Parasites are organisms that live on or within a host, deriving nutrients at the host's expense. In horses, parasitic infections can affect various systems, including the gastrointestinal tract, skin, and respiratory system. Common equine parasites include strongyles, ascarids, tapeworms, and bots. These parasites can lead to a range of health issues, from mild discomfort to severe disease, depending on the type and burden of the infestation. This page compiles peer-reviewed research studies and scholarly articles that explore the biology, life cycle, and impact of parasites on equine health, as well as strategies for diagnosis, treatment, and prevention of parasitic infections in horses.
Guayaquil G, Chávez C, Enríquez S, Arrivillaga-Henríquez J, Vaca F, Eleizalde MC, Mendoza M, Pedelini L, Martínez-Fresneda M, Uzcanga GL....Trypanosoma evansi, a protozoan parasite of the Trypanozoon subgenus, infects domestic and wild animals, and occasionally humans, worldwide. Despite its significant impact on livestock production, epidemiological studies and molecular analyses of T. evansi based on variant surface glycoproteins (VSG) remain limited in South America. We report the first molecular identification of T. evansi in two localities in the Ecuadorian Amazon and provide phylogenetic and structural analyses of the VSG RoTat 1.2 fragment. Using a retrospective biobank approach, we analyzed DNA from blood samples of dogs a...
Sousa JA, Miranda LM, Coutinho DJB, Costa TF, Costa SP, Freitas ÚS, Costa FB, Machado RZ, Nogueira RMS, Costa APD.The hemoprotozoan Trypanosoma evansi is a parasite that infects mammals, causing an infection known as trypanosomiasis. There is no report of T. evansi in horses in the State of Maranhão, highlighting the need to assess exposure and infection by the parasite and generate data for its monitoring. The objectives of this study were to identify T. evansi in blood samples from horses, investigate its occurrence in horses in this region, and analyze the associated risk factors. Three hundred blood samples were collected for parasitological (blood smear), serological (indirect enzyme-linked immunoso...
Nikvand AA, Jalali SM, Bahrami S, Rahij Torfi H.Trypanosoma evansi (T. evansi) is a hemoprotozoan parasite affecting camels and equids, such as horses, mules, and donkeys, and is known to cause surra disease in these animals. Despite the worldwide distribution of T. evansi infections in equids, surra has not been reported in Arabian horses in Khuzestan Province for over 60 years. In September 2018, a 7-year-old Arabian mare was referred from a 10-horse farm in the suburbs of Ahvaz City. The mare presented with a history of weight loss, poor appetite, and proximity to a camel herd. Physical examination revealed a poor body condition score ...
Nielsen MK, Pyatt A, Perrett J, Tydén E, van Doorn D, Pihl TH, Schmidt JS, von Samson-Himmelstjerna G, Beasley A, Abbas G, Jabbar A.Equine parasite control has historically been characterized by confusing and conflicting information, posing significant challenges for veterinarians and horse owners to make evidence-based decisions. Since 2012, equine parasite control guidelines have been developed and published for different parts of the world to address this situation and provide trusted sources of current guidance. At the 2024 International Equine Infectious Disease Conference in Deauville, Normandy, France, lead authors of equine parasite control guideline documents published in the USA, UK, Sweden, Denmark, the Netherla...
Ochigbo GO, Ahn S, Belhumeur KA, Poissant J, Rosa BV.Unmanaged feral horses, naïve to dewormers, offer a unique opportunity to study natural communities of equine parasites. These communities may include parasites that are rare in managed populations, and these may be transmitted to domestic horses in areas where there is contact between feral and domestic equine populations. There have been only a few studies of gastrointestinal parasite populations in horses, and very few from North American equine populations. This study aimed to gain insights into parasite biology through identification of the strongyle parasite species infecting feral hors...
Firdausy LW, Fikri F, Wicaksono AP, Çalışkan H, Purnama MTE.Trypanosomiasis is a vector-borne parasitic disease with significant implications for animal health and rural livelihoods in Indonesia. Despite surveillance efforts, comprehensive national-level estimates of its prevalence in domesticated animals remain lacking. This study aimed to synthesize the pooled prevalence of trypanosomiasis across Indonesian provinces, identify contributing factors, and assess trends over time using a systematic review and meta-analysis. Unassigned: A systematic search was conducted in seven electronic databases (PubMed, Scopus, Web of Science, ScienceDirect, Cochrane...
Duaso J, Perez-Ecija A, Martínez E, Navarro A, De Las Heras A, Mendoza FJ.Equine piroplasmosis (EP) is a tick-borne disease affecting equids worldwide. Diagnosis is based on direct methods (blood smear or PCR) or indirect methods (serology); however, these techniques yield positive and negative results. Thus, an alternative, reliable, rapid, and cost-effective complementary tool, such as hematologic parameters and newly described hematologic ratios, could help in the EP diagnosis. This study describes the changes induced by piroplasmosis infection on hematologic parameters and ratios in horses. PCR-positive horses exhibited anemia and thrombocytopenia, whereas PCR...
