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Strongyle infections and parasitic control strategies in German horses - a risk assessment.

Schneider S, Pfister K, Becher AM, Scheuerle MC - BMC Vet. Res. (2014)

Bottom Line: The mean time since last treatment was 6.3 months.The planned treatment date was already exceeded by 72.5% of the high egg-shedders and by 58.1% of the moderate (200-500 EPG) and low egg-shedders (20-199 EPG).Therefore, to minimize the risks for disease, consistent and efficient parasite control should be implemented.

View Article: PubMed Central - PubMed

Affiliation: Comparative Tropical Medicine and Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, Leopoldstr. 5, D-80802, Munich, Germany. Stephanie_Schneider82@yahoo.de.

ABSTRACT

Background: As a consequence of the increasing levels of anthelmintic resistance in cyathostomes, new strategies for equine parasite control are being implemented. To assess the potential risks of these, the occurrence of strongyles was evaluated in a group of 1887 horses. The distribution of fecal egg counts (FECs), the frequency of anthelmintic drug use, and the deworming intervals were also analyzed. Between June 2012 and May 2013, 1887 fecal samples from either selectively or strategically dewormed horses were collected at 195 horse farms all over Germany and analyzed quantitatively with a modified McMaster technique. All samples with FEC ≥20 eggs per gram (EPG) were subjected to coproculture to generate third-stage larvae (LIII) for species differentiation.

Results: Egg counts were below the limit of detection (20 EPG) in 1046 (55.4%) samples and above it in 841 (44.6%) samples. Strongylus vulgaris larvae were identified in two of the 841 positive samples. Infections with cyathostomes were found on every farm. The most frequently applied anthelmintic was ivermectin (788/50.8%), followed by pyrantel (336/21.6%). The mean time since last treatment was 6.3 months. High-egg-shedding (>500 EPG) strategically dewormed horses (183/1357) were treated, on average, three times/year. The planned treatment date was already exceeded by 72.5% of the high egg-shedders and by 58.1% of the moderate (200-500 EPG) and low egg-shedders (20-199 EPG).

Conclusions: S. vulgaris seems to be rare in Germany and no difference in its frequency has yet been found between selectively treated horses and horses receiving treatment in strategic intervals. However, inconsistent parasite control has been observed. Therefore, to minimize the risks for disease, consistent and efficient parasite control should be implemented.

No MeSH data available.


Related in: MedlinePlus

Time (weeks) since the last anthelmintic treatment. Comparison of the selectively (a) and strategically (b) treated horse groups (numbers in each group and percentages).
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Fig2: Time (weeks) since the last anthelmintic treatment. Comparison of the selectively (a) and strategically (b) treated horse groups (numbers in each group and percentages).

Mentions: The data for 81.5% (1538/1887) of the horses were available for this analysis: 393 selectively treated horses and 1145 strategically treated horses. For all horses, the mean time between the last treatment and sampling was 6.3 months: selective group, 8.6 months; strategic group, 5.5 months. The difference in the mean number of months between the two groups was statistically significant (p = 0.000). The majority of strategically treated horses were dewormed less than 24 weeks before examination: 10.2% (117/1145) between 8–12 weeks and 57.9% (663/1145) between 13–24 weeks (Figure 2). In the strategic group, 27.3% (313/1145) of horses were dewormed 25–36 weeks before examination. In contrast, the horses in the selective group were dewormed less frequently. More than 50% of them were dewormed >24 weeks before sampling, 15.3% (60/393) 25–36 weeks before sampling, 33.8% (133/393) 37–48 weeks before sampling, and 12.5% (49/393) >48 weeks before sampling. Only 4.5% (52/1145) of strategically treated horses were dewormed >36 weeks before sampling: 49 horses 37–48 weeks before sampling and three horses >48 weeks before sampling (Figure 2).Figure 2


Strongyle infections and parasitic control strategies in German horses - a risk assessment.

