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1.
Vet Clin North Am Food Anim Pract ; 37(1): 1-16, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33541693

RESUMO

Small ruminants are increasing in popularity as both production and companion animals in the United States. Among sheep, goats, and camelids, there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. This review focuses on the commonly used medications available for pain management of small ruminants and discusses the benefits and negative aspects of their use.


Assuntos
Camelídeos Americanos , Doenças das Cabras/tratamento farmacológico , Manejo da Dor/veterinária , Dor/veterinária , Doenças dos Ovinos/tratamento farmacológico , Analgésicos/uso terapêutico , Animais , Cabras , Ovinos
2.
Vet Clin North Am Food Anim Pract ; 37(1): 17-31, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33541697

RESUMO

Small ruminants are increasing in popularity as production and companion animals in the United States, and among sheep, goats, and camelids there are many disease processes and management techniques that have the potential to result in painful or noxious stimuli. In these species, many medications and therapeutic techniques can be used to reduce or eliminate the long-term consequences of pain. In this second portion of the review, we focus on the application of pain management in these species. These strategies include mono- and multimodal and the use of precision pain management, such as epidural drug administration, regional perfusions, and transdermal applications.


Assuntos
Camelídeos Americanos , Doenças das Cabras/tratamento farmacológico , Manejo da Dor/veterinária , Dor/veterinária , Doenças dos Ovinos/tratamento farmacológico , Analgesia/métodos , Analgesia/veterinária , Animais , Cabras , Dor/tratamento farmacológico , Manejo da Dor/métodos , Ruminantes , Ovinos , Estados Unidos
3.
J Anim Sci ; 99(1)2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33454733

RESUMO

Plant extracts have been widely used in animal production systems due to the benefits promoted by their bioactive components, mainly through their antioxidant effects and positive effects on animal growth, health, and meat quality. We determined whether bioactive compounds (BC) from grape (Vitis vinifera), olive (Olea europaea), and pomegranate (Punica granatum) have beneficial effects on lamb growth while controlling gastrointestinal parasitism and reducing skeletal lipid peroxidation in muscle. Fourteen lambs (4 to 5 mo of age) were housed in individual pens and assigned to two treatment groups (seven animals/group), where they received: 1) a basal diet of beet pulp:soybean meal (90:10) (CONTROL) and 2) the same diet, but containing 0.3% of BC extracted from grape, olive, and pomegranate (BNP). After 21 d of consuming their respective rations (period 1), all lambs were dosed with 10,000 L3 stage larvae of Haemonchus contortus. Intake, production, and physiological parameters were determined before infection (period 1), after oral dosage with L3 (period 2), and during early (period 3) and later (period 4) developmental stages of infection. Groups of animals did not differ in their ration intake or average daily gain, either before or after the infection, or in their parasitic burdens estimated through fecal egg counts (P > 0.05). Lambs under BNP showed greater feed efficiency before infection (P < 0.001), but the pattern reversed after infection. In addition, the inclusion of plant bioactives to the diet did not have an effect (P > 0.05) on blood or lipid peroxidation in muscle or on hemogram, serum concentration of haptoglobin, and immunoglobulin E. These results could be explained by low dietary doses and constrained absorption or ruminal inactivation of these compounds. Changes in feed efficiencies suggest a negative interaction between BC in the diet and parasitism, which warrants further research.


Assuntos
Parasitos , Doenças dos Ovinos , Ração Animal/análise , Animais , Dieta/veterinária , Peroxidação de Lipídeos , Músculos , Contagem de Ovos de Parasitas/veterinária , Compostos Fitoquímicos , Ovinos , Doenças dos Ovinos/tratamento farmacológico
4.
Exp Parasitol ; 218: 107980, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32877640