Elmahallawy EK, Hassan MF, Cano-Terriza D, Albalawi NO, Fajardo T, Gouda AA, Atiba A, Hendawy A, Villena I, Barakat AM, Alzaylaee H, Almería S....Toxoplasmosis, caused by the intracellular protozoan (), continues to be a widespread parasitic zoonotic disease globally. The seroepidemiology of infection in Egyptian equids, particularly donkeys, remains insufficiently explored. The present study was designed to assess the seroprevalence of in equines from Northern Egypt. Unassigned: A total of 360 serum samples from two equine species (157 horses and 203 donkeys) were obtained during 2023. The Modified Agglutination Test (MAT, cut-off of 1:25) was used to screen for the anti- antibodies. The study also analyzed potential risk factors th...
Bhoora RV, Mbaba TV, Troskie M, Ackermann RE, Collins NE.Theileria haneyi is an apicomplexan parasite closely related to Theileria equi, a known causative agent of equine piroplasmosis. The molecular distinction between these parasites relies on a nested polymerase chain reaction (PCR) assay, which has been reported to be unreliable. A recently reported indirect ELISA based on equi merozoite antigen 11 (Thema-11) of T. haneyi can detect geographically diverse T. haneyi strains. Since the ema-11 gene is exclusive to T. haneyi, it was chosen as the target for developing a TaqMan minor groove binder (MGB™) quantitative real-time PCR (qPCR). Published...
Mizani A, Taherkhani P, Kia Lashaki E, Hosseini SA, Basirpour B, Dodangeh S.Giardia duodenalis as a common zoonotic parasite is a public health problem infecting humans and a wide range of animals, including horses. This systematic review and meta-analysis was conducted to estimate the global pooled prevalence of Giardia infection in horses. Literature searches were conducted using databases including Scopus, ScienceDirect, PubMed, Web of Science and ProQuest to December 2023. A random-effect model was performed to calculate the pooled prevalence and corresponding 95% confidence interval (CI) according to the degree of heterogeneity in the included studies. Of 2661 ar...
Bianchi D, Santos RRD, Peleja PL, de Sousa ABB, da Silva Evangelista M, de Almeida Júnior JS, Barata LES, Moraes WP, Minervino AHH. (tropical horse tick) is a tick species commonly found parasitizing horses and other equids in the Amazon region, causing economic losses. Currently, tick control is based on chemical acaricides, usually in a power formulation for topical use. However, its indiscriminate use results in the emergence of resistant tick lineages. Several plant compounds have been tested for their acaricide activity. In the Amazon, several plants are used for oil extraction, resulting in the production of solid residue (waste) that may contain chemical molecules with biological activities. Thus, we aimed to test ...
Rodriguez Velazquez D, Forte L, Varela Guerrero JA, Díaz Alvarado T, Elghandour MMMY, Maggiolino A, De Palo P, Salem AZM.Exploring new natural-origin antiparasitic alternatives is essential in addressing the resistance issues that have emerged due to the widespread use of chemical or synthetic antiparasitic compounds. This area remains relatively underexplored despite the increasing recognition of plants like (mesquite) for their antiparasitic properties and nutritional value as a high-protein animal feed. This review aims to investigate the antiparasitic potential of against gastrointestinal parasites in horses. The review incorporates sources from 2005 to 2024. It was found that various phytochemical compoun...
Carbonell JD, Fernández N, Escobar MJ, Álvarez MT, Sánchez L, Hernández A, Meana A.Chorioptic mange is a challenging condition to treat due to the superficial locations of the nonhematophagous mite , and while topical acaricides are recommended, the clinical feature relapses are frequent. In a double-blinded clinical trial, three randomized groups of Spanish-Breton horses ( = 32) naturally infected with on their legs were evaluated over a period of 70 days. All treatments were applied once every 14 days for three treatments. Before treatment and on Day (D)10, D25, D37, D56, and D70, each leg per animal was scored according to equine pastern dermatitis clinical presentat...
Yang G, Chen Y, Chen K, Hu Z, Li J, Wang J, Guo W, Wang X, Du C.Equine piroplasmosis (EP), caused by Theileria equi (T. equi) and Babesia caballi (B. caballi), is a tick-borne disease with significant economic impacts on the equine industry. Theileria haneyi (T. haneyi), a newly identified pathogen of EP, is globally distributed but has not been reported in China, where its epidemiological patterns remain undefined. Objective: To develop diagnostic techniques for T. haneyi and to assess its prevalence and risk factors in China. Methods: Assay development and cross sectional survey. Methods: A nested PCR (nPCR) nucleic acid diagnostic technique targeting th...
