Anthelmintic Treatment Research Articles

Triclabendazole resistance in Fasciola hepatica: First report in sheep from the Santa Cruz province, Argentinian Patagonia.

In the fall of 2022, decreased triclabendazole (TCBZ) efficacy against F. hepatica was suspected in a sheep farm located in the Santa Cruz province, Argentinian Patagonia. Since TCBZ-resistance in F. hepatica has never been reported in this province, this study aimed to confirm potential TCBZ-resistance in F. hepatica and to evaluate the efficacy of closantel (CLO) and nitroxinil (NTX), through faecal egg count reduction test (FECRT), and the efficacy of albendazole (ABZ) through the in vitro egg hatch test (EHT) in sheep. Sixty-eight (68) animals were selected from a herd of eighty (80) female Merino naturally infected with F. hepatica based on eggs per gram of F. hepatica (EPGFh) counts and assigned into four (4) groups (n=17 per group): Group Control, animals did not receive anthelmintic treatment; Group TCBZ, animals were orally treated with TCBZ (12mg/kg); Group CLO, animals were orally treated with CLO (10mg/kg); and Group NTX, animals were subcutaneously treated with NTX (10mg/kg). The fluke egg output was monitored on days 0 and 21 post-treatment. For the EHT, liver fluke eggs were isolated from faecal samples (approx. 50g) collected from animals of the control group. TCBZ efficacy against liver fluke was 53.4%, confirming the presence of TCBZ-resistant isolates on the farm. CLO and NTX were highly effective (100%) for the treatment of F. hepatica on this farm. The EHT was carried out in two different laboratories, in which was observed an ABZ efficacy of 95.8 (Bariloche) and 96.5% (Tandil). These results indicate the ABZ susceptibility of this F. hepatica isolate and the inter-laboratory precision of the test.

Association of anthelmintic treatment with malaria prevalence in Rural Sussundenga, Mozambique.

Background: Mozambique has the 4 th highest malaria incidence and mortality globally. Despite the existing malaria control strategies, malaria prevalence remains stagnant. These challenges have increased calls for innovative strategies in areas with the highest disease burden. Community mass treatment with anthelmintic agents have been used as an effective tool for the control of major helminth infections and has emerged as a potential tool for vector control in the fight against malaria. Methods: This was an analysis of data from a cross-sectional community-based survey designed to study malaria risk, prevention, and health seeking behaviors in Sussundenga, Mozambique. Using logistic regression models, we quantified the association between ever receiving anthelmintic treatment and P. falciparum infection. We also fit models to determine the association between recent anthelmintic treatment and malaria infection. Results: Two-hundred, seventy-seven (277) participants from 83 households were included in this analysis. The prevalence of P. falciparum infection measured by rapid diagnostic test (RDT) was 30%. 77% of participants reported having ever received anthelmintics. The prevalence of malaria was slightly higher among participants who reported ever taking anthelmintics. There was no statistically significant association between prior receipt of anthelmintic and P. falciparum malaria infection after adjusting for age, ITN use and head of household full-time employment (OR = 1.37, 95% CI, 0.70-2.70, p = 0.36). However, recent intake of anthelmintics was associated with lower odds of testing positive for in the adjusted models (OR = 0.35, 95% CI, 0.07-1.80, p = 0.21), but this was not statistically significant. Conclusions: Our findings show that the benefit of anthelmintics treatment as a control tool for P. falciparum malaria infection is likely tied to when it is administered rather than if it was ever administered. These findings offer evidence for making decisions in planning mass community deworming in sub-Saharan Africa.

Strongyle faecal egg counts in Swiss horses: A retrospective analysis after the introduction of a selective treatment strategy

