ABSTRACT: Cattle death due to pneumonia-related mortalities (PRM) is a major problem in beef cattle feedlots worldwide. However, compared to other major beef-producing countries, Brazil lacks sufficient data on these losses, having no information to define the optimal feeding duration for cattle. This study investigated PRM at three beef cattle feedlots in the major cattle production states of Brazil over a 24-month period. PRM was the second cause of cattle mortality at these feedlots and accounted for 20.2% (142/703) of all mortalities. Nelore cattle had higher chances (OR = 1.79, p= 0.006) to develop PRM as compared with crossbreed animals, while cattle maintained in feedlots from Mato Grosso were at elevated risk (OR = 1.74, p = 0.031) to develop PRM relative to those maintained in the feedlots from Minas Gerais. Logistic regression revealed that PRM risk decreased with time on feed, confirming that PRM are more likely (p= 0.0005) to be elevated during the earlier days of cattle on-feed at these feedlots. The occurrence of PRM was not influenced by the sex (p= 0.653) of the animal affected nor seasonal variations (p = 0.653). The estimated annual cost of PRM at these feedlots was 105,027 USD, with a projected national cost of 4.040 M USD. A statistical model projected that it may be profitable to maintain cattle in these feedlots for approximately 120-130 days, after which financial investment declines. These results demonstrate the importance of PRM to the local beef cattle industry and emphasize the need to investigate other factors that may influence reduced productivity in beef cattle feedlots in Brazil.
ABSTRACT: Uruguay sustains an extensive, pasture-based beef industry with more than 11 million cattle, dominated by Hereford and Aberdeen Angus breeds. Despite their economic importance, inherited disorders are often underreported because most associated losses occur prenatally, thus escaping routine postnatal detection (iceberg effect). This review synthesizes decades (1996-2025, 30 years) of veterinary surveillance and summarizes the clinicopathological features and population impact of hereditary diseases confirmed in Uruguay through integrated pathology and molecular testing. In Hereford cattle, we describe maple syrup urine disease (OMIA 000627-9913), congenital hypotrichosis (OMIA 002114-9913), epidermolysis bullosa simplex (OMIA 002081-9913), cardiomyopathy with woolly haircoat (OMIA 000161-9913), mandibulofacial dysostosis (OMIA 002288-9913), and idiopathic epilepsy (OMIA 000344-9913). In Aberdeen Angus, we detail osteopetrosis (OMIA 000755-9913), neuropathic hydrocephalus (OMIA 000487-9913), dwarfism (OMIA 001485-9913), syndactyly (OMIA 000963-9913), and arthrogryposis multiplex congenita (OMIA 002135-9913). These disorders exert a significant negative impact on reproductive efficiency and may represent a major hidden cause of the country’s consistently low weaning rates. This study highlights the need for systematic genomic surveillance to prevent the dissemination of genetic defects and to safeguard productivity, animal welfare, and the international reputation of Uruguay’s beef herds.
ABSTRACT: Toxoplasmosis is an infectious disease caused by the obligate intracellular protozoan Toxoplasma gondii, which has a worldwide distribution and is recognized for frequently causing acute and fatal disease in neotropical primates. This study aimed to detect anti-T. gondii antibodies in Callithrix spp. from different locations in Espírito Santo, Brazil, and to describe the distribution of seroreactivity according to environmental and host-related variables. A total of 21 animals were evaluated from 2022 to 2025, both sexes and ranging in age from juveniles to adults, including individuals maintained under human care and free-ranging individuals. Seroreactivity was detected using the modified agglutination test in 23.8% (5/21) of the primates, with titers of 1:25 and 1:50. All seroreactive individuals were identified among those classified under human care at the time of sampling, while no reactivity was observed among free-ranging individuals. The distribution of seroreactivity did not suggest a clear pattern in relation to sex or age and should be interpreted with caution due to the structure of the sampled population. The detected pattern was associated with the environmental and management contexts of the municipalities of origin of the animals, with seroreactive individuals linked to areas with greater anthropogenic influence. The low antibody titers observed are consistent with previous reports involving neotropical primates; however, the exclusive use of a serological method and the high susceptibility of this group may limit the detection of infection, particularly in cases of acute disease progression. These findings provide insights into T. gondii exposure in neotropical primates from Espírito Santo and highlight the importance of integrating serological and molecular approaches in future studies to better characterize parasite circulation and epidemiological dynamics in the region.
