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1.
Pan Afr Med J ; 34: 25, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31803340

RESUMO

Introduction: Estimation of dog population is relevant in Animal Health Planning; some of the benefits include rabies control and possible elimination, estimation of quantity of dog vaccines and drugs required in the state, policy development and implementation. Methods: A cross-sectional study was conducted to estimate the population of dogs in Nasarawa state; a local government area (LGA) was randomly selected from each of the three senatorial districts and two wards were selected randomly from the selected LGA's. Three hundred and thirteen questionnaires were administered through face to face interview with dog owners and their dogs in view. Results: Analysis indicated 97.7% of the dogs were local breeds, 1.7% mixed and 0.3% exotic breeds. Guard dogs were 77% and 23% were used for hunting. Majority of the dogs (67.5%) were owned/stray while 32.5% were owned/confined. In Nasarawa state, 21% of the dogs were vaccinated and 79% had no vaccination history. The low vaccination rate indicates possible threat to animal and human health; hunting dogs are possible source of rabies introduction into their immediate communities from contact with wild reservoirs of the virus. Majority of dogs were between 1-5 years (73%) and more female dogs (52.5%) than males (47.5%) were reported. The dog to household ratio was 1.1:1 while the dog to human ratio is 1.1:6. Estimated number of dogs in Nasarawa state was 462,586 dogs. Conclusion: Proper sensitization of dog owners on annual antirabies vaccination against rabies in dogs and postexposure prophylaxis in humans is recommended. The local authorities should institute effective measures for the control of stray dogs to prevent the risk of dog bites and other environmental hazards posed by such dogs. The state government should enact and enforce laws on responsible dog ownership to include compulsory annual vaccination of all dogs. This exercise should be replicated in other states of the federation for a comprehensive national dog ecological data necessary for planning, policy development and implementation.


Assuntos
Doenças do Cão/prevenção & controle , Propriedade/estatística & dados numéricos , Vacinas Antirrábicas/administração & dosagem , Raiva/prevenção & controle , Animais , Mordeduras e Picadas/prevenção & controle , Estudos Transversais , Cães , Características da Família , Feminino , Humanos , Masculino , Nigéria , Projetos Piloto , Raiva/veterinária , Inquéritos e Questionários , Vacinação/estatística & dados numéricos , Vacinação/veterinária
2.
Vet Clin North Am Equine Pract ; 35(3): 545-560, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31672202

RESUMO

Clinical evaluation and preventative care in donkeys should follow similar guidelines as for horses. There are species-specific differences due to the desert-adapted physiology of the donkey. Donkeys are mainly used as pack animals, companions and for production of meat or milk - they may be kept well into old age. Diseases often present late or may go unrecognized leading to poor welfare and quality of life. Basic knowledge of nutrition, blood values, pharmacology and common disease recognition will help veterinarians improve the health and welfare of donkeys.


Assuntos
Equidae , Doenças dos Cavalos/diagnóstico , Doenças dos Cavalos/prevenção & controle , Animais , Cavalos , Qualidade de Vida , Vacinação/veterinária , Medicina Veterinária/métodos
3.
Vet Microbiol ; 238: 108429, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31648721

RESUMO

Viral haemorrhagic disease (VHD) and colibacillosis are common diseases in rabbits that cause economic losses worldwide. The effect of colibacillosis on the immune response of vaccinated rabbits against rabbit haemorrhagic disease virus (RHDV) was studied. Four groups (G1-G4) were included. G1 was the negative control group; G2 was the RHDV vaccine group; G3 was the E. coli-infected group; and G4 was the E. coli-infected + RHDV vaccine group. The E. coli infection and RHDV vaccination were simultaneously performed, with another previous infection, 3 days before vaccination. At 28 days post-vaccination (PV), the rabbits (G2-G4) were challenged intramuscularly with 0.5 ml of RHDV at a dose of 103 50% median lethal dose (LD50)/rabbit. The rabbits were observed for clinical signs, body weight gain and mortality rates. Tissue, blood, serum, and faecal samples and rectal swabs were collected at 3, 5, 7, 14, 21 and 28 days PV. Significant clinical signs and mortality and a decrease in BW were observed in the infected + RHDV vaccine group. On the 3rd day post-infection (PI), compared with all the other groups, the vaccinated group (G2) had significantly upregulated hepatic tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels; however, the infected + RHDV vaccine group had significantly higher intestinal levels of TNF-α and IL-6 than the other groups. Furthermore, E. coli infection in vaccinated rabbits led to immunosuppression, as shown by significant decreases (P < 0.05) in heterophil phagocytic activity, the CD4+/CD8+ ratio, and HI antibody responses to RHDV and a significant increase in the heterophil to lymphocyte (H/L) ratio. In conclusion, colibacillosis leads to immunosuppression involving a shift in the equilibrium of cytokines and reduced weight gain and mortality in vaccinated rabbits and could be a contributing factor in RHDV vaccination failure in rabbit farming.


