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.
Ueti MW, Palmer GH, Scoles GA, Kappmeyer LS, Knowles DP.Tick-borne pathogens may be transmitted intrastadially and transstadially within a single vector generation as well as vertically between generations. Understanding the mode and relative efficiency of this transmission is required for infection control. In this study, we established that adult male Rhipicephalus microplus ticks efficiently acquire the protozoal pathogen Babesia equi during acute and persistent infections and transmit it intrastadially to naïve horses. Although the level of parasitemia during acquisition feeding affected the efficiency of the initial tick infection, infected t...
Rötting AK, Freeman DE, Constable PD, Moore RM, Eurell JC, Wallig MA, Hubert JD.Eosinophilic granulocytes have been associated with parasite or immune-mediated diseases, but their functions in other disease processes remain unclear. Cause and timing of eosinophil migration into the equine gastrointestinal mucosa are also unknown. Objective: To determine the effects of intestinal parasitism on eosinophils in equine large intestinal mucosa. Methods: Large intestinal mucosal samples were collected from horses and ponies (n = 16) from the general veterinary hospital population, ponies (n = 3) raised in a parasite-free environment, ponies experimentally infected with 500 infec...
Lyons ET, Tolliver SC, Ionita M, Collins SS.Horse foals on five farms in Central Kentucky were used in field studies in 2007 evaluating activity of paste formulations of four compounds (fenbendazole-FBZ, ivermectin-IVM, oxibendazole-OBZ, and pyrantel pamoate-PRT) against internal parasites with emphasis on ascarids (Parascaris equorum). It has been well established the last few years that there is widespread resistance of P. equorum to ivermectin. The main purpose of the present research was to obtain current data on ascaridicidal activity of FBZ, OBZ, and PRT; also, to acquire further information on ascarid resistance to ivermectin. Ad...
Kornas S, Skalska M, Nowosad B, Gawor J.The objective of this study was to evaluate the strongyles species in 34 Pure Blood Arabian Horses: one-year-old mares (n = 12) and two-year old mares (n = 22) from the horse stud in 2005, kept under housed-pastured system and dewormed systematically, twice a year using the ivermectin compounds. Methods: The practical method of in vivo determination of strongyles species in horses is collection of these nematodes from the feaces after treatment. Nematodes were collected 24 hours after deworming from 1000 g sample of feaces, then were classified to appropriate species and relative abundance of ...
Karatepe B, Karatepe M, Cakmak A, Karaer Z, Ergün G.The prevalence of equine piroplasmosis caused by Theileria equi and Babesia caballi in Nigde, in central Anatolia, Turkey has remained unknown. Serum samples were obtained from a total of 125 horses and were tested for antibodies to T. equi and B. caballi using the Indirect Fluorescence Antibody Test (IFAT). Twenty-three (18.4%) horses were seropositive for equine piroplasmosis. Anti-T. equi was observed in 16 horses (12.8%) while anti-B. caballi was detected in 12 horses (9.6%). In addition, 5 serum samples were positive for both parasites. The prevalence rates of antibodies to T. equi and B....
Kuzmina TA, Kharchenko VO.In 2004-2006, 322 brood horses from 11 horse farms were examined using the faecal egg count reduction test (FECRT) to determine the presence and distribution of anthelmintic resistance in strongylids in Ukraine. The anthelmintic drugs "Albendazole-7.5" (7.5mg of albenazole, Ukraine) at a dose of 5mg per kg body weight and "Univerm" (0.2% aversectin C, Russia) at a dose of 0.5mg per kg body weight were used. Seventy-one horses from six farms were examined in vivo to investigate the influence of anthelmintic treatment on the gastrointestinal strongylid community structure. Horses were treated wi...
Lyons ET, Tolliver SC, Ionita M, Lewellen A, Collins SS.Field studies (n=6) were completed on evaluation of activity of ivermectin (200 microg/kg) paste formulation against small strongyles in horses (foals, yearlings, and older animals) on a farm (Farm MC) in Central Kentucky in late 2006 and during 2007. A girth tape was used to estimate body weights which were then used to calculate the proper dose rate of ivermectin. The foals, yearlings, and some of the older horses were born and raised on the farm. However, most of the older horses which were not raised on the farm had been there for several years. The horse herd was given ivermectin exclusiv...
