PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Peixoto P.V., Nogueira V.A., Gonzaléz A.P., Tokarnia C.H. & França T.N. 2009. Accidental and experimental salinomycin poisoning in rabbits. Pesquisa Veterinária Brasileira 29(9):695-699. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br An outbreak of salinomycin poisoning in rabbits is described. At least 27 out of 2,000 rabbits reared on a farm died after the coccidiostatic drug sulfaquinoxaline was substituted by salinomycin in the feed. An average of 26.9ppm salinomycin was detected in the ration given to the rabbits. Clinical signs included anorexia, apathy and bradykinesia, which progressed to incoordination and recumbency. Gross lesions consisted of pale areas in the skeletal muscles. The histopathological findings showed severe necrotic degenerative myopathy in association with infiltration of neutrophils and macrophages. One rabbit exhibited similar alterations in the myocardium. Mineralization was observed in the affected skeletal muscles in some cases. In order to verify if the poisoning was due to salinomycin, 20 rabbits were divided into five groups and a ration containing the drug at doses of 10, 25, 50, 75 and 100ppm was given. The administration of doses higher than 50ppm resulted in manifestation of the clinical signs seen in the outbreak of poisoning. It was concluded, that probably an error related to the mixture of salinomycin in the feed was the cause of deaths in the spontaneous outbreak of poisoning on the rabbit farm.

• Salinomycin poisoning myopathy Salinomicina miopatia

Abstract in Portuguese:

RESUMO.- Peixoto P.V., Nogueira V.A., Gonzaléz A.P., Tokarnia C.H. & França T.N. 2009. Accidental and experimental salinomycin poisoning in rabbits. [Intoxicações natural e experimental por salinomicina em coelhos.] Pesquisa Veterinária Brasileira 29(9):695-699. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: pfpeixoto@terra.com.br Relata-se, pela primeira vez, um surto de intoxicação por salinomicina em coelhos. De 2000 animais, no mínimo 27 morreram após troca do coccidiostático sulfaquinoxalina pela salinomicina. A análise de parte da ração detectou 26,9ppm de salinomicina. Os sinais clínicos observados foram anorexia, apatia e lentidão com evolução para incoordenação dos movimentos e decúbito. As lesões macroscópicas consistiram de áreas pálidas na musculatura esquelética. O exame histopatológico evidenciou miopatia degenerativo-necrótica. Adicionalmente, verificou-se reação inflamatória constituída por neutrófilos e macrófagos. Um coelho apresentou lesões similares no miocárdio. Em alguns casos, mineralização estava presente nos músculos esqueléticos afetados. Vinte coelhos experimentais foram divididos em 5 grupos que receberam 10, 25, 50, 75 e 100ppm de salinomicina por via oral, com a finalidade de reproduzir a intoxicação. Os animais que receberam a partir de 50ppm de salinomicina apresentaram sinais clínicos semelhantes aos observados no surto espontâneo. Nossos resultados indicam que, provavelmente, erro na mistura da substância à ração causou a morte dos coelhos.

Abstract in English:

ABSTRACT.- Coelho S.M.O., Reinoso E., Pereira I.A., Soares L.C., Demo M., Bogni C & Souza M.M.S. 2009. Virulence factors and antimicrobial resistance in Staphylo-coccus aureus isolated from bovine mastitis in Rio de Janeiro. Pesquisa Veterinária Brasileira 29(5):369-374. Departamento de Microbiologia e Imunologia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br The study was conducted to characterize pheno-genotypically the virulence factors and resistance pattern of Staphylococcus aureus isolates from milk samples of cows with subclinical mastitis. All hemolytic isolates presented beta-hemolysin, and 38% of the non-hemolytic isolates were able to express hemolysins in the presence of a beta-hemolytic strain. The amplification of the coa-gene displayed four different size polymorphisms with about 400 bp, 600 bp, 700 bp and 900 bp. The spaA gene that encodes the IgG-binding region of protein A revealed sizes of 700 bp and 900 bp. The amplification of region X from spaA yielded a single amplicon for each isolate with the prevalent amplicon size being of 180 bp. Amplification of sae gene yielded an amplicon size of 920 bp in 71% of the isolates. Antibiotic resistance pattern revealed that 42% S. aureus were susceptible to all antimicrobials tested. Seven different antibiotic patterns were observed. Our results indicated that 47% and 25% of S. aureus strains exhibited resistance to penicillin and oxacillin respectively. All oxacillin-resistant isolates were mecA-positive.