The standard parasite management of horses based on regular anthelmintic treatments, now practiced for decades has resulted in a worrying expansion of resistant helminth populations, which may considerably impair control on the farm level. The aim of the present study was to obtain a retrospective (year 2010 – 2016) nationwide analysis of faecal egg count (FEC) data from the Swiss adult horse population, related to horse age and geographic region. Thirteen labs provided a total of 16,387 FEC data of horses aged four to 39 years (average: 13.6 years). The annual number of performed FEC tests increased from 38 to 4,939 within the observation period. Independent of the annual sample size the yearly patterns of the FEC were very similar. Seventy-eight percent (n = 12,840) of the samples were negative and 90 % (n = 14,720) showed a FEC below 200 strongyle eggs per gram (EPG) of faeces. The annual mean strongyle FEC ranged between 60 and 88 EPG with a total mean of 75 EPG. Horses aged 4–7 years showed a significantly (p < 0.00001) higher mean FEC compared with the other age groups, differences were not significant among the older horses. Based on ZIP codes, samples were allocated by 70.0 %, 6.0 % and 0.2 % to the German-, French- and Italian-speaking regions of Switzerland, respectively. With 222 EPG the mean FEC in the French part of Switzerland was significantly higher (p < 0.05) than in the German-speaking region (60 EPG). Eggs of Parascaris spp., anoplocephalids and Strongyloides westeri were found in 0.36 %, 0.32 % and 0.01 % of the samples, respectively. Based on 3,813 questionnaire feedbacks from owners in 2017 covering a total of 12,689 horses, sixty-eight percent (n = 8,476) were dewormed without diagnosis, two percent (n = 240) were not dewormed at all, whereas for 30 % (n = 3,721) the selective anthelmintic treatment (SAT) concept was applied. The SAT implementation rate differed significantly (p < 0.0005) between regions, with 33 %, 20 % and 25 % for the German-, French- and Italian-speaking areas, respectively. The rate of horses spending 16–24 h on pasture per day was significantly higher in the French-speaking region compared to the German-speaking part of Switzerland (p < 0.0001). In addition, pasture hygiene was practiced at a significantly lower rate in the French-speaking part compared to the German- and Italian-speaking regions (both p < 0.0001). Overall, the shift towards the SAT-concept represents a very promising development with respect to mitigating the further spread of anthelmintic resistance.

Supplementation of minerals and vitamins influences optimal targeted selective treatment thresholds for the control of gastro-intestinal nematodes in lambs

Targeted Selective Treatment (TST) is a gastrointestinal nematode (GIN) control strategy where anthelmintic treatment decisions are made at an individual animal level. TST has been proven to reduce anthelmintic use and subsequently slow down anthelmintic resistance development, however questions remain regarding optimal TST methods and their applicability across farms.In this study, the influence of Mineral and Vitamin (MV) supplementation on optimal energy utilisation (EU) TST thresholds was assessed on three Welsh farms. In total, 360 lambs were split into two groups, MV supplemented and control, and were treated with an anthelmintic against GIN at the midway point of the experiment. Lambs that improved their EU efficiency post treatment were deemed to have benefited from anthelmintic treatment. Optimal EU TST thresholds was determined for each treatment group per farm using Youden’s J statistic where the treatment threshold retrospectively exhibiting the greatest combined sensitivity and specificity in correctly identifying lambs benefiting from treatment was deemed to be optimal.Results demonstrated that the optimal EU TST threshold was higher in MV supplemented groups at 0.72, 0.71 and 0.56 versus 0.58, 0.67, 0.51 for control groups on each respective farm. Identification of lambs for TST was more effective when using an optimised EU TST threshold, compared to when using the standard EU TST threshold of 0.66.The study highlights that applying standard EU TST thresholds may not be appropriate on all commercial farms with factors including MV status as noted in this study likely to influence optimal EU TST thresholds. Additional refinement of TST systems can further strengthen their applicability across sheep flocks.

Validation of targeted selective treatment (TST) methodology for gastrointestinal parasites of adult sheep in different physiological states

We aimed to validate a targeted selective treatment (TST) methodology for treating parasitic gastrointestinal infections in ewes in different physiological states using parasitological and hematological parameters. Forty ewes were monitored from December 2021 to June 2022 and evaluated during various physiological stages in their life cycle. Before starting the experiment, a fecal egg count (FEC) reduction test was performed to evaluate the efficacy of the anthelmintic (AH) treatment. Weekly assessments were performed based on the Famacha© (F) system and body condition score (BCS), and ewes were subjected to AH treatment when necessary, with their physiological states recorded. Ewes were treated when they presented F ≥ 3, BCS ≤ 2.0 (when F = 2), or submandibular edema. Parasitological, i.e., FEC, and hematological, i.e., hematocrit (Ht), parameters were evaluated monthly to determine the efficiency of the TST methodology. Comparisons between the mean Ht and FEC values in ewes subjected to AH treatment and untreated ewes were performed using analysis of variance, followed by Tukey’s test. Spearman’s correlation was performed to determine the correlation between the variables, i.e., F scores, BCS, Ht, and FEC. All tests were performed at a significance level of 5 %. During the experimental period, 1138 evaluations were performed. The main reason for AH treatment was F ≥ 3. Ewes in early pregnancy, lactation and late pregnancy received comparatively more AH treatments than the other physiological states. Ewes in late pregnancy and lactation exhibited lower mean Ht values (23.5 % and 22.9 %) and higher mean FEC values (3269 and 1426) compared with those in early pregnancy (30.2 % and 727 EPG). In addition, a statistically significant difference was observed in the Ht and FEC values of ewes that presented submandibular edema (P < 0.001) compared with those that did not exhibit submandibular edema. The genus Haemonchus sp. showed a 96.4 % prevalence in coprocultures. A positive correlation existed between F scores and FEC (r = 0.3819) and a negative correlation between F scores and Ht (r = −0.4728). Ewes that needed AH treatment had lower mean Ht values than ewes that did not need the treatment (19.2 % × 29.3 %; P < 0.001) and higher mean FEC values (8747 × 1163; P < 0.001), confirming that these ewes needed AH treatment. The TST methodology based on F scores, BCS, and submandibular edema could effectively identify individuals in the herd needing AH treatment, identifying 13 % additional cases requiring treatment than using only the F score criterion.

