Protein profile of extracellular vesicles derived from adult Parascaris spp.

BACKGROUND: Parascaris spp. represent a significant threat to equine health worldwide, particularly in foals. The long-term survival of parasites in the host necessitates persistent modulation of the host immune response. Intercellular communication achieved through the exchange of molecules via extracellular vesicles (EVs) released from the parasite could be a crucial factor in this regard. This study aimed to isolate and characterize EVs released by adult male and female Parascaris worms and conduct a proteomic analysis to identify sex-specific proteins and potential immunomodulatory factors. METHODS: Live adult Parascaris worms were collected, and EVs were isolated from spent culture media using differential ultracentrifugation. Nanoparticle tracking analysis and transmission electron microscopy confirmed the size, concentration, and morphology of the isolated EVs. Proteins within the isolated EVs were analyzed using mass spectrometry-based proteomics (LC-MS/MS). RESULTS: Proteomic analysis revealed a total of 113 proteins in Parascaris EVs, with several proteins showing homology to known helminth exosome proteins and exhibiting immunomodulatory functions. Sex-specific differences in EV protein composition were observed, with a distinct abundance of C-type lectins in female EVs, suggesting potential sex-specific roles or regulation. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analyses revealed metabolic pathways shared between male and female Parascaris EVs, as well as differences in signal transduction, and cell growth and death pathways, indicating sex-specific variations. CONCLUSIONS: These findings imply that Parascaris EVs and their protein cargo are complex. This data potentially opens avenues for discovering innovative approaches to managing and understanding helminth infection.

Serological and molecular detection of Toxoplasma gondii infection in apparently healthy horses in eastern of Spain.

Toxoplasmosis is one of the most common parasitic zoonoses and represents a significant health risk for humans, especially for immunodeficient patients. The main transmission route is by oral uptake of oocysts and consumption of undercooked meat of infected animals. Different species have been evaluated as possible reservoirs of the parasite, but few studies have been carried out to examine the role of horses in transmission of the disease. Given the proximity of these animals to humans and the widespread consumption of their meat in many countries, including the Mediterranean basin, it is important to determine the prevalence of T. gondii infection in this species. In this study, blood samples from 105 horses were collected and the presence of T. gondii was evaluated by serological and molecular methods. Antibodies against T. gondii of 12 horses (11.43%) were detected by enzyme-linked immunosorbent assay (ELISA), whereas 29 horses (27.62%) showed positive for PCR. Seroprevalence was related to use of the animals, being higher in horses used for dressage than in others. Purebreds had higher seroprevalence than crossbred animals. No differences between breed, sex or age were found. The results of this study confirm the presence of T. gondii infection in horses, highlighting the need to analyse the meat of this species before human consumption and to control of this infection in horses, as they could be an important reservoir of this zoonotic parasite.

Cutaneous and conjunctival habronemosis in horses treated at the Veterinary Hospital of the Santa Catarina State University, Brazil.

Habronemosis, also known as habronemiasis or habronematidosis, is a parasitic disease of equids caused by the larval stages of Habronematidae nematodes (Habronema muscae, Habronema microstoma, and Draschia megastoma) that are transmitted by muscid flies. The presence of aberrant infective larvae in the cutaneous and conjunctival tissues of these hosts results in granulomatous, exudative, and ulcerated lesions, also known as "summer sores." In this study, we present a retrospective analysis of habronemosis cases in horses from the municipality of Lages, located on the Santa Catarina Plateau, a region with high altitudes and a temperate climate that differs from regions of Brazil where such parasitosis usually occurs. The equids were examined from 2008 to 2020 at the Veterinary Hospital of Santa Catarina State University. Sixteen patients were diagnosed and treated using macrocyclic lactones and wound cleaning. Most cases were recorded in autumn in horses (10/16, 62.5%) over 15 years of age (11/16, 68.8%), and the lesions were more frequently located in the conjunctiva (11/16, 68.8%). In scientific dissemination media, this is the first report of habronemosis on the Santa Catarina Plateau, Brazil. This information will contribute to the diagnosis, treatment and prevention of skin diseases in horses in this region.

