Fecal Egg Count (FEC) is a diagnostic tool used to quantify the number of parasite eggs present in a horse's feces. This measure is primarily employed to assess the burden of gastrointestinal parasites, such as strongyles and ascarids, in equine populations. FEC is instrumental in informing parasite management strategies, including the timing and effectiveness of anthelmintic treatments. The process involves collecting a fecal sample from the horse, preparing it in a laboratory setting, and examining it under a microscope to count the eggs. This page compiles peer-reviewed research studies and scholarly articles that explore the methodologies, applications, and implications of fecal egg count in equine parasitology.
Slocombe JO.Aims of this study with 13 equids naturally infected with Anoplocephala perfoliata were to document (i) a critical test with a period of 48 h from treatment to necropsy to assess the efficacy of an anthelmintic against the tapeworm, (ii) the efficacy of pyrantel pamoate oral paste at 13.2 mg pyrantel base/kg body weight, and (iii) the time after treatment when fecal egg counts would best estimate the tapeworm's prevalence in a herd. Feces passed in successive 12-h periods after treatment were examined for tapeworms. At necropsy, tapeworms in equids were identified as attached to the mucosa or ...
Grubbs ST, Amodie D, Rulli D, Wulster-Radcliffe M, Reinemeyer C, Yazwinski T, Tucker C, Hutchens D, Smith L, Patterson D.The safety and efficacy of 2% moxidectin/12.5% praziquantel oral gel administered at a rate of 0.4 mg moxidectin and 2.5 mg praziquantel/kg was studied in client-owned horses under field use conditions. Four hundred horses (300 treated with moxidectin/praziquantel oral gel and 100 treated with vehicle) were enrolled, feces were collected, and eggs were counted. Investigators as well as horse owners were masked to treatment assignment. No adverse reactions to treatment were observed in any horses. Moxidectin/praziquantel gel reduced Anoplocephala spp by more than 99% and provided a significant ...
Rehbein S, Holste JE, Doucet MY, Fenger C, Paul AJ, Reinemeyer CR, Smith LL, Yoon S, Marley SE.The efficacy of an oral formulation of ivermectin plus praziquantel in the reduction of nematode and cestode egg counts in horses was assessed in 273 horses under field conditions at 15 sites in North America (n = 6) and Europe (n = 9). Horses were confirmed by fecal examination to have natural infections of strongyles (100%) and tapeworms (76%). Replicates of four horses were formed at each site, and in each replicate three animals received ivermectin (0.2 mg/kg body weight) plus praziquantel (1 mg/kg body weight) oral paste and one animal remained untreated or received vehicle paste. Fecal s...
Tandon R, Kaplan RM.A larval development assay (LDA, DrenchRite) was evaluated to determine the effectiveness of this method in detecting anthelmintic resistance in cyathostomin nematodes of horses. A total of 15 horse farms from Georgia and South Carolina (USA) and Population S ponies from the University of Kentucky (USA) were included in this study. Nematode eggs were extracted from pooled fecal samples and placed into the wells of a DrenchRite plate for testing against thiabendazole (TBZ), levamisole (LEV) and 2 ivermectin (IVM) analogs (IVM-1, IVM-2). After a 7-day incubation larvae in each well were counted ...
Barrett EJ, Farlam J, Proudman CJ.Two hundred and thirty-three horses were screened for the presence of roundworms by faecal egg counts (FECs) and for tapeworms by an ELISA specific for antibodies to the immunodominant 12 kDa and 13 kDa tapeworms antigen. The 62 horses were found to be infected with both parasites were treated with a combination of 0.2 mg/kg ivermectin and 1.5 mg/kg praziquantel. The treatment suppressed the median FEC of the horses to zero for 10 weeks and significantly reduced their anti-12/13 kDa antibody levels. The estimated risk of tapeworm-associated colic in these horses was halved by 12 weeks after th...
