Bunostomum Phlebotomum Research Articles

Multispecies helminth parasitism of grazing dairy cows in Germany and Austria, examined in the housing period

Helminth composition and burden data for dairy cows have not been reported for >40years for Germany and even less information is available for Austria. In the context of two recent studies, helminth parasitism was studied in 32 cows (23 from six farms in Bavaria and Tyrol; 9 from one farm in Saxony) from pasture-based dairy farms necropsied during the housing period. Helminths were enumerated and identified based on morphological characters (all helminths but rumen flukes) or molecular techniques (rumen flukes). Thirteen species of gastrointestinal nematodes and two species each of liver flukes (Fasciola hepatica, Dicrocoelium dendriticum) and rumen flukes (Calicophoron daubneyi, Paramphistomum leydeni) were recorded; no lungworms were recovered from any cow. Early fourth-stage (inhibited) larval Ostertagia species nematodes (210 to 140,600) were recovered from all cows, 31 each had adult Ostertagia ostertagi/Ostertagia lyrata (40 to 2020) and Trichostrongylus axei (10 to 53,400), 23 Oesophagostomum radiatum (1 to 242) and 20 Cooperia punctata (10 to 3330). Other nematodes present in descending order of prevalence were: Cooperia oncophora/Cooperia surnabada, Ostertagia leptospicularis/Ostertagia kolchida, Oesophagostomum venulosum, Bunostomum phlebotomum, Chabertia ovina, Nematodirus helvetianus, Trichostrongylus longispicularis, Haemonchus contortus and Aonchotheca bilobata. The cows from Bavaria and Tyrol harbored more total gastrointestinal nematodes than that from Saxony (geometric mean adult plus inhibited larval nematodes, 6510 vs. 2051, respectively). However, in both cohorts of cows abomasal nematodes accounted for ∼97% of the total nematode burden with inhibited larval Ostertagia species nematodes contributing over 70% of the total gastrointestinal nematode burden and∼96% of the Ostertagia species burden. Approximately 44%, 37% and 19% of the cows harbored <5000, 5000 to 10,000 or>10,000 total gastrointestinal nematodes, respectively. Fecal nematode egg and coproculture nematode larval counts significantly correlated with the cows' total adult nematode burden (rs=0.354, p<0.05, and rs=0.608, p<0.001, respectively). Although the magnitude of nematode burden to exert production effects on dairy cows is not well defined and may vary relative to several factors including nutritional supplementation, the level of mixed parasitism found in this investigation supports consideration of grazing dairy cows in helminth control measures, especially at the time of housing in autumn.

Eprinomectin 5% w/v extended-release injection for the treatment of larval and/or adult Bunostomum phlebotomum, Haemonchus contortus, H. placei, Nematodirus helvetianus, Oesophagostomum radiatum, and Trichostrongylus colubriformis infections in cattle.

In an effort to generate data for regulatory purposes on the therapeutic efficacy of eprinomectin 5% w/v extended-release injection (Eprinomectin ERI) (LongRange®, Boehringer Ingelheim) against infections of immature and adult stages of some nematode species (or stages) which are generally less common or predominantly seen in younger cattle, nine studies (minimum two per parasite and stage) were conducted in the USA and Germany. A total of 218 young cattle were included in seven experimentally induced infection studies (180 animals) and two studies with naturally acquired nematode infections (38 animals), which were compliant with WAAVP and VICH guidelines. In each study, cattle were randomly assigned into groups which received 1mL per 50kg body weight of either saline (controls) or Eprinomectin ERI (equivalent to 1mg eprinomectin per kg body weight) via subcutaneous injection when the parasites were developing fourth-stage larval (L4) or adult nematodes. Following necropsy and parasite recovery, percentage efficacy was calculated based on the comparison of geometric mean nematode counts of the Eprinomectin ERI- vs. the saline-treated animals. Eprinomectin ERI-treated cattle had significantly (p < 0.05) lower counts of each species and stage of nematodes than the controls. Eprinomectin ERI treatment was demonstrated to be efficacious (> 90%) against L4 and adult Bunostomum phlebotomum and Nematodirus helvetianus; against L4 Haemonchus placei, Oesophagostomum radiatum, and Trichostrongylus colubriformis; and against adult H. contortus. Percentage efficacy against L4 H. contortus was variable (69.6 to 100%). All treatments were well accepted, and no treatment-related health problems were observed in any study.