Assuntos
Infecções por Caliciviridae/veterinária , Infecções por Escherichia coli/veterinária , Coelhos/imunologia , Vacinação/veterinária , Vacinas Virais/imunologia , Animais , Infecções por Caliciviridae/imunologia , Infecções por Caliciviridae/mortalidade , Citocinas/genética , Infecções por Escherichia coli/imunologia , Infecções por Escherichia coli/mortalidade , Infecções por Escherichia coli/fisiopatologia , Regulação da Expressão Gênica/imunologia , Vírus da Doença Hemorrágica de Coelhos/imunologia , Coelhos/microbiologia , Coelhos/virologia , Vacinação/normas
4.
Vet Ital ; 55(3): 231-239, 2019 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-31599547

RESUMO

Egypt has a large traditional and exotic poultry sector which is challenged regularly by poultry diseases in endemic and epidemic proportions. The household poultry in particular is a source of livelihoods and employment for millions of low income citizens. Highly pathogenic avian influenza (HPAI) H5N1 and Newcastle disease are the most important poultry diseases in this sector. Whereas poultry vaccines are available to reduce the incidence of disease in Egypt, their effectiveness is doubtful. We conducted a biological evaluation of selected viral vaccines of poultry in three governorates in Egypt. Fifty­four percent of the vaccines had reduced vaccine titres and the effect of secondary vaccine distributions was associated with the observed vaccine titres. External contamination was observed in some vaccines and break in cold chain was reported. Whereas no vaccine distributor used purpose­built vaccine refrigerator, none also had prescribed protocol for vaccine handling or kept record of vaccine. There is a need to review vaccine handling procedure, monitor of vaccine cold chain more critically and review the whole chain that support vaccine distributions in Egypt.


Assuntos
Galinhas , Doenças das Aves Domésticas/prevenção & controle , Vacinação/veterinária , Vacinas Virais/uso terapêutico , Animais , Egito , Doenças das Aves Domésticas/virologia , Vacinação/métodos
5.
BMC Vet Res ; 15(1): 342, 2019 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-31619295

RESUMO

BACKGROUND: The objective of this study was to assess the efficacy of a trivalent vaccine mixture and compare it to the respective monovalent vaccines against Mycoplasma hyopneumoniae, porcine circovirus type 2 (PCV2), and porcine reproductive and respiratory syndrome virus (PRRSV). RESULTS: Pigs that were triple challenged with M. hyopneumoniae, PCV2, and PRRSV following vaccination with the trivalent vaccine mixture exhibited a significantly better growth performance when compared to unvaccinated and challenged pigs. A statistical difference was not found when comparing pig populations which were vaccinated with the trivalent vaccine followed by a triple challenge and pigs vaccinated with monovalent M hyopneumoniae vaccine followed by mycoplasmal single challenge in the following areas: M. hyopneumoniae nasal shedding, the number of M. hyopneumoniae-specific interferon-γ secreting cells (IFN-γ-SC), and mycoplasmal lung lesion scores. Pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge resulted in a similar reduction of PCV2 viremia, an increase in the number of PCV2-specific IFN-γ-SC and reduction in interstitial lung lesion scores when compared to pigs vaccinated with a PCV-2 vaccine and challenged with PCV2 only. Lastly, there was a significant difference in the reduction of PRRSV viremia, an increase in PRRSV-specific IFN-γ-SC and a reduction of interstitial lung lesion scores between pigs vaccinated with the trivalent vaccine mixture followed by a triple challenge and pigs vaccinated with a monovalent PRRSV vaccine followed by PRRSV challenge only. CONCLUSION: The trivalent vaccine mixture was efficacious against a triple challenge of M. hyopneumoniae, PCV2, and PRRSV. The trivalent vaccine mixture, however, did not result in equal protection when compared against each respective monovalent vaccine, with the largest vaccine occurring within PRRSV.