Wirtherle N, Schnieder T, von Samson-Himmelstjerna G.Faecal egg counts (FECs) were made on samples from 1383 horses on 64 farms in northern Germany between August 2000 and November 2001. There were significant differences between the mean FECs in the two years; in 2000, 59.6 per cent of 369 samples were positive and in 2001, 32.6 per cent of 1014 samples were positive for strongyle eggs. The results of a FEC reduction test indicated that resistance to fenbendazole was present on all 10 farms where it had been used, including in 33 of 60 horses tested. In contrast, treatment with ivermectin resulted in the complete elimination of nematode eggs in...
Matthee S.Anthelmintic products form the basis of helminth control practices on horse stud farms at present. Regular evaluation of the efficacy of these products is advisable, as it will provide information on the worm egg reappearance period and the resistance status in the worm population. The aim of this study was to evaluate the efficacy of doramectin, pyrantel pamoate, ivermectin and moxidectin on a Thoroughbred stud farm in the Western Cape Province, South Africa. The study also compared the anthelmintic efficacy of two moxidectin formulations administered at their recommended dosages (an injectab...
Lyons ET, Tolliver SC.Fenbendazole (FBZ) suspension was administered intraorally at the dose rate of 7.0-10.3 mg/kg once a day for 5 consecutive days to 58 thoroughbred yearlings on two farms in central Kentucky in April, 2002. The average dose rates of drug given to groups of colts and fillies on each farm were 7.8-8.5 mg/kg. Only 3 of the yearlings had negative counts of strongyle eggs per gram of feces (EPGs) after treatment which was at 8.4, 8.7, or 9.4 mg/kg; the pretreatment EPG counts were low (10-30). Reduction of EPG values at the highest dose rates was 0% (at 9.5 mg/kg) and 78% (at 10.3 mg/kg). This study...
Hearn FP, Peregrine AS.During September 2002, routine fecal examinations performed on 16 Thoroughbred foals residing on a farm outside Toronto, Ontario, Canada, revealed low to moderate numbers of Parascaris equorum eggs in feces from 9 of the 16. All foals were then treated with ivermectin at a dose of 220 to 280 microg/kg (100 to 127 microg/lb), p.o., and fecal egg counts were repeated 12 days later. Fecal P. equorum egg counts increased between the first and second fecal examination in 7 foals, were unchanged in 1, and decreased in 5. Fecal samples were collected 13 days after treatment from 21 additional foals t...
Königová A, Várady M, Corba J.The objective of the study was to compare the in vitro egg hatch test (EHT), larval development test (LDT) and in vivo faecal egg count reduction test (FECR test) for the detection of benzimidazole resistance in equine strongyles. The presence of resistant or susceptible strongyle populations was determined in 25 stud farms using the in vivo FECR test and in vitro EHT. On the basis of the FECR values, resistance to fenbendazole was detected on 15 of the 25 farms (60%). The ED50 value (anthelmintic concentration producing 50% inhibition of hatching) for suspected resistant populations varied fr...
Epe C, Kings M, Stoye M, Böer M.Wild equids maintained in large enclosures may suffer from helminth diseases because common hygiene practices have only limited effects on parasite populations. Weekly monitoring of helminth prevalences and pasture infestation was performed for 1 yr in several extensive maintenance systems of two wildlife parks with similar climates to determine when veterinary intervention to control parasites would be useful. We also sought evidence of natural immunogenic reactions among herds of Chapman zebras (Equus quagga antiquorum), Przewalski's horses (Equus przewalskii) and dwarf donkeys (Equus asinus...
The Journal of parasitologyMay 23, 2003
Volume 89, Issue 2 309-314 doi: 10.1645/0022-3395(2003)089[0309:POSNIN]2.0.CO;2
Chapman MR, French DD, Klei TR.One hundred and seventeen ponies were surveyed for the seasonal prevalence of strongyloid parasites, particularly cyathostomes, and for host- and age-related differences in these infections. For 56 ponies, all stages of the cyathostome life cycle, both mucosal and luminal, were enumerated. Total numbers of cyathostomes and percentage of developing larvae (DL) encysted in the mucosa remained constant in all 4 seasons of the year, whereas a significant increase in the percentage of adults in the cyathostome population occurred in fall. In yearling ponies, encysted early third-stage larvae consti...
