Gastrointestinal Nematodes Of Sheep Research Articles

Prevalence and Seasonality of Adult and Arrested Larvae of Gastrointestinal Nematodes of Sheep from Mashhad City, Northeastern Iran.

Background:This study was conducted to determine the prevalence and intensity of nematode infections in sheep located in northeastern Iran from Apr 2018 to Mar 2019.Methods:Gastrointestinal nematodes of 300 sheep were inspected. The season of slaughter, anatomic location where the parasite was located, the animal’s sex, infection prevalence and intensity were recorded. Seasonal differences in arrested larvae numbers also were assessed using Cochran’s Q test.Results:Overall, 4,331 adult nematode specimens were collected. Among the examined sheep, 53% (159/300) were infected with one or more nematode species. Among infected sheep, 42.8% were infected with a single species of nematode, 26.4% were infected with two species of nematodes, and 30.8% were infected with three or more species of nematodes. Marshallagia marshalli (13.3%) was the most common nematode recovered from the abomasums of infected sheep, while Trichostrongylus vitrinus (4.6%) was commonly recovered from the small intestines, and Trichuris ovis (25.6%) was commonly recovered from the large intestines. In total, 463 arrested larvae were found in the abomasums of 7.5% of infected sheep and 104 arrested larvae were found in the small intestines of 8.8% of infected sheep. A significantly higher numbers of arrested larvae were found in summer compared to autumn (P<0.001).Conclusion:Intestinal parasites continue to be a problem for sheep in northeastern Iran and additional control measures need to be explored.

Ethnoveterinary survey of plants used for the control of gastrointestinal nematodes in sheep at three agro-ecological zones in the Eastern Cape Province of South Africa

Background: With exception of the desert biome, all of South Africa’s biomes occur in the Eastern Cape. The province is known to have high numbers of livestock that are mostly found in communal farming areas. Multi-drug resistance of gastrointestinal nematodes against major classes of conventional anthelmintics and the high cost of synthetic drugs calls for an urgent search for different control strategies of nematodes.Aim: A survey was conducted to identify and document plant species used to control gastrointestinal nematodes of livestock in Ciko, Goso and Upper Ngqumeya communities in the Eastern Cape Province.Setting: The study included filed observations and transect walks, as well as a standardized questionnaire given to 48 sheep farmers.Methodology: Forty-eight livestock farmers including men and women of mixed ages were interviewed. The information was obtained through the use of a structured questionnaire, field observations and transect walks. Data generated were analysed using descriptive statistics with frequency of citation (FC) and relative frequency of citation (RFC) as quantitative.Results: A total of 11 plant species from different genera were reportedly available and used to control gastrointestinal nematodes. Aloe ferox (0.67) and Zanthoxylum capense (0.44) had the highest values of RFC followed by Strychnos henningsii (0.23) and Elaphantorhhiza elephantine (0.21) and were widely known by the people of the study areas. The three most frequently used plant parts were leaves, roots and bark accounting for about 36.4%, 27.3% and 27.3%, respectively. The ethnoveterinary medicines were prepared in the form of decoctions and infusions. Oral administration of the concoctions was the only route of administration. The major constraints of sheep production as perceived by the farmers were prevalence of internal (36%) and external parasites (18.1%). All medicinal plants used were native and collected from the wild. The most dominant life forms were trees (45.4%), followed by herbs (36.4%) and shrubs (18.2%). Homestead expansion was ranked as the major threat (26%) to medicinal plants followed by firewood (21%). In-situ (protection through rangers) was the most frequently mentioned (67%) conservation practice used by farmers to protect the loss of medicinal plants followed by ex-situ (33%).Conclusion: In the light of data gathered on the surveyed plants, it appeared the plants play a role in the healthcare of sheep in rural communities. Further studies are required to analyse the plants for their chemical composition and biological properties.