Cunha AP, Bello AC, Leite RC, Bastianetto E, Ribeiro AC, Freitas CM, Oliveira PR.The aim of this study was to verify the efficiency of a strategic control program of Amblyomma cajennense in horses under field conditions. Acaricide treatments were applied at seven days intervals and divided in two series, the first one beginning in April 2004 (eight treatments), and the second one beginning in July 2004 (five treatments), aiming to control larvae and nymphs of the tick. A pyrethroid chemical base cypermethrin 0.015% was used for spraying the horses. There was a reduction of 44.85% in the adults infestation of the tick in the period of October 2004 to March 2005, and 59.74%,...
Cunha AP, Bello AC, Leite RC, Ribeiro AC, Freitas CM, Bastianetto E, Oliveira PR.The objective of this study was to evaluate the effect of the Amblyomma cajennense strategic control program on the Anocentor nitens population. The acaricide treatments were carried out every seven days and divided in two series, the first one beginning in April 2004 (eight treatments) and the second beginning in July of the same year (five treatments), using pyrethroid chemical base - cypermethrin in the concentration of 0,015%. Monthly it was evaluated the infestation of A. nitens in the ear and nasal diverticulum of the equines before (October 2003 to March 2004) and after (October of 2004...
Slocombe JO, Coté JF, de Gannes RV.Three clinical trials with fecal egg count reduction tests and coproculture were conducted on 2 standardbred farms in Ontario. On Farm A, the treatment groups were mebendazole and ivermectin in trial 1, and fenbendazole and moxidectin in another. On Farm B, treatment groups were mebendazole and ivermectin. All horses treated with mebendazole or fenbendazole were subsequently treated with ivermectin or moxidectin. Strongyle eggs/g feces were estimated pre- and post-treatment using the Cornell-McMaster dilution and Cornell-Wisconsin centrifugal flotation techniques. After treatment, there was no...
Heskett KA, Mackay RJ.To investigate the use of a specific antibody index (AI) that relates Sarcocystis neurona-specific IgG quotient (Q(SN)) to total IgG quotient (Q(IgG)) for the detection of the anti-S neurona antibody fraction of CNS origin in CSF samples obtained from horses after intragastric administration of S neurona sporocysts. Methods: 18 adult horses. Methods: 14 horses underwent intragastric inoculation (day 0) with S neurona sporocysts, and 4 horses remained unchallenged; blood and CSF samples were collected on days - 1 and 84. For purposes of another study, some challenged horses received intermitten...
Matthews JB, Johnson DR, Lazari O, Craig R, Matthews KR.The Cyathostominae are a complex group of nematodes and are the primary parasitic pathogens of horses. Little is known of their basic biology. As part of an investigation into mechanisms involved in reactivation of mucosal larval stages, we identified a gene encoding a predicted LIM domain-containing protein (Cy-LIM-1). LIM domains are cysteine- and histidine-rich motifs that are thought to direct protein-protein interactions. Proteins that contain these domains have a wide range of functions including gene regulation, cell fate determination and cytoskeleton organization. The Cy-lim-1 mRNA wa...
Rüegg SR, Heinzmann D, Barbour AD, Torgerson PR.For the evaluation of the epidemiology of Theileria equi and Babesia caballi in a herd of 510 horses in SW Mongolia, several mathematical models of the transmission dynamics were constructed. Because the field data contain information on the presence of the parasite (determined by PCR) and the presence of antibodies (determined by IFAT), the models cater for maternal protection with antibodies, susceptible animals, infected animals and animals which have eliminated the parasite and also allow for age-dependent infection in susceptible animals. Maximum likelihood estimation procedures were used...
Pinchbeck GL, Morrison LJ, Tait A, Langford J, Meehan L, Jallow S, Jallow J, Jallow A, Christley RM.The Gambia has an increasing population of equidae largely used for agriculture and transportation. A review of cases at The Gambian Horse and Donkey Trust (GHDT) indicated that a common reason for presentation is a poorly defined medical condition often attributed to trypanosomosis. There are few reports describing the prevalence or the range of clinical signs associated with infection with different species of trypanosomes in horses and donkeys, but given the importance of these animals, the role of trypanosomosis requires investigation. Results: In total 241 animals from the Central River D...