ABSTRACT: Recent ecological disasters following the rupture of mining tailings dams in Brazil, which contaminated the nearby river basin, highlight the urgent need for a better understanding of the effects of short- and long-term exposure of fish to heavy metals. In the present study, acute lead (Pb) toxicity was assessed in zebrafish (Danio rerio) with a focus on clinical and pathological findings. Dilutions of lead acetate, in distilled water, were used in the following concentrations: 0, 0.21, 0.46, 1.02, 2.24, and 4.92 mg/L. The experiment was designed as a semi-static acute toxicity assay. For each concentration, two aquariums with six fish were used, totaling 72 fish (12 fish per group). Evaluations of clinical signs, mortality, and anatomopathological findings were performed. The clinical signs noted included hypoactivity, abnormal surface distribution, under-reactivity, abnormal bottom distribution, loss of shoaling behavior, and changes in ventilatory functions. The 96 h mortalities indices were 33.3% in the 0.46 mg/L group, 41.7% in the 1.02 mg/L group, 75% in the 2.24 mg/L group, and 91.7% in the 4.92 mg/L group. There were no deaths in the control group and in the 0.21 mg/L group. The 96 h LC50 was 1.1 mg/L Pb. No macroscopic lesions were observed, but histological lesions were noted in the gills of fish exposed to 0.46 mg/L and higher concentrations. Given the presence of autolytic changes in fish that died spontaneously during the experiment, only lesions in survivors were considered in this study. Gill lesions include hyperplasia of epithelial cells, with lamellae fusion and the formation of cavities, which were occasionally filled with cell debris (necrotic material). High levels of Pb were identified in the gills of fish from all challenged groups by inductively coupled plasma mass spectrometry (ICP-MS). Pb was toxic to zebrafish at the evaluated doses and caused mortalities that were dose-dependent. The main organ affected was the gill because of its direct contact with dissolved Pb and its role in the absorption of this metal in freshwater fish. The gills had proliferative and necrotic lesions that compromised the fish’s respiratory capacity and triggered clinical signs related to swimming behavior and to the ventilatory function. As the lesions found are nonspecific for Pb toxicity, histopathology in combination with toxicological analyses of water or fish tissues is recommended to confirm the diagnosis in spontaneous cases.
ABSTRACT: The number of free-ranging wild animals seen in routine wildlife veterinary practice has increased in recent years. One factor underlying this observation is the greater proximity between forest areas and urban areas due to the advance of urbanization. Therefore, knowledge of these animals is essential for veterinarians. The crab-eating fox (Cerdocyon thous) is a small wild canid, a species that often requires veterinary care, mainly due to accidents related to territory disputes, predation, sport hunting, and being run over. Skin lesions occur frequently in this species and require either simple or complex treatment, depending on the degree and extent of the lesion, as well as the general condition of the patient when they are rescued. Wound management includes systemic therapies, with the use of antibiotics, and local therapies, with ointments, dressings, debridement procedures, tissue grafting, or a combination of the latter, depending on the type of injury. Complementary therapies have shown excellent results in wound healing, including ozone therapy, which exerts antimicrobial activity when used topically and stimulates tissue cell proliferation and remodeling. This study seems to be the first to report the treatment of a skin lesion in a crab-eating fox cub using a mixture of ozonized sunflower oil and granulated sugar for topical treatment associated with systemic therapy, which yielded beneficial outcomes. Our findings might contribute to the field of complementary therapies for wild animals.