Hookworm infection induces glycometabolic modulation in South Indian individuals with type 2 diabetes

ObjectivesA number of epidemiological studies have demonstrated that there is an inverse relationship between helminth infections and diabetes mellitus, suggesting that helminth infection may have a positive effect on type 2 diabetes mellitus (T2DM). However, the association between hookworm infection and T2DM has barely been studied. Hence, we aimed to investigate and analyze the interaction and association between hookworm infection and T2DM. MethodsWe examined the effect of hookworm infection on biochemical parameters, including plasma random blood glucose, glycated hemoglobin, and the plasma levels of pancreatic hormones, incretins, and adipokines in individuals with T2DM with (INF, n = 35) or without (UN, n = 35) hookworm infection. Moreover, we re-evaluated these analyte concentrations in a subset of INF individuals 6 months following anthelmintic therapy. ResultsCompared to UN individuals, INF individuals had significantly lowered levels of random blood glucose and glycated hemoglobin. INF individuals also exhibited significantly diminished levels of adiponectin, adipsin, C-peptide, insulin, and glucagon compared to UN individuals. In contrast, INF individuals displayed substantially elevated levels of visfatin and incretins compared to UN individuals. Interestingly, this effect was not seen following anthelmintic treatment. ConclusionOur study findings indicate that concomitant hookworm infection exerts a beneficial effect on glycometabolic parameters in T2DM.

Selective Anthelmintic Treatment in Horses in Sweden Based on Coprological Analyses: Ten-Year Results.

In Sweden, routine deworming has been used for several decades; however, to slow down the development of anthelmintic resistance, selective treatment is currently recommended. As part of a monitoring programme, equestrian premises submitted faecal samples to the National Veterinary Institute (SVA) twice per year between 2008 and 2017. Analyses for strongyles (small and large), tapeworms and ascarids, followed by premise-specific advice regarding deworming and parasite control strategies, were provided. In total, 43,330 faecal samples, collected from 26,625 horses on 935 premises in springtime (March to June), were analysed by quantitative or semi-quantitative flotation. Moreover, Strongylus vulgaris was detected by larval culture or PCR. Between 4 and 11% of individual horses tested positive for S. vulgaris and 3-10% were shedding tapeworm eggs. There were recurrent high and low egg shedders; 75% of horses with S. vulgaris appeared to have been recently introduced into the herd; the proportion of S. vulgaris-positive premises increased when individual samples rather than pooled samples were used. Based on the results of S. vulgaris diagnostics and strongyle egg-shedding level, 59% of the horses did not need to be dewormed.

Standard- and large-sized eggs of Trichuris trichiura in the feces of schoolchildren in the Yangon Region, Myanmar: Morphological and molecular analyses.

Standard- and large-sized eggs of Trichuris trichiura were found in the feces of schoolchildren in Yangon, Myanmar during epidemiological surveys and mass deworming with albendazole in 2017-2019. The standard-sized eggs were identified as those of T. trichiura, but it was necessary to exclude the possibility of the large-sized eggs belonging to Trichuris vulpis, a dog whipworm. We conducted morphological and molecular studies to determine the species of the 2 types of Trichuris eggs. Individual eggs of both sizes were isolated from Kato-Katz fecal smears (n=20) and mechanically destroyed using a 23G injection needle. Nuclear DNA was extracted, and the 18S rRNA region was sequenced in 15 standard-sized eggs and 15 large-sized eggs. The average size of standard-sized eggs (T. trichiura) was 55.2×26.1 μm (range: 51.7-57.6×21.3-28.0 μm; n=97), whereas the size of large-sized eggs was 69.3×32.0 μm (range: 65.1-76.4×30.1-34.5 μm; n=20), slightly smaller than the known size of T. vulpis. Regarding standard-sized eggs, the 18S rRNA nucleotide sequences exhibited 100% homology with T. trichiura deposited in GenBank and 88.6-90.5% homology with T. vulpis. Regarding large-sized eggs, the nucleotide sequences showed 99.8-100% homology with T. trichiura in GenBank and 89.6-90.7% homology with T. vulpis. Both standard- and large-sized eggs of Trichuris spp. found in Myanmar schoolchildren during 2017-2019 were morphologically and molecularly confirmed to belong to T. trichiura. The conversion of eggs from smaller to large sizes might be due to anthelmintic treatments with albendazole.