RESUMO

Acacia farnesiana pods are rich in secondary metabolites and their biological activities have been recorded as antibacterial, antioxidant and anthelmintic. Previously, an in vitro bioguided study showed the important ovicidal and larvicidal effects of an organic fraction (EtOAc-F) from a hydroalcoholic extract of A. farnesiana pods against Haemonchus contortus. The present study aimed to assess the in vivo anthelmintic effect of EtOAc-F from A. farnesiana pods on the H. contortus faecal egg elimination in female lambs and on the infective larvae (L3) population reduction in coprocultures. The EtOAc-F was obtained from a hydroalcoholic extract from A. farnesiana pods through chromatographic procedures; additionally, some secondary compounds were identified using high-performance liquid chromatography (HPLC). Twenty-one 'Katahdin' crossbred female lambs ranging from three to four months of age, with body weights 21.9 ± 0.39 kg were used. Animals were orally infected with H. contortus (L3) by a single dose of 350 L3/kg BW. Three experimental groups (n = 7) were assigned as follows: 1) Control (untreated), 2) Albendazole, as a positive control (at 7.5 mg/kg BW, unique dose) and 3) EtOAc-F (at 100 mg/kg BW, once every third day, with three applications in total). Individual faecal samples were collected once a week for 5 weeks (at days 38, 45, 52, 59 and 66) post-treatment, to measure the faecal egg counts (FEC) and to obtain the H. contortus (L3) population from faecal cultures. The highest FEC reduction caused by EtOAc-F was 67.7%; meanwhile, albendazole showed a total FEC reduction after the second week post-treatment (day 45). On the other hand, the fraction caused an important reduction in the larval population in coprocultures (54.3-68.5%). The phytochemical analysis revealed the presence of galloyl derivatives and flavonoids as major compounds. The A. farnesiana pods could serve as a natural anthelmintic for the control of H. contortus, and perhaps for controlling other parasites of veterinary importance.


Assuntos
Acacia/química , Anti-Helmínticos/uso terapêutico , Hemoncose/veterinária , Extratos Vegetais/uso terapêutico , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/isolamento & purificação , Anti-Helmínticos/farmacologia , Fezes/parasitologia , Feminino , Flavonoides/química , Ácido Gálico/química , Hemoncose/tratamento farmacológico , Hemoncose/parasitologia , Haemonchus/efeitos dos fármacos , Haemonchus/isolamento & purificação , Hematócrito/veterinária , Contagem de Ovos de Parasitas/veterinária , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/farmacologia , Distribuição Aleatória , Ovinos , Doenças dos Ovinos/parasitologia
5.
Exp Parasitol ; 218: 107998, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32941889

RESUMO

The aims of this study were to evaluate the efficacy of two injectable formulations of doramectin (DRM) against Psoroptes ovis in sheep infested under controlled experimental conditions and to characterize the DRM plasma disposition kinetics in the infested animals. To this end, sheep were experimentally infested with a P. ovis strain from a farm with a history of treatment failure, and then treated either with DRM 1% (traditional preparation) on days 0 and 7 or with DRM 3.15% (long-acting formulation) on day 0. The efficacy of each treatment was calculated by counting live mites in skin scrapings. Plasma samples were obtained from each animal and DRM concentrations were measured by HPLC. After the two doses of DRM 1%, the maximum efficacy (98.8%) was reached on day 28, whereas after the single dose of DRM 3.15%, the maximum efficacy (100%) was reached on day 35 and ratified on day 42. The long-acting formulation allowed obtaining higher exposure and more sustained concentrations of DRM than the traditional preparation. Although both DRM formulations studied were effective according to international protocols, they did not reach 100% effectiveness in the time required for approved pharmaceutical products against sheep scab, according to Argentine regulations.


Assuntos
Inseticidas/uso terapêutico , Ivermectina/análogos & derivados , Infestações por Ácaros/veterinária , Psoroptidae/efeitos dos fármacos , Doenças dos Ovinos/tratamento farmacológico , Animais , Disponibilidade Biológica , Feminino , Meia-Vida , Injeções Subcutâneas/veterinária , Inseticidas/administração & dosagem , Inseticidas/sangue , Inseticidas/farmacologia , Ivermectina/administração & dosagem , Ivermectina/sangue , Ivermectina/farmacologia , Ivermectina/uso terapêutico , Masculino , Infestações por Ácaros/tratamento farmacológico , Psoroptidae/crescimento & desenvolvimento , Ovinos , Doenças dos Ovinos/parasitologia
6.
PLoS One ; 15(8): e0236143, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32790679

