Worm Counts Research Articles

Anthelmintic effects and toxicity of Cynodon dactylon (L.) Pers. in rodent models

Background: Cynodon dactylon (L.) Pers. is a very widely distributed medicinal herb. Different preparations from this herb are extensively used as a folk medicine in the Middle East, including Turkey, besides in India, Italy, etc. In India, the grinded juice of C. dactylon has been commonly used as a folk medicine for the treatment of intestinal-worm infections. Aim: This study was undertaken to investigate the in vitro and in vivo anthelmintic effects and potential toxicity of whole plant extract of C. dactylon against Hymenolepis diminuta (Hymenolepididae), a zoonotic tapeworm, using two rodent models. Materials and Methods: In in vitro assay, plant extract was tested at 10, 20 and 40 mg/ml concentrations, against adult H. diminuta, and the efficacy was adjudged by physical motility and mortality of parasites. In vivo testing was done in H. diminuta - Wistar rat model, by monitoring the eggs per gram of faeces (EPG) count and worm counts of animals after treatment with 200, 400, and 800 mg/kg doses of extract. Acute toxicity of extract was monitored with 2000 mg/kg oral dose of extract, following the OECD guidelines in Swiss albino mice. In sub-acute toxicity, a low extract dose, i.e. 400 mg/kg and a high extract dose, i.e. 800 mg/kg was tested in mice, as per the guidelines of OECD, for the assessment of some haematological and biochemical parameters of mice. Results: The extract showed a dose-dependent efficacy in both, the in vitro assay as well as in the in vivo assay. In the in vitro test, the 40 mg/ml concentration of extract caused paralysis and mortality of worms in as early as in 4.12 ± 0.55 h and 5.16 ± 0.34 h, respectively. This was comparable with the reference drug praziquantel (PZQ). The in vitro anthelmintic effects were also corroborated by the results of in vivo assay, wherein treatment of rats with 800 mg/kg dose of extract for 5 days revealed up to 77.64% reduction in EPG counts and 79.00% reduction in worm counts at post-treatment period, showing a comparable efficacy with 5 mg/kg dose treatment of PZQ. In the acute toxicity assay, the extract did not reveal any adverse effects or mortality in any animal, during the 14-days observation period. The LD50 of extract was estimated to be greater than 2000 mg/kg. In the sub-acute toxicity study, all the studied parameters of animals were found to be normal at 400 mg/kg dose (low dose), however, treatment with high dose, i.e., 800 mg/kg revealed only a slight elevation of aspartate aminotransferase (AST) in animals. Conclusion: C. dactylon possesses significant anthelmintic properties, and its extract appears to be devoid of any major adverse effects in experimental animals. These pharmacological credentials supports the safe folkloristic use of this plant as an anthelmintic remedy.

Mucosal Expression of T Cell Gene Variants Is Associated with Differential Resistance to Teladorsagia circumcincta.

Resistance of sheep to the gastrointestinal nematode Teladorsagia circumcincta is a heritable characteristic. Control of parasite colonization and egg production is strongly linked to IgA antibody levels regulated by Th2 T cell activation within lymphoid tissue; and persistently-infected susceptible animals develop an inflammatory Th1/Th17 response within the abomasum that fails to control infection. Differential T cell polarization therefore is associated with parasite resistance and/or susceptibility and is controlled by a specific set of transcription factors and cytokine receptors. Transcript variants of these genes have been characterized in sheep, while in humans and mice different variants of the genes are associated with inflammatory diseases. RT-qPCR was used to quantify mucosal expression of the transcript variants of the sheep genes in trickle-infected animals with defined phenotypic traits. Genes that encode full-length GATA3 and IL17RB were shown to be significantly increased in resistant sheep that had controlled parasite infection. Expression levels of both were significantly negatively correlated with abomasal worm count (a parameter of susceptibility) and positively correlated with body weight (a parameter of resistance). These data show that polarized Th2 T cells within the abomasal mucosa play an important role in the maintenance of resistance.