Targeted drug delivery using beeswax-derived albendazole-loaded solid lipid nanoparticles in Haemonchus contortus, an albendazole-tolerant nematode

Targeted delivery has not been achieved for anthelmintic treatment, resulting in the requirement of excess drug dose leading to side effects and therapeutic resistance. Gastrointestinal helminths take up lipid droplets from digestive fluid for energy production, egg development, and defense which inspired us to develop biocompatible and orally administrable albendazole-loaded solid lipid nanoparticles (SLN-A) that were derived from beeswax and showed drug loading efficiency of 83.3 ± 6.5 mg/g and sustained-release properties with 84.8 ± 2.5% of drug released at pH 6.4 within 24 h at 37 °C. Rhodamine B-loaded SLN showed time-dependent release and distribution of dye in-vitro in Haemonchus contortus. The sustained-release property was shown by the particles that caused enhancement of albendazole potency up to 50 folds. Therefore, this formulation has immense potential as an anthelminthic drug delivery vehicle that will be able to reduce the dose and drug-induced side effects by enhancing the bioavailability of the drug.

Retained efficacy of ivermectin against cyathostomins in Swedish horse establishments practicing selective anthelmintic treatment

Cyathostominae are ubiquitous to grazing horses and regarded the most prevalent internal parasite in the horse. Unfortunately, decades of indiscriminate use of anthelmintic drugs have resulted in the development of resistance in cyathostomins to all currently available drug groups, the most recent being a documented lack of efficacy to the macrocyclic lactones (ML). In vivo determination of anthelmintic resistance in horses most often utilises the faecal egg count reduction test (FECRT). Further, a shortened egg reappearance period (ERP) can indicate a change in response to the applied treatment and suggest an upcoming reduction of efficacy. Although both true resistance as demonstrated by the FECRT and shorter ERPs after ML treatment have now been shown in cyathostomins worldwide, the efficacy of ML as regards to cyathostomins in Sweden is currently unknown. The aim of the present study was therefore to determine FECRTs and ERPs after ivermectin (IVM) treatment in Swedish horses. Sixteen equestrian establishments with a minimum of six horses excreting at least 150 eggs per gram faeces (EPG) at screening were selected. For each establishment, FECRTs and ERPs were determined by collecting faecal samples prior to and 14 days after IVM treatment (200 µg/kg), and thereafter at weekly intervals for a total of eight weeks. All participants responded to a questionnaire detailing pasture management methods and anthelmintic routines.Questionnaire results showed that the majority of establishments (69%) only treated horses with anthelmintic drugs if indicated by faecal diagnostics and all of the establishments had a mean FECRT exceeding 99.0% and ERPs ranging from six to over eight weeks. The ERP was shown to increase with age as young individuals were shown to excrete cyathostomin eggs earlier after treatment compared with older horses (R = 0.21, p = 0.015). Riding schools, stud farms and those declaring not to use separate summer and winter paddocks had significantly shorter ERPs (p <0.01).In conclusion, retained ERPs and no confirmed resistance to IVM were found in Swedish equine establishments practising selective anthelmintic treatment, and supports the use of selective deworming regimens as a means of reducing the risk of anthelmintic resistance development.