Getachew AM, Innocent GT, Trawford AF, Feseha G, Reid SJ, Love S.A cross-sectional coprological survey in the regions of Ada, Akaki, Bereh and Boset, and a retrospective postmortem investigation were conducted to study the epidemiology of Parascaris equorum in donkeys and horses in Ethiopia. Faecal samples from 803 working donkeys and 402 horses were collected, and the numbers of worms recovered from 112 donkeys examined postmortem between 1995 and 2004 were analysed. There was a high prevalence of infection and faecal egg output of P equorum in both donkeys and horses, and the severity of the infection in donkeys was increased irrespective of their age. Th...
Quinelato S, Couto MC, Ribeiro BC, Santos CN, de Souza LS, Dos Anjos DH, Sampaio IB, Rodrigues LM.Experimental studies about the recovery, survival and migration to pasture of cyathostomin infective larvae (L(3)) from fresh feces depositions were conducted from February 2005 to March 2007 in a tropical region of southeast Brazil. Grass and feces were collected weekly at 8 a.m., 1 and 5 p.m. and processed by the Baermann technique. Multivariate analysis (principal components method) showed the influence of time and environmental variables on the number of infective larvae recovered from the feces and pasture. In the rainy period (October-March), more infective larvae were recovered on the f...
Soltane R, Guyot K, Dei-Cas E, Ayadi A.1,001 faecal samples were obtained from 89 sheep (lambs and adult), 184 goats, 190 horses, 178 rabbits, 110 camels, 200 broiler chicken and 50 turkeys housed in farms from different localities in Tunisia. All samples were analysed for Cryptosporidium oocysts by microscopic examination of smears stained by modified Ziehl Neelsen technique. The parasite was detected in ten lambs and adult sheep (11.2 %) and nine broiler chicken (4.5 %). Molecular characterization, performed in four animals, identified C. bovis in three lambs and C. meleagridis in one broiler chicken. This work is the first repor...
Trotz-Williams L, Physick-Sheard P, McFarlane H, Pearl DL, Martin SW, Peregrine AS.Infection with the tapeworm Anoplocephala perfoliata has been found to be associated with equine colic in horses in the United Kingdom. Using a matched case-control study design, data collected from 117 pairs of horses in Ontario were examined for evidence of associations between risk of colic and A. perfoliata infection, and between seropositivity to infection and management practices. Cases were horses in southern Ontario diagnosed with colic by local veterinarians, and control horses were from the same stables as cases and were matched by age, breed and gender where possible. Infection stat...
Abbott JB, Mellor DJ, Barrett EJ, Proudman CJ, Love S.The serological changes in two groups of horses known to be harbouring Anoplocephala perfoliata were studied; 12 were treated with 1.5 mg/kg praziquantel and 200 microg/kg ivermectin, and 14 were treated with 200 microg/kg ivermectin. Serological and faecal analyses were carried out on each animal at intervals for 758 days. The titres of antibodies specific for A perfoliata decreased from the day of treatment to day 28 in both groups, and continued to decrease in the group treated with praziquantel and ivermectin, with the first significant decrease from the other group at day 121. From day 15...
Mignon B, Losson B.This is the first documented case report of dermatitis associated with the poultry mite (Dermanyssus gallinae) in a horse. It occurred in a 16-year-old horse that was in contact with domestic hens. Clinical signs consisted of severe pruritus, with self-induced hair loss mainly on the head. Despite the multiple skin scrapings performed during both day- and nighttime, mites were only isolated from the in-contact poultry and from the horse's environment, and not the horse. The animal was treated using a 2% permethrin solution, sprayed on the entire body once a week for 4 weeks, and by decontamina...
Muller S, Grzybowski M, Sager H, Bornand V, Brehm W.This report describes a case of nodular posthitis caused by Halicephalobus gingivalis in a 24-year-old warmblood horse. Macroscopic examination revealed a multinodular, partially ulcerated mass on the external lamina of the prepuce. Nematode migration from unfixed biopsy material in phosphate-buffered saline revealed adult nematodes with the typical morphological features of H. gingivalis: distinctive rhabditiform oesophagus with corpus, isthmus and bulb and the dorsoflexed ovary. The main histopathological features consisted of submucosal confluent granulomatous foci containing cross- and tan...