ANTHELMINTIC EFFECTS OF DRIED GROUND BANANA PLANT LEAVES (MUSA SPP.) FED TO SHEEP ARTIFICIALLY INFECTED WITH HAEMONCHUS CONTORTUS AND TRICHOSTRONGYLUS COLUBRIFORMIS

Background:Helminths is a endoparasites that cause the major losses for profitable sheep production in Brazil. The increased development of resistant strains of endoparasites have enforced the search for sustainable alternatives. The aim of this paper was to provide information about endoparasites control with banana leaves in infected sheep as alternative control strategies and see its viability.Materials and Methods:In this study, we performed two trials to investigate the anthelmintic properties of banana leaves on endoparasites in sheep. In Trial 1, twelve sheep were artificially infected with Trichostrongylus colubriformis; in Trial 2, eleven sheep were artificially infected with Haemonchus contortus. Clinical examinations, packed cell volume, total protein, faecal egg counts (FECs) and egg hatchability tests (EHTs) were performed. At the end of the trials, the sheep were humanely slaughtered, and total worm counts were performed.Results:In Trial 1 and 2, no significant FEC decreases were note but significant diference in EHTs were observed. Total worm counts, clinical and haematological parameters did not reveal significant changes between the treatment and control groups. These results suggest that feeding dried ground banana plant leaves to sheep may reduce the viability of Trichostrongylus colubriformis eggs, and this anthelmintic activity is potentially exploitable as part of an integrated parasite management programme.Conclusion:However, further investigation is needed to establish the optimal dosage, develop a convenient delivery form and confirm the economic feasibility of using banana plantation byproducts as feed for ruminant species.Abbreviations: Coproculture test (CT)., Faecal egg count (FEC)., Egg hatchability test (EHT)

Maternal protection against Ascaridia galli?

Maternally derived antibodies can provide partial protection against certain bacterial and viral infections. We investigated whether chicks descending from nematode-infected hens are more resistant against Ascaridia galli, a prevalent gastrointestinal nematode, than chicks from nematode-free mothers. One-day-old chicks (N=153) from infected (mab+; maternal antibody+) or uninfected control dams (mab-) were experimentally infected with A. galli at two different levels (100 or 1000 eggs/chick). The worm burdens of the chicks were determined at 6 weeks post infection. There was a high correlation (r=0.89) between A. galli-specific antibody concentrations in dam plasma and egg yolk. There was no difference between worm burdens of chicks descending from infected or uninfected dams (P=0.892), indicating no maternally derived protection against A. galli. Chicks receiving the higher infection dose had higher worm burdens (P<0.05). Although there was no difference (P>0.05) between worm counts of female and male chicks infected with 100 eggs, females chicks infected with 100 eggs harboured longer and heavier female worms. We conclude that there is no protective maternal immunity against A. galli infection.

Efficacy of Neem (Azadirachta indica) and Pineapple (Ananas comosus) Leaf Powder on Ascaridiagalli Infection in Chicken

A study was conducted to assess the efficacy of herbs Azadiracta indica (Neem) and Ananus comosus (Pineapple) for the control of ascaridiosis in chicken. Neem leaf powder (@100 mg /kg feed /day), Pineapple leaf powder (1gm /kg feed /day) and combined preparation (100 mg +1gm /kg feed/day) were found effective against Ascaridiagalli. The percent efficacy by declining rate of EPG and worm count revealed that combined preparation of Neem and Pineapple leaf powder was most effective, followed by Pineapple leaf powder and Neem leaf powder at 28 day post treatment. The present study revealed that Neem and Pineapple could be safe and effective dewormer and may provide an alternative of chemical anthelmintics.

Oesophagostomosis, moniaziasis and trichuriasis of small ruminants slaughtered in north-western, Nigeria

Gastro-intestinal helminths have been recognised as a major constraint to both small and large-scale small ruminants production in developing countries. The study was carried out in north-western Nigeria to determine the prevalence and adult worm burden of intestinal helminths of small ruminants. A cross-sectional study was carried out in small ruminants for the period of 12 months. For this study, the intestines (small and large intestines) were collected from 300 small ruminants (200 goats and 100 sheep) at necropsy and examined by the Hansen and Perry method. Out of the 300 small ruminants examined during the study period, the intestines revealed the presence of Oesophagostomum sp, Trichuris sp and Moniezia sp with prevalence rate of 13.3%, 40.7% and 22% respectively. The mean adult worn burden for Oesophagostomum sp, Trichuris sp and Moniezia sp were 18.35±5.546 (1-108), 9.459±1.623 (1-29) and 10.02±1.502 (2-29) respectively. Considering the sex of the small ruminants, the prevalence for Trichuris sp (44.9% in male and 28% in female) being the most prevalent followed respectively by Moniezia sp (22.2% in male and 28% in female) and Oesophagostomum sp (13.3% in both sexes). The mean adult worm counts were generally low in both male (21.68±10.18 Oesophagostomum sp, 8.88±1.96 Trichurisspp and 10.02±1.90 Moniezia sp) and Female (18.60±10.39 Oesophagostomum sp, 9.90±2.00 Trichuris sp and 11.47±2.00 Moniezia sp). The prevalence and the mean adult worm counts showed the same trend irrespectively of the sex, age and species of small ruminants. There was no seasonal variation in the prevalence and mean adult worm counts recovered from small ruminants, except for the prevalence of Oesphagostomum spp and Trichuris sp that was statistically significant difference between the dry season and rainy season. The study established that sheep and goats suffer from low grade infection of Oesophagostomum sp, Trichuris sp and Moniezia sp. It is therefore recommended that the pathological lesions of these parasites especially Oesophagostomum sp on the small ruminants be carried out to estimate the economic and production loses. Keywords: moniaziasis, oesophagostomosis, prevalence, small ruminant, trichuriasis and worm burden