Unexpected Bullae in a 12-year-old Boy

Unexpected Bullae in a 12-year-old Boy

Gastrointestinal nematodes from buffalo in Minoufiya Governorate, Egypt with special reference to Bunostomum phlebotomum.

Gastrointestinal nematodes cause massive economic losses as an important impediment to the development of animals around the world. This study aimed to investigate the microscopical diagnosis of nematode parasites of buffalo from Minoufiya, Egypt and molecular characterization of Bunostomum phlebotomum. We examined 390 fecal samples with floatation and fecal culture techniques to recognize different genera of nematodes. The results revealed B. phlebotomum (2.56%), Strongyloides papillosus (3.85%), Toxocara vitulorum (7.69%), Haemonchus sp. (1.28%), and Dictyocaulus viviparus (1.28%). The recovered eggs and larvae of nematodes were identified as well as the adults of B. phlebotomum. Age-wise, sex-wise, and seasonal prevalences of the recovered nematodes were recorded. Sequence analysis of the ITS-2 gene of B. phlebotomum was highly identical (99-100%) to sequences from Australia and China and occurred in the same clade with B. trigoncephalum. In conclusion, the study presented the coprological survey of gastrointestinal nematodes, and the genetic characterization of B. phlebotomum from Minoufiya Governorate, Egypt for the first time.

Parasitological status of vicuñas (Vicugna vicugna) from southeastern Peru and its relationship with fiber quality.

We aim to describe the parasitic population in vicuñas from three Andean communities and its relationship with fiber quality using 115 fecal and 22 fiber samples, classified according to sex, age, body condition score, and management system. Coproparasitologic diagnostic revealed that 84.4% of animals presented at least one type of parasite egg/oocyst. Most frequent parasite egg/oocyst were Strongyle-type eggs (54.8%) and Eimeria punoensis (38.3%). Wild vicuñas had a higher prevalence of Strongyle-type eggs (91.4%) than semi-captive (38.8%) animals, and age was significative to Eimeria infection; crias had the highest frequency (100%) when compared to yearlings (84.2%) and adults (49.4%). Larvae identification revealed a strong influence of domestic animals on vicuña parasite community, presenting the first report of Bunostomum phlebotomum and Gaigeria pachyscelis in vicuñas from southeastern Peru. Females had a significantly finer diameter of fiber (13.05 ± 0.73 μm) than males (14.22 ± 1.22 μm), and infection with Eimeria spp. affected negatively fiber diameter and resistance. Our results provide data for disease surveillance and encourage further parasitological studies in vicuñas.

The complete mitochondrial genome of the beef cattle hookworm Bunostomum phlebotomum (Nematoda: Bunostominae)

The bovine hookworm Bunostomum phlebotomum (Nematoda: Bunostominae) is a blood-feeding nematode with important socioeconomic impact in the cattle breeding industry. In the present study, the complete mitochondrial genome sequence of a representative individual of B. phlebotomum from beef cattle in Southwest China was determined using the next generation sequencing technology. The genome was 13,799 bp in size and encoded 12 protein-coding genes, 22 tRNA genes and two rRNA genes. The phylogeny revealed that although B. phlebotomum from Chinese beef cattle and yaks were more closely related to each other than to that from Australian cows, these three bovine-originated B. phlebotomum grouped together and formed paraphyletic relationships with Bunostomum trigonocephalum (goat/sheep hookworm) and Necator americanus (human hookworm), supporting their sister-species relationships within Bunostominae. The cumulative mitochondrial DNA data provides a better understanding of phylogenetic relationships of this species in cattle.