RESUMO

The focus of gastro-intestinal parasite control in the sheep industry is increasingly on finding a balance between maintaining productivity of the flock whilst minimising selection for anthelmintic resistance to preserve anthelmintic efficacy for the future. Periparturient ewes represent the major source of gastro-intestinal parasites for growing lambs and are therefore a priority for parasite control. This study examines the impact on ewe faecal egg counts (FECs), lamb FECs, lamb daily live weight gains (DLWGs) and pasture larval counts of treating groups of ewes two weeks prior to lambing with either, a long-acting moxidectin treatment, short-acting doramectin or control. Six groups of twenty ewes were allocated to individual paddocks, two groups allocated to each treatment, and weekly faecal sampling was performed throughout from the ewes and from six weeks after the start of lambing in the lambs. Treatment group was found to have a significant effect on both ewe FEC (p<0.001) and lamb FEC (p = 0.001) with the group receiving the long-acting anthelmintic having the lowest ewe and lamb FECs. There was no significant effect on the DLWGs of the lambs. Pasture larval counts at the end of the study period were lowest in the long-acting wormer treatment group. The use of long-acting moxidectin may be helpful as part of a parasite control programme by reducing the worm burdens of ewes and their lambs, decreasing the number of anthelmintic treatments required in that year and by reducing pasture contamination for those sheep which will graze the pasture in the next year. However, like all anthelmintics, its use should be judicious to avoid selection for resistance.


Assuntos
Criação de Animais Domésticos/métodos , Anti-Helmínticos/administração & dosagem , Infecções por Nematoides/veterinária , Doenças dos Ovinos/tratamento farmacológico , Ovinos/parasitologia , Animais , Anti-Helmínticos/farmacocinética , Fazendas , Fezes/parasitologia , Feminino , Meia-Vida , Ivermectina/administração & dosagem , Ivermectina/análogos & derivados , Ivermectina/farmacocinética , Larva , Macrolídeos/administração & dosagem , Macrolídeos/farmacocinética , Nematoides/isolamento & purificação , Infecções por Nematoides/diagnóstico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas/veterinária , Período Pós-Parto , Gravidez , Doenças dos Ovinos/diagnóstico , Doenças dos Ovinos/parasitologia
7.
Parasitol Res ; 119(8): 2687-2693, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32514648

RESUMO

In this work, we compare and evaluate the efficiency of fosfatriclaben with three commercial fasciolicides in experimentally infected sheep. Fosfatriclaben is a novel prodrug derived from triclabendazole; it is highly water-soluble with excellent aqueous stability at pH 7, properties that make it ideal for developing intramuscular pharmaceutical compositions in the form of solutions. In order to compare, 30 mixed breed sheep, previously diagnosed negative to fluke eggs, were infected with 200 metacercariae of Fasciola hepatica, twice. Five groups of six animals/each were formed for treatments. Group 1 (G1) was treated with closantel 5% injectable at 5 mg/kg subcutaneously, G2 with clorsulon at 2 mg/kg subcutaneously, G3 with triclabendazole at 12 mg/kg per os, G4 with fosfatriclaben at 6 mg/kg intramuscularly (dose equivalent to triclabendazole content), and G5 remained as the non-treated control. On day 110, fecal samples were examined to determine the percentage of egg reduction after treatment, and sheep were humanely euthanized. The livers were collected, the flukes were extracted, measured, and counted. Efficiency in egg reduction was of 86.8, 90.5, 98.4, and 97.3% for closantel, clorsulon, triclabendazole, and fosfatriclaben, respectively, and efficiency against flukes was of 96.2, 91.9, 99.4, and 95.7%, respectively. No statistical differences were found between treatments. It is concluded that fosfatriclaben at 6 mg/kg intramuscularly presented a high fasciolicide efficiency, similar to the best commercial fasciolicides, having advantage over its predecessor since it uses half of the dose required by triclabendazole to remove flukes in sheep under study.