Dynamics of Parascaris and Strongylus spp. parasites in untreated juvenile horses

Parasite control in foals is of utmost importance due to the high susceptibility to parasitic infection and disease in this age group. Foals are commonly co-infected with strongyle and ascarid parasites, which complicate parasite control strategies. The present study retrospectively investigated necropsy records of foals born into a university herd kept without anthelmintic treatment since 1979. The aims were to statistically analyze the relationship between fecal egg counts, worm burdens, foal age, sex, and season with specific focus on Parascaris and Strongylus spp. A total of 83 foals born between 1999 and 2015 were included. Foals were born between January and September within the given year and age at necropsy ranged between 27 and 563 days of age with a mean and median of 202 and 204 days, respectively. One set of multivariate mixed linear models was constructed analyzing strongyle and ascarid fecal egg counts as outcome variables, and another set of analyses investigated the following worm counts as outcome variables: Intestinal Parascaris spp. counts (immatures and adults), S. vulgaris (migrating and intestinal stages), S. edentatus (migrating and intestinal stages). Both ascarid and strongyle egg counts were influenced significantly by differences between study years (p<0.05). In addition, total ascarid egg counts were statistically influenced by age (p=0.020) exhibiting a peak at four months of age and fillies had significantly higher ascarid worm burdens (p=0.043). Foal age had significant influences on intestinal counts of immature Parascaris spp. (p=0.034) and adult S. edentatus counts (p=0.028). Larval counts of S. edentatus were significantly associated with birth month (p=0.023), whereas counts of migrating S. vulgaris larvae were not statistically associated with any of the investigated covariates. This study provides novel information on the dynamics of important parasites in naturally infected foals.

Confirmation of ivermectin resistance in Ostertagia ostertagi in cattle in New Zealand

Six suspected cases of ivermectin resistance in Ostertagia spp. in cattle were investigated after routine anthelmintic efficacy testing on commercial farms. On four farms a comprehensive faecal egg count reduction test (FECRT) was undertaken using oral formulations of ivermectin (0.2mg/kg), albendazole (10mg/kg) and levamisole (7.5mg/kg) while on two farms only ivermectin was tested. The proportions of Ostertagia spp. in the untreated control and post-treatment larval cultures were used to apportion egg counts to genera and determine efficacy against this genus.Isolates of Ostertagia spp. recovered from three of the farms were each used to infect 18 six month old calves. The efficacy of oral formulations of ivermectin and moxidectin, both at 0.2mg/kg, was determined against each isolate by slaughter and worm count.The efficacy of ivermectin against Ostertagia spp., based on differentiated FECRT for each of the farms varied from 0% to 88%. The efficacy of ivermectin based on worm counts in the slaughter trial varied from 13% to 75% but moxidectin was >99% effective against all isolates. In addition, in the FECRT albendazole, at a dose rate of 10mg/kg, failed to achieve 95% efficacy against Ostertagia spp. on two farms (82% and 85%). Levamisole consistently failed to achieve 95% efficacy against Ostertagia spp. which is consistent with its known lesser efficacy against this parasite.These results confirm the presence of macrocyclic lactone resistant O. ostertagi in cattle in New Zealand and the likely presence of dual resistance, to macrocyclic lactones and albendazole, in some isolates. Resistant populations of this highly pathogenic parasite are probably not uncommon in New Zealand and pose a significant threat to animal production and welfare in the future.

