Abstract: The aim of this study was to examine the efficacy of moxidectin treatment on goats naturally infected with gastrointestinal nematodes in Van region, Turkey. Two hundred and forty goats infected with gasterointestinal parasites were treated with 0.2 mg kg-1 moxidectin (Cydectin, Abfar), subcutaneously. Ten randomly selected goats were not treated and allocated as a control group. Faecal samples were examined for gastrointestinal parasites qualitatively and quantitatively (EPG) in 0th, 7th and 14th days of treatment. Larvae of the parasite species of Ostertagia, Haemonchus, Nematodirus and Trichostrongylus were detected in the coprocultures of the infected animals performed before treatment. It was observed that moxidectin was 100% effective against the gastrointestinal nematodes.
INTRODUCTION
Animal breeding is an important economical element for villagers in Van region. Parasitic infections, particularly gastrointestinal nematodosis causes of considerable economic loss in Turkey and the world (Gulanber et al., 1998; Myers, 2002; Cirak et al., 2005; Rahmann and Seip, 2007). In several studies conducted internationally and in Turkey, moxidectin have been found to be highly effective against a wide variety of external and internal parasites in different species of animals and many formulations (pour-on, oral and parenteral) (Kerboeuf et al., 1995; Torres-Acosta and Jacobs, 1999). Moxidectin is very effective in goats than the other drugs. Since, moxidectin formulation is aqueous based solution significantly absorption comes out in domestic animals including goats. Moxidectin plasma concentrations which applied subcutaneously at 1 mg kg-1 dose is 64% longer than doramectin plasma concentrations at the same dose (Escuredo et al., 1999). The mechanism of effect of moxidectin, in treatment of endo and ecto parasites of cattle, sheep and horses has not been exactly known; it leads to loosening of terminal presynaptic nerves and activation similar to GABA stimulation of avermectins advances. Thus, GABA binds next to the postsynaptic receptors and as a result causes blockage of interneuronal transmission and eventually leads to paralyses and deaths (Lonneux and Losson, 1994).
The aim of this study was to examine the efficacy of moxidectin in treating goats naturally infected with gastrointestinal nematodes in Van region.
MATERIALS AND METHODS
Animals
The present study was carried out on goats from three private farms in Van.
All goats in these farms were naturally infected with gastrointestinal (GI)
nematodes. Goats aged between 1-3 years and weighted between 35-50 kg. During
the study period, all animals were housed in their usual winter housing facility
and fed according to their regular feeding regimen with approximately 2 kg of
hay and 1 kg of concentrate feed per goat. They had no limitation for access
to drinking water.
Study Design
In this study, 240 of the 250 goats naturally infected with Trichostrongylidae
sp. were allocated to treated group and 10 goats were allocated to control group
and identified with ear tags. Two hundred and forty goats in the treated group
were administered 0.2 mg kg-1 moxidectin (Cydectin, Abfar), subcutaneously
(Lonneux and Losson, 1994). The other group remained
as an untreated control group.
Sample Collection and Analysis
Individual fecal samples were taken directly from the rectums of the goats
on days 0 (pre-treatment) and 7, 14, (posttreatment) and brought to the Parasitology
Laboratory in Faculty of Medicine, University of Yuzuncu Yil and examined for
the eggs of gastrointestinal nematodes by the Fulleborn saturated salt solution
method. Fecal egg-counts (EPG) (eggs g-1) were determined using the
modified McMaster technique (MAFF, 1986) and geometrical
means of the results taken. Moreover, faecal cultures were done, to differentiate
at genus level of trichostrongylid nematodes.
Statistical Analysis
Percent efficacy of moxidectin, based on reduction in fecal egg counts was
calculated for the undifferentiated trichostrongyle eggs described by Morin
et al. (1996).