In vitro evaluation of the automated hematology analyzer XN-31 for rapid diagnosis of equine piroplasmosis.

Equine piroplasmosis (EP) is a protozoal disease affecting equids, caused by Theileria equi and Babesia caballi. EP is conventionally diagnosed using microscopic, molecular, and/or serological methods, which are time-consuming. Consequently, there is a need for faster testing methods. In this study, we evaluated the application of the Sysmex XN-31 automated hematology analyzer, originally a rapid test for detecting malaria in humans, for the diagnosis of EP. The cultured parasites were measured using the XN-31 that had been customized for horse blood samples (XN-31m). The following parameters were evaluated: limit of detection (LoD), limit of quantification (LoQ), linearity, carryover, precision, and correlation with microscopic examination. The XN-31m detected infected red blood cells (RBCs) in approximately 1 minute. The LoD and LoQ for B. caballi were 4.54 infected RBCs/µL and 14.10 infected RBCs/µL, while those for T. equi were 5.80 infected RBCs/µL and 11.44 infected RBCs/µL, respectively. Linearity showed excellent correlation (R2 > 0.99), and carryover never exceeded 0.5%. The coefficient of variation was under 5%. The correlation between the results obtained using XN-31m and microscopic examination was high (R2 > 0.98). In conclusion, the XN-31 analyzer detected B. caballi and T. equi parasites in approximately 1 minute with high sensitivity. The results indicate the potential of the XN-31 analyzer as a fast and user-friendly diagnostic method for EP. IMPORTANCE: In this study, we demonstrated that the automated hematology analyzer, XN-31, can detect red blood cells infected with Babesia caballi and Theileria equi in about 1 minute. We evaluated the diagnostic performance of the XN-31 analyzer for equine piroplasmosis, providing evidence of its potential as a diagnostic tool for this disease.

Endoparasitism and risk factors in horses from ethnic communities in Andean areas of southern Chile.

Parasitic infections are among the most important causes of morbidity and mortality in horses worldwide. In the Andean mountainous regions of Chile, horses are a highly valued specie, playing a key role as working animals also providing support in cattle transhumance grazing into high mountainous areas during dry season. The breeding and maintenance of horses in the mountainous region of La Araucanía in Chile is a key issue allowing to the subsistence economy of communities with a strong ethnic component represented by Mapuche-Pehuenche origin families. However, the health status of these animals is unknown. Therefore, the objective of this study was to determine endoparasitic infections in horses from this area and the main factors that may influence parasitism. Thus, a cross-sectional study performed in 126 working horses from Andean region was achieved by using different coproparasitologycal analyses, resulting in a 97,6% of prevalence of endoparasitism with the strongyle eggs showing the highest prevalence of infection in analysed horses (96%) followed by Oxyuris equi (27%), Parascaris equorum (17,5%) and protozoans including ciliates (11,1%), Blastocystis spp (5,6%), Giardia spp (2,4%) and Cryptosporidium spp (1,6%) highlighting zoonotic relevance of some of these species. Concerning risk factors, the high prevalence suggests that exposure was high regardless of age or sex. The higher proportion of infected horses were grazing compared to those stabled, likewise drinking non-potable water, being these the main risks factors linked to the high prevalence of horse infections in Andean communities here studied.

Significance of Anaplasma phagocytophilum, Babesia caballi, and Theileria equi as etiologic agents in horses with clinical manifestations from the metropolitan area of Rio De Janeiro, Brazil.