English

Goats (Capra hircus) are valued assets for resource poor farmers globally. Parasitic infections, especially Haemonchus contortus (Trichostrongylid), impact health and production of goats globally. The present study was therefore, intended to evaluate indigenous goat breeds (Teddy and Beetal) of Punjab, Pakistan for their resilience and resistance to experimental infection of H. contortus. Of 60 goats, 30 each of Teddy and Beetal breeds were further divided into six groups, each consisting of five goats. Four groups of each breed received challenged infection with 12000 and 18000 L3 (third stage) larvae of H. contortus under two infection protocols viz; early and trickle and remaining two groups of each breed were kept as controls. Resilience and resistance of each breed was determined on the basis of comparative phenotypic markers like: faecal egg counts (FEC), packed cell volume (PCV), FAMACHA scores, live body weight (LW), total serum protein (TSP), serum albumin (SA) and worm count on 2, 4, 6 and 8 week post artificial infection with H. contortus. Teddy breed showed significantly (P<0.05) better assessment rank based on phenotypic markers and tendency to resist in response to H. contortus infection as compared to Beetal. The sustainable goat farming should include Teddy as important entity to minimize the issue of anthelmintic resistance. Further, evaluation of genetic markers like: quantitative trait loci (QTLs), genes of major histocomplexcity, protein expression, immunoglobulins, histamines and specific interleukins are recommended for future studies, which can be helpful to explore genetic potential of goat breeds on the basis of their molecular makers. © 2016 Friends Science Publishers

Evaluation of the efficacy of monthly oral administration of afoxolaner plus milbemycin oxime (NexGard Spectra®, Merial) in the prevention of adult Spirocerca lupi establishment in experimentally infected dogs

The nematode Spirocerca lupi (Rudolphi, 1809) is widely distributed but mostly occurs sporadically with stable populations only in certain geographic areas. This helminth mainly infects dogs and wild canids. Primary pathology relates to migration of third stage larvae (L3) damaging the thoracic aorta and establishment of adults in nodules in the oesophagus. The objective of the present study was to evaluate the efficacy of milbemycin oxime in combination with afoxolaner (NexGard Spectra®, Merial), administered monthly, in preventing establishment of adult worms after experimental infection. Two groups consisting of eight animals each were experimentally infected with 15 L3 on Days −28, −14 and −2, respectively (45 L3 per animal in total). Group 1 dogs served as untreated (negative) control, whereas animals in group 2 were treated with NexGard Spectra® at a minimum dose of 0.5mg/kg milbemycin oxime on Day 0 and from then onwards every 28 days up to Day 140 (six treatment occasions). Endoscopy was performed on Day 112 and for some animals also Day 140. Necropsy for worm recovery and nodule/lesion scoring was performed on Day 168. All eight animals in the control group (group 1) presented with 1–3 nodules and worm counts ranging from 9 to 41. Six animals in the NexGard Spectra® group presented with 1–4 nodules and worm counts ranging from 1 to 5. Significantly (p<0.05) fewer worms were collected from treated animals in the treated group (geometric mean 1.7) versus the negative control group (geometric mean 22.0) with 92.3% efficacy calculated. There was no significant (p>0.05) difference between groups with reference to number of nodules in the oesophagus. However, nodules in the control group were significantly (p<0.05) larger than those in the treated group.Number and size of lesions in the dorsal aorta did not differ statistically between groups 1 and 2. Because NexGard Spectra® was administered 28 days after onset of inoculation, migrating and developing L3 caused damage to the aorta wall of animals in the treated group. Milbemycin oxime (administered as NexGard Spectra®) demonstrated effectiveness in reducing infection with adult Spirocerca lupi worms in the oesophagus.

Immunization with Fasciola hepatica thioredoxin glutathione reductase failed to confer protection against fasciolosis in cattle

The liver fluke Fasciola hepatica remains an important agent of food-borne trematode disease producing great economic losses due to its negative effect on productivity of livestock grazing in temperate areas. The prevailing control strategy based on anthelmintic drugs is unsustainable due to widespread resistance hence vaccination appears as an attractive option to pursue. In this study we evaluate the effect of vaccination in calves with a functional recombinant thioredoxin glutathione reductase (rFhTGR) from liver fluke, a critical antioxidant enzyme at the crossroads of the thioredoxin and glutathione metabolism in flatworms. The recombinant enzyme produced in Escherichia coli was tested in two vaccination experiments; in the first trial rFhTGR was administered in combination with Freund́s Incomplete Adjuvant (FIA) in a three-inoculation scheme on weeks 0, 4 and 8; in the second trial rFhTGR was given mixed with Adyuvac 50 or Alum as adjuvants on weeks 0 and 4. In both cases calves were challenged with metacercariae (400 in the first and 500 in the second trial) 2 weeks after the last inoculation. Our results demonstrate that two or three doses of the vaccine induced a non-significant reduction in worm counts of 8.2% (FIA), 3.8% (Adyuvac 50) and 23.0% (Alum) compared to adjuvant controls indicating that rFhTGR failed to induce a protective immunity in challenged calves. All vaccine formulations induced a mixed IgG1/IgG2 response but no booster was observed after challenge. No correlations between antibody titres and worm burdens were found.