RESULTS
In other words, the eggs of the parasites in these animals were not encountered
on the 7th and 14th days after treatment. Larvae of the parasite species of
Ostertagia, Haemonchus, Nematodirus and Trichostrongylus
were detected in the coprocultures of the infected animals performed before
treatment (Table 1).
| Table 1: | Geometric average of parasites EPG in samples before, 7 and 14 days post treatment |
DISCUSSION
Gastrointestinal nematodes in goats cause regional economic losses in the world and Turkey. To decrease harmful effects of parasites, animal transportation should be provided under controlled conditions. Epidemiological control and eradication studies should be performed and animals with the parasite should be treated with appropriate anthelmentic drugs. Hoste and Chartier (1993) reported that subclinical and clinical gastrointestinal nematodiasis in goats led to loss of body weight and a constant decrease in milk productivity ranging from 2.5 to 10% and 13 to 25.1%, respectively.
Usage of moxidectin 1% solution at a dose of 0.2 mg kg-1 was decreased weight loss and productivity of milk and wool. Bauer and Conraths (1994) performed a study in lambs which were experimentally infected with H. contortus, Ostertagia sp., Trichostrongylus colubriformis, Cooperia curticei and Oesophagostomum sp. and Chabertia ovina, moxidectin at a dose of 0.2 mg kg-1, both as oral and parenteral formulations, have been found to be 100% effective and with no side effects. Torres-Acosta and Jacobs (1999) performed a study in goats which were experimentally infected with nematodes (H. contortus, T. circumcincta and T. colubriformis) 15, 22 or 29 days after treatment, moxidectin 0.1% oral drench at 0.2 mg kg-1, have been found to be effective for goats treated 15, 22 and 29 days before infection with H. contortus were 100, 100 and 99.7%, respectively and corresponding values for T. circumcincta were 95.7, 99.9 and 94.9% with easy to use and no side effects. The other study was investigated effects of the single and pair applications of 1% of injectable moxidectin solution in 14 sheep aged between 2 and 6 infected with Psoroptes ovis and moxidectin was found to be effective 100% all of the sheep (Coles et al., 1994). Moxidectin was used for the treatment of Strongylus sp. infection in horses and it was determined to be effective 100% (Xiao et al., 1994). Some researchers have used moxidectin at doses of 0.3 and 0.5 mg kg-1 in calves with naturally infected with gastrointestinal and lung nematodes, pour-on formulation. They have been found 100% effective on adult forms of D. viviparus, Trichostrongylus axei, Ostertagia sp. and Nematodirus helvetianus (Hubert and et al., 1995). Tuzer et al. (1999) found successful results in lambs on the 7th (100%), 14th day (99.9%) and 28th day (100%) and in calves on the 7th (100%), 14th day (99.9%) and 28th day (98.9%) after treatment. In the present study, larvae of the parasite species of Haemonchus, Ostertagia, Nematodirus and Trichostrongylus were determined in the coprocultures of the infected animals prior treatment. Use of moxidectin in this study proved a high efficacy (100%) against above mentioned gastrointestinal nematodes when administered subcutaneously 0.2 mg kg-1 on goats. We obtained successful results after the 7 and 14 days of the moxidectin treatment on goats. During and after the treatment of moxidectin, no adverse effects were observed in the goats.
Development of resistance for many antiparasitary drugs requires careful usage of these drugs worldwide (Kieran, 1994; Kulda, 1999). The risk of resistance development may be reduced to minimum by preventing the sales without prescription and by using the drug carefully. Although moxidectin is a novel drug, there are many forms in which resistance development are reported and local usage of moxidectin is required carefully (Besier and Love, 2003; Kaplan et al., 2007). No development of resistance has been come across in present study. These results indicate that the moxidectin should be preferred for treatment of animals having gastrointestinal nematodes.
ACKNOWLEDGMENTS
This study was supported by a grant from the Scientific Research Projects Fund of Yuzuncu Yil University, Van, Turkey with a grant number 2006- MYOB31. Thanks to Prof. Dr. Hasan Yilmaz for diagnosing of parasites, at the Department of Parasitology in Faculty of Medicine.