Assuntos
Circovirus/imunologia , Mycoplasma hyopneumoniae/imunologia , Vírus da Síndrome Respiratória e Reprodutiva Suína/imunologia , Doenças dos Suínos/prevenção & controle , Vacinação/veterinária , Animais , Vacinas Bacterianas/imunologia , Infecções por Circoviridae/imunologia , Infecções por Circoviridae/prevenção & controle , Feminino , Masculino , Pneumonia Suína Micoplasmática/imunologia , Pneumonia Suína Micoplasmática/prevenção & controle , Síndrome Respiratória e Reprodutiva Suína/imunologia , Síndrome Respiratória e Reprodutiva Suína/prevenção & controle , Sus scrofa , Suínos , Doenças dos Suínos/imunologia , Doenças dos Suínos/microbiologia , Doenças dos Suínos/virologia , Vacinas Combinadas/administração & dosagem , Vacinas Combinadas/imunologia , Vacinas Virais/imunologia
6.
Parasitol Res ; 118(11): 3173-3183, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31606835

RESUMO

Prevention of coccidiosis is one of the best ways of controlling disease. Therefore, the present study was carried out to evaluate the protective effect of ultraviolet (UV)-irradiated sporulated oocysts of Eimeria species against coccidiosis in layer chickens. One hundred forty-four one-day-old layer chicks were randomly divided into 4 groups (n = 36), including non-immunized/non-challenged negative control group (NC group), non-immunized/challenged control group (NIC group), non-irradiated sporulated oocyst/challenged group (CA group), and UV-irradiated sporulated oocyst/challenged (UV group). At the age of 4 days, chickens in groups UV and CA were both orally inoculated with 1.0 × 104 UV-irradiated and non-irradiated sporulated oocysts of Eimeria species, respectively. Chickens in groups NIC and NC were served as positive and negative controls, respectively. Chickens in all groups were orally challenged with 7.5 × 104 sporulated oocysts of Eimeria species except the NC group at the age of 21 days. The results revealed that chicks receiving UV-irradiated sporulated oocysts had no signs of illness with minimal or no changes in the cecal integrity and a significantly lower oocyst shedding (OPG) than in the NIC group. Additionally, the cytokine gene expression profiles were evaluated. Expression levels of IL-2, IL-12, and IFN-γ were significantly higher in the spleen of chicks in the UV and CA groups than in the NC group post-challenge. As expected, treatment with irradiated oocysts resulted in a significant reduction in oocyst shedding and maintenance of cecal mucosal integrity. Furthermore, the body weight was higher in chickens inoculated with UV-irradiated oocysts than their non-irradiated counterparts. In conclusion, our results demonstrate that inoculation with UV-irradiated sporulated oocysts of Eimeria species can produce a substantial reduction in infection symptoms.


Assuntos
Galinhas , Coccidiose/veterinária , Eimeria , Oocistos/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Protozoárias/administração & dosagem , Animais , Peso Corporal , Coccidiose/prevenção & controle , Eimeria/imunologia , Eimeria/efeitos da radiação , Masculino , Oocistos/efeitos da radiação , Doenças das Aves Domésticas/parasitologia , Raios Ultravioleta , Vacinação/veterinária
7.
Vet Clin North Am Food Anim Pract ; 35(3): 391-403, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590894

RESUMO

Vaccination is a critical tool in modern animal production and key to maintaining animal health. Adjuvants affect the immune response by increasing the rate, quantity, or quality of the protective response generated by the target antigens. Although adjuvant technology dates back to the nineteenth century, there was relatively little improvement in adjuvant technology before the late twentieth century. With the discovery of molecular pathways that regulate the timing, quantity, and quality of the immune response, new technologies are focused on bringing safer, more effective, and inexpensive adjuvants to commercial use.


Assuntos
Adjuvantes Imunológicos/administração & dosagem , Doenças dos Animais/prevenção & controle , Ruminantes/imunologia , Vacinação/veterinária , Adjuvantes Imunológicos/farmacologia , Doenças dos Animais/imunologia , Animais
8.
Vet Clin North Am Food Anim Pract ; 35(3): 557-573, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590902

RESUMO

A growing body of evidence has shown that calves can mount an immune response when vaccinated in the face of maternal antibodies (IFOMA), albeit inconsistently and often in ways that differ from seronegative calves or older cattle. Several previous reviews have endeavored to explain bovine neonatal immunology and have documented the issue of vaccinating young calves. However, as preweaning vaccination becomes more common in both beef and dairy production systems, so too has research on the impacts of such vaccination programs. This article aims to briefly review the challenges and opportunities for vaccinating calves IFOMA.


