Oesophagostomum Radiatum Research Articles

Identification of Chabertiidae (Nematoda, Strongylida) by PCR-RFLP based method: A new diagnostic tool for cross transmission investigation between domestic and wild ruminants in France

We describe a PCR-RFLP-based method that allows reliable identification of four species of nematode parasites presenting similar infective third-stage larvae (L3) with a flagelliform tail and more than 16 intestinal cells, commonly observed in gastrointestinal tract of ruminants in France. Molecular analysis of the second internal transcribed spacer (ITS2) of ribosomal DNA, considered as a specific marker for Strongylida, revealed four robust monophyletic clades corresponding to species Chabertia ovina, Oesophagostomum sikae, Oesophagostomum radiatum and Oesophagostomum venulosum. One restriction enzyme (DdeI) was used to digest this domain, and we observed four different and clear digestion patterns according to these species (adults or larvae). Hence, this new method is a good tool easy to use for veterinary laboratories to characterize the different species, and allows considering possible cross transmission between domestic and wild ruminants, especially cervids often incriminated as potential reservoir of parasites for cattle. Moreover, thanks to this new tool, necroscopic analyses could be substituted by coprological methods, a non-invasive approach.

Nematode resistance to ivermectin (630 and 700 μg/kg) in cattle from the Southeast and South of Brazil

Two high doses of ivermectin (630μg/kg and 700μg/kg) that are sold commercially in Brazil were evaluated in dose-and-slaughter trials with 144 naturally nematode-infected cattle from eight regions within the states of Minas Gerias, São Paulo and Rio Grande do Sul in Brazil. Treatment groups were based on fecal egg counts 1, 2, and 3days before treatment; all animals studied had a minimum egg count of at least 500 eggs per gram of feces (EPG). Post-mortem analyses were conducted on day 14. The highest levels of resistance to ivermectin were found for Haemonchus placei, Cooperia punctata and Oesophagostomum radiatum; all populations of H. placei were resistant to the 630μg/kg dose, and 67% were resistant to 700μg/kg; 86% of C. punctata were resistant to the 630μg/kg dose, and 33% were resistant to 700μg/kg. A combined analysis revealed that 57% of O. radiatum were resistant to the lower dose of ivermectin. H. placei, C. punctata and O. radiatum, in order, were the nematode populations with the highest indices of resistance, whereas Trichostrongylus axei was the most susceptible to 630 and 700μg/kg dosages of ivermectin. The results of helminthic resistance to ivermectin for different populations of H. placei and C. punctata described in the present study support previous literature data, in which a small decrease in the average parasitic burden of C. punctata and a consequent increase of H. placei were observed in cattle from the Southeast, South and Center-West regions of Brazil.

Resistência de Haemonchus placei, Cooperia punctata e Oesophagostomum radiatum à ivermectina pour-on a 500mcgkg-1 em rebanhos bovinos no Brasil

O amplo espectro de ação dos endectocidas e a praticidade de aplicação das suas formulações pour-on são fatores que têm estimulado uma maior frequência de utilização destes produtos na criação de bovinos. Neste estudo, avaliou-se a eficácia anti-helmíntica da ivermectina, administrada via pour-on, 500mcgkg-1, contra nematódeos de bovinos provenientes de diferentes rebanhos. Foram adquiridos 12 bezerros de cada um dos quatro rebanhos selecionados. Todos os 48 bezerros utilizados apresentavam médias de ovos por grama de fezes (OPG) maiores que 500, considerando-se três contagens consecutivas. Na sequencia, os animais de cada rebanho foram divididos em dois grupos de seis bovinos cada, sendo um tratado com ivermectina 500mcgkg-1 via pour-on e outro mantido como controle. Quatorze dias depois do tratamento, os bovinos foram submetidos à eutanásia para contagem de endoparasitas. A ivermectina demonstrou resultados nulos de eficácia contra H. placei nos quatro rebanhos. Contra C. punctata, tal formulação teve eficácia nula nos rebanhos provenientes de Jaboticabal,SP, e de Formiga,MG, e eficácias de 75,8% e 58,4% nos rebanhos provenientes de São José do Rio Pardo,SP, e de São Sebastião do Paraíso,MG, respectivamente. Valores de eficácia de 94,2% (Jaboticabal), 0,0% (São José do Rio Pardo), 94,2% (Formiga) e 39,2% (São Sebastião do Paraíso) foram detectados contra O. radiatum. Com base nos resultados encontrados, pode-se concluir que as quatro populações de Haemonchus placei e de Cooperia punctata avaliadas foram resistentes à ivermectina, administrada via pour-on, 500mcgkg-1. Foram observadas cepas de Oesophagostomum radiatum resistentes à ivermectina em dois dos quatro rebanhos testados.