Little D, Flowers JR, Hammerberg BH, Gardner SY.Possible anthelmintic resistance on a breeding farm where a rapid rotation anthelmintic programme had been implemented for 9 years was investigated. Cyathostomins resistant to fenbendazole and pyrantel were documented by faecal worm egg count reduction test (FWECRT). Objective: To 1) manage small strongyle transmission in a herd of horses in which resistance to both pyrantel pamoate and fenbendazole was identified and thereby reduce the risk of clinical disease in the individual animal, 2) monitor the change in resistance patterns over time and 3) monitor the efficacy of ivermectin over the st...
Matthee S, Dreyer FH, Hoffmann WA, van Niekerk FE.Fifty-one per cent of 110 questionnaires, designed for obtaining information on helminth control practices and management on Thoroughbred stud farms in South Africa, were completed by farmers during 2000. The number of horses per farm included in the questionnaire survey ranged from 15 to 410. Foals, yearlings and adult horses were treated with anthelmintics at a mean of 7.3 +/- 3.0, 6.6 +/- 2.7 and 5.3 +/- 2.3 times per year, respectively. An average of 3.4 different drugs were used annually, with ivermectin being used bymost farmers during 1997-2000. On 43% of farms the weights of horses wer...
Collobert-Laugier C, Hoste H, Sevin C, Dorchies P.Forty-two horses from Normandy (France) were examined post-mortem for small strongyle infections from October to March. In the positive horses, total worm numbers ranged from 234 to 90,247 (mean 11,297). Encysted larvae represented the major part of the total cyathostome burdens with a high percentage (83%) being early third stage larvae. They were mostly recovered from the caecum (48%) and ventral colon (40%) and were less present in the dorsal colon (12%). Adult cyathostomes were mainly located in the ventral colon (64%) and less frequently in the dorsal colon (27%) and caecum (9%). Twenty s...
Kaplan RM.Suppressive anthelmintic treatment strategies originally designed to control Strongylus vulgaris in horses were extremely successful in reducing morbidity and mortality from parasitic disease. Unfortunately, this strategy has inadvertently resulted in the selection of drug-resistant cyathostomes (Cyathostominea), which are now considered the principal parasitic pathogens of horses. Resistance in the cyathostomes to benzimidazole drugs is highly prevalent throughout the world, and resistance to pyrantel appears to be increasingly common. However, there are still no reports of ivermectin resista...
O'Meara B, Mulcahy G.We report the results of a survey to assess the attitudes of horse owners and managers of equine businesses in Ireland to the control of helminth parasites, and the extent to which veterinary practitioners are involved in providing advice on parasite control of horses. Replies to our questionnaire indicated that there is a high level of awareness on the need for helminth control, typically leading to several doses of anthelmintic being administered to each animal every year. While a majority of respondents (61%) were concerned about the issue of anthelmintic resistance, only a few were of the ...
von Samson-Himmelstjerna G, von Witzendorff C, Sievers G, Schnieder T.A survey on benzimidazole (BZ) resistance in small strongyles was performed on three farms in the tenth region in Chile. Samples from a total of 100 horses were tested using the faecal egg count reduction test (FECRT), the egg hatch assay (EHA) and an allele-specific PCR for the detection of beta-tubulin isotype 1 genes coding for phenylalanine (phe) or tyrosine (tyr) at codon 200. In the past, BZ-type drugs have been used within anthelmintic campaigns on all the three farms. This has predictably led to a high degree of BZ resistance at the Valdivia and Riñihue farms and to a lesser degree at...
Larsen MM, Lendal S, Chriél M, Olsen SN, Bjørn H.A questionnaire survey regarding endoparasite control practices in Danish horse herds was carried out in 1995. The participating veterinarians and herd owners were sampled using convenience and purposive sampling. In the analysis of risk factors for development of a high endoparasitic burden (> 200 eggs per gram faeces) 903 horses were sampled and the analysis of the efficiency of a single anthelmintic treatment was based on 605 horses. The following factors had a significant effect on the endoparasitic burden: herd type, age of the horses, use of pasture rotation, anthelmintic treatment of ho...