Study on Prevalence of Major Gastrointestinal Nematodes of Sheep in Wayu Tuka and Diga District, Oromia Regional State

Aim This study was devised to be conducted to determine the prevalence and identify the major gastrointestinal nematode parasites based on fecal examination. Methods A cross-sectional study was carried out to determine the prevalence and associated factors with ovine gastrointestinal nematode infestation by fecal examination of 384 sheep from Wayu Tuka and Diga district, Eastern Oromia regional state. Results Out of the total 384 sampled sheep, 169 (44.0%) had been infected with gastrointestinal nematode parasite. Haemonchus species were the most frequently (20.8%) recovered nematode eggs followed by Trichostrongylus (13.0%) and Nematodirus (10.2%). There was no significant difference (p&gt;0.05) in prevalence between age groups and sex. Sheep with poor body condition had a significantly higher prevalence of gastrointestinal nematode parasite (p&lt;0.05) than those sheep in moderate or good body condition. There was no significant association between the gastrointestinal nematode infection in animals of different ages and sex groups. Conclusion The study shows that the gastrointestinal nematode parasite was a major important health problem and impact on the production of sheep in the study area. Therefore, a detailed study should be conducted to identify the parasite at the species level and special consideration should be taken on the management of sheep in poor body condition to reduce the burden of gastrointestinal nematodes.

First Report of Multiple Drug-resistant Gastrointestinal Nematodes of Sheep in Arbat District, Sulaymaniyah, Iraq Detected By in Vivo and in Vitro Methods.

IntroductionThe control of gastrointestinal nematodes (GINs) in small ruminants is principally dependent on anthelmintic therapy, which encounters the rising problem of anthelmintic resistance (AR) development. Veterinarians reported anthelmintic failure in several sheep farms in Arbat District, Sulaymaniyah, northern Iraq, which called for a systematic study about the efficacy of three commonly used drugs: albendazole, ivermectin, and levamisole.Material and MethodsA faecal egg count reduction test (FECRT) was conducted to elucidate the anthelmintics’ efficacies, with coprocultures to determine the GINs parasitising sheep in the study area. Larval development assays (LDAs) were conducted to determine the drugs’ median inhibitory concentrations (IC50).ResultsThe FECRT revealed that AR was widespread to all three drugs, and ivermectin was the least effective, reducing the faecal egg counts (FECs) by 50.5% to 57.1%. The coprocultures revealed that the GIN genera of sheep in Arbat District were Trichostrongylus, Nematodirus, and Trichuris, and the resistance was mainly due to Trichostrongylus species. The mean IC50 of albendazole, ivermectin, and levamisole were 0.073 ng/mL, 7.97 ng/mL, and 1.43 ng/mL, respectively.ConclusionThis study is the first Iraqi report of AR confirmed by both in vivo FECRT and in vitro LDA methods.

Carvacryl acetate nanoencapsulated with chitosan/chichá gum exhibits reduced toxicity in mice and decreases the fecal egg count of sheep infected with gastrointestinal nematodes.

The nanoencapsulation of biocomposites with anthelmintic action has been proposed as an alternative for improving their efficiency. Thus, the current study aimed to evaluate the efficacy of carvacryl acetate nanoencapsulated with biopolymers (nCVA) in the control of sheep gastrointestinal nematodes. CVA was nanoencapsulated with chitosan/chichá gum and characterized in terms of its efficacy of encapsulation (EE), yield and zeta potential. The acute toxicity of nCVA was evaluated in mice. For the fecal egg count reduction test, 40 animals were divided into four groups (n = 10) and orally administered the following treatments: G1, 250 mg kg−1 CVA; G2, 250 mg kg−1 nCVA; G3, chitosan/chichá gum (negative control) and G4, 2.5 mg kg−1 monepantel (positive control). Feces were collected on days 0 and 16 posttreatment to determine the eggs per gram of feces (epg). The EE and yield of nCVA were 72.8 and 57.5%, respectively. The nanoparticles showed a size of 764.5 ± 302.5 nm, and the zeta potential at pH 3.2 was +22.0 mV. nCVA presented a 50% lethal dose (LD50) of 2609 mg kg−1. By 16 days posttreatment, CVA, nCVA and monepantel reduced the epg by 52.9.7, 71.5 and 98.7%, respectively, and the epg of sheep treated with nCVA differed from that of the negative control (P > 0.05) but did not differ from that of sheep treated with CVA. In conclusion, the nanoencapsulation of CVA reduced its toxicity, and nCVA showed anthelmintic activity.

