Veterinary parasitology.
Publisher:
Elsevier Scientific Pub. Co.. Amsterdam : Elsevier
Frequency: Monthly, 2019-
Country: Netherlands
Language: English
Start Year:1975 -
ISSN:
0304-4017 (Print)
1873-2550 (Electronic)
0304-4017 (Linking)
1873-2550 (Electronic)
0304-4017 (Linking)
Impact Factor
2.6
2022
| NLM ID: | 7602745 |
| (DNLM): | V05960000(s) |
| (OCoLC): | 01939255 |
| Coden: | VPARDI |
| Classification: | W1 VE933U |
Macrocyclic lactone-resistant Parascaris equorum on stud farms in Canada and effectiveness of fenbendazole and pyrantel pamoate. The aims of studies in 2002 and 2003 on three farms with 76 foals naturally infected with Parascaris equorum were to (i) identify if the nematode was resistant to ivermectin and moxidectin, and (ii) confirm the effectiveness of fenbendazole and pyrantel pamoate for the parasite. Twelve clinical trials, each with a Fecal Egg Count Reduction Test, were conducted on two Thoroughbred and one Standardbred farms in southwestern Ontario, Canada. In each trial, Parascaris eggs/g feces were estimated for each foal pre- and post-treatment using the Cornell-Wisconsin double flotation and Cornell-McMaster...
Association between the presence of serum antibodies against Neospora spp. and fetal loss in equines. A study of the association between the presence of serum antibodies against Neospora spp. and fetal loss was performed using serum samples of horses submitted to the laboratory for the detection of antibodies to Equine Herpesvirus-1 and Equine Infectious Anemia Virus. The sera submitted for equine infectious anemia testing were from horses declared healthy and those submitted for the detection of antibodies to Equine Herpesvirus-1 were from mares with late clinical signs of reproductive disorders or males living in close contact with diseased mares. For the detection of Neospora spp. infection...
Prevalence of antibodies to Encephalitozoon cuniculi in horses from Brazil. Encephalitozoon cuniculi has been associated with natural cases of abortion and stillbirth in horses. However, little is known about the prevalence of this parasite in horses. We examined sera from 559 horses from Brazil for antibodies to E. cuniculi using the indirect immunofluorescent antibody (IFA) test and the direct agglutination test (DAT). We found that 79 (14.1%) were positive in the IFA test and 70 (12.5%) were positive in the DAT. Compared to the IFA as the "gold standard" the sensitivity of the DAG was 94.0% and the specificity was 96.1%. Our study indicates that horses in Brazil ar...
Field study on the survival, migration and overwintering of infective larvae of horse strongyles on pasture in central Ukraine. Experimental studies on the survival of infective stage larvae of horse strongyles and their ability to overwinter on pasture were carried out in central Ukraine (Poltavska oblast). Faecal pats (1.5 kg each) of naturally infected horses were placed on pasture, and samples of faeces and surrounding vegetation (10 g each) were collected each month, excluding the winter months, from November 2002 until April 2004. The number of infective third stage larvae was calculated in each sample and compared with that from the control faecal samples cultivated in the laboratory. In the control samples, the...
Molecular cross-sectional survey of gastric habronemosis in horses. Gastric habronemosis of horses caused by Habronema microstoma and Habronema muscae (Nematoda, Spirurida) is characterized by catarrhal gastritis, diarrhoea, progressive weight loss and ulcers. Despite its importance in the equine industry and in clinical practice, knowledge of the epidemiology of this infection is still incomplete as diagnosis in live animals is challenging. A two-step semi-nested PCR assay using ribosomal DNA (rDNA) markers has recently been used for the molecular diagnosis in vivo of gastric habronemosis based on the detection of H. microstoma and/or H. muscae DNA in equine ...
Clinical and therapeutic studies on mange in horses. At Kafr El-Sheikh province, Egypt, out of 117 examined drafting horses, mites were detected in 20 (17.09%) horses. The recovered mites were 14 Chorioptes, four Psoroptes and two Sarcoptes whereas mites were not detected in four cases clinically showed typical mange lesions. Interestingly, neither the age nor the sex of the examined horses had a clear influence on the prevalence of the infection. Clinical signs observed in mange infested horses were in the form of irregular skin lesions, severe itching and sometimes biting of affected skin areas and decrease feed consumption. The skin lesions m...
A new approach for the diagnosis of myiasis of animals: the example of horse nasal myiasis. The myiasis caused by larvae of Rhinoestrus purpureus and Rhinoestrus usbekistanicus (Diptera, Oestridae) are of importance in the horse medicine since it causes severe respiratory diseases. Therefore an accurate diagnosis of rhinoestrosis is central to its epidemiology and control. This paper describes concisely a molecular diagnostic tool that overcomes the current inherent diagnostic constraints and, therefore, is of importance to understand the actual incidence and epidemiology of this myiasis in live horses.