RESUMO: Este artigo descreve a filosofia por trás do sistema de diagnóstico das doenças dos animais de produção, desenvolvido e consolidado ao longo das últimas seis décadas e atualmente aplicado na maioria dos laboratórios de diagnóstico veterinário no Uruguai, Brasil e Argentina. A origem desse modo de operação é complexa, envolvendo diversos eventos históricos, como o período pós-guerra, mudanças de governo, ditaduras e crises econômicas, além das contribuições de instituições e pessoas. Sem dúvida, o surgimento de patologistas brilhantes entre as décadas de 1950 e 1970 foi decisivo nesse processo. Curiosamente, vários laboratórios de diagnóstico reconheceram a importância de integrar o trabalho de campo à prática laboratorial, transformando essa interação em um estilo de vida e em uma ferramenta crucial para enfrentar os desafios sanitários dos produtores. O resultado foi a criação de um sistema misto de entrada de casos, caracterizado pela investigação ativa por meio de visitas recorrentes ao campo e pela recepção passiva de amostras enviadas por veterinários de campo. Além disso, métodos de diagnóstico modernos e robustos foram aplicados, fornecendo a base para publicações científicas de impacto e teses de pós-graduação. A patologia diagnóstica integra achados morfológicos dos exames anatomopatológicos a métodos laboratoriais complementares que aumentam a precisão diagnóstica. Esse enfoque consolidou uma identidade regional capaz de resistir e superar limitações de investimento em ciência veterinária básica e aplicada, sustentada por uma visão multidisciplinar e interinstitucional. Alguns princípios fundamentais orientaram a fundação dos laboratórios de diagnóstico veterinário: 1) capital humano especializado; 2) infraestrutura, veículos, equipamentos e técnicas diagnósticas modernas; 3) financiamento de longo prazo; 4) pesquisa voltada para a solução dos problemas reais dos produtores; 5) coleta e processamento contínuos de dados epidemiológicos; 6) intercâmbio permanente de técnicas e informações entre laboratórios de diagnóstico; e 7) participação ativa de pesquisadores dos laboratórios como orientadores em programas de pós-graduação, com envolvimento de estudantes de pós-graduação nas atividades diagnósticas. Esse modo de operação desencadeou uma reação catalisadora que transformou a trajetória da saúde animal nas últimas décadas, mesmo quando os princípios 2 e 3 não foram plenamente atendidos. Adaptado às condições da América do Sul, esse modelo permitiu a construção de uma visão holística da saúde humana, animal e ambiental, fortalecendo a integração entre pesquisa, ensino, extensão, desenvolvimento científico e confiança nos serviços veterinários, tanto nos mercados internos quanto internacionais. O novo paradigma é que as futuras gerações de patologistas possam levar esse conhecimento adiante. Porque as vacas continuam no campo!
ABSTRACT: This article outlines the philosophy underlying the livestock diagnostic system that has been developed and consolidated over the past six decades and is now used in most veterinary diagnostic laboratories in Uruguay, Brazil, and Argentina. The origins of this approach are complex, having been shaped by historical circumstances such as the post-war period, political transitions, military dictatorships, economic crises, and the contributions of numerous institutions and individuals. The emergence of outstanding veterinary pathologists between the 1950s and 1970s played a decisive role in this process. Several diagnostic laboratories recognized the importance of integrating fieldwork and laboratory practice, making this interaction both a lifestyle and a crucial tool for addressing the health challenges of livestock. As a result, a mixed case-entry system was established, combining active investigation through regular field visits with the passive reception of samples submitted by field veterinarians. In parallel, modern and robust diagnostic methods were progressively incorporated, providing a strong basis for impactful scientific publications and postgraduate research. Diagnostic pathology combines morphological findings from anatomopathological examinations with laboratory methods to improve diagnostic accuracy. This systematic approach fostered the development of a regional identity capable of enduring, and often overcoming, the limitations imposed by restricted investment in basic and applied veterinary sciences. Such resilience was sustained by a multidisciplinary and interinstitutional perspective. Several fundamental principles guided the establishment of veterinary diagnostic laboratories: (1) the training and availability of specialized human resources; (2) adequate infrastructure, vehicles, equipment, and modern diagnostic techniques; (3) long-term and stable funding; (4) research oriented toward solving the real problems faced by livestock producers; (5) the continuous collection and processing of epidemiological data; (6) the constant exchange of diagnostic techniques and information among laboratories; and (7) the active participation of researchers as mentors in graduate programs, alongside the direct involvement of graduate students in diagnostic activities. Over the past decades, this approach has significantly transformed animal health in the region, even during periods when principles such as infrastructure and long-term funding were only partially fulfilled. Adapted to South American conditions, the model has enabled a holistic perspective on human, animal, and environmental health, strengthening the integration of research, teaching, extension, scientific development, and trust in veterinary services in both domestic and international markets. The emerging paradigm is that future generations of pathologists will carry this knowledge forward, because the cows are still in the field!