High Predatory Capacity of a Novel Arthrobotrys oligospora Variety on the Ovine Gastrointestinal Nematode Haemonchus contortus (Rhabditomorpha: Trichostrongylidae).

With the worldwide development of anthelmintic resistance, new alternative approaches for controlling gastrointestinal nematodes in sheep are urgently required. In this work, we identified and characterized native nematode-trapping fungi. We collected seven isolates of fungi with the capacity to form adhesive, three-dimensional networks as the main mechanism to capture, kill, and consume nematodes. The nematode-trapping fungi were classified into two groups; the first group includes the R2-13 strain, showing faster growth, abundant aerial hyphae, scarce conidia production, bigger conidia, and it formed a clade with Arthrobotrys oligospora sensu stricto. The second comprises the A6, A12, A13, R2-1, R2-6, and R2-14 strains, showing a growth adhering to the culture medium, forming little aerial hyphae, smaller conidia, and these formed a sister clade to A. oligospora. Except for the R2-6 strain, conidia production was induced by light. In all the strains, the predatory capacity against the sheep gastrointestinal nematode Haemonchus contortus was greater than 58% compared with the control group. The A6 and A13 strains were the most active against the infective H. contortus third instar (L3) larvae, with an average capture capacity of 91%. Altogether, our results support evidence for a novel A. oligospora variety with high nematode-trapping activity and promissory in helminthic control.

Physiological, Immunological and Genetic Factors in the Resistance and Susceptibility to Gastrointestinal Nematodes of Sheep in the Peripartum Period: A Review.

SummaryParasitic diseases of sheep involving gastrointestinal nematodes (GIN) are one of the main problems that affect fl ock productivity, especially during the peripartum period. Around lambing, the ewes are immunosuppressed and the nematode faecal egg count (FEC) increases at four weeks before lambing, reaching a peak between the fourth and sixth week postpartum and subsequently decreasing towards weaning. Prolactin has been credited with a suppressive effect on immune system, along with other hormones that intervene in metabolism, such as leptin, which has an important role in the activation of other hormones. Cortisol has also been included; this is stimulated by any stressful event and inhibits the proliferation of T-cells and alters the function of immunoglobulins. Another related hormone is pepsinogen, which is considered a marker of the integrity of the abomasum mucosa, as well as the albumin concentration that increases in the presence of a GIN infection. The humoral and cellular immune response, as well as inflammatory reactions, are the main mechanisms of action against GIN. Lymphocytes direct the effector mechanisms in a Th2 cell response, including interleukins (IL-4, IL-5, IL-9, IL-10) and transforming growth factor beta (TGF-β) together with immunoglobulins (IgA, IgG, IgM and IgE), which prevent the invasion of pathogens. Eosinophils with a cytotoxic effect are indicators of a parasitic infection, with importance in the immune protection of infected individuals. The genetic selection of resistant individuals measured by FEC is dependent on the heritability (h2), which is moderately inheritable and highly repeatable. Effects that influence the resistance or susceptibility of sheep to GIN infections in the peripartum period are determined by the interaction of various factors, such as genotype or breed, nutrition, age, type of birth, season and production system, etc., which are studied in this review.