Khaing Y, Htun LL, Linn KS, Kyaw WO, Nwae TT, Chel HM, Win SY, Murata S, Nakao R, Nonaka N, Bawm S.The study aimed to determine the prevalence of blood parasites in horses and identify risk factors and molecular detection of piroplasm species (Theileria equi and Babesia caballi) of horses in Myanmar. Blood samples (n = 302) were collected from five regions of Myanmar. Blood smears were screened for presence of piroplasms. Samples positive for piroplasms were subjected to molecular identification using primers specific to the small subunit ribosomal RNA (SSU rRNA) of piroplasms. The overall prevalence of blood parasites (piroplasms, Trypanosoma spp., and microfilaria of Setaria equina) w...
Giorgio SD, Monti S, Palmieri V, Marino G, Napoli E, Vullo C, Catone G.A 3-year-old Quarter horse stallion with unilateral left cryptorchidism was referred for the absence of the left testis in the scrotal bursa and an enlarged right testis. The ultrasonographic examination revealed the presence of the left testis at the abdominal level. Two small hyperechogenic lines were observed running parallel and resembling a cylindrical cavitary foreign body, within a non-homogeneous area with blurred margins. The testis was removed by laparoscopy and macroscopically, the testis's cut section revealed the presence of two live adult nematodes emerging from 2 mm blood-filled...
Golamgouse NN.Mauritius hosts a population of approximately 900 equids, but no investigations have delved into issues such as the prevalence of equine helminths, anthelmintic usage, and resistance emergence. This study aimed to devise a qualitative and quantitative profile of common helminthic intestinal parasites in equines at eight out of twenty-eight stables (272 horses, 29 % of local population) and to determine whether helminthic intestinal parasites in equines at one stable have developed resistance to Fenbendazole by quantitatively assessing pre-treatment faecal egg counts, post-treatment faecal egg...
Nielsen MK, Bartholdy ID, Kristensen KS, Borrye JC, Meilvang KSS, Rendtorff CEK, Hjortflod MD, Fuglbjerg V, Karlsson M, Petersen HH, Toft K....Equine strongylids are ubiquitous and can cause severe health issues. Anthelmintic resistance is widely common in cyathostomin parasites, and recent studies have documented increasing incidence of resistance to the macrocyclic lactone drug class. Several European countries have implemented prescription-only restrictions of anthelmintic usage by law to reduce anthelmintic treatment intensity and decrease the selection pressure for drug resistance. However, long term outcomes of this approach have not been thoroughly evaluated. The aim was to determine ivermectin efficacy in strongylids by means...
Poh KC, Oyen K, Onzere CK, Kappmeyer LS, Bastos RG.The recent discovery of , a tick-borne hemoparasite that causes mild clinical signs of equine piroplasmosis, has added complexity to the diagnosis of this reportable disease, which is prevalent among equids globally. Knowledge gaps regarding competent tick vectors that can transmit and the recent outbreak of in the US has prompted us to conduct this study. Our objective was to investigate whether can transstadially transmit to horses. Unassigned: larvae (0.5 g) and nymphs ( = 500) were fed on a splenectomized -infected horse for parasite acquisition. During the tick feeding period, ...
Ryu SH, An SJ, Forbes E, Kim BS, Choe S.Equine strongyle infections are prevalent among grazing horses worldwide, yet research on anthelmintic efficacy and parasite management strategies in South Korea remains limited. This study investigated the infection dynamics and parasite burden in horses managed under different systems (pasture vs. stable) over a one-year period in Jeju, South Korea, assessing the impact of management practices on parasite burden and the effectiveness of current deworming regimens. Thirty-two horses were administered ivermectin/praziquantel in June 2022 and assigned to either pasture (n = 16) or stable (n...
Peris MP, Serrano M, Romero A, García M, Halaihel N, Castillo JA, Gracia MJ.Equine piroplasmosis (EP), a tick-borne disease caused by Babesia caballi and Theileria equi, is of significant concern due to its impact on the international horse trade. According to standards established by the World Organisation for Animal Health (WOAH), horses imported from EP-endemic regions must have a certificate confirming negative serological and molecular test results. In EP-free countries, only seronegative horses are allowed to enter. This entails economic losses for endemic regions such as Spain. Our study aimed to assess the prevalence of B. caballi and T. equi in horses from no...