Pook JF, Power ML, Sangster NC, Hodgson JL, Hodgson DR.Resistance, especially to the anthelmintic benzimidazoles (BZ), has been reported in horse cyathostomes world-wide. Diagnosis of resistance has traditionally been made by faecal egg count reduction (FECR) trials, however, this technique has limitations. Some of the shortcomings may be resolved by refining the test or by using an in vitro test. FECR tests and the larval development assay (LDA) were performed on adult horses held on 15 different horse properties across a wide geographical area of NSW, Australia. FECR were measured before and 10-14 after days treatment with oxibendazole (OBZ), mo...
Martin-Downum K, Yazwinski T, Tucker C, Fincher M, Ralph J, Hamilton J.Commercial preparations of fenbendazole (Safe-Guard, Intervet), ivermectin (Eqvalan, Merial) or moxidectin (Quest, Fort Dodge) were administered once to horses scheduled for routine parasiticide treatment. In total, 93 horses from six cooperating farms were used in the study. Computer generated, random allocation of horses to treatment group was conducted at each farm. Fecal egg counts were determined for all horses on trial days 0, 56, 84 and 112, with corresponding calendar dates that were unique to each farm. Only strongyle egg counts from animals which were positive at day 0 were used for ...
Mercier P, Chick B, Alves-Branco F, White CR.Eighty horses were involved in a comparative, controlled, and randomised field study conducted in Australia and Brazil. This study was undertaken to address the duration of efficacy (by faecal egg count reduction) of four anthelmintic pastes and to measure the time required between treatments on horses naturally infected by gastrointestinal nematodes. The treatment interval was based on the egg reappearance period (ERP), defined as "the period after treatment when horses have reached a positive egg count equal or superior to 200 eggs per gram (epg) of faeces". Horses were ranked according to p...
Klei TR, Rehbein S, Visser M, Langholff WK, Chapman MR, French DD, Hanson P.Two trials were conducted to confirm the efficacy of ivermectin paste against endoparasites of horses. In these trials, 20 ponies were treated with ivermectin oral paste at 200 mcg x kg body weight once on Day 0, and 20 ponies served as unmedicated controls. The animals carried naturally acquired parasite infections as confirmed by pretrial fecal examination. The animals were necropsied for worm recovery on Days 14, 15 or 16. Parasites recovered were identified to species. Horses treated with ivermectin had significantly (P99.0% reduction) adult small strongyles (Coronocyclus spp including C. ...
Tarigo-Martinie JL, Wyatt AR, Kaplan RM.To determine the prevalence and clinical implications of anthelmintic resistance in cyathostomes of horses. Methods: Prospective study. Methods: 80 horses on 10 farms in a 5-county region of northeast Georgia. Methods: On each farm, horses were stratified in descending order according to pretreatment fecal egg count (FEC), blocked into groups of 4, and then randomly assigned to 1 of 4 treatment groups: no treatment (controls), and treatment with pyrantel pamoate, fenbendazole, or ivermectin. Fecal samples were collected 24 hours prior to treatment and 2, 4, and 6 weeks after treatment for dete...
Bairden K, Brown SR, McGoldrick J, Parker LD, Talty PJ.The efficacy of moxidectin 2 per cent equine gel against naturally acquired strongyle infections was assessed in 18 ponies which had grazed on contaminated pasture before being housed for eight weeks. Twenty-four hours before the treatment, two randomly selected ponies were euthanased and their worm burdens were determined. Eight of the remaining 16 ponies were treated with moxidectin 2 per cent gel while the other eight were given a placebo gel. Eight weeks later the 16 animals were necropsied and their worm burdens established. A 100 per cent efficacy was recorded against adult and lumenal L...
Davies JA, Schwalbach LM.The efficacy of ivermectin, fenbendazole, pyrantel pamoate and doramectin was evaluated under field conditions at 2 sites in the Free State Province of South Africa. The study involved 25 horses at each site, divided into 5 groups of equal size. Ivermectin, fenbendazole and pyrantel pamoate were administered orally at doses of 0.2, 10 and 19 mg/kg respectively. Doramectin was administered by intramuscular injection at a dose of 0.2 mg/kg. Treatment efficacy was based on the mean faecal egg count reduction 14 days post treatment. At site A a faecal egg count reduction of 100% was found after tr...