ABSTRACT: Wild canids in Brazil are increasingly affected by habitat fragmentation and emerging infectious diseases, some of which are zoonotic. This study aimed to investigate the pathological findings and causes of death of wild canids admitted to the Mata Ciliar Association (Jundiaí/SP) from 2021 to 2023, including 28 crab-eating foxes (Cerdocyon thous), six maned wolves (Chrysocyon brachyurus), and one hoary fox (Lycalopex vetulus). Tissue samples collected during necropsies were subjected to histopathological and molecular examination. The causes of death were road mortality (11/35, 31.4%), euthanasia (8/35, 22.9%), respiratory disorders (7/35, 20.0%), cachexia/malnutrition (4/35, 11.4%), sepsis (2/35, 5.7%), gastrointestinal disease (2/35, 5.7%), and hypovolemic shock associated with severe flea infestation (1/35, 2.8%). Notable pathological findings included granulomatous pneumonia associated with Angiostrongylus spp. (5/28, 17.85%) in crab-eating foxes, canine distemper virus infection (5/35, 14.3%), sarcoptic mange (2/35, 5.7%), renal parasitism by Dioctophyme renale in maned wolves (3/6, 50%),and an oral squamous cell carcinoma in the hoary fox. These findings highlight the importance of post mortem examinations for wildlife disease surveillance and emphasize the role of health monitoring in biodiversity conservation and the prevention of zoonotic risks.
ABSTRACT: Crustacean production is a vital aquaculture activity in Brazil and worldwide, contributing to food security for various population groups. Quickly and accurately diagnosing emerging and re-emerging diseases poses a significant challenge to shrimp production. Even though several techniques can render a definitive diagnosis, the initial step involves identifying macroscopic lesions and collecting samples for testing. Standardizing a necropsy technique for shrimp is essential. This study aims to establish a necropsy protocol that can be applied orderly and systematically. Eight adult giant river prawn (Macrobrachium rosenbergii) specimens were used: six females and two males, with an average weight of 41 g ± 15 g, an average total length of 14.38 cm ± 1.64 cm, and an age of 6 months. The animals were euthanized using eugenol (100 mg/L) and potassium chloride (100 mg/100 g of body weight) and then subjected to hemolymph collection by ventral hemolymphatic sinus puncture. The specimens were initially examined externally and subsequently sectioned into cephalothorax and abdomen, each undergoing a dorsal incision along the midline to expose anatomical structures such as the intestine, heart, gonads, stomach, hepatopancreas, and nervous tissues. Out of the eight specimens evaluated, three exhibited alterations: absence of appendages, areas of erosion and melanization, and reduced exoskeleton hardness. The technique described by the authors enabled a thorough evaluation of these animals’ main organs and can be adapted to other shrimp species, considering anatomical variations and lesion sites.