Traversa D, Fichi G, Campigli M, Rondolotti A, Iorio R, Proudman CJ, Pellegrini D, Perrucci S.Anoplocephala perfoliata (Cestoda, Cyclophyllidea), the commonest intestinal tapeworm of horses, can cause colic, intussusceptions, ileal impactions and intestinal perforations. Common diagnostic techniques for A. perfoliata infection, i.e. coprology and serology, show inherent limitations in terms of sensitivity and specificity and new approaches are thus required. Hence, the present study compared the reliability of coprological, serological (i.e. ELISA) and molecular (i.e. nested PCR) methods in detecting A. perfoliata infection in naturally infected horses and in horses treated with a comb...
Varcasia A, Garippa G, Pipia AP, Scala A, Brianti E, Giannetto S, Battelli G, Poglayen G, Micagni G.Between March 2003 and February 2007, the livers and the lungs of 2,231 horses from various Italian regions were examined for cystic echinococcosis presence at the time of slaughter. Hydatid cysts were found in six horses, namely four from Sardinia, one from Sicily, and one from Tuscany. The location, number, morphology, and fertility of the cysts found were determined. DNA was extracted from the germinal layers and protoscoleces of the fertile cysts and polymerase chain reactions (PCR) were performed in order to strain type DNA isolates for reduced nicotinamide adenine dinucleotide dehydrogen...
Acici M, Umur S, Guvenc T, Arslan HH, Kurt M.The prevalence of Theileria equi and Babesia caballi was determined in equid blood samples in five provinces of the Black Sea region of Turkey by using the indirect fluorescent antibody test (IFAT). Of 153 samples, 53 (34.6%) and 33 (21.5%) were seropositive to B. caballi and T. equi, respectively. In addition, 8 (5.2%) of samples were seropositive to both T. equi and B. caballi. Anti T. equi and B. caballi antibodies were detected in all five regions. The prevalence of B. caballi was higher than T. equi in all counties. Antibodies to T. equi and B. caballi were detected in horses of all ages,...
Mansfield LS, Mehler S, Nelson K, Elsheikha HM, Murphy AJ, Knust B, Tanhauser SM, Gearhart PM, Rossano MG, Bowman DD, Schott HC, Patterson JS.We tested the hypothesis that brown-headed cowbirds (Molothrus ater) harbor Sarcocystis neurona, the agent of equine protozoal myeloencephalitis (EPM), and act as intermediate hosts for this parasite. In summer 1999, wild caught brown-headed cowbirds were collected and necropsied to determine infection rate with Sarcocystis spp. by macroscopic inspection. Seven of 381 (1.8%) birds had grossly visible sarcocysts in leg muscles with none in breast muscles. Histopathology revealed two classes of sarcocysts in leg muscles, thin-walled and thick-walled suggesting two species. Electron microscopy sh...
Zhang B, Huang H, Wang H, Zhang D, Chu H, Ma X, Ge Y, Ente M, Li K.Gasterophilus species are widely distributed around the world. The larvae of these flies parasitize the digestive tract of equids and cause damage, hindering horse breeding and protection of endangered species. However, study of the genetic structure of geographically distinct Gasterophilus populations is lacking. Here, we analyzed the genetic diversity of Gasterophilus pecorum, G. intestinalis, G. nasalis and G. nigricornis from three typical grasslands (meadow, desert and alpine steppes) in China as compared to published sequences from Italy, Poland and China (Daqing and Yili), based on the ...
The Journal of parasitologyApril 25, 2001
Volume 87, Issue 2 442-445 doi: 10.1645/0022-3395(2001)087[0442:ETPIGN]2.0.CO;2
Medica DL, Sukhdeo MV.Microparasite virulence (the potential to cause harm in the host) is thought to be regulated by a direct trade-off with pathogen transmission potential, but it is unclear whether similar trade-offs occur in macroparasites (helminths). In this analysis, the transmission potentials of 5 nematode species (order Strongylida), known to differ in their virulence, were estimated using an index based on egg production and larval survivability. Virulence estimates were based on the minimum number of worms that cause host death. In nematode species where mature adults cause pathology (trichonematidic de...