Equine Piroplasmosis (EP) and Equine Granulocytic Anaplasmosis (EGA) are diseases that affect horses, transmitted by ixodid ticks, causing a nonspecific febrile syndrome. Equine Piroplasmosis is endemic in Brazil, and most horses are in enzootic stability. Serological and molecular studies carried out on horses in Brazil have shown the presence of Anaplasma phagocytophilum, however, the clinical relevance of this infection has not yet been established. The present study aims to evaluate the importance of Babesia caballi, Theileria equi, and A. phagocytophilum as etiological agents in horses with clinical manifestations suggestive of these diseases in the metropolitan mesoregion of Rio de Janeiro. A total of 45 animals with clinical signs were submitted to DNA extraction followed by qPCR test. Anaplasma phagocytophilum, Neorickettsia risticii and Theileria haneyi were not found in any of the horses with clinical signs, however 62.2% were infected with at least one agent of EP. Theileria equi was the most frequent etiologic agent (35.5%), followed by coinfection (15.5%) and B. caballi (11.2%). These results suggest that A. phagocytophilum has minor clinical importance in the region, while EP is frequently found in symptomatic horses, representing an important differential diagnosis in suspected cases.

Occurrence of fenbendazole resistance in Parascaris spp. on breeding farms in Sweden.

Anthelmintic resistance is an increasing problem in many gastrointestinal parasites of grazing animals. Among these, the equine roundworm, Parascaris spp., has developed wide-spread resistance to macrocyclic lactones over the past decades. Additionally, there are recent observations of emerging treatment failure of both tetrahydropyrimidine and fenbendazole. Therefore, the aims of this study were to further investigate the occurrence of fenbendazole resistance on breeding farms and to explore potential management-related risk factors associated with resistance in Parascaris spp. in Sweden. Eleven farms with 92 foals positive for Parascaris spp. were included in a faecal egg count reduction test during the years 2021-2023. According to the clinical protocol of the guidelines of the World Association for the Advancement of Veterinary Parasitology, fenbendazole resistance was present on four farms with efficacies varying from 45 % to 96 %. Having previously reported reduced efficacy on one of these farms, we can now confirm that fenbendazole resistance in Parascaris spp. has established. Farms with more than 40 yearly born foals had a significantly higher probability of having resistant Parascaris spp. Populations compared with smaller farms, (generalized linear model (GLM), t = 70.39, p < 0.001). In addition, there was a correlation between the number of foals on the farm and the frequency of yearly treatments showing that farms with < 20 foals were notably inclined to administer treatments twice during the first year (GLM, t=2.76, p < 0.05) in contrast to larger farms with > 40 foals that were using more frequent treatment intervals. In conclusion, this study confirms the establishment of fenbendazole resistance in Parascaris spp. populations on Swedish stud farms with the number of foals on the farm identified as a risk factor for development of anthelmintic resistance.

Transient efficacy of buparvaquone against Theileria haneyi in chronically infected horses.

BACKGROUND: Theileria haneyi is one of the three known causative agents of equine piroplasmosis. While imidocarb is generally effective in the clearance of the highly pathogenic Theileria equi, it is ineffective in the treatment of T. haneyi. Moreover, co-infection with T. haneyi has been shown to impede the successful treatment of T. equi. Furthermore, tulathromycin and diclazuril have demonstrated inefficacy in eradicating T. haneyi. The absence of an effective therapeutic agent against this parasite represents a significant obstacle in managing equine piroplasmosis. METHODS: To address this issue, we evaluated the efficacy of buparvaquone in the treatment of T. haneyi in chronically infected horses. RESULTS: Our findings showed that treatment of horses with the recommended dose of 2.5 mg/kg of buparvaquone led to a rapid abatement of T. haneyi levels, to a level where the parasites were not detectable by nested PCR. Following treatment, the horses remained PCR negative for a minimum of seven weeks until recrudescence occurred. Subsequent re-administration of buparvaquone at an increased dosage of 6 mg/kg upon recrudescence failed to exert a theilericidal effect on T. haneyi. Throughout the treatment regimen, the hematological parameters of the horses and most components of the chemistry panel remained within the normal range, except for blood urea nitrogen levels, which fell below the normal range in certain instances. CONCLUSIONS: BPQ at 2.5 mg/kg and 6 mg/kg had a robust theilericidal effect but was ineffective in the clearance of the T. haneyi infection in persistently infected animals.