ABSTRACT: This retrospective study aimed to identify dogs with a presumptive diagnosis of paroxysmal dyskinesia (PD) and describe its phenotypical characterization, treatment, and outcome. A total of 31 dogs (45,2% females and 54,8% males) examined at two veterinary neurology services from January 2020 to April 2025 were included. The mean age at clinical onset was 52.2 months (range, 2-137 months). Nine dogs were mixed-breed (29%), eight were German Spitz (25.8%), four were Dachshunds (12.9%), two were Chihuahuas (6.4%), two were Shih Tzus (6.4%), and one each were Siberian Husky, Labrador Retriever, Pinscher, and Maltese (3.2% each). A presumptive diagnosis was established based on independent analysis of the video recordings of the episodes. Limb dystonia was present in all dogs, whereas associated dystonic head tremors were present in 61.3% of the cases. Other clinical signs included generalized tremors (38.7%), kyphosis (32.2%), and incoordination (12.9%). The mean episode duration was 6.8 minutes (range, 1-60 minutes). Triggers such as stress and/or excitement were identified in 15 dogs (48.4%). Seventeen dogs (54.8%) were treated for the episodes: 11 with antiseizure drugs (54.5% improvement) and 6 with a gluten-free diet (66.7% improvement). Fourteen dogs (45.2%) did not receive any treatment, and spontaneous remission was seen in six (42.8%). Paroxysmal dyskinesia can affect dogs of various breeds and ages with no sex predilection. The disorder manifests as a range of clinical signs, including limb dystonia, which was present in all dogs in this study. Stress and excitement were identified as the main triggers in nearly half of the cases. Both the treated and untreated dogs showed clinical improvement, highlighting the heterogeneity of PD. Further studies are needed to better understand the disease and its progression.
ABSTRACT: One of the most important pathogens of bovine mastitis, Staphylococcus aureus, often shows antibiotic resistance due to the widespread use of antibiotics in dairy herds. Here, we analyzed S. aureus isolates recovered from milk samples of mastitis-affected cows from various dairy farms for the presence of specific antibiotic resistance genes (mecA, blaZ, aacA-aphD, tetK, tetM, vanA, cfr, fusB, and ileS). To isolate and identify S. aureus, milk was inoculated onto Baird-Parker agar plates. The thermonuclease gene (nuc) was used for molecular identification of each S. aureus isolate. The chosen resistance genes were found in 14 verified isolates. The blaZ and tetM genes were found in all isolates (100%), whereas the aacA-aphD, mecA, and cfr genes were found in 42.9%, 14.3%, and 7.1% of the isolates, respectively. TetK, vanA, fusB, and ileS genes were not found in any of the isolates. Every isolate carried at least blaZ and tetM, demonstrating the widespread co-carriage of several genes. The findings show that S. aureus from bovine mastitis in this area exhibits broad genotypic resistance to β-lactams and tetracyclines, and emphasize the need for ongoing regional surveillance of resistance determinants.
ABSTRACT: The systematic collection of parasites from wild animals provides valuable information, highlighting the relationship between hosts and parasites. The study of ixodofauna in wild animals supports research on the transmission of pathogens that cause diseases in in situ and ex situ situations. Over a three-decade period, from 1994 to 2024, 2,709 ticks attached to giant anteaters (Myrmecophaga tridactyla) and southern tamanduas (Tamandua tetradactyla) were collected from the Metropolitan Region of Sorocaba, São Paulo state, Brazil. Tick collections were performed on free-ranging wild animals, which were immediately maintained under human care at the Sorocaba Zoo, and the carcasses of wild giant anteaters and southern tamanduas were sent to the Zoo and the University of Sorocaba. The ixodids were identified with the aid of taxonomic keys and deposited in two acarological collections. The tick species Amblyomma aureolatum, Amblyomma brasiliense, Amblyomma calcaratum, Amblyomma dubitatum, Amblyomma nodosum, Amblyomma sculptum, Amblyomma tigrinum, Dermacentor nitens, Rhipicephalus microplus and Amblyomma sp. larvae were collected from giant anteaters. Ticks collected from southern tamanduas included A. aureolatum, A. calcaratum, A. dubitatum, A. nodosum, A. sculptum and Amblyomma sp. larvae. Over the three decades of research, the tick species A. sculptum and A. nodosum represented 41.0% and 34.5% of the ticks collected from giant anteaters and southern tamandua, respectively. Over the period of collections, the nomenclature of ticks and the order of anteaters was modified, as were the methods of identification of ixodids, highlighting the importance of updating data on the relationships between ectoparasites and hosts.