Peng Z, Shen D, Zhang D, Li X, Wang L, Zhai Q, Hou Z, Li H.The equine Parascaris spp. is large, parasitic nematodes, and predominantly focuses on the intestine of foals and young weanlings. There are two roundworms, Parascaris equorum and Parascaris univalens, recognized among equine hosts. In this study, all fifty-nine Parascaris worms were harvested from three different equine hosts (twenty specimens from Equus zebra, twenty specimens from E. caballus, and nineteen specimens from E. asinus). The ribosomal gene (ITS) and mitochondrial genes (cox1 and nadh1) were amplified to identify and genetically characterize these worms. Analysis of ITS sequences...
Ellse L, Burden F, Wall R.Equine pediculosis is a significant health and welfare issue, particularly in elderly and chronically debilitated animals. Currently infestation is controlled predominantly using topically applied pyrethroid insecticides, allowing limited scope for the rotation of drugs and increasing the risk of selection for resistance. Here the insecticidal efficacies of two pyrethroid-based products against the louse Bovicola (Werneckiella) ocellatus collected from donkeys were examined in vitro. The products were cypermethrin (Deosect™, Pfizer Ltd., 5% (w/v) cypermethrin, cutaneous spray) and permethrin...
Alexander CS, Keller H.Over 130 cases of equine periodic ophthalmia (p.o.), which were treated as in-patients at the Equine Clinic of the Free University of Berlin in the last 35 years, were examined statistically in relation to the age and gender of the animals involved as well as to the development of the illness and the season in which it arose. As regards aetiology, the extraction of 71 affected Trotters was investigated. Antibodies to toxoplasmosis, leptospirosis and intestinal parasites were found only in some of the patients. Younger animals, aged between one and four years, and male animals (63.6%) were pred...
Cano-Terriza D, Franco JJ, Jose-Cunilleras E, Buono F, Almería S, Veneziano V, Alguacil E, García J, Villena I, Dubey JP, Jiménez-Martín D....Toxoplasmosis, caused by the obligate intracellular protozoan Toxoplasma gondii, is a worldwide parasitic zoonosis. A cross-sectional study was carried out to determine the exposure to T. gondii in equids in Europe. Serum samples from 1399 equids (1085 horses, 238 donkeys, and 76 mules/hinnies) bred in four European countries (Italy, Spain, United Kingdom [UK], and Ireland) were collected during the period of 2013-2021. The overall seroprevalence of T. gondii was 18.9% (95% Confidence Interval [CI]: 16.9-21.0) by using the modified agglutination test (MAT) at a cut-off of 1:25. Seropositivity ...
Steuer AE, Loynachan AT, Nielsen MK.Members of Cyathostominae are pervasive parasites of equids that can cause larval cyathostominosis, a potentially life-threatening disease that occurs when a multitude of encysted larvae synchronously excyst from the wall of the large intestine. Moxidectin and fenbendazole are the two current labeled drugs that target the encysted larval stages; however, there is limited knowledge of the local inflammatory response to the larvae and to the two treatments in clinically healthy horses. This study is the first to evaluate the local inflammatory response to cyathostomin larvae and to larvicidal tr...
Vyniarska A, Ziółkowski H, Madej-Śmiechowska H, Jaroszewski JJ.The aim of this study was to compare the pharmacokinetics of ivermectin and its antiparasitic activity in two horse breeds. Eight Hutsul and 14 Toric horses were administered ivermectin orally at a dose of 0.2 mg/kg body weight. Blood samples were collected for 96 hr, and faecal samples were collected one day before and on days 14 and 21 after drug administration. Ivermectin concentrations in plasma samples were determined by high-performance liquid chromatography. Ivermectin concentration was significantly higher in Toric than in Hutsul horses 90 min after ivermectin administration and was...
