Resistance of gastrointestinal nematodes to anthelmintics in sheep (Ovis aries)

Soccol, Vanete Thomaz; Souza, Felipe Pohl de; Sotomaior, Cristina Santos; Castro, Edilene Alcântara de; Milczewski, Viviane; Mocelin, Giovani; Silva, Maria do Carmo Pessoa e

doi:10.1590/s1516-89132004000100006

Cited by 57 publications

(30 citation statements)

References 16 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The aforementioned work represented a pioneering study in Brazil, from the standpoint of anthelmintic combinations and in closantel testing. The latter drug also showed ineffectiveness even when combined to oxfendazole (THOMAZ-SOCCOL et al, 2004), and in this work the highest effectiveness was obtained for moxidectin, a result similar to that found in Londrina by Cunha et al (1998). Recently, the resistance to Monepantel has been reported in sheep in the municipality of Fazenda Rio Grande (CINTRA et al, 2016).…”

Section: Southern Regionsupporting

confidence: 90%

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

View full text Add to dashboard Cite

Frequent and inappropriate use of all classes of antiparasitic drugs in small ruminants has led to failures in their effectiveness, culminating in a global problem of anthelmintic resistance. Brazil stands out as one of the world's leaders in publications about anthelmintic resistance, and for having the most numerous reports of this resistance in small ruminants in the Americas. These studies have involved mainly the fecal egg count reduction test (FECRT) and its correlation with field management practices. In vivo effectiveness testing is conducted in areas where livestock is of greater economic significance, e.g., in the South (sheep) and Northeast (goats), or is important for research and economic centers, such as the Southeast (sheep). The most widely studied species is sheep, for which the widest range of drugs is also evaluated. Despite significant advances achieved in molecular research, laboratory analyses should include knowledge about the reality in the field so that they can become feasible for the producer. Moreover, molecular studies can be underpinned by the analysis of field studies, such as the maintenance of antiparasitic effectiveness over time and the mechanisms involved in this process.Keywords: Small ruminants, anthelmintic resistance, sheep, goat, gastrointestinal nematodes. ResumoO uso frequente e inapropriado de todas as classes de antiparasitários em pequenos ruminantes levou a falhas de eficácia, culminando na problemática global de resistência anti-helmíntica. O Brasil destaca-se como sendo um dos pioneiros nas publicações com resistência anti-helmíntica no mundo e por ter o maior número de relatos em pequenos ruminantes na América. Essas pesquisas envolvem principalmente o teste da redução da contagem de ovos nas fezes (TRCOF) e sua correlação com as práticas de manejo utilizadas no campo. Os estudos de testes de eficácia in vivo localizam-se em áreas onde há maior importância dos rebanhos como nas Regiões Sul (ovinos) e Nordeste (caprinos), ou com importância em polos de pesquisa e econômicos, como a região Sudeste (ovinos). Ovina é a espécie mais estudada e com maior gama de drogas avaliadas. Mesmo com grande avanço em pesquisas moleculares, as análises laboratoriais devem envolver o conhecimento da realidade do campo para que possam se tornar viáveis ao produtor. Além disso, a análise dos estudos de campo pode nortear estudos moleculares como, por exemplo, a manutenção da eficácia das drogas ao longo dos anos e os mecanismos envolvidos em tal processo.

show abstract

Section: Southern Regionsupporting

confidence: 90%

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Salgado

Santos

2016

Rev. Bras. Parasitol. Vet.

View full text Add to dashboard Cite

show abstract

“…With regard to the efficacy noted with the drugs administered individually or in combination, the results of this study corroborate those presented by Sczesny-Moraes et al (2010), but contradict those reported by Soccol et al (2004), Buzzulini et al (2007), Cezar et al (2010), and Holsback et al (2013), all of which found higher efficacies with the administration of drug combinations compared to those obtained with individual drugs.…”

Section: Groupssupporting

confidence: 71%

Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control

Holsback

Luppi

Silva

et al. 2016

Rev. Bras. Parasitol. Vet.