ABSTRACT: Bovine mastitis is characterized by inflammation of the mammary gland, caused by a lack of hygiene or injury to the teat and by the presence of pathogenic microorganisms such as the bacterium Staphlococcus aureus, which can cause infections and lead to milk being discarded. This study proposes a post-dipping teat disinfection product made of Origanum vulgare essential oil, loaded with Carbopol, for topical use. In in vitro tests, the treatment for preventing mastitis inhibited the Staphylococcus aureus strain (ATCC 25923), and the material’s rheological characterization exhibited pseudoclassical thixotropy. In terms of texture characterization, the post-dipping emulgel of Origanum vulgare essential oil (EFOV) showed no significant differences compared to Iodine in hardness (in Newtons - N), compressibility (in Newton-seconds - N-s) and adhesiveness (N-s). In ex vivo studies, the EFOV was more bioadhesive than the Iodine. In the animal test, the EFOV was used for eight weeks. During its use, the animals showed no significant differences in the somatic cell count. Therefore, the treatment was able to prevent the onset of mastitis by acting as an antimicrobial film on the animal’s teat, making it an alternative for veterinary use.
ABSTRACT: With the increasing demand for protein-rich foods and the challenges associated with traditional sources, including those used in animal farming, this study investigated the effects of a 10% supplementation of black soldier fly larvae meal (BSFLM) on the adaptive immunity of mice immunized with recombinant chimeras composed of the alpha (CPA), beta (CPB), and epsilon (ETX) toxins of Clostridium perfringens. The results revealed that the inclusion of BSFLM in the diet did not compromise feed palatability, feed conversion ratio (FCR, 27.2 < 30.4), or animal weight gain (< 24.8 g). The vaccines induced a humoral immune response, and immunoglobulin levels remained unaffected by supplementation. Conversely, BSFLM significantly stimulated the transcription of mRNA for both anti-inflammatory (IL-10) and pro-inflammatory (IL-12 and IFN-γ) cytokines in stimulated splenocytes. These findings suggest that BSFLM supplementation improves vaccine-induced immune responses, especially cell-mediated ones, indicating potential for more efficient and sustainable animal production methods.
ABSTRACT: Adenoviral gizzard erosions have been affecting domestic and wild birds worldwide, highlighting the need for new diagnostic approaches. Therefore, this study aimed to identify and score gizzard lesions caused by fowl adenovirus serotype 1 (FAdV-1) in chickens of different ages from commercial farms located in two states of the South and Central-West regions of Brazil, as well as to apply the fluorescent in situ hybridization (FISH) technique as a diagnostic tool. A total of 56 samples were collected from broilers aged between 1 and 45 days, showing poor performance and suspected gizzard erosion or ulceration. Samples were analyzed macroscopically and histologically, and the presence of the agent was confirmed by polymerase chain reaction (PCR) and FISH techniques. Macroscopically, only 5.35% of the gizzards presented lesions, classified as grades 1 and 2, corresponding to Group 1 (66.67%) and Group 2 (33.33%), respectively. The lesions were focal to multifocal, whitish, and resembled the detachment of the koilin membrane, measuring approximately 0.4 cm in diameter. Histologically, 92.85% of the analyzed samples showed alterations: 9.61% presented only koilin membrane rarefaction (grade 1), 50% exhibited lymphocytic and granulocytic ventriculitis with fragmentation or erosion of the koilin layer (grade 2), and 40.38% showed fibrosis associated with ventriculitis and erosion of the koilin layer. Intranuclear inclusion bodies were also observed in 26.78% of the samples. Positive signals for FAdV-1 were detected in 57.14% and 30.35% of the samples analyzed by FISH and PCR, respectively. Broilers aged one to two weeks exhibited acute lesions, while those aged three weeks or older presented chronic lesions. The chronicity of the lesions, associated with lower viral load in the tissues of broilers older than three weeks, negatively influenced the PCR results. In conclusion, different degrees of gizzard erosion were identified in chickens of various ages in Brazil. The FISH technique can be used as a diagnostic method for the detection of FAdV-1 in gizzard tissues.