Yamazaki A, Suganuma K, Kayano M, Acosta TJ, Saitoh T, Valinotti MFR, Sanchez AR, Inoue N.Animal trypanosomosis, caused by Trypanozoon trypanosomes (Trypanosoma evansi and T. equiperdum), and Trypanosoma vivax, is endemic to South American countries and has a negative impact on the livestock industry. However, the risk factors for trypanosomosis in Paraguay remain unknown. This study aimed to determine the risk factors for equine trypanosomosis in Paraguay based on a PCR-based molecular survey and individual horse sampling data. In this study, 739 blood samples were collected from horses in 16 departments of Paraguay between August 2019 and November 2020. To elucidate the risk fact...
Roelfstra L, Vlimant M, Betschart B, Pfister K, Diehl PA.A morphological study of the midgut and salivary glands of second and third instars of Gasterophilus intestinalis (De Geer) (Diptera: Oestridae) was conducted by light, scanning and transmission electron microscopy. The midgut is anteriorly delimited by a proventriculus, without caeca, and is composed of posterior foregut and anterior midgut tissue from which a double-layered peritrophic matrix is produced. The midgut can be divided into anterior, median and posterior regions on the basis of the structural and physiological variations of the columnar cells which occur along its length. Two oth...
Slocombe JO, Cote JF.Thirteen Standardbred horses, two to five years of age, were treated with ivermectin paste per os at 200 mug/kg of body weight and 13 were untreated. Two weeks after treatment, previously untreated horses were given the paste. Fecal samples were collected from all horses at the time of treatment and periodically thereafter up to 14 weeks and were examined for nematode eggs using the Cornell-McMaster dilution and the Cornell-Wisconsin double centrifugation procedures.All horses consumed the paste readily and had no signs of toxicosis. Strongyle eggs were found in the feces of all horses before ...
Osiyemi TI, Synge EM, Agbonlahor DE, Agbavwe R.Toxoplasma gondii antibodies were found in the sera of 22.86% of people in the Jos area of Plateau State, Nigeria. The incidence of antibodies in Nigerian food animals was 17.40%, the highest being in sheep (21.92%) and lowest in goats (13.88%). Cattle and horses were roughly equally infected--about 17.0%. The zoonotic potential of T. gondii in food animals is stressed and epidemiological factors are reviewed.
Abraham M, Bauquier J.The peripartum period is critical in equine medicine for maintaining healthy mares, and ensuring the delivery of healthy neonatal foals. The field of perinatal mortality in horses is continuously evolving, with several advances being recently made in causes of perinatal fetal and foal loss. This review details the main causes of perinatal loss in horses, through late pregnancy, parturition and the neonatal period. Recent advances in identification of infectious organisms and indicators of survival in neonatal foals will be discussed. Continued advances in reproductive and neonatal medicine wil...
Norris JK, Slusarewicz P, Nielsen MK.The efficacy of anthelmintic treatments against populations of endoparasites infecting livestock throughout the world is decreasing. To mitigate this, the use of fecal egg counts is recommended to determine both the necessity, and to ensure the appropriate choice, of anthelmintic treatment. Traditionally, and in order to facilitate easier identification and/or enumeration, samples are analysed after separating eggs from other fecal particulates by exposing them to a solution with a density higher than that of the eggs, but lower than the remaining fecal contents. While many parasite egg flotat...
Quigley A, Sekiya M, Garcia-Campos A, Paz-Silva A, Howell A, Williams DJL, Mulcahy G.Fasciola hepatica is a common parasite of livestock in Ireland, causing significant economic losses and affecting animal welfare. A previous abattoir study of 200 horses led to an estimated 9.5 % prevalence of infection in horses slaughtered in Ireland. However, the epidemiology and pathogenic significance of this infection in this species is not well-described. The objectives of this study were to determine the susceptibility of horses to oral challenge infection with F. hepatica metacercariae, and to document the course of the infection along with serological and biochemical response. We att...
Reck C, Menin Á, Pisetta NL, Batista F, Miletti LC.This study reports the first autochthonous "surra" outbreak in horses in the State of Santa Catarina, southern Brazil. Six horses with clinical suspicion of trypanosomosis had the natural infection by T. evansi confirmed by PCR and rapid serum agglutination test. Clinical, parasitological, and hematology evaluations were performed at initial observation (T0) and 90 days after (T1). At T0, all animals that tested positive for T. evansi in PCR presented with severe clinical signs and out of normal range hematological hematological (hematocrit, leukocytes, platelets, hemoglobin) and serum bioche...