Comparison of deworming strategies for pre-weaned beef calves

While anthelmintic treatment in young calves at first vaccination has not proven repeatedly effective in improving weight gain, there is evidence that treatment 90 day prior to weaning can enhance weight gain. This is difficult in most California cow/calf operations as after initial vaccination, calves are not again handled until preconditioning just prior to weaning. In an attempt to increase weight gain without the need for anthelmintic retreatment prior to preconditioning, 130 cow/calf pairs were stratified and assigned to three treatments of eprinomectin extended release injection (150 d efficacy), doramectin conventional injection, and an untreated control. Dams and calves received the same treatment. All treatments were commingled on irrigated pasture in Northern California. Sampling included weight (d 0, 75, and 145), fecal parasite (d 0, 14, 75, and 145), cow body condition score (d 0, 75, and 145), and cow pregnancy detection (days bred). Calf weight gain was not impacted by anthelmintic treatment (P = 0.44). However, cow weight gain was impacted by treatment (P < 0.01), with eprinomectin extended release showing higher weight gain than both doramectin conventional and the control (ADG kg 0.29, 0.23, 0.22, respectively). Cow weight gain differences were expressed greater toward the end of the trial than early on. Fecal egg count sampling failed to explain the difference in cow weight gain. Cow body condition score (P = 0.15) and days bred (P = 0.50) were not significantly affected by treatment. Although cow weight gain increased with an extended release anthelmintic treatment, this effect did not seem to be evident in suckling calves on high quality irrigated pastures in Northern California when compared to a conventional injectable and control treatments. Neither anthelmintic treatment appeared beneficial over a control when administered to suckling calves during initial vaccination at approximately 90 days of age.

Validation of a serum ELISA test for cyathostomin infection in equines

Cyathostomins are ubiquitous equine nematodes. Infection can result in larval cyathostominosis due to mass larval emergence. Although faecal egg count (FEC) tests provide estimates of egg shedding, these correlate poorly with burden and provide no information on mucosal/luminal larvae. Previous studies describe a serum IgG(T)-based ELISA (CT3) that exhibits utility for detection of mucosal/luminal cyathostomins. Here, this ELISA is optimised/validated for commercial application using sera from horses for which burden data were available. Optimisation included addition of total IgG-based calibrators to provide standard curves for quantification of antigen-specific IgG(T) used to generate a CT3-specific ‘serum score’ for each horse. Validation dataset results were then used to assess the optimised test’s performance and select serum score cut-off values for diagnosis of burdens above 1000, 5000 and 10,000 cyathostomins. The test demonstrated excellent performance (Receiver Operating Characteristic Area Under the Curve values >0.9) in diagnosing infection, with >90% sensitivity and >70% specificity at the selected serum score cut-off values. CT3-specific serum IgG(T) profiles in equines in different settings were assessed to provide information for commercial test use. These studies demonstrated maternal transfer of CT3-specific IgG(T) in colostrum to newborns, levels of which declined before increasing as foals consumed contaminated pasture. Studies in geographically distinct populations demonstrated that the proportion of horses that reported as test positive at a 14.37 CT3 serum score (1000-cyathostomin threshold) was associated with parasite transmission risk. Based on the results, inclusion criteria for commercial use were developed. Logistic regression models were developed to predict probabilities that burdens of individuals are above defined thresholds based on the reported serum score. The models performed at a similar level to the serum score cut-off approach. In conclusion, the CT3 test provides an option for veterinarians to obtain evidence of low cyathostomin burdens that do not require anthelmintic treatment and to support diagnosis of infection.

Targeted treatment strategies for the control of gastrointestinal nematodes in a goat flock with anthelmintic resistant worm populations and poor nutrition

Combined targeted selective treatment schemes using FAMACHA©, body condition score (BCS), and faecal egg counts (FEC) can reduce the number of anthelmintic (AH) treatments per year in goat farms, which can slow down the selection of AH-resistant worm populations. Supplementary feeding can further reduce the FEC of goats at the farm level. A 19-month survey was implemented to (i) identify the number of times that goats crossed the thresholds of FAMACHA©, BCS, and FEC, (ii) identify the monthly FEC reductions of goats treated with AH in the targeted scheme, and (iii) identify the effect of a supplementation scheme on the goats’ FEC. The survey was performed at a goat farm in tropical México. Goats grazed natural vegetation four h/day and received concentrate feed daily (14% crude protein, 150 g each). Each month, goats (n = 88) were examined, and those with FAMACHA© ≥ 4, BCS ≤ 2, and FEC ≥ 750 eggs per gram of faeces (EPG) were identified (Day 0). From September 2018 to September 2019, goats crossing the FEC threshold (events) were allocated to two different groups distributed according to FEC values: deworming group (DG; n = 71 events) and supplemented group (SG; n = 72 events). From October 2019, all the goats were assigned only to the DG (n = 31 events) due to management problems in the study farm. The DG goats were individually weighed and treated with levamisole (LEV, 12 mg/kg body weight (BW), subcutaneous (sc)) and their normal diet. From November 2019 to March 2020, the DG goats were treated with LEV and benzimidazole (BZ, 7 mg/kg BW, sc). The SG goats were individually supplemented with an additional 300 g of concentrate feed for ten days. From the 88 goats surveyed, 70.5% crossed the FAMACHA©/BCS thresholds, with goats sampled 1–7 times. From the 369 sampled events, only 56% had ≥ 750 EPG. The FEC reduction of DG goats treated with LEV ranged from 46.7% to 96.1%, and with LEV+BZ combination was 100%. The FEC reduction in the SG goats ranged from 27.7% to 95.5%. Supplementation of SG goats had a positive impact on most goats and helped to limit the number of dewormed goats. To be effective, the supplement must be an addition to the normal diet.