ABSTRACT: Brazil stands out as one of the leading pork exporters, driven by advances in pig farming and the adoption of strict sanitary standards. However, non-compliance with these regulations still significantly contributes to the occurrence of infectious and non-infectious diseases, which are among the main causes of pig mortality and carcass condemnation at slaughter. Identifying recurring issues in slaughterhouses can help develop better regulations and improve pig farming production. The present study identifies and describes the main diseases, injuries, and etiologies found in samples of slaughtered pigs submitted for analysis at the Veterinary Pathology Sector of the Federal University of Rio Grande do Sul (SPV-UFRGS) over the 21 years studied. For this, 1,206 samples from Brazil were analyzed, obtained through a retrospective and prospective study, with greater representation from the South region. Among these samples, 1,100 received a conclusive diagnosis (91.2%). Of the diagnosed diseases, 77.5% were of infectious origin, with a focus on respiratory diseases, lymphadenitis caused by Mycobacterium sp., and infections associated with swine circovirus, which together accounted for nearly 80% of the cases. Non-infectious lesions accounted for 22.5% of diagnoses and were classified as neoplastic and non-neoplastic. In the non-neoplastic group, integumentary changes were the most frequent, with umbilical hernias being the main manifestation. On the other hand, in the neoplastic group, lymphoma was the most frequent, with 35.5% of the samples having more than one organ affected in the same animal. Thus, this study aims to demonstrate the importance of continuous surveillance and adherence to sanitary guidelines to enhance swine farming further.
Godinho DAO, Lima PPABM, Paulino PG, Silva NM, Pimenta RL, Machado LS, Santos HA. Genotyping of the infectious bursal disease virus (IBDV) based on the hypervariable region of the vp2 gene in broiler chickens from the State of Rio de Janeiro, Brazil. Pesquisa Veterin & aacute;ria Brasileira 46:e07709, 2026. Departamento de Epidemiologia e Sa & uacute;de P & uacute;blica, Instituto de Veterin & aacute;ria, Universidade Federal Rural do Rio de Janeiro, Rodovia BR-465 Km 07, Seropedica, RJ 23890-000, Brazil. E-mail: huarrisson@yahoo.com.br Infectious bursal disease virus (IBDV) causes immunosuppression in broilers by affecting the bursa of Fabricius. IBDV strains were classified into seven genogroups based on the amino acid composition of the hypervariable region of the VP2 capsid protein. This study aimed to detect and genotype IBDV strains in bursal samples from broilers in Rio de Janeiro and evaluate the genetic variability of the vp2 gene. Sixty-five bursal tissue samples from broilers suspected to have IBD were collected from four farms in Rio de Janeiro and stored in RNAlater. RNA was extracted using TRIzol reagent, and genotyping was performed using RT-qPCR. The VP2 hypervariable region was amplified using conventional PCR, purified, and sequenced. Phylogenetic analysis was conducted using the maximum likelihood method with the Kimura 2-parameter substitution model. IBDV was detected in 75.38% (49/65) of the samples, with 8.16% (4/49) classified as very virulent (vvIBDV) and 91.84% (45/49) as non-vvIBDV strains. This study seems to be the first report of G-3 infection in the state of Rio de Janeiro. Sequence comparison identified multiple missense mutations, including 20 in genogroup 4 and eight in genogroup 3, relative to the reference strain Edgar-USA. The genetic distances among the isolates suggest potential viral evolution and adaptation. These findings highlight the genetic diversity of IBDV in this region and reinforce the importance of continuous molecular surveillance of the virus. The detection of vvIBDV in a previously unreported area underscores the need for monitoring strategies to mitigate the impact of emerging strains on poultry production. Further studies focusing on antigenic variation and vaccine efficacy are essential to ensure effective control of IBDV.
