Efficacy Evaluation of a Commercial Formulation With Duddingtonia Flagrans in Equine Gastrointestinal Nematodes

The indiscriminate use of antiparasitics for the treatment of helminths in horses has caused the ineffectiveness of commonly used chemical active principles, therefore, new alternatives such as the use of helminthophagous fungi have been studied. In this context, this study aimed to evaluate the in vitro efficacy of the commercial formulation Bioverm, composed of the fungus Duddingtonia flagrans strain AC001, in the reduction of gastrointestinal nematode larvae in equine feces. In coproculture, the genus Cyathostomum sp. was the most prevalent in the analyzed samples. The commercial formulation with D. flagrans demonstrated effectiveness in the predation of Cyathostomum sp. in tests. The recommended dose of 0.4 g, containing 105 chlamydospores per gram of product, reduced larvae by 44.23%, while the extrapolated dose of 1.0 g with the same concentrations of chlamydospores (105/g) resulted in a reduction of 57.20%, indicating the effectiveness of the product in controlling infective larvae.

[Interpretation of Detection and identification standard of hookworm-Hook-worm larvae coproculture techniques (WS/T 791-2021)]

Detection and identification standard of hookworm-Hookworm larvae coproculture techniques (WS/T 791-2021) is the first recommended technical standard for hookworm detection and species identification using the hookworm larvae coproculture technique in China. This standard was issued on November 23, 2021, and had been in effect since May 1, 2022. This article provides a detailed interpretation pertaining to the background, drafting process, main contents, and dos and don'ts for better understanding and application of this standard among professionals working in disease control and prevention institutions and medical institutions.

Practical guide to the diagnostics of ruminant gastrointestinal nematodes, liver fluke and lungworm infection: interpretation and usability of results

The diagnostics of ruminant parasites remains one of the cornerstones for parasite control best practices. Field veterinarians have several techniques at their disposal (fecal egg count, coproculture, FAMACHA®, plasma pepsinogen, ELISA-Ostertagia, ELISA-Fasciola, Baermann and ELISA-Lungworm) for the identification and/or quantification of gastrointestinal nematodes, lungworms and liver fluke infecting small ruminants and cattle. Each of these diagnostic tools has its own strengths and weaknesses and is more appropriate for a specific production operation and/or age of the animal (young and adults). This review focuses on the usability and interpretation of the results of these diagnostic tools. The most advanced technical information on sampling, storage, advantages and limitations of each tool for different types of production operations and animal categories is provided.

Reviving a tradition: The Development of Strongylus vulgaris in larval culture

All horses are susceptible to the equine gastrointestinal parasite, Strongylus vulgaris, which is known to cause significant disease and death. The parasite undergoes development from the egg through the first (L1), second (L2) and third (L3) larval stages outside the horse. The L3 is the infective stage. The universally available technique for detection of S. vulgaris larvae is the larval culture method. This requires a 10-14 day culture period to induce development from egg to L3, followed by Baermannization and identification of the L3s to genus and/or species. It is unknown if the culture duration is necessary or ideal for S. vulgaris identification. The purpose of this study was to perform daily examinations of known S. vulgaris positive fecal samples in coproculture. Fresh feces were collected from a horse known to be shedding S. vulgaris eggs. A total of 140 cultures were set up using 10 g of feces. Cultures remained at room temperature and moistened every other day. Every day, 10 samples were examined, and all larvae were identified to stage, genus/species, and enumerated. Throughout the study, L1, L2, and L3 stages were observed, and S. vulgaris, Strongylus edentatus, Triodontophorus spp., and cyathostomin L3s were identified. Third stage larvae were observed on Day 5, and the mean number of L3s significantly increased on Day 10 (P < .001), and declined thereafter. Strongylus vulgaris was first observed on Day 6 with a mean count of 4.1 (95 % CI: 1.1, 7.1) S. vulgaris larvae, accounting for 4.1 % (95 % CI:1.8, 7) of the total L3s observed. The number of S. vulgaris larvae was significantly higher on Day 10 with a mean of 156.8 (95 % CI: 120.7, 192.9) S. vulgaris larvae (P < .001), and the proportion was also significantly higher with S. vulgaris comprising 50 % (95 % CI: 45.9, 54.8) (P = .006) of the total larvae. However, after 10 days, the mean number of S. vulgaris larvae declined, as did the proportion of S. vulgaris larvae compared to the total number of larvae. Using the described methods, it is possible to identify S. vulgaris as early as 6 days, and the optimal period is 10 days to detect the maximum number of S. vulgaris.

Diagnosing Strongylus vulgaris in pooled fecal samples

Strongylus vulgaris is the most pathogenic intestinal helminth parasite infecting horses. The migrating larvae in the mesenteric blood vessels can cause non-strangulating intestinal infarctions, which have a guarded prognosis for survival. Infections are typically diagnosed by coproculture, but a PCR test is available in some countries. While it is ideal to test horses individually, many veterinarians and clients wish to pool samples to reduce workload and cost of the diagnostic method. The purpose of this study was to determine if pooling of fecal samples would negatively impact diagnostic performance of the coproculture and the PCR for determination of S. vulgaris infection. Ten horses with strongylid eggs per gram (EPG) >500 and confirmed as either S. vulgaris positive or negative were selected as fecal donors. Eight pools with feces from five horses were created with 0%, 10 %, 20 %, 30 %, 40 %, 50 %, 80 %, and 100 % S. vulgaris positive feces. From each pool, 20 subsamples of 10 g each were collected and analyzed. Half of these samples were set up for coproculture and the other half for PCR. All pools containing 50 % or greater S. vulgaris positive feces were detected positive by both PCR and coproculture. In the pools with less than 50 % S. vulgaris positive feces, the PCR detected 33 positive samples compared to 24 with the coproculture. Three samples from the 0% pool were detected as low-level PCR positives, but this could be due to contamination. These results indicate that diagnosing S. vulgaris on pooled samples is reliable, when at least 50 % of the feces in a pool are from S. vulgaris positive animals. Since S. vulgaris remains relatively rare in managed horses, however, some diagnostic sensitivity is expected to be lost with a pooled sample screening approach. Nonetheless, pooled sample screening on farms could still be considered useful under some circumstances, and the PCR generally performed better at the lower proportions of S. vulgaris positive feces.

Study of gastrointestinal parasites in water buffalo (Bubalus bubalis) reared under Mexican humid tropical conditions

The objective was to determine the frequency of gastrointestinal parasites (GP) genera affecting water buffalo (Bubalus bubalis) reared under humid tropical conditions of Mexico. Three hundred eighty-three Munrah breed water buffalo were included, 251 adult females and 132 calves. Feces were directly collected form the rectum of the animals and processed by the McMaster technique. Coprocultures were made to identify the genera of the nematodes. The frequency of GP in B. bubalis was 42%, independently of their age, 60% of calves resulted parasitized. Age had a strong association with the presence of GP (Xi² = 77.4014, d.f. = 1, p = 0.001). The family Trichostrongylidae was found in both age groups. The genera identified were Strongyloides sp. (47.2%), Cooperia sp. (33.9%), and Haemonchus sp. (10.4%), as well as Eimeria sp., Moniezia sp., Trichuris sp., and Strongyloides sp. The highest parasite burden corresponded to the genus Strongyloides sp. with 1108.9 EPG. There is a need to carry out further studies in order to know the prevalence and incidence of nematode affecting to B. bubalis as an introduced animal species to Mexican tropics.