• Staphylococcus aureus antimicrobial resistance virulence factors resistência antimicrobiana fatores de virulência

Abstract in Portuguese:

ABSTRACT.- Coelho S.M.O., Reinoso E., Pereira I.A., Soares L.C., Demo M., Bogni C & Souza M.M.S. 2009. Virulence factors and antimicrobial resistance in Staphylo-coccus aureus isolated from bovine mastitis in Rio de Janeiro. Pesquisa Veterinária Brasileira 29(5):369-374. Departamento de Microbiologia e Imunologia Veterinária, Instituto de Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br The study was conducted to characterize pheno-genotypically the virulence factors and resistance pattern of Staphylococcus aureus isolates from milk samples of cows with subclinical mastitis. All hemolytic isolates presented beta-hemolysin, and 38% of the non-hemolytic isolates were able to express hemolysins in the presence of a beta-hemolytic strain. The amplification of the coa-gene displayed four different size polymorphisms with about 400 bp, 600 bp, 700 bp and 900 bp. The spaA gene that encodes the IgG-binding region of protein A revealed sizes of 700 bp and 900 bp. The amplification of region X from spaA yielded a single amplicon for each isolate with the prevalent amplicon size being of 180 bp. Amplification of sae gene yielded an amplicon size of 920 bp in 71% of the isolates. Antibiotic resistance pattern revealed that 42% S. aureus were susceptible to all antimicrobials tested. Seven different antibiotic patterns were observed. Our results indicated that 47% and 25% of S. aureus strains exhibited resistance to penicillin and oxacillin respectively. All oxacillin-resistant isolates were mecA-positive.

Abstract in English:

ABSTRACT.- Coelho A.C., Pinto M.L., Coelho A.M. & Rodrigues J. 2009. [Comparison of two techniques of isolation of Mycobacterium avium subsp. paratuberculosis in faecal samples of ovine with clinical suspicion of paratuberculosis.] Comparação de duas técnicas de isolamento de Mycobacterium avium subsp. paratuberculosis em amostras de fezes de ovinos com suspeita clínica de paratuberculose. Pesquisa Veterinária Brasileira 29(5):415-420. Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal. E-mail: accoelho@utad.pt Paratuberculosis is a chronic enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis. Culture of bacteria from faeces and tissues samples constitutes one of the most effective methods of confirming the diagnosis of para-tuberculosis and the only method available to obtain strains of mycobacteria. However, this method is less sensitive and requires months of incubation before colony growth occurs. In this study, culture method was used on sheep faeces to diagnose paratuber-culosis in animals with compatible signs of the disease. A comparison of two culture media used to isolation was also investigated. Culture was positive in 2.0% of faecal samples. Isolation was obtained using Löwenstein Jensen® with mycobactin® J, and the Middlebrook® 7H11 with OADC®. The Löwenstein Jensen® with mycobactin® J was that provided highest amount of isolations. The percentages of isolation in each culture media were 2.0% (6/300) to Löwenstein Jensen® with micobactina J, and 1.0% (3/300) to Middlebrook® 7H11/OADC. The three positive samples in Middlebrook® 7H11/OADC were also positive in Löwenstein Jensen® with micobactina J. In the Middlebrook® 7H11/OADC alone there was no sample growth. The results of this study suggest that culture media of Löwenstein-Jensen® with micobactina® J is more effective for the isolation of sheep strains in Portugal.

• Paratuberculosis Mycobacterium avium subsp. paratuberculosis paratuberculose

Abstract in Portuguese:

ABSTRACT.- Coelho A.C., Pinto M.L., Coelho A.M. & Rodrigues J. 2009. [Comparison of two techniques of isolation of Mycobacterium avium subsp. paratuberculosis in faecal samples of ovine with clinical suspicion of paratuberculosis.] Comparação de duas técnicas de isolamento de Mycobacterium avium subsp. paratuberculosis em amostras de fezes de ovinos com suspeita clínica de paratuberculose. Pesquisa Veterinária Brasileira 29(5):415-420. Departamento de Ciências Veterinárias, Universidade de Trás-os-Montes e Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal. E-mail: accoelho@utad.pt Paratuberculosis is a chronic enteric disease of ruminants caused by Mycobacterium avium subsp. paratuberculosis. Culture of bacteria from faeces and tissues samples constitutes one of the most effective methods of confirming the diagnosis of para-tuberculosis and the only method available to obtain strains of mycobacteria. However, this method is less sensitive and requires months of incubation before colony growth occurs. In this study, culture method was used on sheep faeces to diagnose paratuber-culosis in animals with compatible signs of the disease. A comparison of two culture media used to isolation was also investigated. Culture was positive in 2.0% of faecal samples. Isolation was obtained using Löwenstein Jensen® with mycobactin® J, and the Middlebrook® 7H11 with OADC®. The Löwenstein Jensen® with mycobactin® J was that provided highest amount of isolations. The percentages of isolation in each culture media were 2.0% (6/300) to Löwenstein Jensen® with micobactina J, and 1.0% (3/300) to Middlebrook® 7H11/OADC. The three positive samples in Middlebrook® 7H11/OADC were also positive in Löwenstein Jensen® with micobactina J. In the Middlebrook® 7H11/OADC alone there was no sample growth. The results of this study suggest that culture media of Löwenstein-Jensen® with micobactina® J is more effective for the isolation of sheep strains in Portugal.