Evaluation of clinical safety and anthelmintic efficacy of aurixazole administed orally at 24 mg/kg in cattle

The current study evaluated, in vivo, the clinical safety and the anthelmintic efficacy of 24% aurixazole (24 mg/kg), administered orally, in bovines. Two experiments were conducted: the first one evaluating the clinical safety of 24% aurixazole (24 mg/kg) in cattle, and a second one evaluating the anthelmintic efficacy of aurixazole (24 mg/kg) against gastrointestinal nematodes on naturally infected cattle. Based on the results of clinical safety, no alterations on clinical and haematological signs and on the biochemical values obtained in animals treated orally with aurixazole 24 mg/kg were observed. Regarding the results of reduction or efficacy, obtained by eggs per gram of faeces (EPG) counts, the formulation of aurixazole reached values superior to 99% (arithmetic means) in all post-treatment dates. In two occasions, this formulation reached maximum efficacy (100%). Comparing these results with the reduction percentages obtained by EPG counts, it is possible to verify that the values obtained by all three formulations were compatible with the efficacy results. Aurixazole reached maximum efficacy (100%) against Haemonchus placei, Cooperia spatulata and Oesophagostomum radiatum. Against Cooperia punctata, this formulation reached an efficacy index of 99.99%. Regarding aurixazole, no specific trials were conducted on the field in order to evaluate the behaviour of this molecule against helminths that are resistant to other molecules, specially isolated levamisole and disophenolat. Due to this fact, future studies will be necessary to assess the effectiveness of aurixazole against strains of nematodes that are resistant to levamisole and disophenolat, but the results of clinical safety and efficacy described in this study allow us to conclude that the aurixazole molecule, concomitantly with other measures and orally administered formulations, can be another important tool in the control of nematodes parasitizing bovines.

A study on helminthiasis of cattle herds in Kachia grazing reserve (KGR) of Kaduna state, Nigeria

Aim: This study was conducted with the aim of determining the prevalence of helminthes in cattle and treatment intervention strategy in Kachia Grazing Reserve (KGR). Materials and Methods: A total of 3,651 cattle from 88 households were randomly selected, sampled and examined . The sampling was spread over three (3) periods; Pre-intervention (1,609), Intervention (1,525) and Post-intervention (517). Both physical examination and laboratory investigation were employed in the study. Results: This study revealed the presence of different types of helminthes in the bovine population of the KGR which include the helminth eggs of Nematodes (Oesophagostomum radiatum, Bonustonum phlebotomum, Tricuris globulosa, Cooperia pectinita, Toxocara vitulorum, Strongiloides papillosus, Strogylus langamus), Cestodes (Moneizia benedeni) and Trematodes ( Schistosoma bovis, Paramphistomum cervi, Fasciola gigantica) at different intervention periods, where by 820 (53.77%) were positive for pre- intervention, 946 (58.79%) positive for intervention and 205 (39.65%) were positive for postintervention period. Among the eleven species of helminthes identified, P. cervi was the most prevalent in all the periods, followed by O. radiatum. The study also revealed that the cattle in the study area were infected with single and multiple infections. Furthermore, 498(32.66%), 585(36.36%) and 171(33.08%) of cattle for the pre- intervention, intervention and post- intervention periods, respectively had single infection. However, 305 (20%), 381 (23.68%) and 37 (7.16%) of the cattle for the three periods, respectively harbored multiple infections (polyparasitism) caused by two to six different parasites. The results also show that age was a factor in the abundance of the parasites in the cattle as parasites were demonstrated more in adult cattle than the young stock (calves and yearlings). Chi-square and Kruskal Wallis showed a significant difference (p < 0.05) in the prevalence during the three periods. Conclusion: The present study revealed that helminthes of cattle are common in KGR; hence there is a need for regular faecal examination and routine treatment of the herds instead of treating the individual cases.

