Piperonyl butoxide enhances triclabendazole action against triclabendazole-resistant Fasciola hepatica

A study has been carried out to determine whether the action of triclabendazole (TCBZ) against the liver fluke, Fasciola hepatica is altered by inhibition of the cytochrome P450 (CYP 450)-mediated drug metabolism pathway. The Oberon TCBZ-resistant and Cullompton TCBZ-susceptible fluke isolates were used for these experiments, the basic design of which is given in the paper by Devine et al. (2010a). Piperonyl butoxide (PB) was the CYP P450 inhibitor used. Morphological changes resulting from drug treatment and following metabolic inhibition were assessed by means of transmission electron microscopy. After treatment with either TCBZ or TCBZ.SO on their own, there was greater disruption to the TCBZ-susceptible than TCBZ-resistant isolate. However, co-incubation with PB+TCBZ, but more particularly PB+TCBZ.SO, led to greater changes to the TCBZ-resistant isolate than with each drug on its own, with blebbing of the apical plasma membrane, severe swelling of the basal infolds and their associated mucopolysaccharide masses in the syncytium and flooding in the internal tissues. Golgi complexes were greatly reduced or absent in the tegumental cells and the synthesis and production of secretory bodies were badly disrupted. The mitochondria were swollen throughout the tegumental system and the somatic muscle blocks were disrupted. With the TCBZ-susceptible Cullompton isolate, there was a limited increase in drug action following co-incubation with PB. The results provide evidence that the condition of a TCBZ-resistant fluke can be altered by inhibition of drug metabolism. Moreover, they support the concept that altered drug metabolism contributes to the mechanism of resistance to TCBZ.     

Influence of verapamil on pharmacokinetics and transplacental transfer of ivermectin in sheep

In pregnant sheep at 120–128 days of gestational age, a study was done to evaluate the effect of the co-administration of verapamil (Vpm) and ivermectin (IVM) on the maternal and fetal disposition kinetics after intravenous administration of IVM. Ten pregnant Suffolk Down sheep of 63.5 ± 6.6 kg body weight (bw) were surgically prepared to insert polyvinyl catheters in the fetal femoral artery and vein and amniotic sac. The ewes were randomly assigned to two experimental groups. In Group 1 (control), 5 ewes were treated with an intravenous bolus of 0.2 mg IVM/kg bw. In Group 2 (Vpm-IVM), 5 ewes were subcutaneously treated with Vpm (2.5 mg/kg × 3 doses at 12 h intervals) and 0.2 mg/kg IVM by intravenous route. Maternal and fetal blood samples were taken before and after IVM administration during a 144 h post-treatment period. Samples were analyzed by liquid chromatography (HPLC). A non-compartmental pharmacokinetic analysis was performed and statistical differences were determined using the Mann–Whitney U-test.Significantly higher IVM levels in maternal plasma concentrations were determined after co-administration of Vpm/IVM compared with the group treated with IVM alone. Significant decreases in the volume of distribution and in the half-life of elimination (t_½β) were observed in the Vpm/IVM treated group. A significantly faster (T_max) and higher (C_max) (P < 0.05) increase in IVM fetal plasma concentrations were observed in the group of fetuses from pregnant ewes treated with Vpm/IVM. The results of our study support the hypothesis that pharmacological blockage of P-glycoprotein with Vpm can increase the transfer of IVM to fetal circulation.     