Várady M, Königová A, Corba J.The present study included 19 stud farms, including 243 horses, that were investigated for the occurrence of anthelmintic resistant cyathostomes. The number of horses on the farms varied from nine to more than 100, and horses of all ages were included. A minimum of seven horses were used for faecal egg count reduction (FECR) tests. The anthelmintics included were: fenbendazole (paste formulation), ivermectin (paste formulation) and pyrantel (powder). Resistance to benzimidazoles was detected on 14 farms, with FECR values ranging from 65.1 to 86.3%. Larval cultures after fenbendazole treatment ...
Lloyd S, Smith J, Connan RM, Hatcher MA, Hedges TR, Humphrey DJ, Jones AC.One hundred and fifty horse owners, primarily private owners and riding schools, replied to a questionnaire concerning the practices they used to control parasites. Twenty-seven had experienced a parasite problem. Faecal samples from 188 horses selected at random showed that worm control practices were generally successful; however, many owners were not following recommendations for slowing the development of resistant parasites. In 1996, 86 per cent of the owners were using either three or two classes of anthelmintic a year, and they used a median of six doses with a range from one to 11. App...
Webster JH, Baird JD, Gunawan M, Martin IC, Kelly JD.The susceptibility of a known thiabendazole-resistant population of small strongyles to anthelmintics of both benzimidazole and non-benzimidazole groups, was determined. In the first study, 42 horses infected with thiabendazole-resistant small strongyles were allocated to 6 groups. Treatment groups received one of the following anthelmintics: mebendazole, febantel, febantel plus trichlorphon, morantel tartrate, or a combination of thiabendazole, piperazine and trichlorphon. Morantel tartrate and the thiabendazole/piperazine/trichlorphon combination produced highly significant (p less than 0.00...
Wilkes EJA, Cowling A, Woodgate RG, Hughes KJ.Faecal egg counts (FEC) are used widely for monitoring of parasite infection in animals, treatment decision-making and estimation of anthelmintic efficacy. When a single count or sample mean is used as a point estimate of the expectation of the egg distribution over some time interval, the variability in the egg density is not accounted for. Although variability, including quantifying sources, of egg count data has been described, the spatiotemporal distribution of nematode eggs in faeces is not well understood. We believe that statistical inference about the mean egg count for treatment decis...
Epe C, Kings M, Stoye M, Böer M.Wild equids maintained in large enclosures may suffer from helminth diseases because common hygiene practices have only limited effects on parasite populations. Weekly monitoring of helminth prevalences and pasture infestation was performed for 1 yr in several extensive maintenance systems of two wildlife parks with similar climates to determine when veterinary intervention to control parasites would be useful. We also sought evidence of natural immunogenic reactions among herds of Chapman zebras (Equus quagga antiquorum), Przewalski's horses (Equus przewalskii) and dwarf donkeys (Equus asinus...
Reinemeyer CR.Efforts to control cyathostome nematodes in temperate climates have not been uniformly successful, as evidenced by contemporary reports of clinical disease and widespread anthelmintic failure. Indeed, effective control is confounded by numerous factors, including ignorance of local transmission patterns, confusing or conflicting control recommendations, and use of ineffective anthelmintics or regimens. Most of these problems are universal rather than being climatically unique, and it is important to recognize that they are mere symptoms of larger and more comprehensive problems. The most basic...
Collas C, Fleurance G, Cabaret J, Martin-Rosset W, Wimel L, Cortet J, Dumont B.Agroecology opens up new perspectives for the design of sustainable farming systems by using the stimulation of natural processes to reduce the inputs needed for production. In horse farming systems, the challenge is to maximize the proportion of forages in the diet, and to develop alternatives to synthetic chemical drugs for controlling gastrointestinal nematodes. Lactating saddle mares, with high nutritional requirements, are commonly supplemented with concentrates at pasture, although the influence of energy supplementation on voluntary intake, performance and immune response against parasi...