Gastrointestinal nematodes in grazing dairy cattle from small and medium-sized farms in southern Poland

This study aimed to estimate the prevalence of gastrointestinal nematodes and the intensity of infection in grazing dairy cattle from small and medium-sized farms in southern Poland. The level of antibodies against Ostertagia ostertagi in the bulk tank milk (BTM) from the animals was also assessed. Rectal fecal samples collected from 361 cows on 20 farms were examined using Willis-Schlaaf flotation and the McMaster method. BTM samples were tested for the presence of O. ostertagi antibodies using ELISA. Multiplex PCR was used to identify the third-stage larvae (L3) of gastrointestinal nematodes derived from the culture of pooled fecal samples from sampled farms. Gastrointestinal nematode eggs were found in the samples from 18 of the 20 herds with a prevalence range from 20.4 to 94.5%. The average number of eggs excreted in the feces of the herds was 200 eggs per gram (EPG). Antibodies to O. ostertagi were found in 20 of the examined herds (100%), of which 6 had optical density ratios (ODR) greater than 0.5. PCR results showed the presence of three nematode species: Ostertagia ostertagi, Cooperia oncophora and Oesophagostomum radiatum.

Lesões parasitárias encontradas em bovinos abatidos para consumo humano

Durante um período de 28 meses (janeiro 2011-abril 2013) foram feitas visitas periódicas a quarto abatedouros frigoríficos de bovinos para colher lesões regularmente encontradas em bovinos abatidos para consumo humano. Trezentas e três lesões foram colhidas, 25% das quais eram causadas por seis parasitas diferentes: o metacestoide de Echinocccus granulosus (cisto hidático), Fasciola hepatica, o metacestoide de Taenia saginata (Cysticercus bovis), Oesophagostomum radiatum, Eurythrema coelomaticum e Paramphistomum cervi. Os aspectos macro e microscópicos causados por esses vermes são profusamente ilustrados e uma descrição macro e microscópicadas lesões é fornecida na esperança de auxiliar o inspetor de carnes iniciante na tarefa de reconhecer e interpretar o significado dessas lesões tanto para a saúde animal quanto para a saúde humana. Com respeito a esses últimos objetivos, o ciclo evolutivo, e os efeitos nos hospedeiros animal e humano, e ainda a destinação da carcaça ou órgão afetado na linha de inspeção, são discutidos para cada parasita.

Control trial and fecal egg count reduction test determinations of nematocidal efficacies of moxidectin and generic ivermectin in recently weaned, naturally infected calves

An anthelmintic efficacy study was performed with young, naturally infected beef-type calves obtained at local farms. Presumably, the study calves had been recently weaned and had not been treated with a parasiticide prior to study acquisition. After blocking the 24 study calves in accordance with calculated Cooperia spp EPG counts, the calves were randomly allocated within each block to one of four treatment groups, resulting in 6 animals per treatment group (untreated controls, topical ivermectin at the rate of 500mcg/kg BW [Noromectin Pour-On® Norbrook], topical moxidectin at the rate of 500mcg/kg BW [Cydectin Pour-On® Boehringer Ingelheim Vetmedica (BIVM)] and injectable moxidectin at the rate of 200mcg/kg BW [Cydectin® BIVM]. After treatment, the animals were penned by treatment group until necropsy. Fecal, strongyle egg count reduction percentages at 2 days post-treatment were 13, 52, 81 and 93 for control, topical ivermectin, topical moxidectin and injectable moxidectin treatment groups, respectively. In the same order as above, egg count reduction percentages at necropsy (15–18 days post-treatment) were −14, 91, 94 and 97. Based on geometric means for worm burdens quantified at necropsy, anthelmintic efficacies ranged from 96 to 100% for adult Oesophagostomum radiatum, Ostertagia ostertagi, Haemonchus placei and Trichostrongylus axei. Against adult Nematodirus helvetianus, percent efficacies based on geometric means were 56.7, 98.3 and 82.2 for topical ivermectin, topical moxidectin and injectable moxidectin, respectively; an observation that is guarded, as only 5 control animals were infected with adult N. helvetianus. Respective anthelmintic efficacies (%’s) against adult Cooperia oncophora and C. punctata were 93.0 and 73.4 (topical ivermectin), 99.3 and 99.9 (topical moxidectin) and 46.1 and 93.6 (injectable moxidectin). Judging from these data, it appears that treatment of calves soon after weaning with topical moxidectin is effective (>90% efficacy) for all common nematodes in cattle, but injectable moxidectin and topical ivermectin have limited effectiveness against Cooperia spp. With Cooperia spp and H. placei infections, the fecal egg count reduction test and the control trial determinations of anthelmintic effectiveness were in disagreement regarding injectable moxidectin and topical ivermectin.