The use of FAMACHA in estimation of gastrointestinal nematodes and total worm burden in Damara and Barbados Blackbelly cross sheep.

The prevalence of gastrointestinal (GI) nematodes and total worm burden of Damara and Barbados Blackbelly cross sheep was investigated among smallholder farms in Salak Tinggi district of Selangor, Malaysia. A total of 50 sheep raised in smallholder farms comprising of 27 Damara cross and 23 Barbados Blackbelly cross were categorized based on their age into young and adults. Fecal samples were collected and examined for strongyle egg count by using modified McMaster technique. Severity of infection was categorized into mild, moderate, and heavy, based on egg per gram (EPG). Five sheep were randomly selected and slaughtered to examine the presence of adult gastrointestinal (GI) nematodes through total worm count (TWC). Faffa Malan Chart (FAMACHA) score was used for investigation of worm load based on the degree of anemia. The study revealed an overall EPG prevalence of 88%, of which 84.1% had mild infection. There was a significant difference (p = 0.002) in EPG among the two breeds. Based on age, significant difference (p = 0. 004) in EPG was observed among Barbados Blackbelly cross, but not for Damara cross (p = 0.941). The correlation between severity of infection and the FAMACHA score was significant (r = 0.289; p = 0.042). Haemonchus spp. were the most predominant nematode found in the gastrointestinal tract, followed by Trichostrongylus and Oesophagostomum spps. EPG and TWC for Haemonchus were positively correlated, but not significant (r = 0.85, p = 0.066). From regression analysis, 73% of the variability in TWC for Haemonchus could be explained by EPG. Thus, it can be concluded that FAMACHA score correlates well with severity of infection of a nematode and can be used to assess the strongyle nematode burden in the different sheep crosses.

Variations in T Cell Transcription Factor Sequence and Expression Associated with Resistance to the Sheep Nematode Teladorsagia circumcincta.

This study used selected lambs that varied in their resistance to the gastrointestinal parasite Teladorsagia circumcincta. Infection over 12 weeks identified susceptible (high adult worm count, AWC; high fecal egg count, FEC; low body weight, BW; low IgA) and resistant sheep (no/low AWC and FEC, high BW and high IgA). Resistance is mediated largely by a Th2 response and IgA and IgE antibodies, and is a heritable characteristic. The polarization of T cells and the development of appropriate immune responses is controlled by the master regulators, T-bet (TBX21), GATA-3 (GATA3), RORγt (RORC2) and RORα (RORA); and several inflammatory diseases of humans and mice are associated with allelic or transcript variants of these transcription factors. This study tested the hypothesis that resistance of sheep to T. circumcincta is associated with variations in the structure, sequence or expression levels of individual master regulator transcripts. We have identified and sequenced one variant of sheep TBX21, two variants of GATA3 and RORC2 and five variants of RORA from lymph node mRNA. Relative RT-qPCR analysis showed that TBX21, GATA3 and RORC2 were not significantly differentially-expressed between the nine most resistant (AWC, 0; FEC, 0) and the nine most susceptible sheep (AWC, mean 6078; FEC, mean 350). Absolute RT-qPCR on all 45 animals identified RORVv5 as being significantly differentially-expressed (p = 0.038) between resistant, intermediate and susceptible groups; RORCv2 was not differentially-expressed (p = 0.77). Spearman’s rank analysis showed that RORAv5 transcript copy number was significantly negatively correlated with parameters of susceptibility, AWC and FEC; and was positively correlated with BW. RORCv2 was not correlated with AWC, FEC or BW but was significantly negatively correlated with IgA antibody levels. This study identifies the full length RORA variant (RORAv5) as important in controlling the protective immune response to T. circumcincta infection in sheep.

In vitro and in vivo anthelmintic effects of Caesalpinia bonducella (L.) Roxb. leaf extract on Hymenolepis diminuta (Cestoda) and Syphacia obvelata (Nematoda).