Reduction of egg reappearance period of cyathostomins in naturally infected horses after increasing doses of ivermectin in Brazil: a grim picture for sustainable parasite control.

Cyathostomins are the largest group of parasites in horses that can be controlled by ivermectin (IVM). This study aimed to run a four-dose titration trial of IVM in 28 naturally infected Thoroughbred yearlings. The local Strongyle population had been recorded to be resistant to IVM (200 µg/kg). The parasite fecal egg count (FEC) was performed to investigate the egg reappearance period (ERP) of two and five weeks (w2pt and w5pt) after IVM treatment. FEC was > 1000 on day zero for all groups. Although 100% FEC reduction was reported at w2pt for all concentrations, the FEC at w5pt revealed < 83% efficacy. This study reports the reduction of ERP using the label dose as well as 300, and 400 µg/kg (double dose) of IVM. The protocol allowed IVM to significantly suppress FEC w2pt although not eliminating adult worms, failing to guarantee an extension of its protection period over 8 weeks. Moreover, the FEC at w5pt possibly means the infection was not cleared, and worms reestablished egg laying. We raised the possibility of withdrawing IVM of control programs when the drug has less than 80% FEC reduction at w5pt.

Molecular identification and genetic variability of equine and bovine ocular setariasis in india: molecular profiling by mitochondrial genes.

BACKGROUND: Ocular setariasis is an ectopic infection caused by a parasite under the genus Setaria. Adult worms belong to the Setariidae family and typically reside in the peritoneal cavity of ungulates. However, immature forms of these species may aberrantly migrate to the eyes of cattle, buffalo, goats, horses and several other hosts, leading to corneal opacity and blindness. Here, we have distinguished the Setaria digitata collected from both equine and buffalo hosts based on the morphology, molecular profiling of mitochondrial cytochrome c oxidase subunit 1 (Cox1), cytochrome c oxidase subunit 3 (Cox3) and, Nicotinamide Adenine Dinucleotide dehydrogenase subunit 1 (NAD1) genes. METHODS AND RESULTS: A single filarial worm was collected from the eye of one equine and one bovine host. These worms were then processed for morphological examination and DNA isolation. Cox1, Cox3 and NAD1 genes were amplified using specific primers and subjected to custom sequencing. The sequences were then used for multiple sequence alignment, assessment of entropy, similarity and haplotype diversity analysis. Key morphological features confirmed the worms collected were male and female Setaria digitata from equine and buffalo hosts, respectively. Cox1, Cox3 and NAD1 gene sequence analysis showed a close association of S.digitata Indian isolates with its counterparts from Sri Lanka and China isolates. CONCLUSION: The phylogram of bovine S. digitata sequences shows a close relationship to other equine S. digitata sequences, indicating the need for further in-depth studies on the prevalence of infection across various host species and intermediate hosts. Although the sequence results suggest that S. digitata is likely the causative agent of ocular setariasis in India, additional samples are needed to confirm this conclusion. Comprehensive analysis of the transcriptome and proteome of S. digitata from both bovine and equine hosts is necessary to explore variations in host-parasite interactions. These findings will aid in future parasite identification, investigations into vector prevalence in India, and the development of control measures against ocular setariasis.

Molecular and immunological studies on Theileria equi and its vector in Egypt.

Equine piroplasmosis is not fully understood regarding pathogenicity, prophylaxis, host immune response expression, and specific vectors. Accurately identifying the parasite vector is crucial for developing an effective control plan for a particular infection. This study focused on morphologically identifying two Hyalomma species (H. anatolicum and H. marginatum) and one Rhipicephalus annulatus (R. annulatus) at the species level. The identification process was followed by phylogenetic analysis using the neighbor-joining method based on the cytochrome oxidase subunit 1 (COXI) gene as a specific vector for Theileria equi (T. equi) in horses. T. equi was diagnosed morphologically and molecularly from infected blood samples and crushed tick species using conventional PCR. Subsequently, phylogenetic analysis based on the amplification of the 18 S rRNA gene was conducted. The obtained sequence data were evaluated and registered in GenBank under accession numbers OR064161, OR067911, OR187727, and OR068139, representing the three tick species and the isolated T. equi, respectively. The study demonstrated that T. equi infection leads to immune system suppression by significantly increasing the levels of oxidative stress markers (CAT, GPx, MDA, and SOD) (P ≤ 0.0001), with this elevation being directly proportional to parasitemia levels in infected blood cells. Furthermore, a correlation was observed between parasitemia levels and the expression of immune response infection genes (IFN-gamma, TGF-ß1, and IL-1ß cytokines) in infected horses compared to non-infected equine. Common macroscopic symptoms indicating T. equi infection in horses include intermittent fever, enlarged lymph nodes (LN), and tick infestation.