We investigated the microbiological etiology of umbilical infections in clinically scored lambs. A total of 128 lambs showing signs of umbilical infection and 41 showing no umbilical signs were sampled. All microorganisms were identified by mass spectrometry (MALDI-TOF MS), and the in vitro antimicrobial susceptibility/resistance patterns of bacteria were assessed. Among the diseased animals and those without umbilical signs, 214 and 116 species of microorganisms (bacteria and yeasts) were identified, respectively. Escherichia coli (11.21%) was the most prevalent microorganism and showed a significant association (p = 0.0039) with moderate (score 2) and severe (score 3) scores for umbilical infection. In lambs without clinical signs of umbilical infection, a predominance of Desemzia incerta was observed. Diseased lambs that exhibited clinical complications showed a high mortality rate (58%). Additionally, a significant association (p < 0.001) was observed between moderate and severe scores and poor prognosis. Bacterial multidrug resistance was observed in 20% (36/182) of isolates. To our knowledge, some bacteria were identified for the first time as primary agents of umbilical infections in lambs, and clinical scoring was applied for the first time in newborn lambs with omphalopathies. Our findings reveal a high complexity of microorganisms in umbilical infections in lambs, identified by mass spectrometry, with a predominance of E. coli in cases of moderate to severe severity scores, and an association between clinical complications and high mortality.
Bovine respiratory disease is a multifactorial syndrome of complex etiology, involving interactions among bacterial and viral agents, and has a significant impact on the cattle industry worldwide. This study aimed to identify agents associated with respiratory infections in dairy herds in S & atilde;o Paulo (SP) and Rio Grande do Sul (RS) states. Nasal swabs obtained from animals with and without nasal/respiratory signs in 10 herds in SP (n = 178) and nine herds in RS (n = 273) were submitted to nucleic acid extraction and to endpoint multiplex reverse transcription polymerase chain reaction (RT-PCR)/PCR assays for bacterial and viral agents. The bacterial multiplex PCR covers four bacteria (Histophilus somni, Mannheimia haemolytica, Mycoplasma bovis and Pasteurella multocida); the viral multiplex encompasses seven viruses (bovine herpesvirus 1-BoAHV-1; bovine viral diarrhea virus 1 and 2-BVDV-1, BVDV-2; HoBilike pestivirus-HoBiPeV; bovine respiratory syncytial virus-BRSV; bovine parainfluenza 3 virus-BPIV-3 and bovine coronavirus-BCoV). The overall frequency of positive samples was 23.7% (107/451) and the most frequently detected agents were H. somni (30.8%, 33/107) and M. bovis (21.5%, 23/107), followed by BCoV (19.6%, 21/107), BPIV-3 (13.1%, 14/107), M. haemolytica (11.2%, 12/107) and BRSV (9.3%, 10/107). Mixed infections were detected in 13.1% samples (14/107), especially involving bacteria of the Pasteurellaceae family, but also BCoV and BRSV. Considering herd prevalence, H. somni was detected in 57.9% herds (11/19), M. bovis in 52.6% (10/19), M. haemolytica in 42.1% (8/19), BPIV-3 in 36.8% (7/19), BCoV in 26.3% (5/19), BoAHV-1 and BRSV in 21% (4/19), P. multocida in 15.8% (3/19) and BVDV in 5.3% (1/19) herds. Overall, these results offer an overview of the main viral and bacterial agents associated with respiratory infection in dairy herds in the studied regions (SP and RS). In addition, the complex etiology of respiratory disease in cattle highlights the importance of employing multi-etiological diagnostic approaches for comprehensive and accurate investigation.