Assuntos
Anti-Helmínticos/uso terapêutico , Fasciola hepatica/efeitos dos fármacos , Fasciolíase/veterinária , Doenças dos Ovinos/tratamento farmacológico , Animais , Fasciolíase/tratamento farmacológico , Fezes/parasitologia , Contagem de Ovos de Parasitas , Ovinos , Resultado do Tratamento
8.
PLoS One ; 15(6): e0235072, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32574178

RESUMO

The abomasal parasitic nematode Haemonchus contortus can influence the abomasal microbiome of the host. On the other hand, no information occurs on the influence of the parasite on the hindgut microbiome of the host. We evaluated the impact of Haemonchus contortus on the fecal microbial community of the experimentally infected lambs treated with a mixture of medicinal herbs to ameliorate the haemonchosis. Twenty-four female lambs were divided into four groups: infected animals (Inf), infected animals supplemented with a blend of medicinal herbs (Inf+Herb), uninfected control animals (Control), and uninfected animals supplemented with medicinal herbs (C+Herb). Inf and Inf+Herb lambs were infected orally with approximately 5000 L3 larvae of a strain of H. contortus susceptible to anthelmintics (MHco1). Herb blend (Herbmix) consisted of dry medicinal plants of Althaea officinalis, Petasites hybridus, Inula helenium, Malva sylvestris, Chamomilla recutita, Plantago lanceolata, Rosmarinus officinalis, Solidago virgaurea, Fumaria officinalis, Hyssopus officinalis, Melisa officinalis, Foeniculum vulgare, and Artemisia absinthium. Each animal was fed meadow hay and a commercial concentrate (600 + 350 g DM/d). Inf+Herb and C+Herb lambs were fed Herbmix (100 g DM/d and animal). Treatment lasted for 50 days. The fecal microbial fermentation parameters (short-chain fatty acids, ammonia, and pH) were evaluated at intervals of 0, 20, 32, and 50 days. The fecal eubacterial populations were evaluated by denaturing gradient gel electrophoresis (DGGE) at day 32 when H. contortus infection was the highest. No substantial effects of the H. contortus infection and the herbal treatment on fecal microbial fermentation parameters and fecal eubacterial populations were observed. Evaluation of DGGE patterns by Principal component analysis pointed to the tendency to branch the C+Herb group from the other experimental groups on Day 32. The results indicate that hindgut microbial activity was not disturbed by H. contortus infection and herbal treatment.


Assuntos
Abomaso/efeitos dos fármacos , Sistema Digestório/efeitos dos fármacos , Hemoncose/tratamento farmacológico , Haemonchus/efeitos dos fármacos , Preparações de Plantas/farmacologia , Plantas Medicinais/química , Doenças dos Ovinos/tratamento farmacológico , Abomaso/microbiologia , Abomaso/parasitologia , Animais , Anti-Helmínticos/farmacologia , Sistema Digestório/microbiologia , Sistema Digestório/parasitologia , Quimioterapia Combinada , Fezes/microbiologia , Fezes/parasitologia , Feminino , Hemoncose/parasitologia , Hemoncose/veterinária , Haemonchus/fisiologia , Microbiota/efeitos dos fármacos , Microbiota/fisiologia , Fitoterapia/métodos , Plantas Medicinais/classificação , Ovinos , Doenças dos Ovinos/parasitologia , Especificidade da Espécie
9.
Vet Parasitol ; 281: 109121, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32361524

RESUMO

The search of novel strategies for anthelmintic control is a crucial need considering the widespread increase in resistant parasitic populations in livestock. Bioactive phytochemicals may contribute to improve parasite control by enhancing the effect of existing anthelmintic drugs. The aim of the current work was to evaluate the in vivo and in vitro pharmaco-chemical interaction and the in vivo efficacy of the combination of albendazole (ABZ) with thymol (TML) in lambs naturally infected with resistant gastrointestinal nematodes. Thirty (30) lambs were allocated into three experimental groups. Each group was treated orally with either ABZ (5 mg/kg), TML (150 mg/kg, twice every 24 h) or the co-administration of both compounds. Blood samples were collected between 0 and 51 h post-treatment and TML, ABZ and its metabolites were measured by HPLC. Individual faecal samples were collected at days -1 and 14 post-treatment to perform the faecal egg count reduction test. Additionally, the effect of TML on the sulphoreduction and sulphonation of ABZ sulphoxide was assessed in vitro using ruminal content and liver microsomes, respectively. The metabolism of TML in the ruminal content was very low and the monoterpene exhibited a low degree of association with the particulate phase of the ruminal content. No changes in the pharmacokinetic behavior of ABZ sulphoxide were observed in the presence of the natural product (TML). In contrast, the ABZ sulphone Cmax and AUC were lower (P 0.002 and 0.001 respectively) in the co-administered animals (0.16 ±â€¯0.07 µg/mL and 3.63 ±â€¯1.21 µg.h/mL) compared with those that received ABZ alone (0.45 ±â€¯0.15 µg/mL and 9.50 ±â€¯2.84 µg.h/mL). TML was detected in the bloodstream between 1 and 48 h post-treatment, which indicates the time of target nematodes being exposed to the bioactive monoterpene. However, the in vivo efficacy of TML was 0% and the presence of this terpene did not increase the efficacy of ABZ. The presence of TML significantly inhibited the ruminal sulphoreduction (P 0.001) and the hepatic sulphonation (P 0.001) of ABZ sulphoxide. These observations point out that in vivo pharmaco-parasitological studies are relevant to corroborate the adverse kinetic/metabolic interactions and the efficacy of bioactive natural products combined with synthetic anthelmintics.