Equidae pythiosis in Brazil and the world: a systematic review of the last 63 years (1960-2023).

This systematic review compiles reports of clinical pythiosis in horses, mules and donkeys from 1960 to 2023 worldwide, focusing on Brazil. We searched databases and included 71 articles detailing clinical characteristics, geographic distribution, epidemiology, diagnostic methods, therapies, and outcomes. The results showed that publications on equine pythiosis have significantly increased since 2010. Brazil reported the highest incidence, comprising 55% of cases, predominantly in the southern, northeastern, and central-western regions during summer and autumn. Cutaneous pythiosis was the most prevalent form, generally presenting as single lesions in the appendicular region, and affected females more than males. Diagnosis typically involved histopathology, used alone or with other methods. Various treatments have been employed, with surgery, often combined with chemotherapy and immunotherapy, being the most common. Notably, 80.84% of treated animals recovered, highlighting the effectiveness of these therapies in enhancing survival rates. The limitations of the study included the lack of data in published case reports, which made it difficult to collect and calculate epidemiological data. Additionally, we recognize that pythiosis in Brazil is underreported, since this disease does not have mandatory notification and several cases are not registered and/or reported in the literature. Lastly, it is hypothesized that equid pythiosis may be more widespread than currently known, and its real occurrence in Brazil remains uncertain.

Seroprevalence of Toxoplasma gondii and Neospora spp. in horse population of Tehran, Iran.

Neospora spp. and Toxoplasma gondii are two closely related protozoan parasites that are widely distributed throughout the world. Horses can act as intermediate hosts for both parasites and can acquire disease. Blood samples were taken from 487 clinically healthy horses from 17 different mechanized stables in Tehran, the capital of Iran, during September and November of 2022. IFAT and ELISA were employed to detect antibodies directed against Neospora spp. and T. gondii. The anti-N. caninum antibodies were detected in 52 of the horses (10.67%) based on IFAT and in 86 of the 487 horses (17.65%) based on the ELISA test. Also, antibodies against T. gondii were detected in 41 horses (8.42%) based on IFAT and in 63 of 487 horses (12.94%) based on the ELISA test. Also, in 6 of the horses (1.23%) based on IFAT and in 13 of the 487 horses (2.67%) based on the ELISA test, double positivity suggested co-infection with both parasites. Gender, age groups, and the presence of dogs for neosporosis, and age groups and the presence of cats for toxoplasmosis, could be considered factors having an influence on the seroprevalences (P < 0.05). The results proved the importance of the urgent implementation of stringent regulatory measures to prevent and control the spread of these parasites.

The first study of the prevalence and genetic diversity of Theileria equi and Babesia caballi in horses in Russia.