Assuntos
Imunidade Materno-Adquirida/imunologia , Vacinação/veterinária , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Feminino , Troca Materno-Fetal/imunologia , Gravidez , Vacinação/métodos
9.
Vet Clin North Am Food Anim Pract ; 35(3): 575-592, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590903

RESUMO

Vaccination is a critical component of cattle health management. Effective cattle vaccine programs should consider the timing of vaccination in relation to expected disease challenge, risk for wild-type exposure of various bovine pathogens, and host factors during vaccination. Nearly all consulting veterinarians recommend vaccination of stressed, high-risk calves on feedlot arrival. However, this recommendation fails to consider several factors associated with vaccine efficiency. Further research evaluating vaccine interactions in stressed cattle and potential additive effects of endotoxin from multiple bacterin administration may reveal new evidence-based vaccination guidelines for cattle in the various segments of beef and dairy production systems.


Assuntos
Bovinos/imunologia , Carne Vermelha , Vacinação/veterinária , Animais , Doenças dos Bovinos/prevenção & controle , Vacinação/métodos , Vacinas Virais/administração & dosagem
10.
Vet Clin North Am Food Anim Pract ; 35(3): 593-604, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31590904

RESUMO

Herd immunity is an important concept of epidemic theory regarding the population-level effect of individual immunity to prevent transmission of pathogens. Herd immunity exists when sufficient numbers of animals in a group or population have immunity against an agent such that the likelihood of an effective contact between diseased and susceptible individuals is reduced. Understanding herd immunity requires consideration of infection dynamics, modes of transmission, as well as the acquisition of immunity by individuals in the population. Loss of herd immunity may also explain age-associated epidemics of disease related to loss of passively acquired maternal immunity.


Assuntos
Imunidade Coletiva , Animais , Epidemias/prevenção & controle , Humanos , Vacinação/métodos , Vacinação/veterinária
11.
Can J Vet Res ; 83(4): 313-316, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31571732

RESUMO

The objective of this study was to evaluate the effect of late-gestation vaccination of beef heifers with 2 doses of a killed-virus (KV) vaccine containing bovine herpesvirus 1 (BoHV-1), bovine viral diarrhea virus 1 (BVDV-1), and bovine viral diarrhea virus 2 (BVDV-2) on the serum concentrations of antibody against BoHV-1, BVDV-1, and BVDV-2 in heifers and their calves and on the IgG concentration in the calves. Of the 47 pregnant beef heifers selected, 26 received 2 doses of the vaccine at 6.5 to 8 mo of gestation (at pregnancy check), and 21 received 2 doses of saline. The mean log2 serum titers of neutralizing antibody against BoHV-1, BVDV-1, and BVDV-2 before vaccination did not differ significantly between the treatment groups; however, at calving all 3 mean titers were significantly greater (P < 0.05) in the vaccinated heifers than in the control heifers. At 24 h after birth the mean serum IgG levels in the calves did not differ significantly between the 2 groups, at 30.18 and 32.28 g/L, respectively (P < 0.05); however, the mean log2 serum titers of antibody to all 3 viruses were greater in the calves nursing colostrum from the vaccinated heifers than in the calves nursing colostrum from the nonvaccinated heifers and significantly so for BoHV-1 and BVDV-1 (P < 0.001 and P = 0.009, respectively). Thus, late-gestation vaccination of beef heifers could result in a greater and more consistent deposition of specific antibodies in colostrum, reducing the variability of initial titers in calves and increasing the duration of maternal immunity.


Assuntos
Anticorpos Antivirais/sangue , Doenças dos Bovinos/prevenção & controle , Vírus da Diarreia Viral Bovina/imunologia , Herpesvirus Bovino 1/imunologia , Imunoglobulina G/sangue , Vacinas Virais/imunologia , Animais , Especificidade de Anticorpos , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/imunologia , Feminino , Imunidade Materno-Adquirida , Gravidez , Vacinação/veterinária
12.
J Fish Dis ; 42(12): 1713-1730, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31625186

RESUMO

The Chilean aquaculture has been challenged for years by piscirickettsiosis. A common prophylactic measurement to try to reduce the impact from this disease is vaccination, but the development of vaccines that induce satisfactory protection of the fish in the field has so far not been successful. Experimental challenge models are used to test vaccine efficacy. The aim of this study was to evaluate the performance of experimental vaccines after challenge by the two most widely used challenge routes, intraperitoneal injection and cohabitation. A total of 1,120 Atlantic salmon were vaccinated with non-commercial experimental vaccines with increasing amounts of an inactivated Piscirickettsia salmonis EM90-like isolate. Differences in mortality, macroscopic and microscopic pathological changes, bacterial load and immune gene expression were compared after challenge by different routes. The results revealed a similar progression of the diseases after challenge by both routes and no gross differences reflecting the efficacy of the vaccines could be identified. The analysis of the immune genes suggests a possible suppression of the cellular immunity by CD8 T cell and with this stimulation of bacterial survival and replication. Comparative studies of experimental challenge models are valuable with regard to identifying the best model to mimic real-life conditions and vaccines' performance.