Buono F, Castaldo E, Veneziano V, Veronesi F, Roncoroni C, Scarcelli S, Sgroi G, Matthews JB, Piantedosi D.Grazing horses are exposed to various intestinal helminths, with tapeworms being of major concern due to their potential pathogenicity. Few regional data are available in Italy on tapeworm infections in horses; therefore, the aim of this study was to investigate the prevalence of Anoplocephala spp. eggs over a nine-year period (2014-2023) in 12,056 faecal samples from horses living in all 18 continental Italian regions. Coprological examinations were performed using the Proudman and Edwards (1992) method using Sheather's sugar solution as the floatation medium. An overall prevalence of 3.7 % ...
do Carmo TA, Fonseca JDS, Braga FR, Paz-Silva A, de Soutello RVG, de Araújo JV.Equine farming faces growing challenges with helminthoses, aggravated by the indiscriminate use of anthelmintics without technical criteria. This practice favors resistance to these drugs, generates residues in animal products, compromises food safety and human health, and, when excreted in large quantities, negatively impacts environmental health by affecting invertebrates and fecal microorganisms. This highlights the importance of the One Health approach. A promising alternative is biological control with nematophagous or helminthophagous fungi such as , , , , and . Due to their different m...
Nadal C, Chanet C, Delaunay C, Pitel PH, Marsot M, Bonnet SI.Equine piroplasmosis, caused by the protozoan parasites Babesia caballi and Theileria equi, is endemic in Europe's Mediterranean basin, creating significant health and economic challenges for the equine sector. With no available vaccine, an eco-epidemiological approach is essential in order to identify and implement effective preventive measures. With this aim in view, we identified risk factors associated with B. caballi and T. equi infections and tick infestation for draught horses in the Auvergne-Rhône-Alpes region of France, known for its high piroplasmosis seroprevalence. During the spri...
Sun Y, Yu YT, Castillo XO, Anderson R, Wang M, Sun Q, Tallmadge R, Sams K, Reboul G, Zehr J, Brown J, Wang X, Marra N, Stanhope B, Grenier J....Fever of unknown origin (FUO) without a respiratory component is a frequent clinical presentation in horses. Multiple pathogens, both tick-borne and enteric, can be involved as etiologic agents. An additional potential mechanism is intestinal barrier dysfunction. This case-control study aimed to detect and associate microbial taxa in blood with disease state. Areas known for a high prevalence of tick-borne diseases in humans were chosen to survey horses with FUO, which was defined as fever of 101.5°F or higher with no signs of respiratory illness or other recognisable diseases. Blood samples ...
Sadeddine R, Righi S, Saidani K, Benakhla A.Equine piroplasmosis (EP) is a tick-borne disease that affects equids and is caused by the parasites Theileria equi, Theileria haneyi and Babesia caballi. This disease leads to significant economic losses for the global equine industry. The current study aimed to evaluate the prevalence of Piroplasmida infections in equines from El Tarf, located in northeastern Algeria, and investigate the phylogenetic diversity within isolates obtained from infected equines in this study and between those from previous studies. Methods: A total of 120 blood samples were collected from equines in three municip...
Brys M, Claerebout E, Saey V, Chiers K.A cross-sectional study was conducted to estimate the prevalence of chorioptic mange affecting the distal legs of horses in Belgium, focusing on the association between mange and chronic progressive lymphedema (CPL) in Belgian draft horses. Clinical examinations and skin scrapings were performed on the distal legs of 156 Belgian draft horses and 142 Belgian warmblood horses. In the Belgian draft horse breed, 144 (92.31%) horses were infested with Chorioptes bovis mites, and 126 (80.77%) displayed clinical signs of CPL. CPL prevalence in draft horses aged < 1 year was 17.86%, while mites we...
Mohtasebi S, Ahn S, Rosa B, Moyes K, Kuzmina TA, Gilleard JS, Poissant J.Equids are infected by a diversity of gastrointestinal nematode parasites, including 64 species of equine strongyle nematodes from19 genera. Despite numerous surveys of horse strongyles worldwide, certain geographic regions and rare species remain understudied. In 1964, a new species of equine strongyle, Cylicocyclus pekingensis, was described from a donkey in China. Subsequently, this species was recorded in horses from Kazakhstan and reclassified as Hsiungia pekingensis (K'ung and Yang, 1964), the only species in this genus. Since then, H. pekingensis has not been reported elsewhere, with li...
Aldayarov N, Tulobaev A, Madumarov A, Risvanli A.While modern veterinary medicine offers effective treatments, traditional ethnoveterinary practices persist among many farming communities, reflecting centuries-old knowledge and cultural beliefs. This study aimed to document ethnoveterinary remedies and their methods of preparation and application, for treating various parasitic diseases in domestic animals used by Kyrgyz farmers. Data on plant, animal and mineral-based remedies, as well as chemicals used for these purposes, were collected through interviews with 173 dialogue partners (DPs). A total of 3403 use reports (URs) were recorded, in...
Kelly RF, Galbraith E, Zahid O, Chaundhry U, Sargison N.Grazing animal species kept in zoological collections can be at risk of significant gastrointestinal nematode (GIN) infections. Little work has been undertaken to understand GIN species dynamics within co-grazed hosts. This study aimed to describe the species diversity of GINs found in faeces of grazing animals in a Scottish zoological collection. Methods: At a single time-point, freshly voided faecal samples were collected randomly from horses, sheep, goats, alpacas and deer. Faecal worm egg counts (FWECs) were conducted using a saturated saline centrifugal flotation cuvette technique. The ne...