Adverse reactions after orange essential oil administration to lambs

The major compound in orange essential oil (OEO) is limonene, which has in vitro anthelmintic properties; however, a safe in vivo dose has not been defined for animals. Therefore, a pilot study was conducted to evaluate the effect of an OEO formulation for the control of gastrointestinal nematodes in sheep and to investigate adverse reactions in lambs after OEO administration. A total of 17 lambs received an oral OEO formulation at a concentration of 600mg/mL, in doses of 200, 300, and 600mg/kg. The most common clinical signs observed were head shaking (88.8%), backward head movement (51.1%), and ataxia (74.4%). Lambs treated with 600mg/kg of OEO showed more severe combined clinical signs and longer duration of symptoms, presenting adverse reactions for up to 2h after OEO administration. Testing of different doses and formulations with slower release of the active ingredient is recommended to minimize or eliminate these effects.

Anthelmintic activity of the ethanolic extract of Carapa guianensis (Meliaceae) on gastrointestinal nematodes of sheep in the Western Amazon

The present study aimed to evaluate the anthelmintic effect of Carapa guianensis (andiroba) on gastrointestinal nematodes in sheep naturally infected in the Western Amazon. Toxicity tests with Artemia salina identified that the ethanolic extracts of the root and stem of andiroba showed an LC50% equal to 530 μg ml-1 and 170 μg ml-1, respectively. As concentrations 1.06mg / ml (andiroba root) and 0.34mg ml-1 (andiroba stem) were tested in groups of crossbred sheep, eaten from four to six months and weighing approximately 19.9 kg naturally infected by gastrintestinal nematodes. In addition, there will be a total of two treated groups and two control groups (negative and positive - 7.5% closantel). Foram extracts applied orally in a single treatment days 1,2,3,4,15,16,17,18. Or treatment lasted 30 days. Samples of fezes and blood foram collected at intervals of seven and 15 days respectively to assess the parasitic and hematological profile. The results showed a reduction in parasitic load of 86% and 59%, respectively, for the root and stem of andiroba in egg count per gram of feces, while in the group treated with closantel 7.5% the reduction was 66%. Regarding the number of third stage larvae recovered from sheep after treatment, it was observed that the groups treated with andiroba root and stem differed (p &lt; 0.05) from the control group, with a reduction in the percentage of larvae from 70 and 55%, respectively. The phytochemical tests in the present study revealed the presence of bioactive metabolites that may be responsible for the anthelmintic activity. As for the hematocrit, there was no statistical difference in its values in the groups treated with andiroba root and stem, that is, in some way there was interference on the adult forms of the nematodes that compromised the hematophagism. Therefore, the extract of Carapa guianensis has anthelmintic potential, being a good alternative in the control of sheep endoparasitosis.

Atividade anti-helmíntica do extrato de etanol de Uncaria guianensis (Rubiaceae) em ovos e larvas de nematoides gastrintestinais de ovinos na região da Amazônia Ocidental

The purpose of this study was to evaluate the anthelmintic effect of the root and stem of Uncaria guianensis on eggs and larvae of gastrointestinal nematodes from naturally infected sheep. The extract of the root of Uncaria guianensis was tested at concentrations of 0.57mg / mL and 1.14mg / mL and the extract of the stem of Uncaria guianensis at concentrations of 1.25mg / mL and 2.5mg / mL. The animals were divided in groups of five animals each, where four groups received the plant extract and a dose / concentration, one group received the anti-helminthic closantel and another group received only distilled water, totaling six treated groups. Ten mL were applied orally on days treatment, in a single dose for the groups treated with the extract, the closantel group received the dose recommended by the manufacturer and the negative group received 10 mL of distilled water. Stool samples were collected weekly for parasitological analysis and blood for hematocrit. The results of the OPG were analyzed after log transformation (x + 1) and submitted to one-way analysis of variance (ANOVA) and Tukey’s test at 5% of probability. Third stage L3 larvae were recovered from co-culture and subjected to the 5% tukey test. The results showed a reduction in the number of eggs per gram of feces, in the group treated with Uncaria guianensis root at a concentration of 1.14mg / mL and in the chemically treated group, where they obtained a statistically significant reduction (p &lt;5%), when compared to the other treated groups, presenting 69% and 66% respectively in the reduction percentage. Regarding the number of third-stage larvae of gastrointestinal nematodes recovered from sheep, after treatment they observed that the groups treated with closantel, Uncaria guianensis root at a concentration of 1.14mg / mL and a stem of Uncaria guianensis at a concentration of 1.25mg / mL were statistically different (p &lt;5%) from the other treatments, with 68%, 68% and 86% respectively reduction in the number of larvae. As for the hematocrit, the results remained within the reference standards for the Amazon Biome. Thus, we conclude that Uncaria guianensis has ovicidal and larvicidal activity on gastrointestinal nematodes in sheep.