Assuntos
Albendazol/administração & dosagem , Resistência a Medicamentos/efeitos dos fármacos , Gastroenteropatias/tratamento farmacológico , Helmintíase Animal/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Timol/administração & dosagem , Animais , Anti-Helmínticos/administração & dosagem , Anti-Helmínticos/farmacologia , Quimioterapia Combinada , Gastroenteropatias/parasitologia , Helmintíase Animal/parasitologia , Compostos Fitoquímicos/farmacologia , Ovinos , Doenças dos Ovinos/parasitologia , Resultado do Tratamento
10.
Trop Anim Health Prod ; 52(5): 2213-2219, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32388661

RESUMO

Endoparasitic nematode infection could have negative impacts on performances of sheep and goats. However, supplementary protein and minerals can also affect nematodes. This paper reviews present information on the importance of protein and minerals supplementation as means to control nematode infection in small ruminants. Protein supplementation seems to improve host resilience by diverting metabolizable protein (MP) towards dealing with detrimental effects of the infection and thus improve production and reproductive performances of animal. A large body of evidence shows that supplementation of copper, iron, and zinc can also enhance host resistance against nematode infection as shown by decreased fecal egg count (FEC) and worm burdens. As such, protein and mineral supplementations can play a major role in sustainable control of parasitic nematode infection and thus reduce reliance on chemotherapic drugs.


Assuntos
Proteínas na Dieta/metabolismo , Doenças das Cabras/tratamento farmacológico , Minerais/metabolismo , Infecções por Nematoides/veterinária , Substâncias Protetoras/farmacologia , Doenças dos Ovinos/tratamento farmacológico , Ração Animal/análise , Animais , Dieta/veterinária , Proteínas na Dieta/administração & dosagem , Suplementos Nutricionais/análise , Doenças das Cabras/parasitologia , Cabras , Minerais/administração & dosagem , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/parasitologia , Ovinos , Doenças dos Ovinos/parasitologia , Carneiro Doméstico
11.
Aust Vet J ; 98(10): 478-485, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32458456

RESUMO

OBJECTIVE: A producer survey by questionnaire assessed supplements used in sheep and reasons for use. This was followed by field trials on eight sheep properties in SE NSW to determine the effect of commonly used commercially available supplements on growth rates of Merino and crossbred lambs. DESIGN: On each property, 450 lambs were selected at weaning and randomly allocated to nine groups of 50 sheep (eight treatment and a control group). Supplements were applied as per manufacturer's recommendation every 6-12 weeks. At each application, all sheep were weighed and data on general flock health and management were collected. RESULTS: All but one of the survey respondents (n = 77) had used supplements in their sheep at some stage. The reasons for use were most commonly for general health and production benefits (n = 21; 26.9%) and to prevent or treat specific diseases/deficiencies (n = 7; 9.0%). The average daily weight gains (ADWG) of the lambs over the trial period varied from 0.074 kg to 0.213 kg/head/day. Statistical analysis showed that overall there was not a significant difference (P = 0.587) between ADWG among lambs that received supplements and lambs that did not. CONCLUSION: Results of this study show that application of supplements were not linked to improved growth rates in clinically normal crossbred and Merino lambs under the trial farm conditions between weaning and 15 months of age. Effects of supplements on health and production in adult sheep and how supplement response can be best measured in sheep flocks (especially in relation to health and welfare) and linked to productivity requires further investigation.