Abstract in English:

ABSTRACT.- Sampaio R.S., Lacerda M.S., Oliveira P.C.L., Paneto J.C.C., Bittar E.R., Borges G.A., Camacho G.M.M. & Braga E.M. 2009. [Variation of the resistance force to the micro-traction of fragments of cortical bones preserved in several means and fresh: Experimental study in rabbits.] Variação da força de resistência à micro-tração de fragmentos de ossos corticais preservados e a fresco: estudo experimental em coelhos. Pesquisa Veterinária Brasileira 29(4):345-352. Instituto de Estudos Avançados em Veterinária “José Caetano Borges”, Universidade de Uberaba, Av. Afrânio Azevedo 2140, Bairro Olinda, Uberaba, MG 38020-450, Brazil. E-mail: relisampa@terra.com.br Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58% of the present power in the fresh bone, and by 180 days, 1.76%. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31% of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72% of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

• Bone graft bone preservation bone resistance bone micro-traction rabbits

Abstract in Portuguese:

ABSTRACT.- Sampaio R.S., Lacerda M.S., Oliveira P.C.L., Paneto J.C.C., Bittar E.R., Borges G.A., Camacho G.M.M. & Braga E.M. 2009. [Variation of the resistance force to the micro-traction of fragments of cortical bones preserved in several means and fresh: Experimental study in rabbits.] Variação da força de resistência à micro-tração de fragmentos de ossos corticais preservados e a fresco: estudo experimental em coelhos. Pesquisa Veterinária Brasileira 29(4):345-352. Instituto de Estudos Avançados em Veterinária “José Caetano Borges”, Universidade de Uberaba, Av. Afrânio Azevedo 2140, Bairro Olinda, Uberaba, MG 38020-450, Brazil. E-mail: relisampa@terra.com.br Due to the increasing use of cortical bone allografts in orthopedic surgeries, de knowledge of its biomechanics characteristics during preservation time is needed. The present study consisted in the analyses of the resistance power to the micro-traction of samples of rabbit cortical bones preserved in several means for up to 180 days and fresh. The results showed that the resistance and the preservation time presented an inversely proportional relation, meaning that, the longer the time of preservation, the shorter the physical resistance evaluated in the biomechanical rehearsal of resistance to the micro-traction. The glycerin has presented lower values in relation to the resistance test, showing, after 30 days, only 24.58% of the present power in the fresh bone, and by 180 days, 1.76%. The samples submitted to autoclavation also showed low values by the end of the experiment, while they remained with just 12.31% of the power present in the fresh bone. The bones preserved in homologous plasma, Dakin liquid and the ones cryopreserved showed the best levels of resistance at the end of the experiment, remaining, respectively with 82.47, 70.34 and 66.72% of the maximum power, while compared with the resistance of the fresh bones. The conclusion is that the choice of methodology and time of preservation interfered directly in the biomechanics of the cortical bones, promoting decrease of the resistance capacity to the traction along the period of preservation.

Abstract in English:

ABSTRACT.- Rezende R.S., Coelho H.E, Kamimura R., Severino R.S, Oliveira, P.C.L., Medeiros A.A. & Magalhães A.O.C. 2009. [Microscopic analysis of the left ventricular myocardium in positive serum dogs to distemper disease.] Análise microscópica do miocárdio ventricular esquerdo em cães soropositivos para cinomose. Pesquisa Veterinária Brasileira 29(2):117-119. Instituto de Estudos Avançados em Veterinária José Caetano Borges, Universidade de Uberaba, Av. do Tutunas 720, Uberaba, MG 38061-500, Brazil. E-mail: rezendehvu@hotmail.com Classified pertaining to the genus Morbillivirus of the Paramyxoviridae family, the canine distemper virus is a RNA single-stranded virus with negative polarity and causes a multisystemic disease, serious and highly contagious for dogs and wild carnivores, with a high mortality rate in non-vaccinated animals or with vaccine fails. With the objective to evaluate heart histopathological alterations, particularly in the left ventricular myocardium, in dogs naturally infected with canine distemper virus, 35 dogs, males and females of different ages, were studied. All the 35 samples sent to the Veterinary Hospital of Uberaba were serum-positive for distemper (immunoassay technique in solid phase) and had in the left ventricular myocardium the following histopathologic alterations: myocarditis, hyalin degeneration, hyperemia and hemorrhage, in 42.8% (15/35), 31.4% (11/35), 14.3% (5/35) and 11.4% (4/35), respectively. Having carried out the Qui-Quadrado test with a significancy level of 0.05, it can be concluded that there is a high correlation (p=0.02) between the infected animals with canine distemper virus and histopathological alterations found in the left ventricular myocardium.

