian Quarter Horses representing various disciplines, 24 each from cutting, reining, barrel racing, and bull-cacthing ("vaquejada"). DNA viability was assessed via PCR targeting the beta-actin gene. Subsequently, a previously described set of specific primers was employed to amplify the region encompassing the CLCN1_c.1775A>C variant. The resulting purified PCR products underwent Sanger direct sequencing, and their electropherograms were analyzed. Notably, none of the horses in this cohort were found to carry the CLCN1_c.1775A>C variant. The inbreeding coefficient (F) was calculated using pedigree data sourced from the 96 Quarter Horses according to Brazilian Quarter Horse Breeders Association records encompassing 4 generations. The average F value for the entire cohort was found to be 0.2%. However, when assessed across disciplines, the average F values varied, with cutting at 0.002 (0.2%), reining at 0.003 (0.3%), barrel racing at 0.0008 (0.08%), and bull-cacthing at 0.001 (0.1%), respectively. Notably, within this cohort, 48 horses were identified as inbred, exhibiting an average F of 1.5%. Discussion: Genetic variants associated with conditions such as hyperkalemic periodic paralysis, myosin heavy chain myopathy, and polysaccharide storage myopathy type 1 have been previously documented in Quarter Horses globally, including Brazil. However, as in the present study, the CLCN1 c.1775A>C variant was also not detected in American Quarter Horses affected by muscular disorders. Although this variant has been implicated as the cause of congenital myotonia in a New Forest pony, its correlation with cases of congenital myotonia in Quarter Horses has not been established yet. Although the inbreeding coefficient and the prevalence of endogamous horses observed in this study were lower compared to findings in other studies, the presence of inbreeding and shared ancestors within Quarter Horses lineages was evident. High rates of inbreeding may disseminate undesirable genetic variants, since popular stallions may improve the athletic performance of its progenies but also may transmit alleles with pathogenic variants, as seen in other genetic disorders in horses. Differently, since it was not observed in this group of evaluated Quarter Horses nor in other previous studies, it may be that the CLCN1 c.1775A>C is a 'de novo' variant related strictly to congenital myotonia in the New Forest pony. Nevertheless, it is imperative to highlight the potential for congenital myotonia to inflict significant harm upon horses. Investigations into new cases are essential to establish both clinical and etiological diagnoses, thereby enabling the assessment of the requisite preventive measures against this disorder.

ABSTRACT: Clostridioides difficile is a strictly anaerobic, spore-forming Gram-positive bacterium associated with diarrhea, known as C. difficile infection (CDI). In domestic animals, C. difficile is considered an important pathogen mostly in pigs and horses, but there are also reports in other domestic species. In wild animals, the epidemiology of C. difficile is largely unknown, and the role of the bacterium as a cause of diarrhea is unclear. The aim of this study was to determine the prevalence of C. difficile in the feces of wild animals referred to the Center of Medicine and Research in Wild Animals (CEMPAS). Fecal samples obtained from 100 animals of 34 different species were subjected to qPCR for the detection of the C. difficile 16S rRNA gene and two major toxin genes (tcdA and tcdB) and to anaerobic bacterial isolation. A total of 63 animals (63%) were positive for C. difficile by qPCR, and 16 isolates were recovered. The opossum (Didelphis spp.) had the highest number of positive animals in both tests (from 21 samples, 19 were qPCR positive, and four isolates were recovered). Three toxigenic strains (RT 002, 004, and 014), all previously described as infecting humans and animals, were isolated in the following species: bearded dragon (Pogona vitticeps), pampas fox (Lycalopex vetulus), and marmoset (Callithrix sp.). The presence of C. difficile in the feces of wild animals highlights the importance of wildlife as potential carriers of infection for production animals or humans.

Staphylococci are well-known opportunistic pathogens associated with suppurative diseases in humans and animals. Antimicrobial resistance is an emergent threat to humans and animals worldwide. This study investigated the prevalence of methicillin-resistant Staphylococcus spp. (MRS) in hospitalized horses and contacting personnel (veterinarians and staff), and assessed possible interspecies transmission in a teaching veterinary hospital. Nasal swabs from horses (n = 131) and humans (n = 35) were collected. The microorganisms were identified by traditional biochemical tests and genotypic methods, i.e., PCR, internal transcript spacer PCR (ITS-PCR), and gene sequencing. Staphylococcal species were isolated in 18% (23/131) of the horses, of which 8% (11/131) were S. hyicus, 4 % (5/131) were S. aureus, 4% (5/131) were S. pseudintermedius, and 2% (2/131) were S. schleiferi subsp. coagulans. The mecA gene was detected in an S. pseudintermedius isolate. Staphylococcus spp. was isolated in 40% (14/35) of the human samples, all of which were S. aureus. In four samples of S. aureus, the clonal profile ST398 was identified; among them, a clonal similarity of 98.1% was observed between a horse and a contacting human. This finding supports the need for biosecurity measures to avoid the spread of multidrug-resistant staphylococci in humans and horses.