Assuntos
Vacinas Bacterianas/uso terapêutico , Doenças dos Peixes/prevenção & controle , Infecções por Piscirickettsiaceae/veterinária , Salmo salar/microbiologia , Vacinação/veterinária , Animais , Aquicultura , Carga Bacteriana , Doenças dos Peixes/microbiologia , Injeções Intraperitoneais , Piscirickettsia , Infecções por Piscirickettsiaceae/prevenção & controle , Vacinação/métodos
13.
J Fish Dis ; 42(12): 1731-1743, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31631353

RESUMO

Atlantic lumpfish were vaccinated by intramuscular (im) or intraperitoneal (ip) injection with a multivalent oil-based vaccine, while control fish were injected with phosphate-buffered saline. Four lumpfish per group were sampled for skin/muscle and head kidney tissue at 0, 2, 7, 21 and 42 days post-immunization (dpi) for histopathology and immunohistochemistry (IHC). Gene expressions of secretory IgM, membrane-bound IgM, IgD, TCRα, CD3ε and MHC class IIß were studied in tissues by using qPCR. Im. vaccinated fish showed vaccine-induced inflammation with formation of granulomas and increasing number of eosinophilic granulocyte-like cells over time. On IHC sections, we observed diffuse intercellular staining of secretory IgM at the injection site at 2 dpi, while IgM + cells appeared in small numbers at 21 and 42 dpi. Skin/muscle samples from im. vaccinated fish demonstrated an increase in gene expression of IgM mRNA (secretory and membrane-bound) at 21 and 42 dpi and small changes for other genes. Our results indicated that im. vaccination of lumpfish induced local IgM production at the vaccine injection site, with no apparent proliferation of IgM + cells. Eosinophilic granulocyte-like cells appeared shortly after im. injection and increased in numbers as the inflammation progressed.


Assuntos
Formação de Anticorpos , Imunoglobulina M/imunologia , Inflamação/imunologia , Perciformes/imunologia , Vacinação/veterinária , Animais , Injeções Intramusculares , Vacinação/métodos
14.
PLoS Negl Trop Dis ; 13(9): e0007739, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31545810

RESUMO

Canine rabies was endemic pre-urbanisation, yet little is known about how it persists in small populations of dogs typically seen in rural and remote regions. By simulating rabies outbreaks in such populations (50-90 dogs) using a network-based model, our objective was to determine if rabies-induced behavioural changes influence disease persistence. Behavioural changes-increased bite frequency and increased number or duration of contacts (disease-induced roaming or paralysis, respectively)-were found to be essential for disease propagation. Spread occurred in approximately 50% of model simulations and in these, very low case rates (2.0-2.6 cases/month) over long durations (95% range 20-473 days) were observed. Consequently, disease detection is a challenge, risking human infection and spread to other communities via dog movements. Even with 70% pre-emptive vaccination, spread occurred in >30% of model simulations (in these, median case rate was 1.5/month with 95% range of 15-275 days duration). We conclude that the social disruption caused by rabies-induced behavioural change is the key to explaining how rabies persists in small populations of dogs. Results suggest that vaccination of substantially greater than the recommended 70% of dog populations is required to prevent rabies emergence in currently free rural areas.


Assuntos
Comportamento Animal , Cães/psicologia , Raiva/veterinária , Animais , Mordeduras e Picadas , Simulação por Computador , Surtos de Doenças/veterinária , Doenças do Cão/epidemiologia , Doenças do Cão/prevenção & controle , Doenças do Cão/transmissão , Raiva/epidemiologia , Raiva/prevenção & controle , Raiva/transmissão , Vacinas Antirrábicas , Vacinação/veterinária
15.
Vet Res ; 50(1): 68, 2019 Sep 23.
Artigo em Inglês | MEDLINE | ID: mdl-31547877