Therapeutic efficacy of eprinomectin extended-release injection against induced infections of developing (fourth-stage larvae) and adult nematode parasites of cattle

The therapeutic efficacy of eprinomectin in an extended-release injection (ERI) formulation was evaluated against induced infections of developing fourth-stage larval or adult gastrointestinal and pulmonary nematodes of cattle in a series of six studies under two identical protocols (three each for developing fourth-stage larvae or adults) conducted in the USA, Germany or the UK (two studies at each location, one per stage).Each study initially included 16 nematode-free cattle. The cattle were of various breeds or crosses, weighed 109–186.5kg prior to treatment, and were approximately 4–7 months old. The animals were blocked based on pre-treatment bodyweight and then randomly allocated to treatment: eprinomectin ERI vehicle (control) at 1mL/50kg body weight or eprinomectin 5% ERI at 1mL/50kg bodyweight (1.0mg eprinomectin/kg) for a total of eight and eight animals in each group. Treatments were administered once on Day 0 by subcutaneous injection in front of the shoulder.In each study, cattle were infected with a combination of infective third-stage larvae or eggs of gastrointestinal and pulmonary nematodes. Inoculation was scheduled so that the nematodes were expected to be fourth-stage larvae or adults at the time of treatment. For parasite recovery, all study animals were humanely euthanized and necropsied 14–15 (adult infections) or 21–22 days after treatment (developing fourth-stage larval infections).When compared with the vehicle-treated control counts, efficacy of eprinomectin ERI against developing fourth-stage larvae and adults was ≥98% (p<0.05) for the following nematodes: Dictyocaulus viviparus, Bunostomum phlebotomum, Cooperia curticei, C. oncophora, C. surnabada, C. punctata, Haemonchus contortus, H. placei, Nematodirus helvetianus, Oesophagostomum radiatum, Oes. venulosum, Ostertagia leptospicularis, O. ostertagi, O. circumcincta, O. pinnata, O. trifurcata (developing fourth-stage larval infections only), Strongyloides papillosus, Trichostrongylus axei, T. colubriformis, and Trichuris ovis (adult infections only).All animals accepted the treatment well. No adverse reaction to treatments was observed in any animal in any study.

Nematode burdens of pastured cattle treated once at turnout with eprinomectin extended-release injection

The efficacy of eprinomectin in an extended-release injection (ERI) formulation was evaluated against infections with third-stage larvae or eggs of gastrointestinal and pulmonary nematodes in cattle under 120-day natural challenge conditions in a series of five studies conducted in the USA (three studies) and in Europe (two studies). For each study, 30 nematode-free (four studies) or 30 cattle harboring naturally acquired nematode infections (one study) were included. The cattle were of various breeds or crosses, weighed 107.5–273kg prior to treatment and aged approximately 4–11 months. For each study, animals were blocked based on pre-treatment bodyweight and then randomly allocated to treatment: ERI vehicle (control) at 1mL/50kg bodyweight or Eprinomectin 5% (w/v) ERI at 1mL/50kg bodyweight (1.0mg eprinomectin/kg) for a total of 15 and 15 animals in each group. Treatments were administered once on Day 0 by subcutaneous injection in front of the shoulder. In each study, all animals grazed one naturally contaminated pasture for 120 days. At regular intervals during the studies, fecal samples from all cattle were examined for nematode egg and larval counts. In four studies pairs of tracer cattle were used to monitor pasture infectivity at 28-day intervals before and/or during the grazing period. All calves were weighed before turnout onto pasture and at regular intervals until housing on Day 120. For parasite recovery, all study animals were humanely euthanized 27–30 days after removal from pasture.Cattle treated with Eprinomectin ERI had significantly (p<0.05) fewer strongylid eggs (≤1 egg per gram; egg count reduction≥94%) than the control cattle and zero lungworm larvae at each post-treatment time point. At euthanasia, cattle treated with Eprinomectin ERI had significantly (p<0.05) fewer of the following nematodes than the ERI vehicle-treated (control) cattle with overall reduction of nematode counts by >92%: Dictyocaulus viviparus (adults and fourth-stage larvae (L4), Bunostomum phlebotomum, Cooperia curticei, Cooperia oncophora, Cooperia punctata, Cooperia surnabada, Cooperia spp. inhibited L4, Haemonchus contortus, Haemonchus placei, Haemonchus spp. inhibited L4, Nematodirus helvetianus, Nematodirus spp. inhibited L4, Oesophagostomum radiatum, Oesophagostomum spp. inhibited L4, Ostertagia leptospicularis, Ostertagia lyrata, Ostertagia ostertagi, Ostertagia spp. inhibited L4, Trichostrongylus axei, Trichostrongylus colubriformis, Trichostrongylus spp. inhibited L4, Trichuris discolor, and Trichuris ovis. Over the 120-day grazing period, Eprinomectin ERI-treated cattle gained between 4.8kg and 31kg more weight than the controls. This weight gain advantage was significant (p<0.05) in three studies.All animals accepted the treatment well. No adverse reaction to treatment was observed in any animal in any study.