Assuntos
Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/prevenção & controle , Animais , Austrália , Suplementos Nutricionais , Micronutrientes , Ovinos , Desmame
12.
Res Vet Sci ; 130: 240-246, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32234614

RESUMO

Ozone (O3) is a triatomic form of oxygen. As O3 rapidly dissociates into water and releases a reactive form of oxygen that may oxidize cells, the gas mixture of O3/O2 is used in medicine. ATP is widely available for cellular activity. O3 can be administered via the systemic and local routes. Although O3 is known as one of the most powerful oxidants, it also promotes antioxidant enzymes. Additionally, it stimulates some of the cells of the immune system and inactivates pathogens, including bacteria, fungi, yeasts, protozoa, and viruses. Owing to these activities, O3 is used to improve several diseases, both in human and in veterinary medicine. Considering the wide scope of O3 application, the aim of this review was to reiterate the mechanisms of action of O3 and its utilization in different mammalian species (bovine, ovine-caprine, equine, canine, porcine).


Assuntos
Ozônio/uso terapêutico , Animais , Antioxidantes , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças do Cão/tratamento farmacológico , Cães , Doenças das Cabras/tratamento farmacológico , Cabras , Doenças dos Cavalos/tratamento farmacológico , Cavalos , Oxidantes , Oxirredução , Ozônio/administração & dosagem , Pró-Fármacos , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Suínos , Doenças dos Suínos/tratamento farmacológico
13.
Artigo em Inglês | MEDLINE | ID: mdl-32251964

RESUMO

Benzimidazoles (BZ) have been the anthelmintic of choice for controlling Nematodirus battus infections since their release in the 1950s. Despite heavy reliance on this single anthelmintic drug class, resistance was not identified in this nematode until 2010 (Mitchell et al., 2011). The study aimed to explore the prevalence of BZ-resistance mutations in N. battus from UK sheep flocks using deep amplicon sequencing and pyrosequencing platforms. Based on evidence from other gastrointestinal nematodes, resistance in N. battus is likely to be conferred by single nucleotide polymorphisms (SNP) within the ß-tubulin isotype 1 locus at codons 167, 198 and 200. Pyrosequencing and deep amplicon sequencing assays were designed to identify the F167Y (TTC to TAC), E198A (GAA to GCA) and F200Y (TTC to TAC) SNPs. Nematodirus battus populations from 253 independent farms were analysed by pyrosequencing; 174 farm populations were included in deep amplicon sequencing and 170 were analysed using both technologies. F200Y was the most prevalent SNP identified throughout the UK, in 12-27% of the populations tested depending on assay, at a low overall individual frequency of 2.2 ±â€¯0.6% (mean ±â€¯SEM, based on pyrosequencing results). Four out of the five populations with high frequencies (>20%) of the F200Y mutation were located in NW England. The F167Y SNP was identified, for the first time in this species, in four of the populations tested at a low frequency (1.2% ±â€¯0.01), indicating the early emergence of the mutation. E198A or E198L were not identified in any of the isolates. Results obtained were comparable between both techniques for F200Y (Lins' CCC, rc = 0.96) with discrepancies being limited to populations with low frequencies. The recent emergence of resistance in this species will provide a unique opportunity to study the early stages of anthelmintic resistance within a natural setting and track its progress in the future.


Assuntos
Benzimidazóis/farmacologia , Resistência a Medicamentos/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Nematodirus/genética , Doenças dos Ovinos/parasitologia , Infecções por Strongylida/veterinária , Animais , Anti-Helmínticos/farmacologia , Fazendas , Fezes/parasitologia , Frequência do Gene , Genótipo , Mutação , Nematodirus/efeitos dos fármacos , Análise de Sequência de DNA , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/epidemiologia , Infecções por Strongylida/tratamento farmacológico , Infecções por Strongylida/epidemiologia , Reino Unido/epidemiologia
14.
Vet Res ; 51(1): 36, 2020 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-32138772