Molecular characterization of Fasciola flukes using mitochondrial 28S rRNA gene in Naimi Saudi sheep

Fasciolosis is a parasitic disease of medical and economic importance. This retrospective study was conducted on 110 Fasciola flukes collected from livers of 14 infected Naimi sheep slaughtered at Riyadh abattoir in Saudi Arabia during winter season of 2016. Collected specimens were analyzed for their species identification on the basis of partial sequences of mitochondrial 28S rRNA gene. Results have shown the presence of both Fasciola hepatica (F. hepatica) and Fasciola gigantica (F. gigantica) species. Where Fasciola hepatica was predominate (80%). Both intra-species and interspecies genetic distance was studied and results showed that the intraspecific variability among individuals of both species i.e., F. hepatica and F. gigantica, ranging between 0 and 1% while the interspecific diversity between F. hepatica and F. gigantica was only 1%. In conclusion, mitochondrial 28S rRNA gene is a proved as a good marker in identifying Fasciola of different species. Where, the F. hepatica and F. gigantica are present in sheep breed in Riyadh region, Saudi Arabia.     

The in vivo effects of rafoxanide on the energy metabolism of Fasciola hepatica

Adult F. hepatica were obtained from sheep which had received a single dose of rafoxanide at the therapeutic dose rate (7·5 mg/kg body weight). Flukes were recovered 12 and 24 h after the sheep were treated. No flukes were present after 4 days. Plasma levels of the drug were high after 24 h and remained so at 4 days. Flukes were being expelled from the liver 24 h after treatment. Glycogen levels within the flukes were diminished in the 24 h treated group, as were concentrations of ATP. These effects were not apparent in the 12 h treated group. Fluctuations in glucose, G6P, F6P and pyruvate pools were observed in both groups. The effects of rafoxanide were irreversible after 24 h exposure to the drug. Flukes from the treated sheep were incubated for 6 and 24 h in a simple maintenance medium with added glucose. They showed progressive deterioration in energy status. The results are considered in the context of the mode of action of rafoxanide.     

Resistance-induced changes in triclabendazole transport in Fasciola hepatica: ivermectin reversal effect

Triclabendazole (TCBZ) and albendazole (ABZ) are flukicidal benzimidazole compounds extensively used in veterinary medicine. Although TCBZ has excellent activity against mature and immature stages of the liver fluke, Fasciola hepatica, ABZ action is restricted to flukes older than 12 wk. The intensive use of TCBZ has resulted in the development of resistance. To gain insight into the mechanisms of resistance to TCBZ, the ex vivo diffusion of TCBZ, TCBZ sulfoxide (TCBZSO, the active metabolite of TCBZ), and ABZ into TCBZ-susceptible and -resistant adult flukes was compared. TCBZ-susceptible (Cullompton) and -resistant (Sligo) flukes were incubated in Krebs-Ringer Tris buffer with either TCBZ, TCBZSO, or ABZ (5 nmol/ ml) for 90 min. Drug/metabolite concentrations were quantified by high-performance liquid chromatography. All the assayed molecules penetrated through the tegument of both susceptible and resistant flukes. However, significantly lower concentrations of TCBZ and TCBZSO were recovered within the TCBZ-resistant flukes. In contrast, ABZ entrance into the susceptible and resistant flukes was equivalent. The influx/efflux balance for TCBZ, TCBZSO, and ABZ in susceptible and resistant flukes in the presence or absence of a substrate (ivermectin) of the drug transporter P-glycoprotein was assessed. The ivermectin-induced modulation of P-glycoprotein activity decreased TCBZ efflux from the resistant flukes. Higher concentrations of TCBZ and TCBZSO were recovered from the resistant liver flukes in the presence of ivermectin. Thus, an altered influx/efflux mechanism may account for the development of resistance to TCBZ in F. hepatica.     