Leathwick DM, Besier RB.In many countries the presence of anthelmintic resistance in nematodes of small ruminants, and in some cases also in those infecting cattle and horses, has become the status quo rather than the exception. It is clear that consideration of anthelmintic resistance, and its management, should be an integral component of anthelmintic use regardless of country or host species. Many years of research into understanding the development and management of anthelmintic resistance in nematodes of small ruminants has resulted in an array of strategies for minimising selection for resistance and for dealin...
Zink MC, Yager JA, Prescott JF, Fernando MA.It has been suggested that R. equi causes pulmonary disease in foals by persisting within the lung as a facultative intracellular parasite of alveolar macrophages. This paper describes an ultrastructural study of the intracellular events after ingestion of R. equi by foal alveolar macrophages, in an attempt to determine the mechanism of intracellular survival of R. equi. Secondary lysosomes of alveolar macrophages recovered from foals by bronchoalveolar lavage were labelled with electron-dense ferritin, and the cells were challenged with either viable or formalin-killed R. equi. After 0-, 3-, ...
Greay TL, Zahedi A, Krige AS, Owens JM, Rees RL, Ryan UM, Oskam CL, Irwin PJ.Apicomplexan tick-borne pathogens that cause disease in companion animals include species of Babesia Starcovici, 1893, Cytauxzoon Neitz & Thomas, 1948, Hepatozoon Miller, 1908 and Theileria Bettencourt, Franca & Borges, 1907. The only apicomplexan tick-borne disease of companion animals that is known to occur in Australia is babesiosis, caused by Babesia canis vogeli Reichenow, 1937 and Babesia gibsoni Patton, 1910. However, no molecular investigations have widely investigated members of Apicomplexa Levine, 1980 in Australian ticks that parasitise dogs, cats or horses, until this present inves...
Gimenez C, Casado N, Criado-Fornelio A, de Miguel FA, Dominguez-Peñafiel G.This study reports a molecular survey of Hepatozoon species and of the order Piroplasmida in the Province of Burgos, northern Spain. The diagnostic techniques employed included PCR and the sequencing of the 18S rRNA gene. Eighty-nine blood samples from domestic animals plus 138 blood/coagulated blood samples from wild mammals were examined. Theilerid protozoa were found at relatively high frequencies in bovines (14.6%) and horses (36%). Theileria buffeli, T. sergenti and T. annulata were diagnosed in cows. T. equi was common in horses and T. annae was found in a donkey for the first time. A ne...
Allsopp MT, Lewis BD, Penzhorn BL.The intra-erythrocytic parasite Theileria equi is one of two tick-transmitted causative agents of equine piroplasmosis. Piroplasms of T. equi can be transmitted across the equine placenta and once a horse is infected, it appears to remain a lifelong carrier, since anti-theilerial drugs suppress but do not eliminate the parasite. Carrier mares may transmit the organism to their offspring and this may result in abortion or neonatal piroplasmosis, but observations by some researchers suggest that foals may be born as carriers yet remain apparently healthy. Using a T. equi-specific oligonucleotide...
Lyons ET, Tolliver SC, Drudge JH.Small strongyles are highly prevalent in horses and can be found worldwide. Even though over 50 species of these parasites have been described, about 10 species comprise the bulk of the total number present in horses. Efforts to control small strongyles and other equine internal parasites have been undertaken for many years. Some of the early medications and control measures provided questionable activity against endoparasites; whether effective or not, they could be detrimental to the horse. Beginning in the early 1900s, scientific effort was used to evaluate activity of antiparasitic compoun...
Rizk MA, El-Sayed SA, Terkawi MA, Youssef MA, El Said el Sel S, Elsayed G, El-Khodery S, El-Ashker M, Elsify A, Omar M, Salama A, Yokoyama N....A rapid and accurate assay for evaluating antibabesial drugs on a large scale is required for the discovery of novel chemotherapeutic agents against Babesia parasites. In the current study, we evaluated the usefulness of a fluorescence-based assay for determining the efficacies of antibabesial compounds against bovine and equine hemoparasites in in vitro cultures. Three different hematocrits (HCTs; 2.5%, 5%, and 10%) were used without daily replacement of the medium. The results of a high-throughput screening assay revealed that the best HCT was 2.5% for bovine Babesia parasites and 5% for equ...