Equine piroplasmosis (EP) is a global worldwide infection, which can lead to the death of animals. Despite the causative agents of EP being well studied, there are no data on the distribution and genetic characteristics of EP agents in any region of Russia. In this study, blood samples from 750 horses from Novosibirsk province, Irkutsk province, and Altai region of Russian Siberia were examined for the presence of EP agents. Theileria equi and Babesia caballi were detected in all examined regions, with mean prevalence rates of 60.4% and 7.2%, respectively. The identified pathogens were genetically characterized by the 18S rRNA gene. The determined T. equi sequences were highly conserved and belonged to genotypes A and E, with genotype E being found in 88.6% of genotyped samples. In contrast to T. equi, B. caballi sequences were genetically diverse. Seven sequence variants of B. caballi were identified, and only two of them matched known sequences from the GenBank database. The determined B. caballi sequences belonged to four distinct branches within genotype A. Mixed infections with several variants of B. caballi or with T. equi and B. caballi were common. The conducted phylogenetic analysis based on all available B. caballi sequences of the 18S rRNA gene (> 900 bp) from GenBank and from this study first demonstrated the presence of five monophyletic clusters within genotype A and three clusters within genotype B. Thus, the genetic study of B. caballi from Siberia has significantly expanded the data on the genetic diversity of this pathogen.

Leishmania spp. in equids and their potential vectors in endemic areas of canine leishmaniasis.

Equids may be infected by zoonotic Leishmania spp., including Leishmania infantum, in regions where canine leishmaniasis (CanL) is endemic, and Leishmania martiniquensis, which has been reported in horses from Central Europe. This study was designed to evaluate the occurrence of both Leishmania spp. among equids living in CanL endemic areas of Italy, as well as to identify dipteran vectors from the same habitats. From March to October 2023, blood, serum and tissue samples from skin lesions were collected from equids (n = 98; n = 56 donkeys and n = 42 horses) living in Italy, as well as sand flies and biting midges. Blood samples (n = 98) and skin lesions (n = 56) were tested for Leishmania spp. by conventional and real time PCRs and sera were tested by immunofluorescence antibody tests (IFAT) for both L. infantum and L. martiniquensis. Insects were morphologically identified, and female specimens (n = 268 sand flies, n = 7 biting midges) analyzed for Leishmania DNA, as well as engorged sand flies (n = 16) for blood-meal detection. Two animals with skin lesions (i.e., one donkey and one horse) scored positive for Leishmania spp. DNA, and 19 animals (i.e., 19.4%; n = 13 donkeys and n = 6 horses) were seropositive for L. infantum, with five of them also for L. martiniquensis. Most seropositive animals had no dermatological lesions (i.e., 68.4%) while both animals molecularly positive for Leishmania spp. scored seronegative. Of the 356 sand flies collected, 12 females (i.e., n = 8 Sergentomyia minuta; n = 3 Phlebotomus perniciosus, n = 1 Phlebotomus perfiliewi) were positive for Leishmania spp. DNA, and one out of seven biting midges collected was DNA-positive for L. infantum. Moreover, engorged sand flies scored positive for human and equine DNA. Data suggest that equids living in CanL endemic areas are exposed to Leishmania spp., but their role in the circulation of the parasite needs further investigations.

The effect of anthelmintic treatment and efficacy on the faecal microbiota of healthy adult horses.

Changes to the faecal microbiota of horses associated with administration of anthelmintic drugs is poorly defined. This study included horses with cyathostomin infection where susceptibility and resistance to oxfendazole and abamectin was known. This study assessed the changes to the faecal microbiota associated with administration of two different anthelmintics in this population. Twenty-four adult horses were included. Faecal egg counts were performed on all horses prior to random allocation into abamectin (n=8), oxfendazole (n=8) or Control groups (n=8) and at Day 14 post treatment. Faecal samples were collected for microbiota analysis prior to anthelmintic administration and on Day 3 and Day 14. From each faecal sample, DNA was extracted prior to PCR amplification, next generation sequencing and analysis using QIIME2. Anthelmintic treatment was associated with changes in alpha diversity (p <0.05), with increased evenness and diversity at Day 14 and increased richness at Day 3 within the abamectin group. Differences in relative abundance of bacteria at the phyla, family and genus taxonomic levels occurred after treatment; indicating that the microbiota was altered with anthelmintic administration. The results support that anthelmintic administration and removal of cyathostomins from the large intestine of horses is associated with changes in the faecal microbiota. The results suggest that removal of cyathostomins is associated with greater differences in microbiota, compared to anthelmintic drug administration that is ineffective in reducing cyathostomin infection. Cyathostomin removal was supported by adequate reduction of faecal egg counts, determined by faecal egg count reduction testing.