Monepantel-based anthelmintic combinations to optimize parasite control in cattle

Improvement in the use of existing anthelmintics is a high priority need for the pharmaco-parasitology research field, considering the magnitude and severity of anthelmintic resistance as an important issue in livestock production. In the work described here, monepantel (MNP) was given alone or co-administered with either macrocyclic lactone (ML) or benzimidazole (BZ) anthelmintics to calves naturally infected with ML- and BZ-resistant gastrointestinal (GI) nematodes on two different commercial cattle farms. Both pharmacokinetic (PK) and efficacy assessments were performed. On Farm A, male calves (n = 15 per group) were treated with either MNP orally (2.5 mg/kg), IVM s.c. (0.2 mg/kg), ricobendazole (RBZ) s.c. (3.75 mg/kg) or remained untreated. On Farm B, eight groups (n = 15) of male calves received treatment with either: MNP, abamectin (ABM, oral, 0.2 mg/kg), RBZ (s.c., 3.75 mg/kg), albendazole (ABZ, oral, 5 mg/kg), MNP+ABM, MNP+RBZ, MNP+ABZ (all at the above-mentioned routes and doses) or remained untreated. Seven animals from each treated group (Farm B) were randomly selected to perform the PK study. MNP and its metabolite monepantel sulphone (MNPSO₂) were the main analytes recovered in plasma after HPLC analysis. The combined treatments resulted in decreased systemic exposures to MNP parent drug compared with that observed after treatment with MNP alone (P < 0.05). However, the systemic availability of the main MNP metabolite (MNPSO₂) was unaffected by co-administration with either ABM, RBZ or ABZ. Efficacies of 98% (Farm A) and 99% (Farm B) demonstrated the high efficacy of MNP given alone (P < 0.05) against GI nematodes resistant to ML and BZ in cattle. While the ML (IVM, ABM) failed to control Haemonchus spp., Cooperia spp. and Ostertagia spp., MNP achieved 99% to 100% efficacy against those nematode species on both commercial farms. However, MNP alone failed to control Oesophagostomum spp. (60% efficacy) on Farm A. The co-administered treatments MNP+ABZ and MNP+RBZ reached a 100% reduction against all GI nematode genera. In conclusion, the oral treatment with MNP should be considered to deal with resistant nematode parasites in cattle. The use of MNP in combination with BZ compounds could be a valid strategy to extend its lifespan for use in cattle as well as to reverse its poor activity against Oesophagostomum spp.     

Fasciola hepatica in Snails Collected from Water-Dropwort Fields using PCR

Fasciola hepatica is a trematode that causes zoonosis mainly in cattle and sheep and occasionally in humans. Fascioliasis has been reported in Korea; however, determining F. hepatica infection in snails has not been done recently. Thus, using PCR, we evaluated the prevalence of F. hepatica infection in snails at 4 large water-dropwort fields. Among 349 examined snails, F. hepatica-specific internal transcribed space 1 (ITS-1) and/or ITS-2 markers were detected in 12 snails and confirmed using sequence analysis. Morphologically, 213 of 349 collected snails were dextral shelled, which is the same aperture as the lymnaeid snail, the vectorial host for F. hepatica. Among the 12 F. hepatica-infected snails, 6 were known first intermediate hosts in Korea (Lymnaea viridis and L. ollula) and the remaining 6 (Lymnaea sp.) were potentially a new first intermediate host in Korea. It has been shown that the overall prevalence of the snails contaminated with F. hepatica in water-dropwort fields was 3.4%; however, the prevalence varied among the fields. This is the first study to estimate the prevalence of F. hepatica infection using the vectorial capacity of the snails in Korea.     

Genotypic characterization and species identification of Fasciola spp. with implications regarding the isolates infecting goats in Vietnam

Ribosomal RNA sequences (361 or 362 bp) of the second internal transcribed spacer 2 (ITS-2) and a portion of mitochondrial cox1 (423 bp) for Fasciola spp. obtained from specimens collected in indigenous and hybrid goats and sheep in Vietnam were characterized for genotypic status and hybridization/introgression. Alignment of 48 ITS-2 sequences (also those from goats and sheep in this study) indicates that F. gigantica and F. hepatica differ typically from each other at seven sites whereas one of these is a distinguishing deletion (T) at the 327th position in F. gigantica relative to F. hepatica. The isolates from the mountainous goats in the North of Vietnam (Yen Bai province) showed the ITS-2 composition relatively identical to that of F. hepatica. The ITS-2 sequences from populations of Fasciola isolates in goats had probably experienced introgression/hybridization as reported previously in other ruminants and humans. All Vietnamese goat-of-origin specimens had high pairwise percentage of mitochondrial cox1 sequences to F. gigantica (97-100%), and very low identity to F. hepatica (91-93%), suggesting their maternal linkage to be traced to F. gigantica. The presence of hybrid and/or introgressed populations of liver flukes bearing genetic material from both F. hepatica and F. gigantica in the goats/sheep in Vietnam, regardless of indigenous or imported hosts, appears to be the first demonstration from a tropical country.     