An eprinomectin extended-release injection formulation providing nematode control in cattle for up to 150 days

A series of 10 dose confirmation studies was conducted to evaluate the persistent activity of an extended-release injectable (ERI) formulation of eprinomectin against single point challenge infections of gastrointestinal and pulmonary nematodes of cattle. The formulation, selected based on the optimal combination of high nematode efficacy, appropriate plasma profile, and satisfactory tissue residue levels, includes 5% poly(d,l-lactide-co-glycolic)acid (PLGA) and is designed to deliver eprinomectin at a dose of 1.0mg/kg bodyweight. Individual studies, included 16–30 cattle blocked based on pre-treatment bodyweight and randomly allocated to treatment with either ERI vehicle or saline (control), or the selected Eprinomectin ERI formulation. Treatments were administered once at a dose volume of 1mL/50kg bodyweight by subcutaneous injection in front of the shoulder. In each study, cattle were challenged with a combination of infective stages of gastrointestinal and/or pulmonary nematodes 100, 120 or 150 days after treatment and were processed for parasite recovery according to standard techniques 25–30 days after challenge. Based on parasite counts, Eprinomectin ERI (1mg eprinomectin/kg bodyweight) provided >90% efficacy (p<0.05) against challenge with Cooperia oncophora and Cooperia surnabada at 100 days after treatment; against challenge with Ostertagia ostertagi, Ostertagia lyrata, Ostertagia leptospicularis, Ostertagia circumcincta, Ostertagia trifurcata, Trichostrongylus axei, and Cooperia punctata at 120 days after treatment; and against challenge with Haemonchus contortus, Bunostomum phlebotomum, Oesophagostomum radiatum and Dictyocaulus viviparus at 150 days after treatment. Results of a study to evaluate eprinomectin plasma levels in cattle treated with the Eprinomectin ERI formulation reveal a characteristic second plasma concentration peak and a profile commensurate with the duration of efficacy. These results confirm that the Eprinomectin ERI formulation can provide high levels of parasite control against a range of nematodes of cattle for up to 5 months following a single treatment.

Resistance against gastrointestinal nematodes in Crioulo Lageano and crossbred Angus cattle in southern Brazil

Gastrointestinal nematode (GIN) infection is a major cause of production losses in cattle. This study was carried out to evaluate the natural resistance against nematode infection in Crioulo Lageano and crossbred Angus male calves. Crioulo Lageano is a local cattle breed in the state of Santa Catarina, in southern Brazil. Ten weaned calves of each breed were grazed together on pasture and naturally infected with nematodes between July 2009 and December 2010. Once every 28 days, we collected fecal and blood samples for parasitological and immunological tests, as well as recording body weights. After 19 samplings, all animals were slaughtered for quantification and identification of GINs. We found that the animals had been infected with the following nematode species, in decreasing order by the mean number of specimens: Trichostrongylus axei, Cooperia punctata, Ostertagia ostertagi, Haemonchus placei, Oesophagostomum radiatum, and Trichuris spp. There were no significant differences between the Crioulo Lageano and crossbred Angus groups in terms of worm burden or nematode fecal egg count, nor in terms of the mean levels of immunoglobulin (G and A) against C. punctata and H. placei antigens, except in IgA mean level in abomasal mucus against H. placei adult worms that was significantly higher in crossbred Angus cattle (p<0.05). At the end of the study, the crossbred Angus cattle were heavier than were the Crioulo Lageano cattle (mean live weight, 507.35 and 390.3kg, respectively). Comparative parasitological and immunological evaluation revealed no difference between two breeds in terms of their natural resistance against GINs.