Intestinal parasitic infections and risk analysis among urban refugees in the Klang Valley, Malaysia.

Global studies show intestinal parasitic infections (IPIs) have been introduced and spread with refugee inflows from low to high socio-economic countries. However, there is relatively limited information on the prevalence of infections among the community. A 2-year cross-sectional study was conducted to determine the prevalence and associated risk factors for infections among urban refugees in the Klang Valley, Malaysia. A total of 418 faecal samples were collected and examined by microscopy. Faecal screening revealed moderate levels (32.3%) of infections in the community. Three nematode (Ascaris lumbricoides, Trichuris trichiura and hookworm) and three protozoan species (Entamoeba, Giardia and Cryptosporidium) were recorded, with the highest prevalence being A. lumbricoides (20.6%) followed by T. trichiura (10.3%), while other infections were <5%. Statistical analysis found that young males with less education were more likely to be infected with helminths. Additionally, living near waste disposal sites, the presence of stray animals, eating with bare hands, bare footedness, poor handwashing practices and no anthelmintic treatment constituted significant risk factors for helminth infections. Protozoan infections were linked to drinking tap water or from water dispensers and poor handwashing practices. These findings emphasize the importance of health education in addition to introduction of biannual anthelmintic treatment to promote community health and well-being.

Emergence of canine hookworm treatment resistance: Novel detection of Ancylostoma caninum anthelmintic resistance markers by fecal PCR in 11 dogs from Canada.

To describe dogs with detected Ancylostoma caninum anthelmintic treatment resistance markers in Canada. 11 client-owned dogs with fecal quantitative PCR (qPCR) assay detected A caninum with benzimidazole (BZ) resistance genotypic markers. Signalment, presenting concern, duration of clinical signs, fecal testing, treatment, and outcomes were obtained. Where available, follow-up data were collected via telephone or email with the primary veterinarian. Ancylostoma spp was detected from 184/32,205 dog fecal samples by reference laboratory qPCR surveillance, between May 15, 2022, and April 26, 2023. 11 of these 184 samples had A caninum with genetic BZ F167Y resistance marker detection. 4 dogs had not traveled outside Canada, 6 had been imported from the US, and the travel history was unclear in 1 dog. 7 of the dogs had gastro-intestinal signs (diarrhea or soft stool) on initial presentation. Clinical improvement was reported in 6 of these dogs (resolution of diarrhea and soft stool), with 1 dog lost to follow-up. All 11 dogs received anthelmintic treatment (varied drugs and duration). Identification of genetic markers of BZ resistance raises concerns about the potential animal and human impacts of resistant hookworms. 4 dogs lacked an origin from or travel history to the US, indicating true emergence and/or novel spread within Canada, not just importation from an area where resistance has been reported. Fecal surveillance was performed with a qPCR test incorporating treatment (BZ) resistance markers. There is a need to raise clinician awareness around treatment-resistant hookworm in dogs and the capability of fecal surveillance for genotypic and phenotypic resistance.

The effect of the addition of a companion forage to a perennial ryegrass sward on ewe and lamb performance