• Distemper myocarditis immunoassay dog

Abstract in Portuguese:

ABSTRACT.- Rezende R.S., Coelho H.E, Kamimura R., Severino R.S, Oliveira, P.C.L., Medeiros A.A. & Magalhães A.O.C. 2009. [Microscopic analysis of the left ventricular myocardium in positive serum dogs to distemper disease.] Análise microscópica do miocárdio ventricular esquerdo em cães soropositivos para cinomose. Pesquisa Veterinária Brasileira 29(2):117-119. Instituto de Estudos Avançados em Veterinária José Caetano Borges, Universidade de Uberaba, Av. do Tutunas 720, Uberaba, MG 38061-500, Brazil. E-mail: rezendehvu@hotmail.com Classified pertaining to the genus Morbillivirus of the Paramyxoviridae family, the canine distemper virus is a RNA single-stranded virus with negative polarity and causes a multisystemic disease, serious and highly contagious for dogs and wild carnivores, with a high mortality rate in non-vaccinated animals or with vaccine fails. With the objective to evaluate heart histopathological alterations, particularly in the left ventricular myocardium, in dogs naturally infected with canine distemper virus, 35 dogs, males and females of different ages, were studied. All the 35 samples sent to the Veterinary Hospital of Uberaba were serum-positive for distemper (immunoassay technique in solid phase) and had in the left ventricular myocardium the following histopathologic alterations: myocarditis, hyalin degeneration, hyperemia and hemorrhage, in 42.8% (15/35), 31.4% (11/35), 14.3% (5/35) and 11.4% (4/35), respectively. Having carried out the Qui-Quadrado test with a significancy level of 0.05, it can be concluded that there is a high correlation (p=0.02) between the infected animals with canine distemper virus and histopathological alterations found in the left ventricular myocardium.

Abstract in English:

ABSTRACT.- Pereira I.A., Soares L.C., Coelho S.M.O., Pribul B.R. & Souza M.M.S. 2009. [Susceptibility to azithromycin of bacteria isolated from infectious processes in dogs and cats.] Suscetibilidade à azitromicina de isolados bacterianos de processos infecciosos em cães e gatos. Pesquisa Veterinária Brasileira 29(2):153-156. Departamento de Microbiologia e Imunologia Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br The susceptibility pattern to azithromycin of bacterial pathogens from various infectious sites, and the in vitro activity and minimum inhibitory concentration (MIC) of azithromycin were studied. Tests such as disc diffusion and broth microdilution detected respectively 48.6% and 55% of resistant Staphylococcus spp., and 55.3% and 72.7% resistant gram-negative rods. MIC50 for S. aureus was 4.0mg/mL, that for S. intermedius was 1.0mg/mL, for coagulase-negative Staphylococcus e”512mg/mL, and for gram-negative rods 256mg/mL. Fifteen percent (9/60) of oxacilin-resistant, multidrug-resistant and mecA-positive Staphylococcus spp. isolates were also azithromycin resistant. The dissemination of multidrug resistant bacteria points out to the need of antimicrobial evaluation activity in order to select the best indicated drug and thus minimizing therapeutic failures in veterinary practice.

• Diseases of dogs and cats bacterial diseases bacterial antibiotic resistance azithromycin

Abstract in Portuguese:

ABSTRACT.- Pereira I.A., Soares L.C., Coelho S.M.O., Pribul B.R. & Souza M.M.S. 2009. [Susceptibility to azithromycin of bacteria isolated from infectious processes in dogs and cats.] Suscetibilidade à azitromicina de isolados bacterianos de processos infecciosos em cães e gatos. Pesquisa Veterinária Brasileira 29(2):153-156. Departamento de Microbiologia e Imunologia Veterinária, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23890-000, Brazil. E-mail: miliane@ufrrj.br The susceptibility pattern to azithromycin of bacterial pathogens from various infectious sites, and the in vitro activity and minimum inhibitory concentration (MIC) of azithromycin were studied. Tests such as disc diffusion and broth microdilution detected respectively 48.6% and 55% of resistant Staphylococcus spp., and 55.3% and 72.7% resistant gram-negative rods. MIC50 for S. aureus was 4.0mg/mL, that for S. intermedius was 1.0mg/mL, for coagulase-negative Staphylococcus e”512mg/mL, and for gram-negative rods 256mg/mL. Fifteen percent (9/60) of oxacilin-resistant, multidrug-resistant and mecA-positive Staphylococcus spp. isolates were also azithromycin resistant. The dissemination of multidrug resistant bacteria points out to the need of antimicrobial evaluation activity in order to select the best indicated drug and thus minimizing therapeutic failures in veterinary practice.