Debeffe L, McLoughlin PD, Medill SA, Stewart K, Andres D, Shury T, Wagner B, Jenkins E, Gilleard JS, Poissant J.In wild and domestic animals, gastrointestinal parasites can have significant impacts on host development, condition, health, reproduction and longevity. Improving our understanding of the causes and consequences of individual-level variation in parasite load is therefore of prime interest. Here we investigated the relationship between strongyle fecal egg count (FEC) and body condition in a unique, naturalized population of horses that has never been exposed to anthelmintic drugs (Sable Island, Nova Scotia, Canada). We first quantified variation in FEC and condition for 447 individuals accordi...
Nielsen MK, Kaplan RM, Thamsborg SM, Monrad J, Olsen SN.Development of resistance to anthelmintic drugs by horse strongyles constitutes a growing threat to equine health because it is unknown when new drug classes can be expected on the market. Consequently, parasite control strategies should attempt to maintain drug efficacy for as long as possible. The proportion of a parasite population that is not exposed to anthelmintic treatment is described as being "in refugia" and although many factors affect the rate at which resistance develops, levels of refugia are considered the most important as these parasites are not selected by treatment and so pr...
Frederick J, Giguère S, Sanchez LC.Diarrhea is common in foals but there are no studies investigating the relative prevalence of common infectious agents in a population of hospitalized diarrheic foals. Objective: To determine the frequency of detection of infectious agents in a population of hospitalized foals with diarrhea and to determine if detection of specific pathogens is associated with age, outcome, or clinicopathologic data. Methods: Two hundred and thirty-three foals < or = 10 months of age with diarrhea examined at a referral institution. Methods: Retrospective case series. Each foal was examined for Salmonella s...
Poissant J, Gavriliuc S, Bellaw J, Redman EM, Avramenko RW, Robinson D, Workentine ML, Shury TK, Jenkins EJ, McLoughlin PD, Nielsen MK, Gilleard JS.Horses are ubiquitously infected by a diversity of gastro-intestinal parasitic helminths. Of particular importance are nematodes of the family Strongylidae, which can significantly impact horse health and performance. However, knowledge about equine strongyles remains limited due to our inability to identify most species non-invasively using traditional morphological techniques. We developed a new internal transcribed spacer 2 (ITS2) DNA metabarcoding 'nemabiome' assay to characterise mixed strongyle infections in horses and assessed its performance by applying it to pools of infective larvae ...
von Samson-Himmelstjerna G.During the past two decades anthelmintic resistance in equine parasites has been found in the group of small strongyle species (cyathostomins) and in the ascarid species Parascaris equorum. The ubiquitous nature and possible severe consequences of disease with these nematodes make them the prime targets of current worm control programmes. Traditional control strategies mainly rely on the strategic application of anthelmintics, currently represented by three major drug classes: benzimidazoles (BZ), the tetrahydropyrimidine pyrantel (PYR) and macrocyclic lactones (ML). Following decades of routi...
Nielsen MK.Anthelmintic resistance is reported in equine nematodes with increasing frequency in recent years, and no new anthelmintic classes have been introduced during the past 40 years. This manuscript reviews published literature describing anthelmintic resistance in cyathostomins, Parascaris spp., and Oxyuris equi with special emphasis on larvicidal efficacy against encysted cyathostomin larvae and strongylid egg reappearance periods (ERP). Resistance to benzimidazoles and pyrimidines is highly prevalent in cyathostomin populations around the world, and macrocyclic lactone resistance has been docume...
Almazán C, Scimeca RC, Reichard MV, Mosqueda J.Babesia and Theileria are apicomplexan parasites that cause established and emerging diseases in humans, domestic and wild animals. These protozoans are transmitted by Ixodid ticks causing babesiosis or theileriosis, both characterized by fever, hemolytic anemia, jaundice, and splenomegaly. In North America (NA), the most common species affecting humans is B. microti, which is distributed in the Northeastern and Upper Midwestern United States (US), where the tick vector Ixodes scapularis is established. In livestock, B. bovis and B. bigemina are the most important pathogens causing bovine babe...
Blazejewski T, Nursimulu N, Pszenny V, Dangoudoubiyam S, Namasivayam S, Chiasson MA, Chessman K, Tonkin M, Swapna LS, Hung SS, Bridgers J....Sarcocystis neurona is a member of the coccidia, a clade of single-celled parasites of medical and veterinary importance including Eimeria, Sarcocystis, Neospora, and Toxoplasma. Unlike Eimeria, a single-host enteric pathogen, Sarcocystis, Neospora, and Toxoplasma are two-host parasites that infect and produce infectious tissue cysts in a wide range of intermediate hosts. As a genus, Sarcocystis is one of the most successful protozoan parasites; all vertebrates, including birds, reptiles, fish, and mammals are hosts to at least one Sarcocystis species. Here we sequenced Sarcocystis neurona, th...