Ashrafzadeh-Shiraz M, Tavassoli M, Dalir-Naghadeh B, Sazmand A.This study aimed to evaluate the efficacy of fenbendazole and ivermectin on strongyles and Parascaris sp. infecting adult riding horses in three regions with different climates. During 2021 and 2022 fecal specimens were randomly collected from 483 horses older than three years in 31 equestrian clubs in Hamedan (n = 217), Yazd (n = 146) and Tabriz cities (n = 120). Eggs were counted by McMaster technique, and the strongyle larvae were identified using coproculture, PCR and sequencing. Horses with strongyles and Parascaris egg counts ≥150 were enrolled in fecal egg count reduction (FECR)...
Bell J, Raidal S, Peters A, Hughes KJ.Management of diarrhoea in horses is usually non-specific and supportive. Faecal microbiota transplantations (FMT) are used to manage dysbiosis in horses with diarrhoea. There are few studies investigating the effects of storage on prepared FMT solutions. This study was an in vitro non-randomised controlled experiment that investigated the effects of FMT solution preparation and storage on the faecal microbiota. Fresh faeces were collected from five healthy adult horses and used for DNA extraction and preparation of FMT. From each FMT, seven aliquots were collected and DNA was extracted immedi...
Steuer A, Fritzler J, Boggan S, Daniel I, Cowles B, Penn C, Goldstein R, Lin D.Current methods for obtaining fecal egg counts in horses are often inaccurate and variable depending on the analyst's skill and experience. Automated digital scanning of fecal sample slides integrated with analysis by an artificial intelligence (AI) algorithm is a viable, emerging alternative that can mitigate operator variation compared to conventional methods in companion animal fecal parasite diagnostics. Vetscan Imagyst is a novel fecal parasite detection system that uploads the scanned image to the cloud where proprietary software analyzes captured images for diagnostic recognition by a d...
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...
Nowak AC, Macho-Maschler S, Biermann NM, Palme R, Dengler F.Horses are highly sensitive to stress, which can affect their wellbeing and lead to various health issues. Effective and objective stress assessment is therefore crucial for improving their care and management. The production of the glucocorticoid cortisol is increased in response to stressful stimuli and its metabolites can be measured non-invasively in feces. Therefore, this study aimed to explore the impact of different environmental and physiological stressors on fecal cortisol metabolite (FCM) concentrations in horses, with a particular focus on the relationship between stress, health, an...
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...
Lu Y, Ru P, Qin S, Zhang Y, Fu E, Cai M, Tuohuti N, Wu H, Zhang Y, Zhang Y.Gastrointestinal parasitic diseases pose significant health risks to equine populations. This study investigated the epidemiological patterns of equine gastrointestinal parasites in Xinjiang by analyzing 83 fecal samples collected from Ili ( = 62) and Urumqi ( = 21) between August and November 2024. The modified McMaster technique was employed to quantify fecal egg counts (EPG) and was complemented by morphological identification to assess infection dynamics related to geography, breed specificity, and management practices. The results demonstrated an overall infection prevalence of 66.3% (55/...
Martin F, Halvarsson P, Alm YH, Tydén E.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. Ele...
TURK RD, UECKERT BW, BELL RR.No signs of intoxication were seen in horses dosed with thiabendazole at either 200 mg. or 400 mg. per kg. body-weight. 17 horses were dosed with the drug at a level of 100 mg. per kg. These horses had a mean egg count of 1, 296 e.p.g. before treatment; all were negative for strongyle eggs by the 7th day after treatment. 3 of these horses were killed and few or no strongyles were found; an untreated control animal killed at the same time had many thousands of strongyle worms. Thiabendazole was effective when given either by stomach tube or when mixed in the feed.
Schumacher J, Livesey L, DeGraves F, Blagburn B, Ziska S, Caldwell M, Brock K.This study was undertaken to determine whether resistance to moxidectin had developed in a large herd of draught horses, maintained on a small acreage, which had been routinely treated with moxidectin for five years. Faeces were collected for egg counts immediately before moxidectin gel was administered orally, and seven, 30, 60 and 90 days later. The faecal egg counts were significantly reduced at seven and 30 days after treatment, but were not significantly different from pretreatment counts at 60 and 90 days after treatment. There was no evidence of resistance having developed.