Abstract in English:

ABSTRACT.- Flores E.F., Weiblen R, Vogel F.S.F., Dezengrini R., Almeida S.R., Spilki F.R. & Roehe P.M. 2009. [Experimental neuropathogenesis of bovine herpesvirus 5 infection in rabbits.] Neuropatogênese experimental da infecção pelo herpesvírus bovino tipo 5 em coelhos. Pesquisa Veterinária Brasileira 29(1):1-16. Departamento de Medicina Veterinária Preventiva. Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS. Brazil. E-mail: eduardofurtadoflores@gmail.com Several aspects of the biology of bovine herpesvirus 5 (BoHV-5) have been studied in rabbits, which develop acute infection and neurological disease upon experimental inoculation. The acute infection is followed by the establishment of latent infection, which can be naturally or artificially reactivated. The first experiments in rabbits established a protocol for virus inoculation and monitoring the infection, and characterized the main virological, clinical and pathological aspects of the acute infection. The pathogenesis of acute infection, from the initial viral replication at site of inoculation, pathways and kinetics of viral transport to the brain, distribution and virus replication in the central nervous system (CNS), cellular and tissue tropism, clinical signs and CNS pathology have been extensively studied using this animal model. Subsequently, several biological and molecular aspects of latent BoHV-5 infection have also been elucidated upon inoculation of rabbits. Rabbits have also been used to investigate the phenotype (neuroinvasiveness, neurogrowth) of field isolates and recombinant vaccine candidates, protection by passive immunity, vaccine protection, the efficacy of anti-viral drugs and support therapies for neurological disease. This animal model was also used to investigate the origin and distribution of electric impulses involved in seizures - a hallmark of BoHV-5 induced neurological infection - and also to test the efficacy of anti-convulsivants. In spite of the possible differences between rabbits and cattle - the natural host of the virus - the observations taken from this experimental model have greatly contributed to the knowledge of the biology of BoHV-5 infection. The present article presents a review of the main published and unpublished results and observations by our group, comprising more than a decade of studies on the pathogenesis of BoHV-5 infection in the rabbit model.

• Bovine herpesvirus 5 BoHV-5 rabbits experimental model

Abstract in Portuguese:

ABSTRACT.- Flores E.F., Weiblen R, Vogel F.S.F., Dezengrini R., Almeida S.R., Spilki F.R. & Roehe P.M. 2009. [Experimental neuropathogenesis of bovine herpesvirus 5 infection in rabbits.] Neuropatogênese experimental da infecção pelo herpesvírus bovino tipo 5 em coelhos. Pesquisa Veterinária Brasileira 29(1):1-16. Departamento de Medicina Veterinária Preventiva. Universidade Federal de Santa Maria, 97105-900 Santa Maria, RS. Brazil. E-mail: eduardofurtadoflores@gmail.com Several aspects of the biology of bovine herpesvirus 5 (BoHV-5) have been studied in rabbits, which develop acute infection and neurological disease upon experimental inoculation. The acute infection is followed by the establishment of latent infection, which can be naturally or artificially reactivated. The first experiments in rabbits established a protocol for virus inoculation and monitoring the infection, and characterized the main virological, clinical and pathological aspects of the acute infection. The pathogenesis of acute infection, from the initial viral replication at site of inoculation, pathways and kinetics of viral transport to the brain, distribution and virus replication in the central nervous system (CNS), cellular and tissue tropism, clinical signs and CNS pathology have been extensively studied using this animal model. Subsequently, several biological and molecular aspects of latent BoHV-5 infection have also been elucidated upon inoculation of rabbits. Rabbits have also been used to investigate the phenotype (neuroinvasiveness, neurogrowth) of field isolates and recombinant vaccine candidates, protection by passive immunity, vaccine protection, the efficacy of anti-viral drugs and support therapies for neurological disease. This animal model was also used to investigate the origin and distribution of electric impulses involved in seizures - a hallmark of BoHV-5 induced neurological infection - and also to test the efficacy of anti-convulsivants. In spite of the possible differences between rabbits and cattle - the natural host of the virus - the observations taken from this experimental model have greatly contributed to the knowledge of the biology of BoHV-5 infection. The present article presents a review of the main published and unpublished results and observations by our group, comprising more than a decade of studies on the pathogenesis of BoHV-5 infection in the rabbit model.

Abstract in English:

ABSTRACT.- Graça F.A.S., Peixoto P.V., Coelho C.D., Caldas S.A. & Tokarnia C.H. 2008. [Clinical and pathological aspects of experimental Crotalus poisoning in cattle.] Aspectos clinicos e patológicos do envenenamento crotálico experimental em bovinos. Pesquisa Veterinária Brasileira 28(6):261-270. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: flaviograca@uol.com.br Crotalus poisoning was experimentally reproduced by subcutaneous inoculation of Crotalus durissus terrificus (South American rattlesnake) venom into 10 clinically healthy mixed bred 12 to 36-month-old cattle, weighing 125 to 449 kg. Two animals were used as controls. The animal that received a dose of 0.03mg/kg body weight died 7h40min after inoculation. A 0.015mg/kg dose provoked death in 4 out of 7 young oxen. Two animals given 0.0075mg/kg became slightly sick and recovered. Onset of symptoms occurred from 1h30min to 13h45min after inoculation. The clinical course varied from 5h25min to 45h for animals that died, and from 33h15min to 17 days for animals that recovered. The main nervous signs observed were diminished response to external stimuli, hypotonic reflexes, dragging of the hooves, apathy, difficulties in moving around obstacles, ocular globe paralysis, lateral and sternal decubitus, and tongue paralysis. Adipsia and sometimes petechiae in the conjunctival and vaginal mucosa were observed. A slight to moderate increase in bleeding time was noted in 6 animals, and a moderate increase in partial thromboplastin time was found in 7 others. Moderate leukocytosis with neutrophilia, relative lymphopenia, eosinopenia, and monocytosis was found. There was a significant increase in creatine kinase serum levels of a ten-fold order. No significant alterations were revealed by urinalysis. Necropsy revealed minimal edema at the inoculation site, few petechiae and equimoses in the epicardium, omentum, biliary vesicle and bladder mucosa of some animals. Histopathological examination revealed necrosis (hyalinization) of groups or isolated myocytes in different muscles examined, both near and far from the inoculation site, in all animals. The diagnosis of Crotalus poisoning and its differentiation from diseases causing paralysis and muscular necrosis in cattle in Brazil are discussed.

• Poisoning Crotalus durissus terrificus cattle snake bite

Abstract in Portuguese:

ABSTRACT.- Graça F.A.S., Peixoto P.V., Coelho C.D., Caldas S.A. & Tokarnia C.H. 2008. [Clinical and pathological aspects of experimental Crotalus poisoning in cattle.] Aspectos clinicos e patológicos do envenenamento crotálico experimental em bovinos. Pesquisa Veterinária Brasileira 28(6):261-270. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: flaviograca@uol.com.br Crotalus poisoning was experimentally reproduced by subcutaneous inoculation of Crotalus durissus terrificus (South American rattlesnake) venom into 10 clinically healthy mixed bred 12 to 36-month-old cattle, weighing 125 to 449 kg. Two animals were used as controls. The animal that received a dose of 0.03mg/kg body weight died 7h40min after inoculation. A 0.015mg/kg dose provoked death in 4 out of 7 young oxen. Two animals given 0.0075mg/kg became slightly sick and recovered. Onset of symptoms occurred from 1h30min to 13h45min after inoculation. The clinical course varied from 5h25min to 45h for animals that died, and from 33h15min to 17 days for animals that recovered. The main nervous signs observed were diminished response to external stimuli, hypotonic reflexes, dragging of the hooves, apathy, difficulties in moving around obstacles, ocular globe paralysis, lateral and sternal decubitus, and tongue paralysis. Adipsia and sometimes petechiae in the conjunctival and vaginal mucosa were observed. A slight to moderate increase in bleeding time was noted in 6 animals, and a moderate increase in partial thromboplastin time was found in 7 others. Moderate leukocytosis with neutrophilia, relative lymphopenia, eosinopenia, and monocytosis was found. There was a significant increase in creatine kinase serum levels of a ten-fold order. No significant alterations were revealed by urinalysis. Necropsy revealed minimal edema at the inoculation site, few petechiae and equimoses in the epicardium, omentum, biliary vesicle and bladder mucosa of some animals. Histopathological examination revealed necrosis (hyalinization) of groups or isolated myocytes in different muscles examined, both near and far from the inoculation site, in all animals. The diagnosis of Crotalus poisoning and its differentiation from diseases causing paralysis and muscular necrosis in cattle in Brazil are discussed.

Abstract in English:

ABSTRACT.- Caldas S.A., Tokarnia C.H., França T.N., Brito M.F., Graça F.A.S., Coelho C.D. & Peixoto P.V. 2008. [Clinic and pathological and laboratory aspects of experimental poisoning by Bothrops alternatus venom in cattle.] Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos. Pesquisa Veterinária Brasileira 28(6):303-312. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: saulo-andrade@bol.com.br The aim of this study was to determine the clinical-pathological alterations and laboratory findings in cattle inoculated with Bothrops alternatus venom, with the intention of providing information for the establishment of diagnosis and differential diagnosis procedures, as well as to elucidate some obscurities observed in the pertinent literature. The lyophilized venom was diluted in 1 ml of physiologic solution. It was administered to 5 bovines by the subcutaneous route at doses of 0.0625, 0.125 and 0.25mg/kg body weight, and to 2 bovines by the intramuscular route at doses of 0.25 e 0.45mg/kg. Six bovines died and the only animal that survived, who had subcutaneously received the venom at a dose of 0.0625mg/kg, recovered. The first clinical signs were observed from 25min to 5h30min after the inoculation. The clinical evolution time varied from 7 hours 18 minutes to 92 hours. Regardless of the dose, the clinical picture was characterized by swelling (hemorrhage/hematoma) at the site of inoculation, increase in bleeding time and capillary refill time, paleness of mucous membranes and apathy. The laboratory exams revealed progressive normocytic normochromic anemia, thrombocytopenia, reduction in fibrinogen and total plasma proteins, decreased hematocrit and hemoglobin, and slight increase in creatine kinase and lactate dehydrogenase. When subjected to necropsy, the animals that received the venom through the subcutaneous route showed large hematomas and hemorrhagic areas in the subcutaneous tissue, extending from the site of inoculation. The animals in which inoculation was performed intramuscularly exhibited, in addition, intramuscular hemorrhage. The left endocardium showed extensive hemorrhagic lesions, and petechiae were found on the serosae of rumen, omasum, abomasum and gall bladder. The colon, rectum and perirenal areas were surrounded by clotted blood in three animals. Besides hemorrhage, the histological examination revealed hemorrhage and coagulative muscle necrosis in the vicinities of the inoculation site in the animals that received the venom by the intramuscular route. These lesions were mild in the muscles close to the site of inoculation in the animals inoculated by the subcutaneous route. The swelling on the site of inoculation and its surroundings was a consequence of blood accumulation and not merely edema. Myoglobinuria and gross or microscopic lesions were not observed in the kidneys. This study indicates that B. alternatus can lead adult bovines to death if they release all their venom during a bite. Conversely, since venomous ophidians can control the amount of poison they inoculate and they probably do not identify bovines as potential preys, it is likely that the number of accidents involving this species is small, which is in agreement with the findings of the majority of the centers for anatomical-pathological diagnosis in Brazil.

• Bothrops alternatus cattle pathology symptoms

Abstract in Portuguese:

ABSTRACT.- Caldas S.A., Tokarnia C.H., França T.N., Brito M.F., Graça F.A.S., Coelho C.D. & Peixoto P.V. 2008. [Clinic and pathological and laboratory aspects of experimental poisoning by Bothrops alternatus venom in cattle.] Aspectos clínico-patológicos e laboratoriais do envenenamento experimental por Bothrops alternatus em bovinos. Pesquisa Veterinária Brasileira 28(6):303-312. Projeto Sanidade Animal Embrapa/UFRRJ, Seropédica, RJ 23890-000, Brazil. E-mail: saulo-andrade@bol.com.br The aim of this study was to determine the clinical-pathological alterations and laboratory findings in cattle inoculated with Bothrops alternatus venom, with the intention of providing information for the establishment of diagnosis and differential diagnosis procedures, as well as to elucidate some obscurities observed in the pertinent literature. The lyophilized venom was diluted in 1 ml of physiologic solution. It was administered to 5 bovines by the subcutaneous route at doses of 0.0625, 0.125 and 0.25mg/kg body weight, and to 2 bovines by the intramuscular route at doses of 0.25 e 0.45mg/kg. Six bovines died and the only animal that survived, who had subcutaneously received the venom at a dose of 0.0625mg/kg, recovered. The first clinical signs were observed from 25min to 5h30min after the inoculation. The clinical evolution time varied from 7 hours 18 minutes to 92 hours. Regardless of the dose, the clinical picture was characterized by swelling (hemorrhage/hematoma) at the site of inoculation, increase in bleeding time and capillary refill time, paleness of mucous membranes and apathy. The laboratory exams revealed progressive normocytic normochromic anemia, thrombocytopenia, reduction in fibrinogen and total plasma proteins, decreased hematocrit and hemoglobin, and slight increase in creatine kinase and lactate dehydrogenase. When subjected to necropsy, the animals that received the venom through the subcutaneous route showed large hematomas and hemorrhagic areas in the subcutaneous tissue, extending from the site of inoculation. The animals in which inoculation was performed intramuscularly exhibited, in addition, intramuscular hemorrhage. The left endocardium showed extensive hemorrhagic lesions, and petechiae were found on the serosae of rumen, omasum, abomasum and gall bladder. The colon, rectum and perirenal areas were surrounded by clotted blood in three animals. Besides hemorrhage, the histological examination revealed hemorrhage and coagulative muscle necrosis in the vicinities of the inoculation site in the animals that received the venom by the intramuscular route. These lesions were mild in the muscles close to the site of inoculation in the animals inoculated by the subcutaneous route. The swelling on the site of inoculation and its surroundings was a consequence of blood accumulation and not merely edema. Myoglobinuria and gross or microscopic lesions were not observed in the kidneys. This study indicates that B. alternatus can lead adult bovines to death if they release all their venom during a bite. Conversely, since venomous ophidians can control the amount of poison they inoculate and they probably do not identify bovines as potential preys, it is likely that the number of accidents involving this species is small, which is in agreement with the findings of the majority of the centers for anatomical-pathological diagnosis in Brazil.