Antihelminthic action of the Anethum graveolens essential oil on Haemonchus contortus eggs and larvae.

Gastrointestinal nematodes are responsible for great economic losses in sheep raising, and their control has long been carried out almost exclusively by the administration of anthelmintics, which have led to serious resistance problems. In the search for alternative control measures, phytotherapic research is highlighted. The aim of this study was to evaluate the action of Anethum graveolens (dill) essential oil on different stages of Haemonchus contortus life cycle, as well its cytotoxicity MDBK (Madin-Darby bovine kidney) cells. H. contortus larvae and eggs were obtained from infected sheep feces, and essential oil extracted from plant seeds through the Clevenger apparatus. 9.4, 4.7, 2.35, 1.17. 0.58 and 0.29 mg/mL concentrations were evaluated. The Egg Hatch Inhibition (HI), Larval Development Inhibition (LDI) and Larval Migration Inhibition (LMI) techniques were used. Thybendazole 0.025 mg/mL in HI and Levamisole 0.02 mg/mL in the LDI and LMI tests were used as positive controls, while distilled water and a Tween 80 solution were used as positive negative controls. The inhibition results obtained for the highest oil concentration were: HI 100%, LDI 98.58% and LMI 63.7%, differing (𝑝 <0.05) from negative controls. Main A. graveolens oil components present in 95.93% of the total oil were Dihydrocarvone (39.1%), Carvone (22.24%), D-Limonene (16.84%), Apiol (10.49%) and Trans-dihydrocarvone (7.26%). Minimum A. graveolens essential oil concentrations required to inhibit 50% (IC50) of egg hatching, larval development and larval migration were 0.006 mg/mL, 2.536 mg/mL and 3.963 mg/mL, respectively. Cell viability in MDBK (Madin-Darby bovine kidney) cells, when incubated with A. graveolens essential oil, was 86% for the highest (9.4 mg/mL) and 99% for the lowest concentration (0.29 mg/mL). A. graveolens essential oil, according to the results obtained in this study, is a promising alternative in sheep gastrointestinal nematode control.

Clinical effectiveness of autohemotherapy as an adjuvant in the control of gastrointestinal nematodes in naturally infected sheep

Abstract This study aimed to evaluate the effects of autohemotherapy as an adjuvant in the control of gastrointestinal nematodes in sheep. Four experimental groups were formed: G1, 10 animals receiving autologous venous blood; G2, 10 animals receiving autologous venous blood and vermifuge containing levamisole; G3, 10 animals receiving only vermifuge containing levamisole; and G4, 10 animals as the control group receiving no treatment. We performed fecal egg count (eggs per gram, EPG) of strongyles, larval culture, hemogram, leukogram, and serum protein dosage prior to the start of treatment (D0), and on days 14 (D14) and 42 (D42). There was a significant decrease in the EPG of the groups receiving levamisole (G2 and G3) from D14 to the end of the experimental period. At the end of the evaluations, the mean EPG of G2 and G3 was significantly lower than that of G1 and G4. The most common nematode genus was Haemonchus (88%), and the least common was Trichostrongylus (1%). The Fecal Egg Count Reduction Test (FECRT) of G2 and G3 on D14 were 98.1% and 97.9%, respectively, however, in G1, the FECRT was zero on the two days when evaluation took place. G1 and G2 showed a significant increase in monocyte counts on D14 and D42. There was a significant increase in hematocrit and hemoglobin values in G2 and G3, however, a significant increase in the absolute value of red blood cells was observed only in G2. Two doses of autohemotherapy at 21-day intervals, administered alone or as an adjuvant to levamisole, is ineffective in controlling gastrointestinal nematodes in naturally infected sheep.