Sequence heterogeneity in a repetitive dna element of Fasciola

A repetitive DNA sequence used as a specific probe for Fasciola hepatica infections in snails was examined in F. hepatica and Fasciola gigantica (36 individuals) specimens from five continents. The degree of intraspecific identity ranged from 79 to 99% in F. hepatica and from 93 to 99% in F. gigantica. The interspecific identity ranged from 81 to 100%, confirming the suggestion that the DNA probe sequence could be used worldwide as an epidemiological tool for the examination of the intermediate host snail in fasciolosis. Differentiation between F. hepatica and F. gigantica infections in snails was not possible using the probe.     

Further observations on the nature and characteristics of cross protection against Fasciola hepatica produced in sheep by infection with Cysticercus tenuicollis

Dineen J. K., Kelly J. D. and Campbell N. J. 1978. Further observations on the nature and characteristics of cross protection against Fasciola hepatica produced in sheep by infection with Cysticercus tenuicollis. International Journal for Parasitology8: 173–176. Previous studies showed that sheep infected with Cysticercus tenuicollis were protected against a subsequent infection with Fasciola hepatica given at 12 weeks (Campbell, Kelly. Townsend & Dineen, 1977). The present studies showed that these animals were again protected against re-challenge with F. hepatica at 9 months. Resistance was detected about 10 weeks after re-challenge with metacercariae.Sheep in which the initial C. tenuicollis infections were terminated by anthelmintic at 12 weeks, were resistant to the primary infection with F. hepatica but became fully susceptible to the re-challenge at 9 months.These results suggest that maintenance of resistance depends upon persistence of the C. tenuicollis infections. They also indicate that resistance is maintained by cysts in the peritoneum which is remote from the reactive site (liver).Infection with F. hepatica at 3 weeks after infection with C. tenuicollis prevented cross protection against both the primary infection with F. hepatica and re-challenge at 9 months.     

Molecular characterization of Fasciola hepatica from Sardinia based on sequence analysis of genomic and mitochondrial gene markers

The aim of the present study is to investigate for the first time the genetic diversity of samples identified morphologically as Fasciola hepatica (Platyhelminthes: Trematoda: Digenea) (n = 66) from sheep and cattle from two localities of Sardinia and to compare them with available data from other localities by partial sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes, the mitochondrial cytochrome c oxidase subunit I (COI), and nicotinamide adenine dinucleotide dehydrogenase subunit I (ND1) genes. Comparison of the sequences from Sardinia with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. hepatica. The nucleotide sequencing of ITS rDNA showed no nucleotide variation in the ITS-1, 5.8S and ITS-2 rDNA sequences among all Sardinian samples, comparing with two ITS-2 haplotypes in standard F. hepatica, showing a substitution C/T in 20 position 859, reported previously from Tunisia, Algeria, Australia, Uruguay and Spain. The present study shows that in Sardinian sheep and cattle there is the most frequent haplotype (FhITS-H1) of F. hepatica species from South Europe. Considering NDI sequences, the phylogenetic trees showed reliable grouping among the haplotypes of F. hepatica from Sardinia and the mitochondrial lineage I, including the main N1 haplotype, observed previously from Europe (Russia, Belarus, Ukraine and Bulgaria), Armenia, West Africa (Nigeria), America (Uruguay and USA), Asia (Turkey, Japan, and China), Georgia, Turkmenistan, Azerbaijan and Australia. Furthermore, common haplotypes FhCOI-H1 and FhCOI-H2 of F. hepatica from Sardinia also corresponded mostly to the first lineage including the main C1 haplotype reported previously from Eastern European and Western Asian populations, they belonged just to a phylogenically distinguishable clade, as F. hepatica from Australia, France, Turkey, Uruguay, Russia, Armenia, Ukraine, Belarus, Turkmenistan, USA, Tunisia and Algeria, indicating that this is the main haplotype involved in the spread of F. hepatica throughout all continents.     