RESUMO

Mannheimia haemolytica serotype A2 is the principal cause of pneumonic mannheimiosis in ovine and caprine livestock; this disease is a consequence of immune suppression caused by stress and associated viruses and is responsible for significant economic losses in farm production worldwide. Gram-negative bacteria such as M. haemolytica produce outer membrane (OM)-derived spherical structures named outer membrane vesicles (OMVs) that contain leukotoxin and other biologically active virulence factors. In the present study, the relationship between M. haemolytica A2 and bovine lactoferrin (BLf) was studied. BLf is an 80 kDa glycoprotein that possesses bacteriostatic and bactericidal properties and is part of the mammalian innate immune system. Apo-BLf (iron-free) showed a bactericidal effect against M. haemolytica A2, with an observed minimal inhibitory concentration (MIC) of 16 µM. Sublethal doses (2-8 µM) of apo-BLf increased the release of OMVs, which were quantified by flow cytometry. Apo-BLf modified the normal structure of the OM and OMVs, as observed through transmission electron microscopy. Apo-BLf also induced lipopolysaccharide (LPS) release from bacteria, disrupting OM permeability and functionality, as measured by silver staining and SDS and polymyxin B cell permeability assays. Western blot results showed that apo-BLf increased the secretion of leukotoxin in M. haemolytica A2 culture supernatants, possibly through its iron-chelating activity. In contrast, holo-BLf (with iron) did not have this effect, possibly due to differences in the tertiary structure between these proteins. In summary, apo-BLf affected the levels of several M. haemolytica virulence factors and could be evaluated for use in animals as an adjuvant in the treatment of ovine mannheimiosis.


Assuntos
Antibacterianos/farmacologia , Exotoxinas , Lactoferrina/farmacologia , Mannheimia haemolytica/efeitos dos fármacos , Pasteurelose Pneumônica/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Mannheimia haemolytica/fisiologia , Ovinos
15.
Vet Clin North Am Food Anim Pract ; 36(1): 17-30, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029182

RESUMO

Control of gastrointestinal nematodes has been based on anthelmintics. However, this strategy is unsustainable owing to anthelmintic resistance. Parasitic nematodes have biologic and genetic features that favor the development of drug resistance, making the emergence of resistant nematodes inevitable. The rate of resistance development is affected controllable factors. There is a need to change the paradigm of how gastrointestinal nematodes are controlled to decrease the rate at which resistance develops. This article reviews the biology and prevalence of anthelmintic resistance, and provides recommendations for diagnosing resistance and for strategies that should be implemented to reduce the development of resistance.


Assuntos
Anti-Helmínticos/farmacologia , Doenças dos Bovinos/tratamento farmacológico , Doenças das Cabras/tratamento farmacológico , Gado/parasitologia , Infecções por Nematoides/veterinária , Doenças dos Ovinos/tratamento farmacológico , Animais , Bovinos , Doenças dos Bovinos/epidemiologia , Doenças dos Bovinos/parasitologia , Resistência a Medicamentos , Doenças das Cabras/epidemiologia , Doenças das Cabras/parasitologia , Cabras , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Prevalência , Ovinos , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/parasitologia
16.
Vet Clin North Am Food Anim Pract ; 36(1): 31-43, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029187

RESUMO

Refugia-based strategies are intended to help slow the development of anthelmintic resistance by providing a population of parasites that are not exposed to the treatment. Evidence from field studies is lacking. There is no single way to incorporate refugia into a parasite control program. There are many options available varying greatly in complexity and practicality, and none are suitable for all situations. Incorporating refugia into production systems typically requires a change in farmer mindset and greater input of time, labor, and/or technology, but is necessary to help preserve anthelmintic efficacy and promote sustainable animal production systems.


Assuntos
Criação de Animais Domésticos/métodos , Anti-Helmínticos/administração & dosagem , Doenças dos Bovinos/tratamento farmacológico , Doenças das Cabras/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Bovinos , Resistência a Medicamentos , Cabras , Gado/parasitologia , Refúgio de Vida Selvagem , Ovinos
17.
Vet Clin North Am Food Anim Pract ; 36(1): 73-87, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029190

RESUMO

Strongylid gastrointestinal nematodes are an important cause of disease and economic loss in small ruminants. These parasites are important in most of the United States, with the bloodsucking parasite Haemonchus contortus being the predominant species of concern. Sheep and goats are infected while grazing, and the biology of infective larvae on pastures is important in the design of parasite management programs. Widespread resistance to anthelmintics requires strategies designed to preserve remaining drug activity; these include combination treatments with multiple classes of anthelmintics and targeted treatments.