Erratum: Anthelmintic activity of nanoencapsulated carvacryl acetate against gastrointestinal nematodes of sheep and its toxicity in rodents.

[This corrects the article doi: 10.1590/s1984-29612019098].

In vitro anthelmintic activity of an aqueous extract of Glycyrrhiza glabra and of glycyrrhetinic acid against gastrointestinal nematodes of small ruminants.

This study evaluated the in vitro anthelmintic activity of a liquorice (Glycyrrhiza glabra) root aqueous extract and of glycyrrhetinic acid at 30, 10, 5, 1, and 0.5mg/mL against sheep gastrointestinal nematodes (GINs), using the egg hatch test (EHT), the larval development test (LDT), and the larval migration inhibition test (LMIT). The compounds were applied on a mixture of GIN eggs and larvae, mainly Trichostrongylus spp. and Teladorsagia/Ostertagia spp. Cytotoxicity assays were also performed. In the EHT, both candidates showed significant concentration-dependent efficacy and were significantly more effective (p<0.001) at the highest concentrations (30 and 10mg/mL) than the lowest ones. In the LDT, only G. glabra showed a concentration-dependent effect (R2=0.924), but glycyrrhetinic acid (R2=0.910) had significantly higher efficacy than G. glabra root extract. Moreover, the efficacy of glycyrrhetinic acid at 30, 10, and 5mg/mL was significantly higher (p<0.001) than at lower concentrations. In the LMIT, G. glabra showed concentration-dependent efficacy (R2=0.971), while considerably reduced efficacy was observed for glycyrrhetinic acid (R2=0.855) at the lowest concentrations. These data suggest that the two compounds may have different mechanisms of action. In the LMIT, the 50% lethal concentration (LC50) of glycyrrhetinic acid (~5.12mg/mL) was > 2.0-fold lower when compared to G. glabra (12.25mg/mL). Analysis and previous findings indicated low toxicity for both compounds. The results obtained encourage in vivo studies aimed at evaluating the potential use of the tested compounds as natural de-wormers in ruminants.

Phenotypic and genotypic approaches for detection of anthelmintic resistant sheep gastrointestinal nematodes from Brazilian northeast.

The aim of this study was to characterize the anthelmintic resistance (AR) of a sheep gastrointestinal nematode population, named Caucaia, from northeastern Brazil. Phenotypic tests performed were: egg hatch (EHT), larval development (LDT) and fecal egg count reduction (FECRT). Benzimidazoles (BZs) genotypic evaluation was by frequency of single nucleotide polymorphisms (SNPs) F200Y, F167Y and E198A, and for levamisole (LEV), by frequency of resistance alleles of Hco-acr-8 gene. The primers were designed specifically for Haemonchus contortus. Effective concentrations 50% (EC50) for BZs (EHT), and for macrocyclic lactones (MLs) and LEV (LDT) were 1.02 µg/mL, 1.81 ng/mL and 0.04 µg/mL, respectively. Resistance ratios for MLs and LEV were 0.91 and 3.07, respectively. FECRT efficacies of BZs, MLs, monepantel (MPTL) and LEV were 52.4; 87.0; 94.5 and 99.6%, respectively. qPCR for BZs demonstrated resistance allele frequencies of 0%, 26.24% and 69.08% for SNPs E198A, F200Y and F167Y, respectively. For LEV, 54.37% of resistance alleles were found. There was agreement between EHT, FECRT and qPCR for BZs, and agreement between LDT and qPCR for LEV. Thus, based on higher sensitivity of qPCR, and phenotypic evaluation, the Caucaia population was considered resistant to BZs, MLs, LEV and suspect for MPTL.