Is Muta™Mouse insensitive to clastogens?

Several studies suggest that Muta™Mouse is insensitive to clastogens, including the accompanying paper by Mahabir et al., which describes a study with bleomycin, camptothecin, m-AMSA (4′-(9-acridinylamino)-methanesulfon-m-anisidide) and its ortho-analogue, o-AMSA (4′-(9-acridinylamino)-methanesulfon-o-anisidide). Only camptothecin was clastogenic in Muta™Mouse and none of these four compounds induced mutations at the lacZ locus. However, to improve exposure, dose range-finding studies were performed in CD2F1 mice, the parental strain of Muta™Mouse. Male CD2F1 mice (n = 3) were treated with bleomycin (25–100 mg/kg bw, p.o. and i.p.), camptothecin (1–10 mg/kg bw p.o.) and m-AMSA (10–50 mg/kg bw p.o. and 1–5 mg/kg bw i.p.) for 5 days and blood was sampled on day 3 and/or day 6 for analysis by flow cytometry to determine % MN-RETs. Camptothecin (1 mg/kg bw, day 6) induced a 3.6-fold increase in % MN-RET (P < 0.05) but was toxic at higher doses. All day-3 camptothecin samples were positive (P < 0.05). Bleomycin was negative when administered p.o. but positive at all doses on both days when given i.p. (P < 0.05) whereas m-AMSA was negative when given i.p. or orally. Based on these results, male Muta™Mouse mice (5 per group) were dosed daily with bleomycin (50 mg/kg bw) for 5 days or with camptothecin (5 mg/kg bw) for 2 days. Peripheral blood was sampled 24 h after the final dose in each group and tissues were sampled 37 days later. Both compounds induced significant increases in % MN-RET, but only bleomycin induced a significant increase in MF (6-fold in liver, 4.5-fold in kidney and 2-fold in lung) compared with the untreated control. These studies support the view that Muta™Mouse is insensitive to compounds where the genotoxic mechanism of action is predominantly clastogenesis, but demonstrates that the peripheral blood micronucleus test is a useful adjunct to the transgenic gene-mutation assay.     

Pharmacokinetics of triclabendazole in rabbits

1.Pharmacokinetic profiles of triclabendazole (TCBZ) following intravenous (i.v.) and oral administration of the drug in rabbits were carried out.2. In normal rabbits, TCBZ was metabolized rapidly to its sulphoxide (TCBZ-SO) and sulphone (TCBZ-SO₂) derivatives following administration, with undetectable concentrations of unchanged TCBZ in the plasma of the treated animals at any time (detection limit, 10 ng/ml).3. The disposition kinetics of this drug in rabbits can be described by a two-compartment open model.4. Mean peak concentrations in plasma of TCBZ-SO and TCBZ-SO₂ of 12.41 μg/ml and 9.5 μg/ml occurred 7.5 and 9.5 hr after oral administration, respectively.5. Both metabolites were eliminated slowly from plasma with elimination half-lives of 16.86 hr for the sulphoxide and 13 hr for the sulphone.6. The area under the plasma concentration versus time curve (AUC) was 240 mg hr/l for the sulphoxide, higher than that found for the sulphone, 185 g hr/l.     