Schneider S, Pfister K, Becher AM, Scheuerle MC - BMC Vet. Res. (2014)

Time (weeks) since the last anthelmintic treatment. Comparison of the selectively (a) and strategically (b) treated horse groups (numbers in each group and percentages).
© Copyright Policy - open-access
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4232665&req=5

Fig2: Time (weeks) since the last anthelmintic treatment. Comparison of the selectively (a) and strategically (b) treated horse groups (numbers in each group and percentages).
Mentions: The data for 81.5% (1538/1887) of the horses were available for this analysis: 393 selectively treated horses and 1145 strategically treated horses. For all horses, the mean time between the last treatment and sampling was 6.3 months: selective group, 8.6 months; strategic group, 5.5 months. The difference in the mean number of months between the two groups was statistically significant (p = 0.000). The majority of strategically treated horses were dewormed less than 24 weeks before examination: 10.2% (117/1145) between 8–12 weeks and 57.9% (663/1145) between 13–24 weeks (Figure 2). In the strategic group, 27.3% (313/1145) of horses were dewormed 25–36 weeks before examination. In contrast, the horses in the selective group were dewormed less frequently. More than 50% of them were dewormed >24 weeks before sampling, 15.3% (60/393) 25–36 weeks before sampling, 33.8% (133/393) 37–48 weeks before sampling, and 12.5% (49/393) >48 weeks before sampling. Only 4.5% (52/1145) of strategically treated horses were dewormed >36 weeks before sampling: 49 horses 37–48 weeks before sampling and three horses >48 weeks before sampling (Figure 2).Figure 2

Bottom Line: The mean time since last treatment was 6.3 months.The planned treatment date was already exceeded by 72.5% of the high egg-shedders and by 58.1% of the moderate (200-500 EPG) and low egg-shedders (20-199 EPG).Therefore, to minimize the risks for disease, consistent and efficient parasite control should be implemented.

View Article: PubMed Central - PubMed

Affiliation: Comparative Tropical Medicine and Parasitology, Faculty of Veterinary Medicine, Ludwig-Maximilians-Universität, Leopoldstr. 5, D-80802, Munich, Germany. Stephanie_Schneider82@yahoo.de.

ABSTRACT

Background: As a consequence of the increasing levels of anthelmintic resistance in cyathostomes, new strategies for equine parasite control are being implemented. To assess the potential risks of these, the occurrence of strongyles was evaluated in a group of 1887 horses. The distribution of fecal egg counts (FECs), the frequency of anthelmintic drug use, and the deworming intervals were also analyzed. Between June 2012 and May 2013, 1887 fecal samples from either selectively or strategically dewormed horses were collected at 195 horse farms all over Germany and analyzed quantitatively with a modified McMaster technique. All samples with FEC ≥20 eggs per gram (EPG) were subjected to coproculture to generate third-stage larvae (LIII) for species differentiation.

Results: Egg counts were below the limit of detection (20 EPG) in 1046 (55.4%) samples and above it in 841 (44.6%) samples. Strongylus vulgaris larvae were identified in two of the 841 positive samples. Infections with cyathostomes were found on every farm. The most frequently applied anthelmintic was ivermectin (788/50.8%), followed by pyrantel (336/21.6%). The mean time since last treatment was 6.3 months. High-egg-shedding (>500 EPG) strategically dewormed horses (183/1357) were treated, on average, three times/year. The planned treatment date was already exceeded by 72.5% of the high egg-shedders and by 58.1% of the moderate (200-500 EPG) and low egg-shedders (20-199 EPG).

Conclusions: S. vulgaris seems to be rare in Germany and no difference in its frequency has yet been found between selectively treated horses and horses receiving treatment in strategic intervals. However, inconsistent parasite control has been observed. Therefore, to minimize the risks for disease, consistent and efficient parasite control should be implemented.

No MeSH data available.


Related in: MedlinePlus