In vitro ovicidal activity of two chemotypes of the yarrow (Achillea millefolium L.) essential oil against sheep gastrointestinal nematodes

Abstract The economic losses caused by gastrointestinal nematodes of small ruminants are increasing today due to the development of anthelmintic resistance. Therefore, researchers from different parts of the world are searching for new, alternative strategies to control these parasites. As a valuable natural resource, medicinal plants and their products have emerged as a viable option. The aim of this study was to evaluate in vitro ovicidal activity of two chemotypes of the yarrow (Achillea millefolium L.) essential oil against sheep gastrointestinal nematodes. For this purpose, nematode eggs were collected from naturally infected sheep of two farms located in Southern Italy to perform the egg hatch test. In both farms, the coproculture examination identified the presence of four genera of sheep GINs: Haemonchus, Trichostrongylus, Teladorsagia and Chabertia. Main components of the yarrow essential oil identified by GC-MS analysis were 1,8-cineole (41.69%), camphor (8.37%) and trans-chrysanthenyl acetate (4.90) for the type 1 and β-pinene (28.53%), β-caryophyllene (18.71%) and 1,8-cineole (11.69%) for the type 2. In vitro ovicidal activity was evaluated at six different concentrations (50, 12.5, 3.125, 0.781, 0.195 and 0.049 mg/mL), whereby the inhibitory effect of the essential oil (Achillea millefolium L.) on egg hatchability varied from 46.5-99.5% (type 1) and 69.6-97.25% (type 2) and all concentrations tested showed a significantly higher efficacy compared to the negative control (p&lt;0.0001). Furthermore, the inhibitory effect on egg hatching was similar (p&gt;0.05) to the positive control (98.0%) at concentrations of 50 mg/mL (99.5%), 12.5 mg/mL (98.0%) and 3.125 (95.25%) of the type 1, and at concentrations of 50 mg/mL (97.25%) and 12.5 mg/mL (90.0%) of the type 2. The obtained results suggested that the A. millefolium essential oil has high anthelmintic potential, especially azulene-free chemotype rich in 1,8-cineole and camphor, which requires confirmation in further in vivo studies.

Efficacy of anthelmintic Eprimek against gastrointestinal nematodes in sheep

The purpose of the research is studying the efficacy of Eprimek (Eprinomectin) against gastrointestinal nematodes in sheep.Materials and methods. A commercial experiment to study the antiparasitic efficacy of Eprimek was carried out in June 2020 on 300 lambs of the North Caucasian breed in a private flock of Filimonovskaya Village, Izobilnensky District, the Stavropol Territory, which were divided into two groups. The experimental group of lambs (290 animals) was injected Eprimek subcutaneously at the earset at a dose of 1 ml/50 kg of live weight (10 mg of Eprinomectin in 1 ml), and 10 lambs were not treated; they were used as control. We collected feces from the lambs of the experimental and control groups before administration of the drugs and after 15 and 30 days. Fecal samples were examined by the flotation technique with a saturated solution of ammonium nitrate with counting nematode eggs in 1 g of feces. The results were processed statistically.Results and discussion. Eprimek showed a decrease in the number of excreted helminth eggs from 225.1±28.2 to 4.1±2.3 in production environment at a dose of 1 ml/50 kg of live weight, according to coprological studies on the 15th day after treatment in the experimental group of lambs. The efficacy was 98.2%, and 70% of the animals were free from the infection. The intensity of infection of the control lambs by gastrointestinal nematodes was 131–151 eggs per 1 g of feces at 100% prevalence.

In Vitro Anthelminthic Efficacy of Aqueous Pomegranate (Punica granatum L.) Extracts against Gastrointestinal Nematodes of Sheep.