Meier A, Hertzberg H.Small strongyles (cyathostomes) that are resistant against anthelmintics have become a major problem in equine medicine in the recent years. In many European countries benzimidazole-resistant cyathostomes are widespread and are now present in well over 50% of equine populations investigated. In contrast, resistance against ivermectin has not been reported despite its widespread use in the recent years. Optimising the frequency of treatments based on quantitative faecal monitoring is of great importance to preserve remaining anthelmintic efficacy.
Anderson IG, Hasslinger MA.The faeces of 34 horses of the "Bavarian main and state studfarm Schwaiganger" (Group I) and 10 ponies (Group II) from various regions of the Federal Republic of Germany, were examined and 4 834 small strongyles were identified. Three species Cyathostomum catinatum, Cylicostephanus longibursatus and Cylicocylus nassatus, were found to be widely distributed. Although various modern anthelmintics with different effective components were used over the past 20 years, no remarkable change has been brought about in the composition of the parasitic species of the horses in the Federal Republic of Ger...
Lyons ET, Tolliver SC, Rathgeber RA, Collins SS.Foals (79), born in 2004 on three thoroughbred horse farms (C, M, and S) in central Kentucky, were fed pyrantel tartrate daily, beginning at about 3 months of age. In addition, other parasiticides [fenbendazole (FBZ), ivermectin (IVM) alone or with praziquantel (PRAZ), oxibendazole (OBZ), pyrantel pamoate (PRT), and moxidectin (MOX)] were given periodically. All treatments were administered by farm personnel. Over a 14-month period, from May 2004 to July 2005, collections (n=989) of feces were made from the foals for determination of presence of internal parasite eggs/oocysts by qualitative an...
de Favare GM, de Almeida Cipriano I, do Carmo TA, Mena MO, Guelpa GJ, do Amarante AFT, de Soutello RVG.The indiscriminate use of drugs to control gastrointestinal helminths in horses can lead to serious consequences for the animals, which represents a growing problem for health, animal welfare and productivity. Therefore, the present study aimed to evaluate the anthelmintic efficacy of ivermectin in naturally infected horses in the western region of the state of São Paulo. From May 2021 to April 2022, 123 naturally infected adult horses in 12 equine breeding farms (7 to 14 animals per farm) were evaluated with the fecal egg count reduction test. The horses had not been treated with anthelminti...
Duncan JL, McBeath DG, Preston NK.The efficacy of a fenbendazole divided dose regime against immature stages of Trichonema spp, Strongylus vulgaris and Strongylus edentatus was evaluated. A group of 8 naturally infected 30 to 36-month-old ponies was divided into 2 equal groups on the basis of previous treatment and faecal egg counts, one group being treated with 7.5 mg/kg bwt of fenbendazole daily for 5 days. This treatment regime removed 80 per cent of migrating S vulgaris larvae, 100 per cent of migrating S edentatus larvae and 95 per cent of the mucosal stages of Trichonema spp. In addition, a virtual 100 per cent eliminati...
Kornaś S, Cabaret J, Nowosad B.Faecal egg counts were performed in 187 foals of a large Polish stud farm between February and September 2007. Eggs of Parascaris equorum were present in faeces of 7% and those of cyathostomins in 13% of the foals aged less than 194 days. Information dealing with age of foals and/or efficiency of ivermectin treatment as well as the nematode parasite prepatent periods, it can be conducted that most of the infections recorded on the basis of faecal egg counts were false-infections in animals up to the age of six months, probably due to the ingestion of infected faeces of their dam or some other ...
Sokół R, Raś-Noryńska M, Michalczyk M, Raś A, Rapacz-Leonard A, Koziatek S.Studies were carried out in year 2014 during the pasture period (from April to October) in Warmia and Mazury Region. Fecal samples were taken from cold- and warmblood horses from individual and agrotouristic farms with the different housing, feeding and pasture- care practices. Total of 512 horses were examined (320 mares, 170 geldings and 22 stallions). In the group of 185 horses from individual farms, 119 animals (64.3%) were infected with gastro-intestinal parasites. Among the 372 horses from agrotouristic farms 169 (51.7%) were infected with parasites. Most of the animals expelled the eggs...