Background:Leaves of Caesalpinia bonducella (L.) Roxb. have been traditionally used as an herbal remedy to treat the intestinal helminthic infections in traditional medicine of India.Aim:This study was undertaken to evaluate the potential in vitro and in vivo anthelmintic effects of C. bonducella leaf extract against Syphacia obvelata (Nematoda) and Hymenolepis diminuta (Cestoda).Materials and Methods:The in vitro anthelmintic activity of the extract was investigated on adult worms of S. obvelata (Nematoda) and H. diminuta (Cestoda) in terms of physical motility and mortality of parasites. The in vivo study was performed in H. diminuta-rat model and S. obvelata-mice model, by monitoring the egg per gram of feces count and worm count of animals following the treatment with different doses of plant extract.Results:The study recorded significant and dose-dependent anthelmintic effects of the extract on both the parasites. In the in vitro study, 30 mg/ml concentration of extract caused mortality of H. diminuta in 2.5 ± 0.2 h and S. obvelata in 3.57 ± 0.16 h. In the in vivo study, the extract showed a comparatively better efficacy on S. obvelata, where its 800 mg/kg dose revealed 93% reduction of worm load in mice, as compared to 85% worm load reduction of H. diminuta in rats.Conclusions:The findings suggest that leaf extract of C. bonducella possesses significant anthelmintic effects and supports its use as an anthelmintic in traditional medicine. This appears to be the first report of in vivo anthelmintic activity of C. bonducella against these parasites.

Anthelmintic activity of a standardized extract from the rhizomes of Acorus calamus Linn. (Acoraceae) against experimentally induced cestodiasis in rats.

Background:The rhizomes of a herb Acorus calamus Linn. (Acoraceae) have been widely used as a traditional medicine to cure intestinal-helminthic infections in India and South Africa.Aim:This study was undertaken to investigate the in vivo anthelmintic activity of a standardized methanolic extract obtained from the rhizomes A. calamus in a rodent model.Materials and Methods:A methanolic extract obtained from rhizomes of A. calamus was characterized for active principle using nuclear magnetic resonance 1H NMR, 13C NMR, mass and infrared spectroscopy. The amount of active principle in rhizome isolated active fraction of plant was assayed using high-performance liquid chromatography (HPLC). Later, the standardized rhizome extract of plant and its active principle were tested for in vivo anthelmintic efficacy against experimentally induced Hymenolepis diminuta, a zoonotic cestode, infections in rats.Results:The study revealed that b-asarone is the active principle of plant. The HPLC analysis of local variety of A. calamus revealed that active fraction contains 83.54% (w/w) of b-asarone. The in vivo study revealed that treatment of H. diminuta infected rats by a single 800 mg/kg dose of rhizome extract for 5 days results into 62.30% reduction in eggs per gram of feces counts and 83.25% reduction in worm counts of animals. These findings compared well with the efficacy of a reference drug, praziquantel. The active principle b-asarone showed slightly better anthelmintic effects than crude extract. In acute toxicity assay, a single oral 2000 mg/kg dose of extract did not reveal any signs of toxicity or mortality in mice, and the LD50 of the extract was noted to be >2000 mg/kg.Conclusion:Taken together, the results of this study indicate that rhizomes of A. calamus bear significant dose-dependent effects against intestinal helminths. Further, the Indian variety of A. calamus contains high b-asarone content. Therefore, there exists a great potential to develop some suitable anthelmintic herbal products from this plant.

Investigation of possible pumpkin seeds and ginger effects on gastrointestinal nematode infection indicators in meat goat kids and lambs