Comparative H-gal-GP and H11 specific antibody binding in equine cyathostomins

The biological-based vaccine (Barbervax®) generates effective antibodies against the biologically essential H-gal-GP and H11 protein complex of the ruminant parasite Haemonchus contortus to target and kill the parasites after taking a blood meal. A comparative analysis of several parasite genera was performed to determine if a similar protein complex or one that is recognized by H-gal-GP and H11 specific antibodies was present. If so, it suggests the vaccine could be effective for other nematode parasites. Ancylostoma caninum, H. contortus, equine cyathostomins, bovine Bunostomum phlebotomum, Dracunculus lutrae, Parascaris sp., Ixodes scapularis, Amblyomma americanum, Dirofilaria immitis and Brugia malayi were evaluated for specific antibody binding using hyperimmunized antibodies against H-gal-GP and H11 native proteins. Of the parasites evaluated, specific and reproducible staining was observed in H. contortus and adult and encysted cyathostomins only. To further evaluate the similar reactivities between cyathostomins and H. contortus, cross-reactivity of equine serum with antibodies to cyathostomins on a H. contortus adult histology cross-section was observed using immunofluorescence. These findings pave the way for future studies on the safety and efficacy of H-gal-GP and H11 protein complex as a potential control for cyathostomins.

GASTROINTESTINAL NEMATODES OF DOMESTIC RUMINANTS IN PRIMORSKY KRAI

The species composition of nematodes found during necropsies of cattle and small cattle in Primorsky Krai (Russian Far East) was determined. Mecistocirrus digitatus, Bunostomum phlebotomum, Cooperia punctata and Ostertgia ostertagi were found in cattle. Trichostrongylus colubriformis was registered in sheep and Teladorsagia circumcincta was found in goats. Small cattle had low rates of intensity and extensity of invasion, apparently, because of antiparasitic treatment performed by animal owners. The intensity of invasion in cattle reached 827 specimens. All nematode species found in this study were previously registered in Primorsky Krai. However, helminthological studies of goats in Primorsky Krai have been conducted for the first time. Thus, the registration of T. circumcincta is the first detection of this parasite in goats in Primorsky Krai. Since two of the detected nematodes (T. colubriformis and T. circumcincta) were repeatedly recorded in humans in several countries, these species deserve a special attention as potential causative agents of zoonosis.

The Incidence Rate of Helminthiasis in The Digestive Tract of Dairy Cattle in The Partnership of PT. Greenfields Indonesia

Background: One of the partnerships of PT. Greenfields Indonesia is located on the slopes of Mount Kawi, precisely in Pijiombo, Ngadirenggo Village, Wlingi District, Blitar Regency. The tropical situation in this area is very humid and has high rainfall. It causes dairy cattle to be infected with helminths. Therefore, observations of the incidence rate of gastrointestinal helminthiasis in dairy cattle are needed. Purpose: To determine the prevalence of gastrointestinal helminths in dairy cattle in the partnership of PT. Greenfields Indonesia. Method: Fecal samples from 36 dairy cattle were collected and examined using native, sedimentation, and flotation techniques. Result: Indicated that the prevalence of gastrointestinal helminths in the dairy cattle was about 66,66%. There were 24 dairy cattle positively and 12 cattle negatively. Helminth species found included class Nematoda (Haemonchus contortus, Oesophagostomum radiatum, Bunostomum phlebotomum, Mecistocirrus digitatus, and Gaigeria pachyscelis) and Cestoda (Moniezia expansa). Conclusion: The incidence rate of helminthiasis was quite high dairy cattle in the partnership of PT. Greenfields Indonesia.

Effect of deworming on milk production in dairy cattle and buffaloes infected with gastrointestinal parasites in the Kavrepalanchowk district of central Nepal

BackgroundIn Nepal, knowledge of proper handling, management and causes of cattle diseases is still limited. The main objective of this study was to explore the impact of deworming on milk...

Helminth infections of great concern among cattle in Nigeria: Insight to its prevalence, species diversity, patterns of infections and risk factors.