Reevaluation of efficacy against nematode parasites and pharmacokinetics of topical eprinomectin in cattle

A study was conducted to confirm the efficacy of topical eprinomectin against nematodes and to evaluate the pharmacokinetics in cattle prevented from having physical contact with other cattle and from self-grooming. Sixteen male Brown Swiss calves were infected with larvae of recently isolated nematode parasites. Inoculation was scheduled so that the nematodes were expected to be adults at the time of treatment. Animals were blocked based on pretreatment body weight and randomly allocated to the untreated control group or the group treated with EPRINEX® Pour-On (Merial; 0.5 mg eprinomectin per kilogram body weight). Plasma samples were collected prior to and between 1 and 21 days following treatment and analysed for eprinomectin (B1a component) concentrations. For parasite recovery, identification and counting, animals were humanely euthanized 21 days after treatment. Calves treated with eprinomectin had significantly (p < 0.05) fewer (>99 % reduction) adult Dictyocaulus viviparus, Bunostomum phlebotomum, Cooperia oncophora, Cooperia surnabada, Cooperia punctata, Nematodirus helvetianus, Oesophagostomum radiatum, Ostertagia ostertagi, Ostertagia lyrata, and Trichostrongylus axei and inhibited fourth-stage Nematodirus and Ostertagia larvae than the controls. The main pharmacokinetic parameters of eprinomectin B1a were: AUC(inf), 124 ± 24 day ng/mL; T (1/2), 5.2 ± 0.9 days; and C (max), 9.7 ± 2.2 ng/mL. Individual maximal concentrations were observed 3-7 days after treatment. This study confirmed the continued high level of efficacy of topically administered eprinomectin against a wide range of recently isolated nematodes. In addition, this study demonstrates that oral ingestion is not required to achieve adequate exposure for efficacy following topical administration of eprinomectin.

Clinico – Hemato and Biochemical Study of Anemia in Cachectic Cattle in Baghdad

The study was carried out in order to evaluate clinically and laboratory cachectic animals suffering from anemia. Animal examined were 50 cow and calf. The study include clinical, hemato and biochemical test for accurate diagnosis of cachexia in cows and calves . Blood smears were conducted for detection of blood parasites , fecal examination for gastrointestinal parasites and Different parameters were applied for classification of cachexia , depending on bony projection specially ribs and pelvic and generalized muscular atrophy. However , The study revealed an incidence of cachexia and anemia of blood parasites was including Theileria, Anaplasma, gastrointestinal parasites, ten cases were shown foreign body syndrome while other tens were diagnosed as other clinical cases. A significant decrease ( P &lt; 0.05) of RBCS, Hb, PCV and WBC count in debility animals were observed . However , a significant lymphocytosis were seen in blood parasites infection and other clinical cases , Neutrophilia in foreign body syndrome and other clinical cases , Esenophilia in gastrointestinal parasites infestation ,Monocytosis in all clinical cases were detected . Different parameters were applied for classification of anemia mainly morphological classification including macrocytic hypochromic anemia mainly recorded in blood parasites infection and other clinical cases while Normocytic hypochromic anemia appeared in gastrointestinal parasites infestation, and foreign body Syndrome.Fecal examination of cachectic animal indicate the identification of (7) species of gastrointestinal parasites including: Cooperia onchophora, Haemonchus contortus, Bunostomum phlebtomum, Ostertagia spp., Oesophagostomum radiatum, Trichostrongylus axei and Strongyloides papillosus. However , a mixed infestation parasite was dominant and recorded in Animal.Biochemical changes revealed a. Hypoprotenemia appears in all cachectic animal except in foreign body syndrome cases .

Clinico – Hemato and Biochemical Study of Anemia in Cachectic Cattle in Baghdad

The study was carried out in order to evaluate clinically and laboratory cachectic animals suffering from anemia. Animal examined were 50 cow and calf. The study include clinical, hemato and biochemical test for accurate diagnosis of cachexia in cows and calves . Blood smears were conducted for detection of blood parasites , fecal examination for gastrointestinal parasites and Different parameters were applied for classification of cachexia , depending on bony projection specially ribs and pelvic and generalized muscular atrophy. However , The study revealed an incidence of cachexia and anemia of blood parasites was including Theileria, Anaplasma, gastrointestinal parasites, ten cases were shown foreign body syndrome while other tens were diagnosed as other clinical cases. A significant decrease ( P &lt; 0.05) of RBCS, Hb, PCV and WBC count in debility animals were observed . However , a significant lymphocytosis were seen in blood parasites infection and other clinical cases , Neutrophilia in foreign body syndrome and other clinical cases , Esenophilia in gastrointestinal parasites infestation ,Monocytosis in all clinical cases were detected . Different parameters were applied for classification of anemia mainly morphological classification including macrocytic hypochromic anemia mainly recorded in blood parasites infection and other clinical cases while Normocytic hypochromic anemia appeared in gastrointestinal parasites infestation, and foreign body Syndrome.Fecal examination of cachectic animal indicate the identification of (7) species of gastrointestinal parasites including: Cooperia onchophora, Haemonchus contortus, Bunostomum phlebtomum, Ostertagia spp., Oesophagostomum radiatum, Trichostrongylus axei and Strongyloides papillosus. However , a mixed infestation parasite was dominant and recorded in Animal.Biochemical changes revealed a. Hypoprotenemia appears in all cachectic animal except in foreign body syndrome cases .