Abstract in English:

ABSTRACT.- Torres M.B.A.M. & Coelho K.I.R. 2008. Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells. Pesquisa Veterinária Brasileira 28(1):43-50. Laboratório de Patologia Veterinária, Universidade Federal do Paraná, Campus Palotina, Rua Pioneiro 2153, Jardim Dallas, Palotina, PR 85950-000, Brazil. E-mail: torres@ufpr.br Extracellular matrix plays an important role in chronic hepatic lesions and has been studied in experimental intoxication models. However in cattle, studies on chronic disease have focused on the hepatocellular damage and extracellular matrix (ECM) changes are usually overlooked. There are no specific studies on the hepatic ECM in either normal or chronically damaged bovine liver. Thus an experimental model of hepatic toxicity model using Senecio brasiliensis poisoned calves was designed. Senecio brasiliensis contains pyrrolizidine alkaloids which cause either acute or chronic progressive dose dependent liver damage. Five calves were orally fed with 0.38g of dry leaves of S. brasiliensis/kg/day for 24 days. Liver needle biopsy specimens were obtained every 15 days for 60 days. Clinical signs of digestive complications appeared at 3rd week. One calf died on 45th day and four were evaluated up to 60th day. Biopsy samples were processed for routine light microscopy, immuno-histochemistry and transmission electron microscopy. From 30th day on progressive liver damage characterized by hepatocellular ballooning, necrosis, apoptosis and megalocytosis, centrilobular, pericellular and portal fibrosis were seen by light microscopy. Quantitative and semi-quantitative measurements of hepatic ECM components were performed before and after the onset of lesions. Morphometric analysis of total collagen and elastic fiber system was conducted. Total collagen and I and III collagen types progressively increased in throughout the liver of affected calves. Changes in location, amount and disposition of the elastic fiber system were also observed. Then numbers of Kupffer cells were significantly increased at 30th day and total numbers of sinusoidal cells were significantly increased at 45th and 60th days. Liver damage was progressive and irreversible even after the exposure to the plant was discontinued. Severe fibrotic lesions occurred mainly in portal tracts, followed by veno-occlusive and pericellular fibrosis. Collagen types I and III s were present in every normal and damaged liver, with predominance of type I. In affected calves the increase of total collagen and elastic fibers system paralleled the number of total sinusoidal cells.

• Hepatic extracellular matrix sinusoidal cells hepatic fibrosis pyrrolizidine alkaloids

Abstract in Portuguese:

ABSTRACT.- Torres M.B.A.M. & Coelho K.I.R. 2008. Experimental poisoning by Senecio brasiliensis in calves: quantitative and semi-quantitative study on changes in the hepatic extracellular matrix and sinusoidal cells. Pesquisa Veterinária Brasileira 28(1):43-50. Laboratório de Patologia Veterinária, Universidade Federal do Paraná, Campus Palotina, Rua Pioneiro 2153, Jardim Dallas, Palotina, PR 85950-000, Brazil. E-mail: torres@ufpr.br Extracellular matrix plays an important role in chronic hepatic lesions and has been studied in experimental intoxication models. However in cattle, studies on chronic disease have focused on the hepatocellular damage and extracellular matrix (ECM) changes are usually overlooked. There are no specific studies on the hepatic ECM in either normal or chronically damaged bovine liver. Thus an experimental model of hepatic toxicity model using Senecio brasiliensis poisoned calves was designed. Senecio brasiliensis contains pyrrolizidine alkaloids which cause either acute or chronic progressive dose dependent liver damage. Five calves were orally fed with 0.38g of dry leaves of S. brasiliensis/kg/day for 24 days. Liver needle biopsy specimens were obtained every 15 days for 60 days. Clinical signs of digestive complications appeared at 3rd week. One calf died on 45th day and four were evaluated up to 60th day. Biopsy samples were processed for routine light microscopy, immuno-histochemistry and transmission electron microscopy. From 30th day on progressive liver damage characterized by hepatocellular ballooning, necrosis, apoptosis and megalocytosis, centrilobular, pericellular and portal fibrosis were seen by light microscopy. Quantitative and semi-quantitative measurements of hepatic ECM components were performed before and after the onset of lesions. Morphometric analysis of total collagen and elastic fiber system was conducted. Total collagen and I and III collagen types progressively increased in throughout the liver of affected calves. Changes in location, amount and disposition of the elastic fiber system were also observed. Then numbers of Kupffer cells were significantly increased at 30th day and total numbers of sinusoidal cells were significantly increased at 45th and 60th days. Liver damage was progressive and irreversible even after the exposure to the plant was discontinued. Severe fibrotic lesions occurred mainly in portal tracts, followed by veno-occlusive and pericellular fibrosis. Collagen types I and III s were present in every normal and damaged liver, with predominance of type I. In affected calves the increase of total collagen and elastic fibers system paralleled the number of total sinusoidal cells.