Tabanidae (Diptera) collected on horses in a Cerrado biome in the state of Tocantins, Brazil.

Tabanidae (Diptera), popularly known as horse flies, is an important vector group. This is the first study to ascertain the abundance and diversity of horse flies in horses at the cerrado biome of the state of Tocantins, Brazil. Collecting took place in typical Cerrado, and sampling occurred in the dry and rainy seasons. The horseflies were collected from horses using an entomological net. A total of 249 individuals were collected and spread over 25 species. The prevalent species were Stypommisa aripuana (25.8%) and Catachlorops rufescens (6.4%), in the dry period, and Fidena lissorhina (22.5%), Tabanus occidentalis var. dorsovittatus (10%) and Poeciloderas quadripunctatus (6.4%), in the rainy season. The results suggest that tabanids attack horses throughout the dry and rainy seasons, posing a constant threat to their health in the Cerrado of Tocantins.

A retrospective study of the prevalence in equine postmortems of cranial mesenteric arteritis caused by Strongylus vulgaris in Alberta (2010 to 2022).

Background: Strongylus vulgaris is one of the most pathogenic nematodes affecting equids. Larval migration through the cranial mesenteric artery (CMA) with attendant arteritis and thromboembolism can result in fatal non-strangulating intestinal infarction. Once considered a historical disease, recent studies have described the reemergence of this pathogen in several European countries; however, little is known of the current prevalence of S. vulgaris in the Canadian horse population. Objective: To determine the prevalence of active S. vulgaris cranial mesenteric arteritis in horses submitted for postmortem examination to the Diagnostic Services Unit (DSU) at the University of Calgary Faculty of Veterinary Medicine. Animals and procedure: We conducted a retrospective review of all equine postmortem cases submitted to the DSU between July 1, 2010 and June 30, 2022. Over 12 y, 510 horses > 2 mo of age from Alberta were submitted to the DSU for necropsy. Active cases were defined as those with endarteritis and thrombosis in the CMA or its branches. Those cases with only intimal scarring of the CMA were classified as historical. Results: The prevalence of all CMA lesions (both historical and active) over the study period was 17.3% (88/510). Active S. vulgaris cranial mesenteric arteritis was documented in 6.1% (31/510) of equine postmortems and the sequelae of verminous arteritis were the cause of euthanasia or death in 1.5% (8/510) of the cases submitted. Conclusion and clinical relevance: Even after historically intense efforts to eradicate this parasite, the continued effects of S. vulgaris are demonstrated by the results of this study. Strongylus vulgaris should not be regarded as a parasite of the past and verminous arteritis remains an important differential diagnosis for horses in western Canada presenting with mild colic or dull demeanor and anorexia of duration > 24 h. Furthermore, S. vulgaris should be taken into careful consideration when implementing antiparasitic control strategies. Practitioners should remain current on prevention, diagnosis, and treatment of this potentially reemerging and fatal equine disease.