In four experiments, 77 naturally-infected Boer crossbred kids and 28 artificially-inoculated Katahdin lambs were used to evaluate the effect of pumpkin seeds (Exp 1; 21 kids), ginger or pumpkin seed drench (Exp 2; 30 kids) and pumpkin seed oil (Exp 3 and 4: 28 lambs and 26 kids, respectively) on gastrointestinal nematode (GIN) indicators. In all experiments, kids and lambs were placed in individual pens and received pre-weighed rations of a commercially pelleted meat goat or sheep diet daily. In Exp 1, kids were supplemented with ground pumpkin seeds (PUM; n=10) mixed into feed daily at a rate of 5g/kg body weight (BW) or were not supplemented (CON; n=11) for 21 days. In Exp 2, kids were orally drenched with water (CON; n=10), 5g pumpkin seed/kg BW (PUM; n=10) or 3g ginger/kg BW (GIR; n=10) every other day for 42 days. In Exp 3, lambs were orally drenched with 2ml/kg water (CON; n=7), 2.0ml/kg BW pumpkin seed oil once every 7 days (PUM1; n=10), or 2.0ml/kg BW pumpkin seed oil daily for 3 out of every 7 days (PUM2; n=11) for 28 days. In Exp 4, kids were orally drenched with 2ml/kg water (CON; n=13), or 2.0ml/kg BW pumpkin seed oil (PUM; n=13) every other day for 35 days. In all experiments, BW, daily feed intake and blood and fecal samples were collected every 7 days. All animals in Exp 2 were harvested at a USDA-inspected abattoir and abomasal and small intestinal contents were collected for total worm counts. The FEC were similar for treatments in all experiments. Treatment influenced PCV (P<0.05) only in Exp 1 and 4. In Exp 2, at harvest, there was a tendency (P=0.08) for CON animals to have a higher number of total GIN than GIR-treated animals, but PUM-treated animals were intermediate. BW were similar for treatments in Exp 1, 2 and 3 while CON animals in Exp 4 had a greater BW than PUM-treated animals on day 7 only and were similar thereafter (treatment by day interaction, P<0.05). In these studies, pumpkin and ginger treatments administered were not effective in reducing FEC in meat goat kids or lambs.

Efficacy of a single dose of milbemycin oxime/praziquantel combination tablets, Milpro®, against adult Echinococcus multilocularis in dogs and both adult and immature E. multilocularis in young cats

Two single-site, laboratory, negatively controlled, masked, randomised dose confirmation studies were performed: one in dogs, the other in cats. After a period of acclimatisation, both the dogs and cats were orally infected with Echinococcus multilocularis protoscoleces. In the dog study, 10 dogs received a single dose of Milpro® tablets at a minimum dose of 0.5 mg/kg milbemycin oxime and 5 mg/kg praziquantel 18 days post-infection and 10 dogs received no treatment. In the cat study, 10 cats received a single dose of Milpro® tablets at a minimum dose of 2 mg/kg milbemycin oxime and 5 mg/kg praziquantel 7 days post-infection, 10 cats received a single dose of the treatment 18 days post-infection and 10 cats remained untreated. In both studies, intestinal worm counts were performed 23 days post-infection at necropsy. No worms were retrieved from any of the 30 treated animals. Nine of 10 control dogs had multiple worms (geometric mean 91, arithmetic mean 304) and all 10 control cats had multiple worms (geometric mean 216, arithmetic mean 481). The difference in worm counts between all three treated groups and their controls was highly significant (ANOVA p values of log transformed data <0.0001). Efficacy of 100 % was demonstrated for the elimination of adult E. multilocularis in dogs and cats as well as for elimination of immature E. multilocularis in cats as evidenced by the effectiveness of treatment 7 days post-infection. The treatments were well accepted and tolerated, and there were no adverse drug reactions observed.

Anthelmintic effects of Oroxylum indicum stem bark extract on juvenile and adult stages of Hymenolepis diminuta (Cestoda), an in vitro and in vivo study

Worldwide, traditional usage of herbal medicines is a common practice to treat various parasitic infections. In India, bark decoction of Oroxylum indicum (L.) Kurz. (Bignoniaceae) is used as a traditional medicine to cure intestinal-helminthic infections. This study investigated the anthelmintic efficacy of methanolic bark extract of O. indicum on Hymenolepis diminuta (Cestoda), using both in vitro and in vivo methods. Utilizing a mini-questionnaire, first, we collected information about the pattern of anthelmintic use of this plant. Later, in vitro efficacy of extract was tested at 10, 20 and 30 mg/ml on both the artificially excysted juveniles and adult H. diminuta worms. Herein, scanning electron microscopy (SEM) was also utilized to determine the possible effects of extract on tegumental surfaces of juvenile and adult cestode. In vivo, extract was tested at 250, 500 and 1000 mg/kg in H. diminuta albino rat model, against juvenile and adult cestode. Praziquantel (PZQ) served as reference drug in anthelmintic assays. The acute toxicity of extract was determined as per the OECD guidelines. The field questionnaire data revealed that 78 % of people in the area use O. indicum stem bark against intestinal helminths, and of these, 75 % of people also believed it highly efficacious anthelmintic remedy. In vitro testing of extract revealed significant effects on juvenile worms, and 30 mg/ml of extract caused mortality of juveniles at the initial period (0.25 ± 0.00 h). Conversely, PZQ (1 mg/ml) showed paralysis and mortality of juvenile cestodes in 0.44 ± 0.04 and 1.11 ± 0.06 h, respectively. As determined by SEM, in vitro exposure to extract showed substantial effects on both juveniles and adult worms in the form of wrinkled scolex, distorted tegument and eroded microtriches. In vivo study revealed better efficacy of extract against juveniles than adult stages of parasite. Treatment of rats with 1000 mg/kg of extract caused 79.3 % reduction in EPG counts and 70.8 % of reduction in worm counts, which compared well to PZQ efficacy. In acute toxicity study, administration of a single oral dose of 2000 mg/kg of extract to mice did not cause any signs of toxicity or mortality within 2-week observation. Hence, the LD50 of extract was estimated to be greater than 2000 mg/kg. In conclusion, the bark extract of O. indicum possesses concentration-dependent effects against the larval and adult H. diminuta worms, and thus the extract holds promise in the control of intestinal helminthiases. This also supports the common belief of people about the reputation of this plant as anthelmintic in traditional medicine. There is a need to standardize the formulations of this plant for their possible use as standardized herbal anthelmintic agents in the future.