Assuntos
Doenças das Cabras/epidemiologia , Doenças das Cabras/prevenção & controle , Infecções por Nematoides/veterinária , Doenças dos Ovinos/epidemiologia , Doenças dos Ovinos/prevenção & controle , Animais , Anti-Helmínticos/administração & dosagem , Trato Gastrointestinal/parasitologia , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Cabras , Nematoides/isolamento & purificação , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/epidemiologia , Infecções por Nematoides/prevenção & controle , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia
18.
Vet Clin North Am Food Anim Pract ; 36(1): 89-107, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32029191

RESUMO

It is increasingly difficult to manage and control gastrointestinal nematode parasites in pasture-based ruminant livestock operations because of the high prevalence of anthelmintic resistance. Anthelmintics should be combined with alternative forms of control. Sustainable tools include copper oxide wire particles and condensed tannin-rich plants, which target primarily Haemonchus contortus in small ruminants. Nematophagous fungi reduce larvae on pasture and target nematode larvae in feces of most livestock species. In addition, and perhaps most importantly, genetic selection focuses on parasite resistance. Producers should use as many tools as possible to minimize the need for pharmaceutical interventions and optimize animal production.


Assuntos
Hemoncose/veterinária , Animais , Anti-Helmínticos/administração & dosagem , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Cobre/administração & dosagem , Doenças das Cabras/tratamento farmacológico , Doenças das Cabras/parasitologia , Cabras , Hemoncose/tratamento farmacológico , Haemonchus/isolamento & purificação , Gado/parasitologia , Proantocianidinas/administração & dosagem , Ruminantes/parasitologia , Ovinos , Doenças dos Ovinos/tratamento farmacológico , Doenças dos Ovinos/parasitologia
20.
Rev Bras Parasitol Vet ; 29(1): e013119, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32049139

RESUMO

The objective of this study was to evaluate the efficacy of carvacryl acetate (CVA) and nanoencapsulated CVA (nCVA) on gastrointestinal nematodes of sheep. The CVA was nanoencapsulated with chitosan/gum arabic and the efficacy of nanoencapsulation (EE), yield, zeta potential, nanoparticle morphology and release kinetics at pH 3 and 8 were analyzed. Acute and subchronic toxicity were evaluated in rodents and reduction of egg counts in the faeces (FECRT) of sheep. The sheep were divided into four groups (n = 10): G1, 250 mg/kg CVA; G2, 250 mg/kg nCVA; G3, polymer matrix and G4: 2.5 mg/kg monepantel. EE and nCVA yield were 65% and 57%, respectively. The morphology of the nanoparticles was spherical, size (810.6±286.7 nm), zeta potential in pH 3.2 (+18.3 mV) and the 50% release of CVA at pHs 3 and 8 occurred at 200 and 10 h, respectively. nCVA showed LD50 of 2,609 mg/kg. CVA, nCVA and monepantel reduced the number of eggs per gram of faeces (epg) by 57.7%, 51.1% and 97.7%, respectively. The epg of sheep treated with CVA and nCVA did not differ from the negative control (P>0.05). Nanoencapsulation reduced the toxicity of CVA; however, nCVA and CVA presented similar results in the FECRT.


Assuntos
Anti-Helmínticos/administração & dosagem , Trato Gastrointestinal/parasitologia , Monoterpenos/administração & dosagem , Nanocápsulas/administração & dosagem , Nematoides/efeitos dos fármacos , Infecções por Nematoides/tratamento farmacológico , Doenças dos Ovinos/tratamento farmacológico , Animais , Anti-Helmínticos/toxicidade , Fezes/parasitologia , Feminino , Camundongos , Monoterpenos/toxicidade , Nanocápsulas/toxicidade , Nematoides/classificação , Nematoides/isolamento & purificação , Infecções por Nematoides/parasitologia , Contagem de Ovos de Parasitas , Testes de Sensibilidade Parasitária , Reação em Cadeia da Polimerase em Tempo Real , Roedores , Ovinos , Doenças dos Ovinos/parasitologia , Testes de Toxicidade
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