Ireland's competitive advantage in sheepmeat production is based on the efficient and cost effective production and utilisation of pasture. The objective of this study was to assess the influence of binary mixtures of perennial ryegrass (Lolium perenne L.) plus a companion forage on ewe and lamb performance at pasture. Five sward mixtures were compared, namely; i) perennial ryegrass (Lolium perenne L.;PRG), ii) PRG plus white clover (Trifolium repens L.;PRG + WC), iii) PRG plus red clover (Trifolium pratense L.;PRG + RC), iv) PRG plus plantain (Plantago lanceolate L.;PRG + Plan) and v) PRG plus chicory (Chicorium intybus L.;PRG + Chic). Five farmlets with one sward treatment assigned to each were established which 23 ewes plus their lambs grazed from March to December for the years 2018 to 2021 inclusive. Farmlets were rotationally grazed, stocked at 11.5 ewes/ha and received 130 kg nitrogen/ha/year. Lambs were weaned on average at 15 weeks of age. Post-weaning a leader-follower grazing system was implemented with lambs grazing ahead of the ewes. Post weaning, lambs were weighed fortnightly and drafted at a live weight of 42 kg in June and increasing by 1 kg per month thereafter to produce a target carcass weight of 20 kg. Results show that lamb lifetime average daily gain (ADG) was greater for lambs grazing all binary sward mixtures relative to grazing PRG. Relative to PRG, lamb lifetime ADG was increased by between 17 g/day (PRG + Plan; P < 0.01) to 31 g/day (PRG + RC, and PRG + Chic; P < 0.001) and subsequently the number of days required to reach slaughter (DTS) was reduced by between 15.8 days (PRG + Plan; P < 0.01) to 28.6 days (PRG + RC; P < 0.001) with the addition of a companion forage. As a result of lower DTS, the average total number of anthelmintic treatments administered per lamb was significantly reduced for lambs grazing on all of the binary sward mixtures relative to PRG (P < 0.001). Scanned litter size and ewe milk yield were similar across all sward types as were ewe body weight (BW) and body condition score (BCS) from mating up until 6 weeks post-lambing (P > 0.05). Of the ewes retained from one production year to the next, those grazing PRG + WC, PRG + RC and PRG + Plan had a greater BW than those grazing PRG at the second mating event (P < 0.05), whilst, PRG + RC, PRG + Plan and PRG + Chic ewes had a greater BCS than PRG ewes (P < 0.05). These results suggest the suitability of binary sward mixtures under an intensive sheep grazing system to improve ewe and lamb performance at pasture.

Report of three patients with extensive neurocysticercosis in rural southern Tanzania: neurological, serological and neuroradiological findings

BackgroundNeurocysticercosis (NCC) is common in eastern Africa, but disease presentation varies considerably. Most patients have single or few NCC-typical lesions in their brain but some present with a large number of lesions. We present three patients with positive antibody-based serology for Taenia solium cysticercosis screened at the Vwawa district hospital, Mbozi district, southern Tanzania, in whom extensive NCC was confirmed by neuroimaging.Case presentationsPatient 1 was a 55-year-old female from the tribe Malila smallholder farmer who has had four generalized tonic–clonic epileptic seizures over a period of 11 years and one episode of transient left hemiparesis one year before seizure onset. The patient also reported monthly to weekly episodes of severe, progressive, unilateral headache. The computed tomography (CT) scan of the brain showed 25 NCC lesions of which 15 were in the vesicular stage. Patient 2 was a 30-year-old male from tribe Nyha mechanic who reported monthly episodes of moderate to severe, progressive, bilateral headache, but no epileptic seizures. The CT scan showed 63 NCC lesions of which 50 were in the vesicular stage. Patient 3 was a 54-year-old female from the tribe Malila smallholder farmer who suffered from frequent generalized tonic–clonic epileptic seizures with potential signs of focal seizure onset. She also reported weekly to daily episodes of severe, progressive, unilateral headache. The CT scan showed 29 NCC lesions of which 28 were in the vesicular stage.ConclusionsClinical presentation of NCC with multiple brain lesions varies considerably ranging from few epileptic seizures and severe headache to severe epilepsy with frequent epileptic seizures. Individuals with neurological signs/symptoms that may be due to NCC, based for example on epidemiological criteria or serological evidence of cysticercosis, are recommended to undergo neuroimaging before anthelminthic treatment is considered.

Incidence, risk factors, and therapeutic management of equine colic in Lamongan, Indonesia.

Colic is among the common health issues in equine health management. Gastrointestinal (GI) disorders are the most frequent causes of colic, but dysfunction of other organs and systems inside the abdominal cavity may also contribute. Therefore, it is crucial to identify risk factors for colic of specific etiologies. This study aimed to examine the incidence, risk factors, and best therapeutic management practices for horses with colic. A cohort of 256 horses living in Lamongan, East Java, Indonesia, was randomly recruited based on reports of colic symptoms by owners. Diagnosis and treatment were then conducted with the help of owners. Symptom profiles, risk factors, and therapeutic management strategies were analyzed by Chi-square tests. Of 256 horses enrolled, 217 (84%) were diagnosed with colic, of which 172 (79.3%) were cases of spasmodic colic, 33 (15.2%) of impaction colic, and 12 (5.5%) of intestinal obstruction/displacement. Male sex (χ2 = 16.27; p < 0.001), wheat bran feeding (χ2 = 15.49; p < 0.001), concentrate feed intake >5 kg/day (χ2 = 24.95; p < 0.001), no regular anthelmintic drug treatment (χ2 = 67.24; p < 0.001), GI parasite infection (χ2 = 65.11; p < 0.001), recurrent colic (χ2 = 91.09; p < 0.001), poor body condition score (χ2 = 71.81; p < 0.001), limited daily water access (χ2 = 127.92; p < 0.001), and indications of dental disease (χ2 = 9.03; p < 0.001) were identified as risk factors. The most effective therapies were gastric intubation (χ2 = 153.54; p < 0.001), Vitamin B complex injection (χ2 = 32.09; p < 0.001), fluid therapy (χ2 = 42.59; p < 0.001), and non-steroidal anti-inflammatory drug injection (NSAID). Colic is highly prevalent among horses in Lamongan, East Java, Indonesia. Proper diet, workload management, regular access to clean drinking water, and dental care can reduce colic risk. Recommended therapies include NSAID injection without other analgesics or spasmolytics, fluid therapy, Vitamin B complex, and gastric intubation.