Sauermann CW, Nielsen MK, Luo D, Leathwick DM.Previously described models for the free-living and parasitic phases of the cyathostomin life-cycle were combined into a single model for the complete life-cycle. The model simulates a single free-living population on pasture utilising parasite egg output from the horses and localised temperature and rainfall data to estimate infective larval density on herbage. Multiple horses of different ages are possible, each with an individualised anthelmintic treatment programme. Genotypes for anthelmintic resistance are included allowing for up to three resistance genes with 2 alleles each. Because lit...
Sorrell MS, Fish RE, Taylor KH.Horses and ponies are used infrequently in research but may be valuable animal models for studying both equine-specific diseases and biomedical applications. We report here 2 cases of pediculosis in random-source ponies. Infestation and clinical signs were not present during a 4-wk quarantine period or for 3 to 9 mo thereafter but became apparent coincident with the ponies' movement from pasture to indoor housing. These 2 geldings presented with pruritus associated with excoriating lesions on the neck, and infestation with Bovicola (Werneckiella) equi Denny, 1842 was diagnosed. Ponies were tre...
Salas-Romero J, Gómez-Cabrera KA, Salas JE, Vázquez R, Arenal A, Nielsen MK.Anthelmintic resistance in equine cyathostomins has been described worldwide, with resistance to the benzimidazole class being particularly widespread. The status of anthelmintic efficacy in Cuba has been virtually unknown due to the lack of equine labelled products. One recent report documented suboptimal efficacy levels of extra-label albendazole products against cyathostomins, but it remains unknown to which extent benzimidazole resistance exists in the population. The aim of the present study was to evaluate the anthelmintic efficacy of two benzimidazole products labelled for equines, fenb...
Klei TR, Torbert BJ, Chapman MR, Turk MA.A controlled test method was used to evaluate the efficacy of injectable micelle and oral paste formulations of ivermectin (22,23-dihydroavermectin B1) against 8-week-old Strongylus vulgaris larvae in experimentally infected pony foals. The dosage level of the drug in both formulations tested was 0.2 mg/kg. Ponies were euthanatized and necropsied 5 weeks after treatment. Based on the recovery of live vs dead S vulgaris from mesenteric arteries, both formulations were greater than 99% effective. Increased weight gains and marked reductions in the severity of arterial lesions were observed in tr...
Liao D, Shen J.In the present article, we summarize our studies of antrycide-resistance of Trypanosoma brucei evansi in four aspects in the last recent several years, the analysis of quinapyramine-sensitive situation of T. b. evansi in China, biological characteristics of T. b. evansi population in quinapyramine-resistance and biological materials of quinapyramine-resistance in T. b. evansi population. Firstly, the correlative assays of effective dosage of quinapyramine on T. b. evansi disease between in vivo and in vitro methods showed that their relationship was parabolic with positive correlation. On the ...
Moreira CJC, De Cicco NNT, Galdino TS, Feder D, Gonzalez MS, Miguel RB, Coura JR, Castro HC, Azambuja P, Atella GC, Ratcliffe NA, Mello CB.Chagas disease, infecting ca. 8 million people in Central and South America, is mediated by the protozoan parasite, Trypanosoma cruzi. The parasite is transmitted by the bite of blood sucking triatomine insects, such as Rhodnius prolixus, that had previously fed on parasite-infected vertebrate blood and voided their contaminated feces and urine into the wound. The stages of the parasite life cycle in both the insect vector and human host are well-known, but determinants of infection in the insect gut are complex and enigmatic. This paper examines the possible role of the R. prolixus gut agglut...
Pavlásek I, Hess L, Stehlík I, Stika V.The first occurrence of Giardia spp. in horses in the Czech Republic is reported. During preventive examination of 360 five-month up to 14-year horses from various parts of the region of Central Bohemia carried out from January 1993 to June 1994 in the parasitological laboratory of the State Veterinary Institute in Prague, the Giardia cysts were detected in the excrements of 18 (5%) horses, mostly 2-4 years of age, and in two foals 3 and 6 weeks old. During the period between March 1993 and June 1994, systematic and repeated observation was aimed at a group of 38 racing horses two up to four y...