Background and Aim:Helminth infections are one of the greatest causes of productive and reproductive loss in animals and man, and in some cases, it results in heavy mortalities. This study was conducted to determine the prevalence, species diversity, patterns of infections and risk factors associated with helminth infections of cattle in Ilorin, Nigeria.Materials and Methods:A total of 478 fecal samples were collected from abattoirs and cattle farms over a year period (March, 2018-February, 2019). Fecal samples were visually examined then observed using simple flotation and formalin-ethyl acetate sedimentation techniques. Eggs and worms were identified according to standard procedures. The packed cell volume was determined using the hematocrit centrifugation technique.Results:A total of 79.92% of the cattle examined were found positive with one or more helminth species. Eighteen helminth species (cutting across all classes of helminths) were detected, with Haemonchus contortus (60.46%), Trichostrongylus spp. (46.44%), Ostertagia ostertagi (42.05%), Bunostomum phlebotomum (28.87%), Cooperia spp. (24.27%), Oesophagostomum radiatum (21.97%), Strongyloides papillosus (12.13%), and Fasciola gigantica (10.67%) been the most prevalent. Helminth infection was detected all through the year with the least prevalence recorded in February (55.00%). About 61% of the examined cattle harbored double/multiple helminth species. There was a significant difference between breed, sex, physiological status, and season with the prevalence rate of helminth infections (p<0.05).Conclusion:Our investigation demonstrated high prevalence and wide diversity of helminth species, which suggests that helminth infections are of great concern among cattle in Ilorin and Nigeria in general. There is a need for a radical veterinary intervention to curb the menace so as to have an economically robust cattle industry in Nigeria.

Keragaman dan Intensitas Infeksi Endoparasit Gastrointestinal pada Sapi Bali dengan Sistem Ekstensif di Kabupaten Kupang

Tanah Putih Village has the potential for the development of Bali cattle because it has extensive grazing land and the majority of farmers raise Bali cattle. The aim of the study was to obtain data on the diversity and intensity of gastrointestinal endoparasitic infection in Balinese cattle with an extensive breeding system in Tanah Putih Village, Kupang Timur District, Kupang Regency, East Nusa Tenggara Province. Gastrointestinal endoparasitic diversity was identify using sedimentation and flotation methods while the intensity of endoparasitic infection was carried out using McMaster method, while data on the diversity and rates of gastrointestinal endoparasitic infection were analyzed descriptively. The results of the study on the diversity of gastrointestinal endoparasites found there are five types of nematode worm eggs namely Haemonchus contortus, Oesophagostomum radiatum, Strongyloides papillosus, Bunostomum phlebotomum, and Trichostrongylus axei. Factors that support the diversity of endoparasites are feed sources, livestock populations, and grazing rotation. The average number of worm eggs found based on the total eggs per gram of faeces for Haemonchus contortus as many as 100 eggs and the other four types of worm eggs amounted to 50 eggs. The average number of eggs indicates that endoparasitic infections in these animals fall into the mild intensity category, is influenced by season, feed source, and age of livestock. The five types of gastrointestinal endoparasites found namely Haemonchus contortus, Oesophagostomum radiatum, Strongyloides papillosus, Bunostomum phlebotomum, and Trichostrongylus axei.

Occurrence of internal parasites in cattle in various management systems in South-East Poland

The changes in the cattle farming system in Poland observed in the last two decades and related to its evolution into massive scale, specialized farming may have an influence on the occurrence of parasitoses. The study was aimed at showing differences in the prevalence of internal parasites in cattle depending on the herd size, management system and production type. In the period of October to December in 2016 and 2017, the study covered 46 farms with a livestock density from 2 to 160 animals (over 1 year of age), including 25 farms with a confined management system, 12 farms using pastures occasionally and 7 farms with animals using pastures during the whole season. Out of these farms, 36 were oriented towards dairy cattle and 10 to beef cattle. The analytical methods involved flotation, sedimentation and the Baermann technique. In total, 276 feces samples were analyzed. The analysis involved a representative number of samples from each farm, depending on the herd size: from 100% of the animals in the smallest farms to 10% in the largest ones. In total, eleven different taxa of parasites were identified, and their general prevalence was as follows: Eimeria spp. 24.6%, Buxtonella sulcata 25.7%, Strongyloides papillosus 7.6%, gastrointestinal nematodes (Trichostrongylidae, Chabertia, Oesophagostomum) 35.1%, Nematodirus spp. 4.7%, Bunostomum phlebotomum 7.6%, Trichuris spp. 6.2%, Fasciola hepatica 6.9%, Paramphistomum spp 2.5%, Moniezia spp. 2.9%, Dictyocaulus viviparus 2.5%. The forms of parasites were found in samples coming from all studied herds. Invasions of protozoa (Eimeria, Buxtonella) were most commonly found in dairy cattle, in large herds managed in a free stall barn system and in beef cattle, in large herds managed in a pasture system. These herds were also most frequently infected with gastrointestinal nematodes. The invasions of trematodes, tapeworms and pulmonary nematodes were detected only in cattle using pastures, most commonly in large herds..