A recombinant thioredoxin-glutathione reductase from Fasciola hepatica induces a protective response in rabbits

Antioxidant systems are fundamental components of host–parasite interactions, and often play a key role in parasite survival. Here, we report the cloning, heterologous expression, and characterization of a thioredoxin glutathione reductase (TGR) from Fasciola hepatica. The deduced polypeptide sequence of the cloned open reading frame (ORF) confirmed the experimental N-terminus previously determined for a native F. hepatica TGR showing thioredoxin reductase (TR) activity. The sequence revealed the presence of a fusion between a glutaredoxin (Grx) and a TR domain, similar to that previously reported in Schistosoma mansoni and Echinococcus granulosus. The F. hepatica TGR sequence included an additional redox active center (ACUG; U being selenocysteine) located at the C-terminus. The addition of a recombinant selenocysteine insertion sequence (SECIS) element in the Escherichia coli expression vector, or the substitution of the native selenocysteine by a cysteine, indicated the relevance of this unusual amino acid residue for the activity of F. hepatica TGR. Rabbit vaccination with recombinant F. hepatica TGR reduced the worm burden by 96.7% following experimental infection, further supporting the relevance of TGR as a promising target for anti Fasciola treatments.     

Molecular characterization of Fasciola gigantica from Mauritania based on mitochondrial and nuclear ribosomal DNA sequences

Fasciolosis caused by Fasciola hepatica and Fasciola gigantica (Platyhelminthes: Trematoda: Digenea) is considered the most important helminth infection of ruminants in tropical countries, causing considerable socioeconomic problems. From Africa, F. gigantica has been previously characterized from Burkina Faso, Senegal, Kenya, Zambia and Mali, while F. hepatica has been reported from Morocco and Tunisia, and both species have been observed from Ethiopia and Egypt on the basis of morphometric differences, while the use of molecular markers is necessary to distinguish exactly between species. Samples identified morphologically as F. gigantica (n = 60) from sheep and cattle from different geographical localities of Mauritania were genetically characterized by sequences of the first (ITS-1), the 5.8S, and second (ITS-2) Internal Transcribed Spacers (ITS) of nuclear ribosomal DNA (rDNA) genes and the mitochondrial Cytochrome c Oxidase I (COI) gene.Comparison of the sequences of the Mauritanian samples with sequences of Fasciola spp. from GenBank confirmed that all samples belong to the species F. gigantica. The nucleotide sequencing of ITS rDNA of F. gigantica showed no nucleotide variation in the ITS-1, 5.8S, and ITS-2 rDNA sequences among all samples examined and those from Burkina Faso, Kenya, Egypt and Iran. The phylogenetic trees based on the ITS-1 and ITS-2 sequences showed a close relationship of the Mauritanian samples with isolates of F. gigantica from different localities of Africa and Asia. The COI genotypes of the Mauritanian specimens of F. gigantica had a high level of diversity, and they belonged to the F. gigantica phylogenically distinguishable clade. The present study is the first molecular characterization of F. gigantica in sheep and cattle from Mauritania, allowing a reliable approach for the genetic differentiation of Fasciola spp. and providing basis for further studies on liver flukes in the African countries.     

In vitro evaluation of the action of the nematophagous fungi Duddingtonia flagrans, Monacrosporium sinense and Pochonia chlamydosporia on Fasciola hepatica eggs