The worldwide increased difficulty to counteract gastrointestinal nematode (GIN) infection in sheep, due to progressing anthelmintic resistance, has led to the evaluation of other alternative helminth control options, mainly from plants. The anthelmintic efficacy of an aqueous Punica granatum macerate was evaluated in sheep naturally infected by GIN in southern Italy. The macerate was chemically characterized by chromatographic analysis coupled with high-resolution mass spectrometry (LC/HRMS) and an aliquot was concentrated to obtain a dry extract. A part was characterized, the remaining washed with methanol to obtain an insoluble residue and methanol phase. In the methanol fraction, the quantitatively predominant gallic acid was purified to obtain the pure molecule. The three fractions thus obtained were used for in vitro studies (i.e., egg hatch test) to verify anthelmintic efficacy. For this purpose, fecal samples were collected from sheep naturally infected by GINs. Fractions were diluted in H2O/DMSO 0.5% at 1.00, 0.5, 0.25, 0.125, 0.05, and 0.005 mg/mL concentrations. Thiabendazole (0.25 and 0.5 mg/mL) and deionized water were used as positive and negative controls, respectively. Egg hatch test results indicated that all fractions caused a significant (p < 0.05) egg hatch inhibition within 48 h of exposure highlighting a high (>82%) efficacy in vitro at all tested doses. Maximal egg hatching inhibition effect was exhibited by the methanol fraction (99.3% and 89.3% at 1 and 0.005 mg/mL concentrations), followed by the insoluble residue and gallic acid (94.7% and 85.3% and 94.0% and 82.7% at 1 and 0.005 mg/mL, respectively). The current study validated the anthelmintic potential of traditional P. granatum macerate against GIN infection in sheep, thus highlighting the role of gallic acid as principal component and justifying a need to undertake further in vivo studies on these ethno-veterinary remedies.

Re-evaluation of the efficacy of Oxfendazole Oxyclozanide combination against gastrointestinal nematodes in sheep, a long time after the introduction into the Turkish antiparasitic drug market

Re-evaluation of the efficacy of Oxfendazole Oxyclozanide combination against gastrointestinal nematodes in sheep, a long time after the introduction into the Turkish antiparasitic drug market

The prevalence of gastrointestinal nematodes in sheep (Ovisaries) in the central and south-eastern regions of Ukraine

The article investigates into the species composition of agents causing gastrointestinal tract nematodes in sheep. It determines the forms of nematodes communities. For this purpose, 710 sheep were examined, 79.58% of which were infected. The fauna of nematodes was represented by 15 species of helminths from 12 genera: Bunostomum, Oesophagostomum, Nematodirus, Chabertia, Cooperia, Trichostrongylus, Ostertagia, Haemonchus, Тrichuris, Aonchotheca, Strongyloides, and Skrjabinema. The indicators of infestation intensity in sheep ranged from 1 to 93 specimens per animal, and the abundance index ranged from 0.01 to 16.96 specimens per animal. The most common nematodes are H. contortus (prevalence, 61.97%), O. circumcincta (59.58%), T. colubriformis (57.35%), Т. оvis (55.21%), N. spathiger (49.01%), Oe. venulosum (42.54%), S. ovis (41.13%), Ch. оvina (36.76%), and T. skrjabini (26.34%). Gastrointestinal nematodes in the body of 99.12% of the infected sheep proceeded as parasitic communities. Most frequently, coinvasions were represented by parasitic communities which consisted of five (prevalence, 14.51%), six (19.44%), or seven (15.92%) species. The study revealed 361 varieties of mixed coinvasions. The most frequent comembers were H. contortus, O. circumcincta, T. colubriformis, Т. оvis, N. spathiger, S. ovis, and Ch. оvina. The data obtained provide an opportunity to increase the effectiveness of measures to combat and prevent gastrointestinal tract nematodes in sheep farms.