Assessment of roundworm species prevalence in cattle, sheep and goats slaughtered at Lafia Abattoir, Nasarawa State, Nigeria

Intestinal parasites pose a great constraint to livestock production and cause high incidence of mortality and low production in livestock. This study was designed to identify the roundworm species infections in cattle, sheep and goats that were slaughtered at Lafia abattoir during the rainy seasonwithr&nbsp; theidespread of the infections&nbsp; and the methodology used was &nbsp;(April to June, 2016). The aim was to sensitize livestock stakeholders to strategize effective means of disrupting the life cycles of the roundworms in order to prevent their widespread within the herds. Faecal samples were collected from 22 cattle, 25 sheep and 23 goats and were examined by simple floatation method and microscopy for the presence of roundworms. Results showed that out of a total of 70 animals examined, 36 representing 51.4% of the animals were infected with various species of roundworms. Those found in the animals examined included Haemonchus contortus, Bunostomum phlebotomum, Ascaris suum and Neoascaris vitulorum. It was observed that both sexes of all the animal breeds examined were infected, though males were more susceptible than the females. Animals in all the age categories were infected and those on extensive management system were more infected than those in semi-intensive. Since different species of roundworms were found in cattle, sheep and goats slaughtered at Lafia abattoir, it indicated that there was probably high prevalent rate of roundworms in the area. More so, mixed species infection of Ascaris suum and Neoascaris vitulorum were recorded in goats, suggesting severe burden that may hinder optimum physiological performance. It could be necessary therefore to advise that careful disposal of the gastrointestinal contents, regular deworming, implementation of strict biosecurity measures and intensive animal production system should be adopted in the study area. This may disrupt the life cycles of the roundworm species thus, preventing parasitic infections from spreading to other animals in the study area.

FERTILITY OF GOATS AFFECTED OF PARASITIC DISEASES

In modern conditions of management there is a need for systematical regulation of individual stages of the animal reproduction process in order to ensure the effective use of genetic resources of the breeding stock, planning of production processes and the timing of their implementation. One of the problems of the zootechnical and veterinary sciences are parasitic diseases and pathology parturition, which relates to the urgent issues of reducing the reproductive capacity of animals and inhibits the rapid development of livestock, in particular, goats breeding. In the case of a chronic course of parasitic diseases, animals do not enter hunting or note an inferior sexual cycle and, accordingly, farmers do not receive the applause and there are significant losses in milk productivity.&#x0D; The purpose of our research was to consider the main indicators characterizing reproducible ability of goats and the preservation of the offsprings in the presence of parasitic diseases. For this purpose we have applied parasitological and zootechnical methods of research. We examined 98 goats from 25 individual farms in the city Borispol. It was established that only 4,1% of our investigated 98 goats were free from parasites. 12.3% of goats were affected by one type of worms (Trichostrongylus axei), 26.5% of goats were affected by two types of worms (Trichostrongylus axei and Cooperia punctata), 21.4% – by three types of worms (Trichostrongylus axei, Cooperia punctata and Nematodirus spatiger, 20.4% – by four types of worms (Trichostrongylus axei, Cooperia punctata, Nematodirus spatiger, Ostertagia ostertagi), 10.2% – by five types of worms (Trichostrongylus axei, Cooperia punctata, Nematodirus spatiger, Ostertagia ostertagi Oesophagostomym radiatum) and 6.1% – by six types of worms (Trichostrongylus axei, Cooperia punctata, Nematodirus spatiger, Ostertagia ostertagi Oesophagostomium radiatum, Bunostomum phlebotomum). All revealed worms belonged to the Strongylata order and were pathogens gastrointestinal Strongylata infections in goats. In 25.5% of the examined animals, a significant defeat of Trichodectidae ectoparasites was observed. The analysis of the results showed the need for parasitological studies of animals kept in individual farms. The death of the goats predominantly accounts for the first 20 days of their post-embryonal life, which we observed in 77.8% of cases of death of the goats born from goats that revealed the presence of parasitic diseases. 6.4% of the goats from the coughing-affected parasites were unsatisfactory with a low clinical development status. In goats free from parasites, all born goats have a satisfactory clinical condition with high development potential.&#x0D; In the article we present the prospect of conducting further parasitological studies to ensure healthy clinical condition of animals, obtaining viable young animals and full realization of the productive potential of the animal.