View full text Add to dashboard Cite

The anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, used individually or in combination, was determined by the Fecal Egg Count Reduction (FECR) test and cultivation of larvae of anthelminthic-treated sheep grouped as follows: G1 (doramectin), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectin + fenbendazole), G5 (doramectin + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectin + nitroxynil + fenbendazole), G8 (untreated). In addition to individually used doramectin and fenbendazole, the helminths were also resistant to the combination of doramectin + fenbendazole; nitroxynil + fenbendazole; and doramectin + nitroxynil + fenbendazole, with their FECR rates ranging from 62-83%. The helminths showed possible nitroxynil-resistance, but had low resistance when the drug was administered in combination with doramectin. The evaluation of individual helminth species revealed that fenbendazole was fully effective against Cooperia; doramectin (G1), moderately effective against Haemonchus and insufficiently active against Cooperia; nitroxynil, effective against Haemonchus and insufficiently active against Cooperia. It was concluded from the results that herd nematodes are resistant to doramectin, fenbendazole, and nitroxynil, and that the combined use of the drugs not only fails to significantly improve the anthelmintic efficiency against Haemonchus and Cooperia, but is also cost-ineffective.Keywords: Parasitic resistance, Haemonchus, Cooperia, small ruminants, anthelmintic association. ResumoEficiências da doramectina, fenbendazole e nitroxynil, utilizados individualmente ou associadamente, foram determinadas através do Teste de Redução na Contagem de Ovos nas Fezes (RCOF) e cultivo de larvas. Os grupos experimentais foram os seguintes: G1 (ovinos tratados com doramectina), G2 (fenbendazole), G3 (nitroxynil), G4 (doramectina + fenbendazole), G5 (doramectina + nitroxynil), G6 (fenbendazole + nitroxynil), G7 (doramectina + fenbendazole + nitroxynil) e G8, não tratados. Os helmintos foram considerados resistentes a doramectina e ao fenbendazole isoladamente e às associações doramectina + fenbendazole, fenbendazole + nitroxynil, e doramectina + fenbendazole + nitroxynil, com taxas de RCOF variando de 62-83%. Helmintos foram considerados suspeitos de resistência ao nitroxynil e apresentaram baixa resistência, quando esta droga foi associada à doramectina. Dos tratamentos isolados, o fenbendazole demonstrou total eficácia (100%) contra Cooperia. Doramectina (G1) foi moderadamente efetiva contra Haemonchus e insuficientemente ativa contra Cooperia, e o nitroxynil efetivo contra Haemonchus (93,2%) e insuficientemente ativo contra Cooperia (0%). Concluiu-se neste estudo que os nematódeos do rebanho são resistentes à doramectina, fenbendazole e nitroxynil, e que, ainda que associadas, não devem ser utilizadas no rebanho por não melhorarem a eficiência anti-helmíntica nem a efetividade contra Haemonchus e Cooperia e por não apresentarem custo-benefício justificado.

show abstract

“…In Paraná State, the indiscriminate use of anthelmintics, including blanket treatment of all animals at fixed intervals as short as monthly, bimonthly or even weekly, and treating the entire group when one or more animals demonstrate clinical helminthosis has resulted in high levels of parasitic resistance to all the anthelmintic activity groups available in Brazil for use in sheep flocks (Thomaz-Soccol et al, 2004).…”

Section: Introductionmentioning

confidence: 99%

Sotomaior

Rosalinski-Moraes

Costa

et al. 2012

Veterinary Parasitology

View full text Add to dashboard Cite

Sheep and goats are the species of farm animal with the highest growth rate in Paraná State. The main problems facing Paraná State flocks are gastrointestinal parasites and anthelmintic resistance. One of the newest resources used to slow down the development of anthelmintic resistance is the FAMACHA © system, a selective method useful for controlling gastrointestinal verminosis in small ruminants. The purpose of the present research was to evaluate the sensitivity and specificity of the FAMACHA © system in sheep and goats and to compare the results for both species. The conjunctivae of 83 Suffolk ewes and 60 adult cross-bred Boer does were evaluated by the same trained person using the FAMACHA © system. The packed cell value (PCV) served as the gold standard for clinical FAMACHA © evaluation. To calculate the sensitivity and specificity of the FAMACHA © system, different criteria were adopted in turn: animals classified as FAMACHA © (F © ) 4 and 5, or 3, 4 and 5, were consid-ered to be anemic (positive test), and animals classified as F © 1, 2 and 3, or 1 and 2 were considered to be non-anemic (negative test). Three standard values of PCV, namely ≤19%, ≤18% or ≤15%, were used to confirm anemia. At all cut-off levels, the sensitivity increased if F © 3 animals were included as being anemic. However, changes in levels of sensitivity were associated with reciprocal changes in specificity. The sensitivity was higher for sheep than for goats, excepting when the criteria included PCV ≤ 18 and F © 3, F © 4 and F © 5 were considered positive. In contrast, the specificity was always lower in sheep for any criteria adopted. Other than in goats, using the ≤15 cut-off level for sheep, it is possible to opt not to drench the animals that were shown to be F © 3 because the sensitivity is still high, indicating that few animals that should have been drenched were overlooked. In goats, in contrast, the low sensitivity at all cut-off levels made it too risky to leave F © 3 animals undrenched. Even though the number of correct treatments for goats was always higher than that for sheep, the opposite was true for the kappa index for all the criteria tested. Therefore, the FAMACHA © system is suitable for the identification of anemic animals of both species. It is necessary that all small ruminants classified as FAMACHA © level 3 are also treated to increase the sensitivity of the method.

show abstract

Resistance of gastrointestinal nematodes to anthelmintics in sheep (Ovis aries)

Abstract: The fecal egg count reduction test (FECRT)

Cited by 57 publications

References 16 publications

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Overview of anthelmintic resistance of gastrointestinal nematodes of small ruminants in Brazil

Anthelmintic efficiency of doramectin, fenbendazole, and nitroxynil, in combination or individually, in sheep worm control

Sensitivity and specificity of the FAMACHA© system in Suffolk sheep and crossbred Boer goats

Contact Info

Product

Resources

About