Comparative Efficacy of Trichlorphon and Trichlorphon/Ivermectin Combination Treatment against Anthelmintic-Resistant Cattle Nematodes in Argentina

Twenty-four Holando Argentino male calves were treated orally with 50 mg/kg body weight trichlorphon (TCF); 0.2 mg/kg body weight subcutaneous ivermectin (IVM); a combination of TCF+IVM at the same doses and administration routes; or remained untreated (control group). All calves were necropsied at day 14 post treatment for counting and identification of worms from abomasum, small and large intestines and lungs to determine the absolute efficacy (controlled efficacy test) for each treatment. Using the faecal egg count reduction test, the efficacy was 63.7 % for TCF, 72.3 % for IVM and 99.2 % for TCF+IVM. The absolute efficacy of IVM and IVM+TCF was 100 % against Haemonchus placei, Trichostrongylus axei and Ostertagia ostertagi (p < 0.05). TCF showed a similar level of efficacy except against O. ostertagi (84.7 %). Efficacy of the treatments against Cooperia oncophora/pectinata/mcmasteri was 80.4 % for IVM, 95.7 % for TCF and 99.6 % for TCF+IVM; against Trichostrongylus colubriformis was 79 % for IVM, 86.2 % for TCF and 94.1 % for TCF+IVM; against Nematodirus helvetianus was 0 % for IVM, 100 % for TCF and 93.8 % for TCF+IVM. The efficacies of TCF, IVM and TCF+IVM were 100 % against Oesophagostomum radiatum and Trichuris spp. The efficacy of TCF against Dictyocaulus viviparus was 52 % and 100 % for IVM and IVM+TCF, respectively. This is the first report of Trichostrongylus colubriformis and Nematodirus helvetianus resistant to ivermectin treatment in cattle of Argentina. The TCF+IVM combination could be an alternative for the control and treatment of nematode infections including IVM-resistant strains.

EFFECT OF INTERNAL PARASITIC INFESTATION ON ANTIOXIDANT ENZYMES IN BUFFALO-CALVES

This study aimed to investigate the effect of the internal parasites on the erythrocyte oxidative status through determining the activities of the antioxidant enzymes, catalaze (CAT), glutathione peroxidase (GSH-Px) and superoxide dismutase (DOS), in buffalo-calves. A total of 102 faecal samples were collected randomly from both sex buffalo-calves of one week — 12 months old, belonging to some private farms in Sharkia Province. The microscopic examination of faecal samples revealed that the prevalence rate of gastro-intestinal nematodes was 24.5% (Toxocara vitulorum 10.8%, Oesophagostomum radiatum 7.6% and Trichostrongylus spp. 5.9%). The infestation rate of trematodes (Paramphistomum) and Cestodes (Moniezia spp.) was 3.9% for both. Lastly, the percentage of Eimena spp. and Cryptosporiaum sp. was 4.9% and 2.9%, respectively in examined samples. The blood samples with anticoagulant were collected from only infested calves and used for determination of haemoglobin and evaluation of the level of malondialdehyde (MDA) and the activities of the antioxidant enzymes (CAT, GSH-Px and DOS) in the hemolysate. The results of this study revealed a significant increase in both the activities of the antioxidant enzymes and the level of MDA in the parasite infested calves than the healthy group, where the parasitic infestation as a stress factor led to release voluminous amounts of oxyradicals (free radicals and oxygen reactive species). So, large amounts of antioxidant enzymes are produced to neutralize these free radicals.