Mirck MH, van Meurs GK.Seven foals naturally infected with Strongyloides westeri were injected intramuscularly with ivermectin at a dosage rate of 200 mcg per kg body weight. No adverse effects to treatment were observed. Weekly faecal egg counts showed a greater than 99 per cent reduction of S. westeri egg output compared with 7 untreated foals during the 21 days following treatment.
Knubben-Schweizer G, Pfister K.Anthelmintic resistance of gastrointestinal nematodes in small ruminants, but also in cattle and horses, is now found worldwide. The reason for increasing anthelmintic resistance is, in particular, the extensive use of all the anthelmintic agents available on the market. A non-targeted use leads to the selection of naturally occurring resistance genes within parasite populations. The most practical method for evaluating the efficacy of an anthelmintic is the fecal egg-count reduction test. To reduce the rate of anthelmintic resistance development, the available active substances must be applie...
Dorchies P, de Lahitte JD, Flochlay A, Blond-Riou F.The efficacy of moxidectin 2% oral gel (Equest, Fort-Dodge) against European worm strains was studied through post-mortem worm counts and feacal egg counts (FECs) in 12 young ponies naturally infected. The animals were allocated in two groups of six ponies each: the first one was treated at 0.4 mg/kg b.w. and the second one received a placebo and served as control. All the ponies were necropsied 14 days post-treatment. The efficacy of moxidectin in reducing strongyle FECs ranged from 99.8% to 100% from 3 to 14 days after treatment. Moxidectin efficacy was 100% against Trichostrongylus axei and...
Eysker M, Boersema JH, Kooyman FN.Overwintering of horse cyathostomes as inhibited third stage larvae (L3) and the effect of repeated oxfendazole (OFZ) treatment on strongyle infections were studied in an experiment with two groups of three Shetland ponies. Both groups were grazed together from May 28 to November 11, 1986 and subsequently housed. Treatments with 10 mg OFZ kg-1 were given on May 26, July 1 and July 28 and again one week before each group was necropsied in December and April, respectively. Worm populations of both groups were dominated by inhibited early L3. The proportion of fourth stage larvae (L4) was signifi...
Reinemeyer CR, Prado JC, Andersen UV, Nielsen MK, Schricker B, Kennedy T.Strongylid infections are ubiquitous in grazing horse populations. Infections with cyathostomin (small strongyle) and strongylin (large strongyle) nematodes have long been associated with clinical disease in horses, but little is known about their subclinical impact. A masked, randomized, controlled study was conducted to evaluate the effects of daily administration of pyrantel tartrate on body condition scores, weight gain, fecal egg counts, and total worm counts of young horses repeatedly inoculated with strongylid larvae. Twenty eight immature horses were treated with larvicidal anthelminti...
Salas-Romero J, Gomez-Cabrera K, Molento MB, Lyons ET, Delgado A, González L, Arenal A, Nielsen MK.Equine cyathostomin parasites are ubiquitous in grazing horses and have been shown to cause severe inflammatory disease in the large intestine of horses. Decades of intensive anthelmintic therapy have led to widespread anthelmintic resistance in cyathostomins across the world. In Cuba, no anthelmintic products are formulated and sold for equine usage and little is known about anthelmintic efficacy of ruminant and swine formulations used. A strongyle fecal egg count reduction test was used to assess the efficacy of a liquid formulation of ivermectin labelled for use in swine, ruminants and carn...
Roelfstra L, Betschart B, Pfister K.In a study on the seasonal dynamics of the gastro-intestinal nematode egg production in horses, one breeding farm also revealed a particularly high prevalence of Anoplocephala spp. infection. Consequently, this farm was chosen for analysing the seasonal pattern of the tapeworm egg excretion over a one year period in order to establish the most favourable periods for an appropriate and successful cestocidal treatment. The seasonal analysis showed a significantly higher (p < 0.05) Anoplocephala spp. egg excretion between July and October, i.e. during the second part of the grazing period. This r...