Selection for anthelmintic resistant Teladorsagia circumcincta in pre-weaned lambs by treating their dams with long-acting moxidectin injection

Administration of long-acting anthelmintics to pregnant ewes prior to lambing is a common practice in New Zealand. Today, most of these products contain macrocyclic lactone (ML) actives, which because of their lipophilic nature, are detectable in the milk of treated animals and in the plasma of their suckling offspring. This study was conducted to confirm the transfer of ML actives to lambs in the ewe's milk, and to assess whether this could result in selection for ML resistant nematodes in the lamb. Ninety, twin bearing Romney ewes were treated before lambing with a long-acting injectable formulation of moxidectin, a 100-day controlled release capsule (CRC) containing abamectin and albendazole, or remained untreated. After lambing, seven ewes from each treatment group were selected for uniformity of lambing date and, along with their twin lambs, relocated indoors. At intervals, all ewes and lambs were bled, and samples of ewe's milk were collected, for determination of drug concentrations. Commencing 4 weeks after birth all lambs were dosed weekly with 250 infective larvae (L3) of either an ML-susceptible or –resistant isolate of Teladorsagia circumcinta. At 12 weeks of age all lambs were slaughtered and their abomasa recovered for worm counts. Moxidectin was detected in the plasma of moxidectin-treated ewes until about 50 days after treatment and in their lambs until about day 60. Abamectin was detected in the plasma of CRC-treated ewes until the last sample on day 80 and in the plasma of their lambs until about day 60. Both actives were detectable in milk of treated ewes until day 80 after treatment. Establishment of resistant L3 was not different between the treatment groups but treatment of ewes with moxidectin reduced establishment of susceptible L3 by 70%, confirming the potential of drug transfer in milk to screen for ML-resistance in the suckling lamb.

Prevalence and magnitude of helminth infections in organic laying hens (Gallus gallus domesticus) across Europe

Helminths are associated with health- and welfare problems in organic laying hens. The present observational cross-sectional study therefore aimed to estimate the prevalence and worm burdens of intestinal helminths in organic flocks of laying hens in 8 European countries, and to identify management factors that might be associated with helminth infections, with emphasis on Ascaridia galli. Data on flock-level management factors (e.g. nutritional factors, litter quality, housing system, opening- and closing hours of popholes, pasture rotation and provision of occupational materials) were collected during a farm visit when the hens were on average 62 weeks old. Worm counts were performed for 892 hens from 55 flocks and the number of ascarid (presumably primarily A. galli) eggs per g faeces (EPG) for 881 hens from 54 flocks. The association between parasitological parameters (prevalence, worm burden and EPG) and the management factors were analysed by multivariate models. Results showed that A. galli was highly prevalent across Europe with an overall mean prevalence of 69.5% and mean worm burden of 10 worms per hen. The overall mean prevalence and worm burden for Heterakis spp. were 29.0% and 16 worms per hen, respectively, with a large variation between countries. On average, the hens excreted 576 ascarid EPG. The mean prevalence of Raillietina spp. was 13.6%. A positive correlation was found between mean A. galli worm burden and ascarid EPG. Of the analysed management factors, only pasture access time had a significant negative association with A. galli worm burden which was in contrast to the general belief that outdoor access may increase the risk of helminth infections in production animals. In conclusion, the complexity of on-farm transmission dynamics is thus a challenge when evaluating the relative importance of management factors in relation to helminth infections.