Parasites of farmed marals in Kazakhstan

The farming of maral (a type of red deer- Cervus elaphus) is an expanding livestock industry in Kazakhstan. However, to date there is little knowledge of the parasitic fauna that infect farmed deer in Kazakhstan. This study investigated the gastrointestinal parasites of 508 farmed marals from the south and east of Kazakhstan between spring and autumn 2015. When fecal samples were being collected, the presence of any ectoparasites were also noted and specimens taken for identification. This study revealed 6 species of nematodes: Bunostomum phlebotomum, Capillaria bovis, Haemonchus contortus, Nematodirus spathiger, Oesophagostomum venulosum and Trichuris skrjabini. Two cestode species were identified: Mоniezia benedeni and Moniezia expansa. Three species of coccidia: Eimeria cervi, E. gallivalerioi and E. robustus were found. Ectoparasites recovered were the deer ked Lipoptena cervi, larvae of Hypoderma diana and Booponus borealis and the tick Dermacentor marginatus.

Comparative analyses of the complete mitochondrial genomes of the two ruminant hookworms Bunostomum trigonocephalum and Bunostomum phlebotomum

Bunostomum trigonocephalum and Bunostomum phlebotomum are blood-feeding hookworms of sheep and cattle, causing considerable economic losses to the live stock industries. Studying genetic variability within and among hookworm populations is critical to addressing epidemiological and ecological questions. Mitochondrial (mt) DNA is known to provide useful markers for investigations of population genetics of hookworms, but mt genome sequence data are scant. In the present study, the complete mitochondrial DNA (mtDNA) sequences of the sheep and goat hookworm B. trigonocephalum were determined for the first time, and the mt genome of B. phlebotomum from yak in China was also sequenced for comparative analyses of their gene contents and genome organizations. The lengths of mt DNA sequences of B. trigonocephalum sheep isolate, B. trigonocephalum goat isolate and B. phlebotomum China yak isolate were 13,764bp, 13,771bp and 13,803bp in size, respectively. The identity of the mt genomes was 99.7% between B. trigonocephalum sheep isolate and B. trigonocephalum goat isolate. The identity of B. phlebotomum China yak isolate mt genomes was 85.3% with B. trigonocephalum sheep isolate, and 85.2% with B. trigonocephalum goat isolate. All the mt genes of the two hookworms were transcribed in the same direction and gene arrangements were consistent with those of the GA3 type, including 12 protein-coding genes, 2 rRNA genes and 22 tRNA genes, but lacking ATP synthetase subunit 8 gene. The mt genomes of B. trigonocephalum and B. phlebotomum were similar to prefer bases A and T, the contents of A+T are 76.5% (sheep isolate), 76.4% (goat isolate) and 76.9% (China yak isolate), respectively. Phylogenetic relationships reconstructed using concatenated amino acid sequences of 12 protein-coding genes with three methods (maximum likelihood, Bayesian inference and neighbor joining) revealed that the B. trigonocephalum and B. phlebotomum represent distinct but closely-related species. These data provide novel and useful genetic markers for studying the systematics, and population genetics of the two ruminant hookworms.

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.