Gastrointestinal parasitic worms in equines in the Paraíba Valley, State of São Paulo, Brazil. Over a period of 12 years, from 1988 to 2000, a total of 20 individual equines (16 horses and 4 mules) were selected at random, from 10 municipalities in the Paraíba Valley, in the State of São Paulo, Brazil, and then subjected to necropsy for collection of gastrointestinal worms. Individual samples of 10% of the intestinal contents were also taken for counting and identifying the species present, and to establish the prevalence of worms in equine species in the Paraíba Valley. In the sample considered, the presence of parasites ranged from 155 to 1249 worms. Tapeworms (Cestoidea) were pres...
Cyathostomes in horses in Canada resistant to pyrantel salts and effectively removed by moxidectin. Clinical trials using fecal egg count reduction tests and coproculture were conducted with yearlings and mares on a farm in 1997. Fecal samples were taken from each horse to estimate the number of strongyle eggs/g feces with Cornell-Wisconsin centrifugal flotation and Cornell-McMaster dilution techniques. Eleven of 15 yearlings, which had been on a daily feeding of grain with pyrantel tartrate for 66 d were found with strongyle eggs in feces. This was the first time the in-feed medication had been used on the farm. Nine yearlings were randomised into three groups; continuation of daily pyrante...
Small strongyle infection: consequences of larvicidal treatment of horses with fenbendazole and moxidectin. The study was undertaken to evaluate adverse effects of larvicidal treatment in horses naturally infected with cyathostomins. Out of 24 ponies kept on pasture, four animals were housed in September and anthelmintically cured to serve as worm-free controls (group C-0). The others were housed in December. Eight animals each were treated 8 weeks later with 5 x 7.5mg/kg fenbendazole (FBZ) or 1 x 0.4 mg/kg moxidectin (MOX). Four animals remained untreated (group C-i). Two, 4, 6 and 14 days after the end of treatment two animals of each of the treated groups were necropsied together with group C-0 a...
Evaluation of enzyme-linked immunosorbent assays with recombinant antigens for the serodiagnosis of equine Babesia infections. Two enzyme-linked immunosorbent assays (ELISA) with recombinant protein as antigens were evaluated by comparison with the indirect fluorescent antibody tests (IFAT) for the detection of specific antibodies to Babesia caballi and Babesia equi, respectively in 380 sera from experimentally infected, uninfected, and field horses. The high concordances of 92.4% (351/380) and 98.2% (373/380) between ELISA and IFAT for B. caballi and B. equi, respectively suggest that ELISA, especially for B. equi infection, could be alternative to the corresponding IFAT for serodiagnoses of equine piroplasmosis, alt...
Haycocknema-like nematodes in muscle fibres of a horse. A 14-year-old horse (imported to Switzerland from Ireland 8 years earlier) showed signs of chewing muscle atrophy. A severe chronic myositis, caused by numerous immature and mature female nematodes, was diagnosed in muscle samples obtained by biopsy and subsequently at necropsy. Most of the nematodes had invaded muscle fibres of the masseter, root of the tongue and anterior breast, only a few were found in the intermuscular interstitium. Isolated nematodes and parasite sections were clearly different from muscle larvae of Trichinella spp. but showed morphological similarities to Haycocknema pe...
Immune response to Sarcocystis neurona infection in naturally infected horses with equine protozoal myeloencephalitis. Equine protozoal myeloencephalitis (EPM) is one of the most common neurologic diseases of horses in the United States. The primary etiologic agent is Sarcocystis neurona. Currently, there is limited knowledge regarding the protective or pathophysiologic immune response to S. neurona infection or the subsequent development of EPM. The objectives of this study were to determine whether S. neurona infected horses with clinical signs of EPM had altered or suppressed immune responses compared to neurologically normal horses and if blood sample storage would influence these findings. Twenty clinical...
Dose-confirmation studies of the cestocidal activity of pyrantel pamoate paste in horses. Dose confirmation studies of the cestocidal activity of pyrantel pamoate paste were conducted at two sites in North America during 2001. Horses with naturally-acquired cestode infections were identified by detection of typical Anoplocephala spp. eggs in feces collected between 7 and 92 days prior to treatment. Twenty and 22 horses were enrolled at Site 1 (Urbana, IL) and Site 2 (Knoxville, TN), respectively. Candidate horses were acclimated to study conditions for 14 days, ranked by length of interval since coprologic confirmation, and allocated randomly to one of two treatment groups: (T1) py...