Evaluation of the persistent activity of moxidectin (10%) long-acting (LA) injectable formulation against Dictyocaulus viviparus, Haemonchus placei, Trichostrongylus axei and Oesophagostomum radiatum infections in cattle

Two controlled studies were conducted to evaluate the persistent efficacy of moxidectin (10%) long-acting (LA) injectable formulation against Dictyocaulus viviparus, Haemonchus placei, Trichostrongylus axei and Oesophagostomum radiatum in cattle. The moxidectin LA injectable formulation was administered as a single subcutaneous injection into the proximal third of the ear at a dose rate of 0.01 ml/kg BW to provide 1.0 mg moxidectin/kg BW. The product had persistent efficacy of >90% against D. viviparus, H. placei and Oe. radiatum for at least 150 days post-treatment and against T. axei for at least 90 days post-treatment.

Anthelmintic efficacy of oral trichlorfon solution against ivermectin resistant nematode strains in cattle

Infected calves from two different rural estates in Brazil were studied to assess the anthelmintic efficacy of oral trichlorfon against naturally occurring ivermectin resistant parasitic nematode strains. In experiment I, infected animals were from a region where ivermectin resistant populations of Haemoncus placei, Cooperia punctata, Cooperia spatulata and Trichuris discolor have recently been identified. Six calves with natural gastrointestinal nematode infections were treated with 48.5 mg/kg aqueous trichlorfon administered orally and six calves acted as a non-treated control group. In experiment II 24 naturally infected calves were selected to enter one of four treatment groups, six animals each received: 48.5 mg/kg oral trichlorfon; 200 μg/kg subcutaneous 1% ivermectin; 630 μg/kg subcutaneous 3.15% ivermectin; or no treatment (control group). Gastrointestinal helminths were counted and identified post-mortem at 7 days (trichlorfon and 1% ivermectin treated and untreated animals) or 14 days (3.15% ivermectin treated and untreated animals) after administration of the test agents. Experiment I identified a high level efficacy for oral trichlorfon against four helminth species that have previously been shown to be ivermectin resistant in this geographical region: percentage efficacy was 99.82% against adult H. placei, 99.18% against C. punctata, 99.33% against C. spatulata, 81.06% against T. axei, 98.46% against Oesophagostomum radiatum and 100% against T. discolor. Trichlorfon also showed activity against the ivermectin (1% and 3.15%) resistant helminth species identified in experiment II, attaining efficacy levels of 99.17% against H. placei, 98.46% against C. punctata and 100.00% against T. discolor. These findings indicate that oral trichlorfon is an effective treatment option in the management of cattle infected with ivermectin resistant helminths.

Moxidectin-resistant nematodes in cattle in Brazil

The frequent use of anthelmintics in cattle has contributed to the emergence of gastrointestinal nematode populations resistant to the drugs available in the market. This study aimed to evaluate moxidectin efficacy in a property with suspected presence of Oesophagostomum spp. resistant to such anthelmintic. The accuracy of fecal egg count reduction test (FECRT) was also assessed through comparison with the data obtained in the controlled efficacy test (worm burden determination after necropsy). Twenty worm free steers were placed together with cattle of the farm with suspected moxidectin resistance. They became naturally infected with the parasite species present in the farm, and when fecal egg counts (FEC) were higher than 200 eggs/g, the animals were randomly distributed into two groups. One group ( n = 10) was treated with moxidectin (0.2 mg/kg; Cydectin ®, Fort Dodge) and the other was the control group ( n = 10). Fecal samples from each steer were collected on the treatment day and three, seven, 10 and 14 days later for FEC and fecal cultures. At 14 days after treatment, all animals were sacrificed and the gastrointestinal nematodes were recovered, identified and counted. Mean FEC reduction in the treated group (compared with control group) was of 88, 85, 88 and 92% at days three, seven, 10 and 14 after treatment, respectively. In fecal cultures, third stage larvae of Cooperia spp. and Oesophagostomum spp. were predominant. As regards the controlled efficacy test, moxidectin had 100% efficacy against the genera Haemonchus spp. and Trichostrongylus spp., and efficacy of 65.2% for Cooperia spp. ( Cooperia punctata and Cooperia pectinata), 44.8% for Oesophagostomum radiatum, and 81.4% for Trichuris spp. Most of the Cooperia spp. females obtained from the control animals showed eggs inside the uterus (98.5%); conversely, only 48.2% of the females from the treated group had eggs ( P < 0.001). Considering the suppression in egg output following moxidectin treatment, FECRT has to be employed with caution to avoid under estimation of the anthelmintic resistance. From necropsy results, it can be concluded that C. punctata, C. pectinata, O. radiatum and Trichuris spp. showed resistance to moxidectin.