RESUMO

Parameters such as pathogen dose and inoculation route are paramount in animal models when studying disease pathogenesis. Here, clinical findings, including foetal mortality, parasite transmission rates and lesion severity, and immune responses were evaluated in Asturiana pregnant heifers at day 110 of gestation challenged with a virulent (Nc-Spain7) Neospora caninum isolate. Four different doses of parasite tachyzoites were inoculated intravenously (IV1, 107 parasites, n = 6; IV2, 105, n = 6; IV3, 103, n = 6; and IV4, 102, n = 5), and the subcutaneous (SC) inoculation route was also assessed for the dose of 105 tachyzoites (SC, n = 6). In addition, a control group (n = 4 pregnant heifers) was evaluated. Foetal death was observed in all infected groups from 25 to 62 days post-infection, varying with the dose (IV1:4/6, IV2:3/6; IV4:2/5, IV3:1/6), and was three times less frequently associated with the SC route than IV inoculation (1/6 vs. 3/6). A dose-dependent effect for parasite loads in placental and foetal brain tissues was also detected. After SC challenge, a reduced number of tachyzoites were able to reach foetal brain tissues, and no lesions were observed. In calves, specific IgG responses in precolostral sera were mainly associated with high-dose groups (IV1 [100.0%] and IV2 [66.7%]), and cerebral parasite DNA detection was scarce (3/18). In dams, IFN-γ production and the dynamics of anti-N. caninum IgG antibodies varied with the dose, and the cell-mediated immune response was also found to be route-dependent. Our results confirm the influence of parasite dose and inoculation route on the outcome and dynamics of bovine neosporosis at mid-gestation.


Assuntos
Doenças dos Bovinos/mortalidade , Coccidiose/veterinária , Imunidade Celular , Neospora/imunologia , Complicações Parasitárias na Gravidez/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/mortalidade , Coccidiose/parasitologia , Feminino , Feto/parasitologia , Injeções Intravenosas/veterinária , Gravidez , Complicações Parasitárias na Gravidez/mortalidade , Complicações Parasitárias na Gravidez/parasitologia , Distribuição Aleatória , Vacinação/veterinária
16.
BMC Vet Res ; 15(1): 333, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533718

RESUMO

BACKGROUND: Haemonchosis is one of the most economically important parasitic diseases affecting small ruminants all over the world. Chemotherapeutic control has several shortcomings (limited anthelmintic arsenal, frequent resistance) and is hardly affordable by many farm economies. A recombinant antigen (rHc23) was shown to induce significant protection in vaccination trials with single dose challenges and different adjuvants. RESULTS: Lambs were vaccinated with 100 µg rHc23/dose + bacterial immunostimulant (BI) (LPS from Escherichia coli + Propionibacterium acnes extract) (days - 2, 0, 7 and 14) and subjected to a trickle infection with two dosages [6x, 1000 infective larvae (L3) or 6x, 2000 L3]. Vaccinated lambs showed a significant antibody response against rHc23 and Haemonchus contortus soluble extract as assessed by ELISA and Western blot (WB). Fecal egg counts (epg) along the experiment of vaccinated and BI treated lambs were significantly reduced. All vaccinated animals showed total egg output and abomasal helminth burdens (median, average) lower than those from unvaccinated or BI-treated animals lambs although differences were not statistically significant. CONCLUSIONS: Vaccination with 100 µg rHc23/dose + BI against H.contortus trickle infections apparently induced lower epg values and helminth burdens at the end of the experiment. Intragroup individual variations did not allow to obtain conclusive results and more research is needed including adjuvants and larger groups of animals to validate the potential value of rHc23 as candidate to develop a recombinant vaccine for lambs haemonchosis.


Assuntos
Antígenos de Helmintos/imunologia , Hemoncose/veterinária , Doenças dos Ovinos/parasitologia , Abomaso/parasitologia , Adjuvantes Imunológicos/administração & dosagem , Animais , Feminino , Hemoncose/imunologia , Hemoncose/prevenção & controle , Haemonchus/imunologia , Contagem de Ovos de Parasitas/veterinária , Proteínas Recombinantes/imunologia , Ovinos , Doenças dos Ovinos/imunologia , Doenças dos Ovinos/prevenção & controle , Carneiro Doméstico , Vacinação/veterinária
17.
BMC Vet Res ; 15(1): 335, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31533724