Bello TR, Allen TM.To compare the McMaster and centrifugal flotation techniques and larval culture for recovery of cyathostomin (small strongyle) eggs from the feces of horses. Methods: Fecal samples from 101 horses. Methods: In experiment I, homogenized fresh feces from a single horse were randomly subsampled by use of each technique for 10 replicates. In experiment II, samples from 43 horses that had no anthelmintic treatment were analyzed by use of McMaster, centrifugal flotation, and larval culture techniques. In experiment III, 57 horses were treated with an anthelmintic by owners, and fecal samples were an...
de Oliveira Lima AN, da Silva Santos S, Herrera HM, Gama C, Cupolillo E, Jansen AM, Fernandes O.The protozoan Trypanosoma evansi is described as presenting high morphological and genetic similarities among the isolates despite its biological heterogeneity and wide geographical distribution. PCR amplification of the internal transcribed spacers of the ribosomal gene in combination with the coding region of the 5.8S ribosomal subunit further submitted to restriction enzymes digestion were carried out in DNAs extracted from 41 T. evansi strains isolated from horses, dogs, coatis and capybaras from two distinct regions of the Brazilian Pantanal. We also used one T. evansi isolate from Africa...
Pavone S, Veronesi F, Piergili Fioretti D, Mandara MT.Gastrointestinal motility disorders represent a significant cause of morbidity and mortality in horses. Previously regarded as a non-pathogenic tapeworm, Anoplocephala perfoliata has been recently associated with equine colic. In this study, pathological changes related to A. perfoliata at the ileocecal junction were investigated in 31 slaughtered horses. Our results showed a significant relationship between parasitic burden and grading of histopathological lesions in both the mucosa and submucosa. Moreover, in infested horses, hypertrophy of the circular muscle layer was determined. Finally, ...
Clausen PH, Gebreselassie G, Abditcho S, Mehlitz D, Staak C.A field study of horses was conducted in the province of Bale, Ethiopian highlands. A rapid questionnaire analysis indicated that dourine, known as "Dirressa", is a major health problem of equines in this area. A total of 121 horses suspected of dourine were examined by use of clinical, parasitological, serological and DNA based techniques. Incoordination of hindlegs (76%), swelling of external genitalia (48.8%) and emaciation (39.7%) were the most common clinical signs observed. Using the haematocrit centrifugation technique (HCT), no trypanosomes were detected in blood, genital washes or tis...
Drudge JH, Lyons ET, Tolliver SC.Critical tests were conducted on eight horses naturally infected with several species of large and small strongyles from population B. Tested were six benzimidazoles, including thiabendazole (2 lots) (44 mg/kg of body weight); mebendazole (8.8 mg/kg); cambendazole (two formulations) (20 mg/kg); fenbendazole (10 mg/kg); oxibendazole (10 mg/kg); and oxfendazole (10 mg/kg). All compounds were administered by stomach tube except one of the two cambendazole formulations which was an intraoral paste. Removal of large strongyles (when present), Strongylus vulgaris and Strongylus edentatus, was 100% b...
Smith HJ, Snowdon KE.Light Trichinella infections were established in three ponies given 1000, 5000 and 25000 T. spiralis spiralis infective larvae respectively by stomach tube. A predilection site of infection in all ponies was the tongue. Anti-Trichinella antibodies were detected in all ponies by the enzyme-linked immunosorbent assay using a T. spiralis spiralis excretory-secretory antigen. The ponies given 5000 and 25000 infective larvae reacted positively on days 26 and 24 postinfection, respectively, using a criterion of greater than or equal to 5 X mean optical density readings of preinfection sera as positi...
Soundararajan C, Nagarajan K, Muthukrishnan S, Arul Prakash M.The prevalence of tick infestation and their predilection sites on sheep, goat, horse and wild hare were studied at various places of Tamil Nadu, India. The prevalence of tick infestation in Madras red sheep, Tellicherry goat and horse was 77.11, 78.21 and 13.33%, respectively. Sheep were heavily infested with followed by , and . . The ticks from goats were identified as . , . , . and . . Horses were infested with and . . The ticks on wild hare () were identified as . and . . Wild hare acts as a source of infestation to the sheep and goats since these animals shared the same field.