Penetration of equine leukocytes by merozoites of Sarcocystis neurona. Horses are considered accidental hosts for Sarcocystis neurona and they often develop severe neurological disease when infected with this parasite. Schizont stages develop in the central nervous system (CNS) and cause the neurological lesions associated with equine protozoal myeloencephalitis. The present study was done to examine the ability of S. neurona merozoites to penetrate and develop in equine peripheral blood leukocytes. These infected host cells might serve as a possible transport mechanism into the CNS. S. neurona merozoites penetrated equine leukocytes within 5 min of co-culture. I...
Seroprevalences of Toxoplasma gondii and Neospora sp. infections in Swedish horses. Sera from 414 Swedish horses were investigated for the presence of antibodies to Toxoplasma gondii and Neospora sp. by the T. gondii direct agglutination test (DAT), and an Neospora caninum iscom-ELISA. Five sera (1%) had a titre >1:40 in DAT, but when analysed by immunoblotting against T. gondii antigens only two of them were positive, giving a seroprevalence of 0.5%. Since the Neospora iscom ELISA had not been validated for equine sera it was used for an initial screening, and all sera with an optical density exceeding 0.200 absorbance units were selected for further investigation by immu...
Babesia–a historical overview. The history of the genus Babesia is briefly outlined. The classical differences with the main other genus of non-pigment-forming hemoparasites, Theileria, are the absence of extra-erythrocytic multiplication (schizogony) in Babesia and the cycle in the vector tick, which includes transovarial transmission in Babesia but only transstadial transmission in Theileria. Also, the multiplication in the red cell of Babesia, by budding, most often results in two daughter cells (merozoites), while that of Theileria gives four merozoites, often as a Maltese cross. In particular this means that what is st...
Rhythm of engorgement and detachment of Anocentor nitens females feeding on horses. The present study evaluated the engorgement and drop-off rhythms of Anocentor nitens females feeding on horses. Drop-off rhythm was evaluated at 6h-intervals (06:00, 12:00, 18:00, and 00:00 h) on horses held in stalls or in a pasture. A new method of marking feeding female ticks (the bowknot technique) was developed to evaluate ticks on horses in pasture that attached to different parts of the horse's body. This technique was highly successful, indicating no significant interference on tick engorgement rate or final tick weight, length and reproductive capability. Horses held in the pasture du...
Epidemiological study of the cystic echinococcosis in Morocco. The objectives of this epidemiological study on cystic echinococcosis (CE) in Morocco (2001-2004) were to update the prevalence of CE in different animal species living in the most important areas of the country and to collect protoscoleces and germinal layers for genetic research purposes. The post mortem inspection concerned 2948 sheep, 2337 goats, 618 cattle, 482 camels and 455 equines (325 horses, 60 mules and 70 donkeys) in five different regions: the Rif (Mediterranean coast and high mountains of the Rif), the Loukkos (Atlantic northwest plain), the center (Rabat and Casablanca regions),...
Clinical field efficacy and safety of pyrantel pamoate paste (19.13% w/w pyrantel base) against Anoplocephala spp. in naturally infected horses. Clinical field trials were conducted at five geographical locations in the USA (Oklahoma, Wisconsin, Tennessee, Virginia and Idaho) to evaluate the efficacy and safety of pyrantel pamoate paste (19.13%, w/w, pyrantel base) administered at the recommended dosage of 13.2 mg pyrantel base/kg (6.0 mg pyrantel base/lb) body weight (b.w.) against tapeworm infections of Anoplocephala spp. in naturally infected horses. Horses at each study site were allocated by restricted randomization based on the cestode status (positive or negative) of pre-treatment fecal egg counts to complete sets of four animal...
Molecular diagnosis and equine parasitology. The future implementation of improved and sustainable control strategies for the major equine parasites will be dependent on a greater insight into their basic biology, pathogenicity and epidemiology together with an enhanced ability for accurate diagnosis. This paper will provide a review of the current molecular methods under development for the detection of equine parasites and their application to current scientific questions. In particular, the strongyles are recognised as important pathogens of horses and recent advances made in the study of this parasitic group at the single species lev...
The detection of anthelmintic resistance in nematodes of veterinary importance. Before revised World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines on the detection of anthelmintic resistance can be produced, validation of modified and new methods is required in laboratories in different parts of the world. There is a great need for improved methods of detection of anthelmintic resistance particularly for the detection of macrocyclic lactone resistance and for the detection of resistant nematodes in cattle. Therefore, revised and new methods are provided here for the detection of anthelmintic resistance in nematodes of ruminants, horses and ...
A multicenter evaluation of the effectiveness of Quest Gel (2% moxidectin) against parasites infecting equids. Controlled trials with a common protocol were conducted in Idaho, Illinois and Tennessee to evaluate anthelmintic effectiveness of Quest Gel (QG; 2% moxidectin) against lumenal parasites in horses. Candidate horses were required to have naturally acquired nematode infections, as confirmed by presence of strongylid eggs in feces. At each site, 24 equids were blocked on the basis of pretreatment strongyle fecal egg counts (EPG) and randomly assigned to treatments within blocks. Within each block of two animals, one received QG on Day 0 at a dosage of 0.4 mg moxidectin/kg b.w. and one was an untr...