Étude rétrospective de la prévalence lors d'autopsies équines de l'artérite mésentérique crâniale causée par Strongylus vulgaris en Alberta (2010 à 2022). Contexte: Strongylus vulgaris est l'un des nématodes les plus pathogènes affectant les équidés. La migration des larves à travers l'artère mésentérique crâniale (CMA), accompagnée d'artérite et de thromboembolie, peut entraîner un infarctus intestinal non étranglant mortel. Autrefois considérée comme une maladie historique, des études récentes ont décrit la réémergence de cet agent pathogène dans plusieurs pays européens; cependant, on sait peu de choses sur la prévalence actuelle de S. vulgaris dans la population équine canadienne. Objectif: Déterminer la prévalence de l'artérite mésentérique crâniale active à S. vulgaris chez les chevaux soumis pour examen post mortem au Diagnostic Service Unit (DSU), College of Veterinary Medicine, University of Calgary. Animaux et procédure: Nous avons effectué un examen rétrospectif de tous les cas post-mortem d'équidés soumis au DSU entre le 1er juillet 2010 et le 30 juin 2022. Sur 12 ans, 510 chevaux âgés de plus de 2 mois de l'Alberta ont été soumis au DSU pour autopsie. Les cas actifs ont été définis comme ceux présentant une endartérite et une thrombose dans la CMA ou ses branches. Les cas présentant uniquement des cicatrices à l'intima de la CMA ont été classés comme anciens. Résultats: La prévalence de toutes les lésions de CMA (anciennes et actives) au cours de la période d'étude était de 17,3 % (88/510). Une artérite mésentérique crâniale active à S. vulgaris a été documentée dans 6,1 % (31/510) des autopsies équines et les séquelles de l'artérite vermineuse ont été la cause de l'euthanasie ou du décès dans 1,5 % (8/510) des cas soumis. Conclusion et pertinence clinique: Malgré des efforts historiquement intenses pour éradiquer ce parasite, les effets continus de S. vulgaris sont démontrés par les résultats de cette étude. Strongylus vulgaris ne doit pas être considéré comme un parasite du passé et l'artérite vermineuse demeure un diagnostic différentiel important pour les chevaux de l'ouest du Canada présentant des coliques légères ou un comportement abattu et une anorexie de durée > 24 h. De plus, S. vulgaris doit être attentivement pris en compte lors de la mise en œuvre de stratégies de contrôle antiparasitaire. Les praticiens doivent rester informés de la prévention, du diagnostic et du traitement de cette maladie équine potentiellement ré-émergente et mortelle.(Traduit par Dr Serge Messier).

On the faecal detection of Halicephalobus gingivalis in equines in Iran.

The life-cycle of the parasitic forms of Halicephalobus gingivalis is yet to be fully understood. In cases where there is evidence to support the presence of eggs from this parasite or its DNA in the faeces of equines, a thorough investigation of the clinical status and gastro-intestinal tract of the affected animals is warranted, as well as detailed descriptions of the employed coprological technique. Since reports of the identification of H. gingivalis eggs in faeces are sparse, objective measurements and high-quality images must be provided, in order to ensure optimal criteria for classification. Regarding research concerning H. gingivalis, no piece of information should be regarded as superfluous.

Molecular prevalence and genotypic diversity of Theileria equi and Babesia caballi infecting horses in Kyrgyzstan.

Equine piroplasmosis is caused by Theileria equi and Babesia caballi, which are hemoprotozoan parasites. Understanding the epidemiology and genotypes of T. equi and B. caballi is crucial for developing effective control strategies in endemic countries. However, the endemic status of these two parasite species remains uncertain in Kyrgyzstan due to lack of surveys. Our study, therefore, aimed to detect T. equi and B. caballi infections in Kyrgyzstan and identify their genotypes. Blood samples were collected from 226 horses across all seven provinces of Kyrgyzstan, namely Chuy, Issyk-Kul, Naryn, Talas, Jalal-Abad, Osh, and Batken. These blood samples were subjected to DNA extraction, followed by specific PCR assays targeting T. equi and B. caballi. We found that 56 (24.8%, confidence interval (CI): 19.6-30.8%) and 7 (3.1%, CI: 1.5-6.3%) of the tested horses were positive for T. equi and B. caballi infections, respectively. Theileria equi was detected in all surveyed provinces, whereas B. caballi was found in five provinces, except for Talas and Osh. Subsequent genotype-specific PCR assays showed that T. equi-positive horses harbored all five genotypes: A, B, C (also known as Theileria haneyi), D, and E. On the other hand, phylogenetic analysis of B. caballi rap-1 sequences detected the genotypes A and B1. The prevalence of T. equi and B. caballi suggests a potential risk of clinical equine piroplasmosis among horses in Kyrgyzstan, and the observed genotypic diversity underscores the challenges in managing the disease. Our findings emphasize the need for comprehensive control measures to effectively address equine piroplasmosis in Kyrgyzstan.