RESUMO

BACKGROUND: Current guidelines recommend parvovirus revaccination of adult dogs no more frequently than every 3 years. The aim of this study was to determine the prevalence of dogs showing protective serum antibody titres against canine parvovirus 2 in breeding kennels in Northern Italy and to assess the effect of time from vaccination and the sex of the dog on antibody titres. The study was carried out on 370 animals of different breeds kept in 33 breeding kennels. Antibodies to canine parvovirus 2 in serum samples were measured with an indirect immunoenzymatic assay validated by the manufacturer in relation to the 'gold standard' haemagglutination inhibition test. The number of months that had elapsed since the last vaccination was calculated for each animal and categorized into the following classes: < 12 months; 13-24 months; 25-36 months; 37-48 months; and > 49 months. RESULTS: The prevalence of 'unprotected' dogs was 4.6%. A satisfactory solid herd immunity was present in the majority of breeding kennels, although some vaccination failures were detected. A significant negative correlation was found between antibody titre and months since last vaccination. Comparable antibody titres were found in the first 3 years after vaccination. Although the antibody titre over time was not affected by the sex of the dog, 'unprotected' females had been vaccinated more recently than males with analogous low titres. CONCLUSIONS: Parvovirus revaccination of adult dogs every 3 years, as currently recommended, is also the appropriate recommendation for breeding kennels. Serological tests could be a useful tool to assess the effectiveness of vaccination.


Assuntos
Anticorpos Antivirais/sangue , Doenças do Cão/imunologia , Infecções por Parvoviridae/veterinária , Animais , Doenças do Cão/prevenção & controle , Cães , Feminino , Itália , Masculino , Infecções por Parvoviridae/imunologia , Infecções por Parvoviridae/prevenção & controle , Parvovirus Canino/imunologia , Fatores de Tempo , Vacinação/estatística & dados numéricos , Vacinação/veterinária
18.
Vet Res ; 50(1): 72, 2019 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-31551079

RESUMO

Early Neospora caninum infection dynamics were investigated in pregnant heifers intravenously inoculated with PBS (G-Control) or 107 tachyzoites of high (G-NcSpain7)- or low (G-NcSpain1H)-virulence isolates at 110 days of gestation. Serial culling at 10 and 20 days post-infection (dpi) was performed. Fever was detected at 1 dpi in both infected groups (P < 0.0001), and a second peak was detected at 3 dpi only in G-NcSpain7 (P < 0.0001). At 10 dpi, Nc-Spain7 was detected in placental samples from one animal related to focal necrosis, and Nc-Spain7 transmission was observed, although no foetal lesions were associated with this finding. The presence of Nc-Spain1H in the placenta or foetuses, as well as lesions, were not detected at 10 dpi. At 20 dpi, G-NcSpain7 animals showed almost 100% positive placental tissues and severe focal necrosis as well as 100% transmission. Remarkably, foetal mortality was detected in two G-NcSpain7 heifers. Only one animal from G-NcSpain1H presented positive placental samples. No foetal mortality was detected, and lesions and parasite transmission to the foetus were not observed in this group. Finally, 100% of G-NcSpain7 heifers at 20 dpi presented specific antibodies, while only 60% of G-NcSpain1H animals presented specific antibodies at 20 dpi. In addition, earlier seroconversion in G-Nc-Spain7 was observed. In conclusion, tachyzoites from Nc-Spain7 reached the placenta earlier and multiplied, leading to lesion development, transmission to the foetus and foetal mortality, whereas Nc-Spain1H showed delayed infection of the placenta and no lesional development or transmission during early infection.


Assuntos
Doenças dos Bovinos/imunologia , Coccidiose/veterinária , Feto/parasitologia , Neospora/patogenicidade , Placenta/parasitologia , Complicações Parasitárias na Gravidez/veterinária , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Coccidiose/imunologia , Coccidiose/parasitologia , Feminino , Idade Gestacional , Neospora/fisiologia , Gravidez , Complicações Parasitárias na Gravidez/imunologia , Complicações Parasitárias na Gravidez/parasitologia , Vacinação/veterinária , Virulência/genética
19.
J Anim Sci ; 97(10): 4362-4369, 2019 Oct 03.
Artigo em Inglês | MEDLINE | ID: mdl-31504608