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+ + B + CDT-)- ) and RT126 (4/17 = 20.53 %, A+B+ + 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 multidrugresistant. Calves can be an important source of toxigenic C. difficile strains, including multidrug-resistant isolates from ribotypes commonly observed in humans.

Background: Canine degenerative myelopathy represents a progressive neurodegenerative disorder impacting the spinal cord. Initial clinical signs of canine degenerative myelopathy are typically observed in animals around 8 years of age. The clinical signs are characterized by general proprioceptive ataxia and spastic paresis of the pelvic limbs, with an irrepressible progression to flaccid paraplegia after 1 year of the appearance of the signs. Therefore, canine degenerative myelopathy is considered a differential diagnosis for medullary neoplasms, disc protrusion, and hip dysplasia, and since the clinical signs presented by the animals are similar in all these diseases, genetic testing plays an important role in diagnosis. In several dog breeds degenerative myelopathy was linked to the c.118G>A autosomal recessive variant in exon 2 of the superoxide dismutase 1 (SOD1) gene (SOD1:c.118G>A). In addition, the SOD1 :c.118G>A variant in more than 124 breed dogs, suggests that this variant is widely spread and fixed in the species before the breeds' origin. However, there are few studies evaluating this variant in brazilian dogs, and none of them have evaluated it in the Brazilian Golden Retriever dogs. Therefore, this study aimed to evaluate the allele frequency of the SOD1 :c.118G>A variant in Golden Retriever dogs from Brazilian kennels. Materials, Methods & Results: A total of 122 Brazilian Golden Retriever DNA samples were used in a PCR procedures with specific primers, previously described, to amplify a 779 base pairs amplicon containing the SOD1 :c.118G>A variant in this study, and a non-template control reaction was performed to check possible contamination in the PCR preparation. The genotyping of the animals was performed by direct Sanger sequencing of PCR products that amplified a fragment containing the variant. Considering the 95% confidence interval, the sample size used in the present study was slightly larger than the minimum required to assess the allele frequency of SOD1 :c.118G>A variant (122 versus 113 samples). All animals assessed in this study were clinically normal at the time of sampling and were identified as wild-type for the SOD1 :c.118G>A variant. Therefore, no alleles of the pathogenic variant (A) were found in the studied population. Discussion: Although all animals assessed in this study were classified as wild-type, this study is the 1st report in Brazil to evaluate the prevalence of this variant in Golden Retriever dogs. The poor prognosis and inexorable progression of canine degenerative myelopathy force most owners to opt for early euthanasia of affected animals. Knowledge of the disease by owners and breeders, as well as the genotyping of their animals, may prevent the spread of the variant among lineages and also assist veterinarians in differential diagnosis and management of cases of canine degenerative myelopathy. The genetics of Brazilian Golden Retriever were mainly derived from USA bloodlines. With this in mind, we may speculate that the results observed in this study may be influenced by the lower prevalence of the SOD1 :c.118G>A variant previously found in American Golden Retrievers. The results obtained in the present study, combined with previous studies that described the occurrence of this variant as rare in Golden Retrievers, lead us to speculate that this variant does not impact the Brazilian Golden Retriever dogs.

Africanized crossbred bees (Apis mellifera) originated in Brazil in 1957, and since then, the number of accidents involving humans and animals has significantly increased. Although they are considered clinical emergencies, there are few reports describing the clinical and pathological aspects of bee envenomation in horses. In this context, this report aims to describe the clinical and pathological features of bee toxicity after massive bee envenomation in three horses. The horses were referred to the veterinary hospital the day following the attack, and after clinical and laboratory examination, they presented with vascular, muscular, pulmonary, hepatic, and renal impairment. Even after the initiation of therapy immediately upon admission, the clinical condition of the two horses worsened, and they died within two days of hospitalization, with pathological analysis confirming the previously observed clinical alterations of generalized vasculopathy, liver degeneration, pulmonary edema, and renal tubular necrosis. Many cases of massive bee envenomation have been documented in both humans and animals, particularly in dogs. Understanding the mechanism of action of apitoxin, its effects on various tissues, and the ideal therapy for each patient has proven crucial for improving survival rates.