Molecular diagnosis of anthelmintic resistance. Conventional and real time polymerase chain reaction-based tests have been developed for the diagnosis of anthelmintic resistance (AR) in populations of several small and large ruminant as well as horse gastro-intestinal nematode species. To date, molecular markers that correlate well with AR are available only for the detection of benzimidazole resistance. Recently, however, a single nucleotide polymorphism was found in vitro to be of functional relevance for reduced drug efficacy to macrocylic lactones. The focus of the present review, therefore, is the molecular mechanism of action of these...
Diversity of the infracommunities of strongylid nematodes in the ventral colon of Equus caballus from Rio de Janeiro state, Brazil. Nematodes from the ventral colon of 31 adult horses, 24 males and 9 females, in the metropolitan region of the state of Rio de Janeiro were analysed. There were 53,444 (86.4%) adults of the total recovered strongylid nematodes. They belonged to 21 species of Cyathostominae and seven of Strongylinae. Larval forms made up 13.6% (8407) of the total recovered, and 49% of the strongylid nematodes were observed in ventral colon. The most prevalent and abundant species were Cyathostomum tetracanthum, Cylicocyclus nassatus, Cylicostephanus minutus, Cylicostephanus longibursatus, Cylicostephanus leptos...
Prevalence of Sarcocystis neurona and Neospora spp. infection in horses from Brazil based on presence of serum antibodies to parasite surface antigen. Sera from 961 horses from Brazil were tested for antibodies against the major surface antigens SnSAG4 and NhSAG1 to determine the seroprevalence of Sarcocystis neurona and Neospora hughesi, respectively. Antibodies against SnSAG4 were detected in 669 (69.6%) of the horses, while antibodies against NhSAG1 were detected in only 24 (2.5%) of the horses. These serologic results suggest that there is a high concentration of S. neurona in the environment of Brazil, which results in marked exposure of horses to this parasite. Additionally, the data further confirm that infection with Neospora spp. is...
A modified critical test and its use in two dose titration trials to assess efficacy of praziquantel for Anoplocephala perfoliata in equids. Aims of this study with 43 equids naturally infected with Anoplocephala perfoliata in two dose titration trials were to document (i) the usefulness of a critical test with a 48 h treatment to necropsy period, (ii) efficacy of an oral paste of 0.5-2.0 mg praziquantel/kg body weight, and (iii) when after treatment would fecal egg counts provide best estimates of the tapeworm's prevalence in a herd. All feces passed by an equid after treatment and collected in successive 12 h batches were examined for tapeworms. At necropsy, tapeworms were identified as attached to the mucosa or unattached. Tapew...
Prescription-only anthelmintics–a questionnaire survey of strategies for surveillance and control of equine strongyles in Denmark. In 1999, legislation in Denmark made anthelmintic drugs available only by prescription, and prohibited their use for routine, prophylactic treatment. A questionnaire survey was conducted in 2004 to determine current strategies for surveillance and control of equine strongyles used in Danish equine veterinary practices. Eighty-seven of 170 (51.2%) registered equine veterinary practices responded. Ninety seven percent of the respondents used faecal egg counts for diagnosis and surveillance, and 41% used larval cultures. Logistic regression revealed that the use of larval cultures was positively ...
Investigation of Neospora sp. and Toxoplasma gondii antibodies in mares and in precolostral foals from Parana State, Southern Brazil. Antibodies to Neospora sp. and Toxoplasma gondii were measured in mares and precolostral foals from a farm in Parana State, Brazil. An indirect fluorescent antibody test (IFAT) was used to determine specific antibodies. Three sampling points, 2003, 2004 and at parturition were included in the study, but not all horses are represented at a parturition time point. In 2003, antibodies to Neospora were detected in 17 mares (47%) at 1:50 dilution and in 5 mares (13.8%) at 1:100 dilution. In 2004, antibodies to Neospora were found in 11/36 (30%) horses with titers of 1:50 and in 6 mares (16.6%) at 1...
Strongyle egg shedding consistency in horses on farms using selective therapy in Denmark. Knowledge of horses that shed the same number of strongyle eggs over time can lead to the optimization of parasite control strategies. This study evaluated shedding of strongyle eggs in 424 horses on 10 farms when a selective anthelmintic treatment regime was used over a 3-year period. Faecal egg counts were performed twice yearly, and horses exceeding 200 eggs per gram (EPG) of faeces were treated. The results are presented as probabilities of the egg count outcome, when two previous egg counts are known. A horse with no strongyle eggs detected in the two previous faecal examinations had an 8...