RESUMO

This study utilized 204 Angus-based beef steers (249 ± 23 kg SD) from a single ranch with initial serum α-tocopherol concentrations of 3.9 ± 1.0 mg/L to determine the effect of varying doses of vitamin E (VE) on feedlot performance, antibody response to vaccination, and antioxidant defense. Seven days after arrival, steers were blocked by body weight and weaning protocol (preweaned, unweaned heavy, and unweaned light) and randomly assigned to pens within blocks (12 pens per block). Preweaned steers had been weaned for approximately 35 d prior to arrival, and unweaned steers were weaned when leaving the origin ranch. Pens within block were randomly assigned to supplemental VE (ROVIMIX E-50 Adsorbate, DSM Nutritional Products, Heerlen, The Netherlands) treatments (n = 9 pens per treatment): no supplemental VE (CON), 25 IU/kg dry matter (DM; LOW), 500 IU per steer daily (MED), or 1,000 IU per steer daily (HIGH). Back-calculated supplemental VE intake was 0, 151 (24.8 IU/kg DM), 484, and 995 IU/d for CON, LOW, MED, and HIGH, respectively. On day 6, all steers received a booster vaccine against bovine viral diarrhea virus (BVDV; Bovi-Shield Gold, One Shot, Zoetis, Parsippany, NJ). Steers were weighed on day -1, 0, 14, 26, and 27. One steer per pen representative of the average body weight of the pen was chosen as a sampling animal for blood (day -1, 6, 14, 26, and 28) and liver (day -3 and 24). Data were analyzed as a randomized complete block design using Proc Mixed of SAS with pen as the experimental unit and the fixed effects of treatment and block. Linear, quadratic, and cubic contrast statements were constructed using Proc IML; morbidity data were analyzed using Proc Glimmix. Day 24 liver and day 26 serum α-tocopherol concentrations were linearly increased by supplemental VE (P < 0.01). Supplemental VE did not affect DM intake, average daily gain, or gain:feed from day 0 to 27 (P ≥ 0.37), or the percentage of steers treated for respiratory disease (P ≥ 0.44). Day 24 liver glutathione concentrations decreased linearly due to supplemental VE (P ≤ 0.02). Total- and Mn-superoxide dismutase activities were quadratically affected by supplemental VE (P ≤ 0.07), with MED steers exhibiting the greatest activity. Over time, BVDV type 1 and 2 antibody titers numerically decreased, whereas the decrease in BVDV type 1 titers was lesser for HIGH steers (linear P = 0.04). Increasing doses of VE improved VE status but did not affect overall receiving period performance in steers with minimal to adequate VE status upon arrival.


Assuntos
Antioxidantes/farmacologia , Bovinos/fisiologia , Suplementos Nutricionais/análise , Vacinação/veterinária , Vitamina E/farmacologia , Ração Animal/análise , Animais , Formação de Anticorpos/efeitos dos fármacos , Peso Corporal , Bovinos/crescimento & desenvolvimento , Bovinos/imunologia , Dieta/veterinária , Fígado/efeitos dos fármacos , Masculino , Distribuição Aleatória , Desmame
20.
Vet Microbiol ; 236: 108393, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31500729

RESUMO

Monitoring of Marek's disease virus (MDV) and infectious laryngotracheitis virus (ILTV) genome using poultry dust can be useful to monitor on-farm vaccination protocols but there are no set guidelines for collection of this sample type. This study assessed different dust collection methods for MDV and ILTV detection in a vaccinated layer flock (n = 1700) from day-old to 50 weeks of age. Birds were vaccinated against MDV at day-old, and ILTV by drinking water at week 6 and eye drop at week 12. Dust samples were collected weekly by settle plates (1-3 plates/15 m2) or by scraping surfaces in the poultry shed and tested for ILTV and MDV genomic copies (GC) by PCR. ILTV GC were detected 4 weeks post water vaccination, peaked at weeks 12-14 and became mostly undetectable after week 18. MDV was detected in dust on week 1, peaked at weeks 3-6, declined 3 logs by week 26 and remained detectable at this level until week 50. There was no difference in the detection rates of ILTV and MDV collected from settle plates in different locations of the shed (P > 0.10). There was no difference between settle plate and scraped samples in ILTV GC load but higher MDV GC were found in scraped samples. The settle plate method appears to reflect the current level of vaccine virus in the flock while the scrape method likely represents a cumulative record of shedding. Assessment of viral GC in dust samples is a good candidate for a practical method of estimating successful vaccine administration.


Assuntos
Galinhas , Infecções por Herpesviridae/veterinária , Herpesvirus Galináceo 1/isolamento & purificação , Herpesvirus Galináceo 2/isolamento & purificação , Herpesvirus Galináceo 3/isolamento & purificação , Doença de Marek/prevenção & controle , Animais , DNA Viral/genética , Poeira , Feminino , Genoma Viral , Infecções por Herpesviridae/prevenção & controle , Abrigo para Animais , Vacinação/veterinária , Vacinas Virais/administração & dosagem , Vacinas Virais/imunologia
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