Ueti MW, Palmer GH, Kappmeyer LS, Statdfield M, Scoles GA, Knowles DP.The protozoan parasite Babesia equi replicates within erythrocytes. During the acute phase of infection, B. equi can reach high levels of parasitemia, resulting in a hemolytic crisis. Horses that recover from the acute phase of the disease remain chronically infected. Subsequent transmission is dependent upon the ability of vector ticks to acquire B. equi and, following development and replication, establishment of B. equi in the salivary glands. Although restriction of the movement of chronically infected horses with B. equi is based on the presumption that ticks can acquire and transmit the ...
Janssen IJ, Krücken J, Demeler J, Basiaga M, Kornaś S, von Samson-Himmelstjerna G.Macrocyclic lactones (MLs) represent the major drug class for control of parasitic infections in humans and animals. However, recently reports of treatment failures became more frequent. In addition to human and ruminant parasitic nematodes this also is the case for the horse-nematode Parascaris equorum. Nevertheless, to date the molecular basis of ML resistance is still not understood. Unspecific resistance mechanisms involving transporters such as P-glycoproteins (Pgps) are expected to contribute to ML resistance in nematodes. Here, complete sequences of two P. equorum Pgps were cloned and i...
Sears WJ, Qvarnstrom Y, Dahlstrom E, Snook K, Kaluna L, Baláž V, Feckova B, Šlapeta J, Modry D, Jarvi S, Nutman TB.Angiostrongylus cantonensis (Ac), or the rat lungworm, is a major cause of eosinophilic meningitis. Humans are infected by ingesting the 3rd stage larvae from primary hosts, snails, and slugs, or paratenic hosts. The currently used molecular test is a qPCR assay targeting the ITS1 rDNA region (ITS1) of Ac. In silico design of a more sensitive qPCR assay was performed based on tandem repeats predicted to be the most abundant by the RepeatExplorer algorithm. Genomic DNA (gDNA) of Ac were used to determine the analytical sensitivity and specificity of the best primer/probe combination. This assay...
Alhassan A, Thekisoe OM, Yokoyama N, Inoue N, Motloang MY, Mbati PA, Yin H, Katayama Y, Anzai T, Sugimoto C, Igarashi I.Loop-mediated isothermal amplification (LAMP) is a novel nucleic acid method whereby DNA is amplified with high specificity, efficiency, and rapidity under isothermal conditions using a set of four specifically designed primers and a DNA polymerase with strand displacement activity. In this study, we used LAMP primer sets designed from EMA-1 and Bc 48 genes for detection of Theileria equi and Babesia caballi infections, respectively. These primer sets specifically amplified DNA of the respective parasites. Both primer sets amplified T. equi and B. caballi up to 10(-6) dilution of 10-fold seria...
Vaughan JA, Tkach VV, Greiman SE.Digeneans are endoparasitic flatworms with complex life cycles and distinct life stages that parasitize different host species. Some digenean species harbour bacterial endosymbionts known as Neorickettsia (Order Rickettsiales, Family Anaplasmataceae). Neorickettsia occur in all life stages and are maintained by vertical transmission. Far from benign however, Neorickettsia may also be transmitted horizontally by digenean parasites to their vertebrate definitive hosts. Once inside, Neorickettsia can infect macrophages and other cell types. In some vertebrate species (e.g. dogs, horses and humans...
Slusarewicz P, Pagano S, Mills C, Popa G, Chow KM, Mendenhall M, Rodgers DW, Nielsen MK.Intestinal parasites are a concern in veterinary medicine worldwide and for human health in the developing world. Infections are identified by microscopic visualisation of parasite eggs in faeces, which is time-consuming, requires technical expertise and is impractical for use on-site. For these reasons, recommendations for parasite surveillance are not widely adopted and parasite control is based on administration of rote prophylactic treatments with anthelmintic drugs. This approach is known to promote anthelmintic resistance, so there is a pronounced need for a convenient egg counting assay...
Birhanu H, Fikru R, Said M, Kidane W, Gebrehiwot T, Hagos A, Alemu T, Dawit T, Berkvens D, Goddeeris BM, Büscher P.African animal trypanosomosis, transmitted cyclically by tsetse flies or mechanically by other biting flies, causes serious inflictions to livestock health. This study investigates the extent of non-tsetse transmitted animal trypanosomosis (NTTAT) by Trypanosoma (T.) evansi and T. vivax in domestic animals in the tsetse-free regions of Northern Ethiopia, Afar and Tigray. Methods: A cross sectional study was conducted on 754 dromedary camels, 493 cattle, 264 goats, 181 sheep, 84 donkeys, 25 horses and 10 mules. The microhaematocrit centrifugation technique was used as parasitological test. Plas...
Kim CM, Blanco LB, Alhassan A, Iseki H, Yokoyama N, Xuan X, Igarashi I.We developed a TaqMan real-time polymerase chain reaction (PCR) assay for the quantitative detection of Theileria equi from the in vitro-cultured parasite and field blood samples collected from horses living in Ghana and Brazil. The detection limit for the assay was determined to be 1.5 parasites/microl per sample, and the quantitative capacity was demonstrated using the in vitro-cultured parasite. For field applications, the real-time PCR assay was compared to a previously established nested PCR assay used as the gold standard for the real-time PCR assay. Of 65 field blood samples, 46 samples...
