Enumeration of nematode eggs in fecal samples using the McMaster technique and morphological identification of third stage larvae from fecal cultures have been extensively used with satisfactory results in the diagnosis of the gastrointestinal nematode infections in ruminants. In order to improve sensitivity and accuracy, other approaches for quantification of eggs have been employed, like the FLOTAC and Mini-FLOTAC techniques. Results obtained in different studies indicate that fecal egg counts are a reliable measure of the size of the worm burden. However, the immunological status of the animals should be taken into consideration to interpret the results of the fecal examination. Molecular techniques have also been useful in the diagnosis of parasitic diseases. The ultimate in diagnosis has been the development of robotic platforms that enable separation of eggs from feces. Because manipulation is minimal, good quality DNA from eggs is obtained, which is used for amplification, and finally, produces a result indicating the degree of the infection by the different parasite species in mix infections. The ideal method should be reliable, friendly to non-experts and quick to perform. With the advance in robotics, bioinformatics and molecular biology, methods with such characteristics are expected to become available and affordable to be used in laboratories for the routine diagnosis of gastrointestinal nematodes of ruminants.

mature Ostertagia ostertagi and immature Ostertagia spp. in naturally infected dairy calves, activity of levamisole; overwinter survival on pasture of gastrointestinal helminth free-living stages as found in necropsy of previously helminth free calves placed on pasture in April: Kentucky

The activity of ivermectin against common nematode parasites of sheep was examined in 2 experiments. In the 1st experiment, 14 sheep with naturally acquired infections were assigned to 2 groups of 7 sheep each. Sheep in 1 group were treated with 200 micrograms of ivermectin/kg of body weight and the remainder served as nontreated controls. In the 2nd experiment, 15 sheep with experimentally supplemented infections (including a benzimidazole-resistant strain of Haemonchus contortus) were assigned to 3 groups of 5 each. The 1st group was treated with 200 micrograms of ivermectin/kg, the 2nd was treated with 88 mg of thiabendazole/kg, and the 3rd served as nontreated controls. Ten to 12 days after treatment, all sheep were euthanatized and necropsied, and the parasites they harbored were recovered and identified. Efficacy of ivermectin was excellent (greater than 96%) against Dictyocaulus filaria, H contortus, Ostertagia circumcinta, Marshallagia marshalli, Trichostrongylus axei, T colubriformis, and T vitrinus. Treatment was not as uniformly effective for Nematodirus spathiger (73% to 85%), N filicollis (80% to 96%), Cooperia curticei (92% to 100%), immature nematodes (92% to 100%), and early 4th-stage larvae (46% to 100%). Efficacy of thiabendazole was poor for H contortus (42%) and early 4th-stage larvae in the abomasum (52%), but approached 100% for most of the other parasites.

nematodes, lambs, 11 anthelmintics compared using medicated feeds or multiple small doses

Parasitic nematode infection in animal is one of the main causes for the mortality of animals and most of the treatment relies on the use of the anthelmintic drugs to overcome such a problem. However, the heavy use of anthelmintic contributed to the problem of multidrug resistance. This study was carried out to investigate the infectiveness of Punica granatum (aqueous leaf and peel extracts) as an alternative treatment. This study utilised the in-vitro assay technique (motility assayand larval migration inhibition assay) to determine the effect of the extracts on the survival of L3 stage of parasitic nematodes.The results showed that incubation of L3 in different concentrations (5, 10, 20, 50 and 100 mg/ml) of extracts paralysed and killed the worms after 24 hours and 48 hours ofincubation periods. The same results were obtained from larval migration inhibition assay, showing that both extracts of Punicagranatum inhibited the migration of the L3. After 2 hours of incubation in the leaf extract (5 mg/ml), the migration of nematode larvae was inhibited to 56±12.29% as compared tothe control. While for the peel extract the percentage of migration was reduced to 53 ±3.33%. Further reduction of the migration was observed at 10, 20 and 50 mg/ml of leaf extract.

Anthelmintic efficacy of doramectin, a macrocyclic lactone of the avermectin family, was evaluated against larval parasitic nematodes in calves. The investigational product was given sc at a dosage of 0.2 mg/kg of body weight to 10 calves infected 6 days previously with third-stage larvae of the genera Haemonchus, Ostertagia, Cooperia, and Nematodirus. Ten additional calves with identical larval exposure were given saline solution SC also at 6 days after inoculation, and served as the nonmedicated controls. At 14 or 15 days after treatment, the calves were slaughtered in complete replicate for nematode recovery and subsequent quantifications. In comparing nematode numbers at necropsy for the saline- and doramectin-treated groups, nematocidal effectiveness as directed against fourth-stage larvae was: 100% for Haemonchus placei and Cooperia spp, > 99% for Ostertagia ostertagi, and 64.5% for Nematodirus helvetianus. All treatments were easily administered, and adverse behavioral or tissue reactions were not seen to result from doramectin administration.

Ostertagia ostertagi, beef cattle, acquisition of inhibited larvae during winter and spring, efficacy of ivermectin against inhibited early 4th-stage larvae of O. ostertagi and other nematodes of abomasum and intestinal tract: Louisiana

nematodes of ruminants, large scale technique for recovery of worms migrating from gastro-intestinal ingesta gelled in agar, significantly more male than female worms failed to migrate, L4 stages generally migrated more efficiently than did adult worms, some genera migrated more efficiently than others, applications for use in quantitative worm recovery such as in anthelmintic testing

During the United States Department of Agriculture (USDA) National Animal Health Monitoring System’s (NAHMS) 2007‐2008 beef study, 567 producers from 24 US States were offered the opportunity to collect fecal samples from weaned beef calves and have them evaluated for the presence of parasite eggs (Phase 1). Participating producers were provided with instructions and materials for sample collection. Up to 20 fresh fecal samples were collected from each of the 99 participating operations. Fresh fecal samples were submitted to one of 3 randomly assigned laboratories for evaluation. Upon arrival at the laboratories, all samples were processed for the enumeration of strongyle, Nematodirus, and Trichuris eggs using the modified Wisconsin technique. The presence or absence of coccidian oocysts and tapeworm eggs was also noted. In submissions where the strongyle eggs per gram exceeded 30, aliquots from 2 to 6 animals were pooled for DNA extraction. Extracted DNA was subjected to genus level polymerase chain reaction (PCR) identification for the presence of Ostertagia, Cooperia, Haemonchus, Oesophagostomum, and Trichostrongylus. In this study, 85.6% of the samples had strongyle type, Nematodirus, and Trichuris eggs. Among the samples evaluated, 91% had Cooperia, 79% Ostertagia, 53% Haemonchus, 38% Oesophagostomum, 18% Nematodirus, 7% Trichuris, and 3% Trichostrongylus. The prevalence of coccidia and tapeworm eggs was 59.9% and 13.7%, respectively.