This work evaluated the in vitro action of four isolates of the nematophagous fungi Duddingtonia flagrans (AC001), Monacrosporium sinense (SF53) and Pochonia chlamydosporia (VC1 and VC4) on eggs of Fasciola hepatica. The eggs were plated on 2% water-agar with the grown isolates and control without fungus. After 7, 14 and 21 days, the eggs were removed and classified according to the following parameters: effect type 1, lytic effect with no morphological damage to eggshells; type 2, lytic effect with morphological changes in eggshells and embryos; and type 3, lytic effect with morphological changes in embryos and eggshells, with hyphal penetration and internal egg colonization. Pochonia chlamydosporia showed ovicidal activity on F. hepatica eggs in the studied intervals of the type-3 effect, of 12.8% (VC1) and 16.5% (VC4); 14.4% (VC1) and 18.7% (VC4), 20.1% (VC1) and 21.5 % (VC4), over 7, 14 and 21 days respectively. No statistical difference was found (P > 0.01) among the isolates VC1 and VC4 for effects type 1, 2 and 3 during the studied intervals. Duddingtonia flagrans (AC001) and Monacrosporium sinense fungi only showed effect type 1, with no significant difference between them, with the following results: 60.1% (AC001) and 57.5% (SF53); 62.3% (AC001) and 62.0% (SF53); 66.5% (AC001) and 73.4% (SF53), over 7, 14 and 21 days respectively. Pochonia chlamydosporia fungi negatively influenced the in vitro F. hepatica viability. Therefore it can be considered as a potential biological control agent for this helminth.     

Molecular characterization and phylogenetic analysis of Fasciola hepatica from Peru

The causative agent of fasciolosis in South America is thought to be Fasciola hepatica. In this study, Fasciola flukes from Peru were analyzed to investigate their genetic structure and phylogenetic relationships with those from other countries. Fasciola flukes were collected from the three definitive host species: cattle, sheep, and pigs. They were identified as F. hepatica because mature sperms were observed in their seminal vesicles, and also they displayed Fh type, which has an identical fragment pattern to F. hepatica in the nuclear internal transcribed spacer 1. Eight haplotypes were obtained from the mitochondrial NADH dehydrogenase subunit 1 (nad1) sequences of Peruvian F. hepatica; however, no special difference in genetic structure was observed between the three host species. Its extremely low genetic diversity suggests that the Peruvian population was introduced from other regions. Nad1 haplotypes identical to those of Peruvian F. hepatica were detected in China, Uruguay, Italy, Iran, and Australia. Our results indicate that F. hepatica rapidly expanded its range due to human migration. Future studies are required to elucidate dispersal route of F. hepatica from Europe, its probable origin, to other areas, including Peru.     

Evaluation of losses in carcasses of cattle naturally infected with Fasciola hepatica: effects on weight by age range and on carcass quality parameters

Although fasciolosis is a relatively common disease, the productive and economic losses resulting from cattle with chronic fasciolosis are unclear. This paper aims to investigate the effect of fasciolosis on the parameters of carcass quality and discuss the hypothesis that the effects on weight differ among age ranges of cattle. For this, we analysed abattoir data of 30,151 bovines, from 928 farms, slaughtered in Uruguay in 2016, of which 33.9% (95% confidence interval (CI): 27.3–41.1%) had Fasciola hepatica (liver fluke). A mixed model was built to assess whether the effect of fasciolosis on weight differs depending on the age range, using the interaction term ‘age*F. hepatica’. The effect on the carcass parameters was tested using a proportional logistic regression. The interaction of age and F. hepatica was statistically significant (P < 0.001). Differences in carcass weights between infected and non-infected animals were observed mostly at younger ages (up to 30 months), with the highest difference observed in the 23–30 months age range (estimated marginal mean difference of 6.34 kg). Overall, the presence of F. hepatica was positively associated with poor conformations and lower fat scores of carcasses (P < 0.001). The carcasses of cattle infected with F. hepatica had 0.16 times greater odds of having worse conformation scores than carcasses of cattle without F. hepatica (proportional odds ratio (POR) = 1.16; 95% CI: 1.07–1.26). Similarly, carcasses of cattle with F. hepatica had 0.30 times (POR = 1.30, 95% CI: 1.23–1.39) greater odds of having poorer fat scores than carcasses of cattle without F. hepatica. Therefore, infection with F. hepatica is associated with poorer carcass quality parameters and lower weights, and the effect on weight differs across age ranges.