The abundance of parasitic nematodes Halicephalobus species (Nematoda: Rhabditida) invading humans and animals in national parks of Vietnam

Halicephalobus nematodes are parasites in horses, ruminants, and humans. They with the most demonstrated H. gingivalis infect the hosts and cause granulomas to fatalities. Anthelmintic treatments are not effective in many cases, so precautions against Halicephalobus infection based on the understanding of life history may help. So far, ten species have been globally identified. We isolated many wild-type Halicephalobus sp. strains in vegetation samples collected from two national parks (Cat Tien and Cuc Phuong National Parks) in Vietnam and cultured them on bacteria. Thus, Halicephalobus nematodes could live in the wild and feed on bacteria. In previous studies, horses were predominantly found to be hosts of Halicephalobus sp. nematodes, but in this study they are not presented in the parks, suggesting that other wild animals such as ruminants in the parks should be their hosts. In addition, we analyzed the 18S rDNA sequences of the isolated nematodes and found that they are likely divergent between the two ecological systems, suggesting the two nematode communities have evolved differently.

#6189 PRECLINICAL VALIDATION OF REPURPOSABLE CANDIDATE DRUG COMPOUNDS FOR CYSTIC NEPHROPATHIES

Abstract Background and Aims Early-onset cystic kidney disease is a clinically and genetically heterogeneous and overlapping group of rare and often severe disorders with limited, mostly symptomatic treatment options. We developed and utilized inherited polycystic cystic kidney disease (PKD) models to search for pharmacological agents that can rescue or mitigate the disease phenotype. Method A high-content screening platform for identification of chemical modifiers of cyst formation and progression in a zebrafish genetic cystic nephropathy model (IFT172 Morpholino-based knockdown in Tg(wt1b:eGFP)), using robotic microscopy with automated image classification and phenotype quantification was used to screen 1280 compounds from the Prestwick library for their cyst-inhibiting activity. Compounds with cyst-inhibitory efficacy and low toxicity in the Zebrafish and oral and trans-placental availability were selected for further study in two rodent PKD models, i.e. PCK and PKD/Mhm (cy/+) rats. Groups of 3-week-old homozygous PCK and heterozygous PKD/Mhm rats were administered orally for 10 weeks three candidate compounds, which included an antihistamine, an anthelmintic and an antifungal agent, or regular ROD16 chow (sick controls). In experimental week 5, blood was taken, and the kidneys were imaged sonographically under anaesthesia. In the last experimental week, glomerular filtration rate was determined by transcutaneous FITC-sinistrin injection. Masson trichrome staining was used to evaluate cyst formation in kidneys. Results 60 compounds with cyst preventive or cyst size reducing activity were identified in the zebrafish screening model. While one third of these compounds caused severe general toxicity, 12 of them showed medium and 4 strong cyst-inhibitory activity with no or mild off-target effects. These substances were from anthelminthic, antihistamine, antifungal and proton pump inhibitor drug classes. Preliminary results in the rodent models suggest that anthelminthic treatment reduced the number of cysts in female (3.3±1.3 vs. untreated control, 5.4±0.9) but not male PCK rats (3.7±0.6 vs. 3.9±0.7) after 10 weeks of treatment. These changes were accompanied by improved glomerular filtration rate (GFR) in treated females (t½: 0.22±0.04 min vs. 0.3±0 min). An improvement in GFR was also observed in female PKD/Mhm rats after 10 weeks of treatment with the anthelmintic compound compared to untreated control animals (t½: 0.24±0.06 vs. 0.51±0.16 min, p = 0.02). Conclusion Candidate cyst-inhibitory drugs identified in a zebrafish model were applied in rat models of PKD. The administration of an anthelmintic agent had a positive impact on the progression of polycystic kidney disease. The beneficial effect appears to be sex specific. If further corroborated, our findings may allow repurposing of a drug approved for another indication to slow disease progression in patients with cystic kidney diseases.