Wood EL, Matthews JB, Stephenson S, Slote M, Nussey DH.Cyathostomins are the most prevalent equine intestinal parasites and resistance has been reported in these nematodes against all 3 licensed anthelmintic classes. Strategies need to be developed that are less dependent upon drugs and more reliant on management-based control. To develop these we need to understand natural transmission patterns better. Here, we analysed longitudinal fecal egg count (FEC) data from 5 pony populations used for conservation purposes. We tested how egg excretion varied amongst populations and individuals, and how this was affected by age and climate. There was eviden...
Qi M, Wang R, Wang H, Jian F, Li J, Zhao J, Dong H, Zhu H, Ning C, Zhang L.In present study, 262 fecal specimens were collected from 12 groups of grazing horses in the Xinjiang Uyghur Autonomous Region of China. The specimens were subjected to PCR and sequencing analyses of the ribosomal internal transcribed spacer (ITS). The overall prevalence of E. bieneusi in horses was 30.9% (81/262). No significant differences in prevalence were observed between horses of different ages or sexes. Nineteen genotypes were identified: 15 known genotypes (BEB6, CHG19, CM6, CM7, CM8, CS-1, CS-4, D, EpbA, EbpC, G, horse1, horse2, O, and Peru8) and four new genotypes (XJH1-XJH4). Six ...
Li Y, Wen X, Li M, Moumouni PFA, Galon EM, Guo Q, Rizk MA, Liu M, Li J, Ji S, Tumwebaze MA, Byamukama B, Chahan B, Xuan X.Ticks carry and transmit a wide range of pathogens (bacteria, viruses, and protozoa) that are of importance to humans and animals globally. However, information about the tick-borne pathogens harbored by ticks in the Xinjiang Uygur Autonomous Region (XUAR), northwestern China, is scarce. This study investigated the occurrence of tick species of domestic animals and tick-borne pathogens by using morphological molecular identification and sequence analysis in Turpan, Qitai, Altay, Hejing, Nileke, and Zhaosu counties (XUAR). A total of 5822 adult ticks (females and males) from 12 tick species wer...
Nielsen MK, Peterson DS, Monrad J, Thamsborg SM, Olsen SN, Kaplan RM.Strongylus vulgaris is an important strongyle nematode with high pathogenic potential infecting horses world-wide. Several decades of intensive anthelmintic use has virtually eliminated clinical disease caused by S. vulgaris, but has also caused high levels of anthelmintic resistance in equine small strongyle (cyathostomin) nematodes. Recommendations aimed at limiting the development of anthelmintic resistance by reducing treatment intensity raises a simultaneous demand for reliable and accurate diagnostic tools for detecting important parasitic pathogens. Presently, the only means available t...
Equine trypanosomosis is a complex of infectious diseases called dourine, nagana and surra. It is caused by several species of the genus Trypanosoma that are transmitted cyclically by tsetse flies, mechanically by other haematophagous flies, or sexually. Trypanosoma congolense (subgenus Nannomonas) and T. vivax (subgenus Dutonella) are genetically and morphologically distinct from T. brucei, T. equiperdum and T. evansi (subgenus Trypanozoon). It remains controversial whether the three latter taxa should be considered distinct species. Recent outbreaks of surra and dourine in Europe illustrate ...
Reed SM, Furr M, Howe DK, Johnson AL, MacKay RJ, Morrow JK, Pusterla N, Witonsky S.Equine protozoal myeloencephalitis (EPM) remains an important neurologic disease of horses. There are no pathognomonic clinical signs for the disease. Affected horses can have focal or multifocal central nervous system (CNS) disease. EPM can be difficult to diagnose antemortem. It is caused by either of 2 parasites, Sarcocystis neurona and Neospora hughesi, with much less known about N. hughesi. Although risk factors such as transport stress and breed and age correlations have been identified, biologic factors such as genetic predispositions of individual animals, and parasite-specific factors...
Campbell AJ, Gasser RB, Chilton NB.In the current study, molecular techniques were evaluated for the species identification of individual strongyle eggs. Adult worms of Strongylus edentatus, S. equinus and S. vulgaris were collected at necropsy from horses from Australia and the U.S.A. Genomic DNA was isolated and a ribosomal transcribed spacer (ITS-2) amplified and sequenced using polymerase chain reaction (PCR) techniques. The length of the ITS-2 sequence of S. edentatus, S. equinus and S. vulgaris ranged between 217 and 235 nucleotides. Extensive sequence analysis demonstrated a low degree (0-0.9%) of intraspecific variation...
