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Topic:Parasites
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.
Experimental intraspinal trypanosoma equiperdum infection in a horse. To establish the ability of Trypanosoma equiperdum to cross the blood-brain-barrier in the horse, a susceptible stallion was infected via the cerebrospinal fluid of the subarachnoid space by lumbosacral puncture. Cerebrospinal fluid with low detectable levels of trypanosomes removed from a dourine-infected mare by lumbosacral puncture was used for infecting the animal. The parasite was detected in blood smears of the recipient 13 days after infection and the subsequent parasitaemia and clinical course of the disease followed that of naturally infected horses.
Thelazia lacrymalis in horses in Kentucky and observations on the face fly (Musca autumnalis) as a probable intermediate host. Eyes from 114 (30.3%) of 376 dead horses, examined from 3 April 1975 to 3 April 1976, were naturally infected with adult Thelazia lacrymalis; 1 horse was also infected with 1 male Thelazia skrijabini. Adult T. lacrymalis from dead horses were successfully transferred mechanically to the eyes of 3 of 4 Shetland ponies raised helminth-free. Larvae from gravid female T. lacrymalis underwent development in experimentally infected, laboratory-raised face flies (Musca autumnalis) and third-stage larvae ranging from 1.82 to 2.94 mm in total length were recovered at 12 to 15 days postexposure. A total...
Lungworm infection (Dictyocaulus arnfieldi) of horses and donkeys. Dictyocaulus arnfieldi (Cobbold 1884) infects the respiratory tract of horses, donkeys, mules, hinnies and zebra. A review of the literature has been given by Round (1972). In the western hemisphere it is popularly believed that donkeys are the natural host and that horses become infected by association with infected donkeys. There is scant documentary evidence for this and, in the Soviet Union, patent infections may reach 70 per cent without mention of donkey association (Koulikov 1935, Borovkova 1948, Akramovskii 1952a). Poynter (1963) considered the infection to be rare in the United Kingdo...
The capybara (Hydrochoerus hydrochaeris) as a reservoir host for Trypanosoma evansi. Discovery of two ill horses and three dogs naturally infected with Trypanosoma evansi near an experimental station in the Eastern Plains of Colombia led to a search for reservoir hosts of the parasite. Infection was detected in 8/33 healthy capybaras (Hydrochoerus hydrochaeris), none of the remaining 14 horses, and none of 32 Zebu cattle (Bos indicus), 18 paca (Cuniculus paca) and 20 spiny rats (Proechimys sp.). Contrary to common opinion, the results indicated a carrier state in the capybara. Diagnosis was based on morphology, behaviour in albino rats, and pathogenicity and host range in dome...
Strongyle infections in ponies. I. Response to intermittent thiabendazole treatments. A group of seven ponies naturally infected with large numbers of small strongyles and raised under conditions to minimize reinfection were treated periodically over a three year span with thiabendazole at the rate of 44 mg/kg body weight. Based on the absence of worm eggs in the feces following each treatment, thiabendazole removed the adult strongyles present with a new population subsequently developing by maturation of inhibited larvae. It took as many as four or five treatments to eliminate or reduce significantly the worm burdens present in the ponies under the conditions of this study. S...
Strongyle infections in ponies. II. Reinfection of treated animals. Five of seven ponies whose strongyle worm burdens had previously been removed or markedly reduced by repeated thiabendazole treatments were reinfected with doses ranging from 100,000 to 500,000 small strongyle infective larvae. Reinfection of ponies resulted in the development of clinical signs characterized by abnormal feces, marked loss of weight and delayed shedding of winter hair coats. An abrupt increase in circulating eosinophils occurred during the first three weeks following reinfection. Patent infections developed in all ponies with worm eggs appearing in the feces from 12 to 15 weeks...
[On Setaria spp; (Nematoda, , Filarioidea, Setariidae) from the peritoneal cavity of equine spp.: two new sub-species, Setaria equina theilerae from wild Zebra of Africa, and Setaria equina dafaallai from horse and donkey of southern Sahara area (author’s transl)]. 1) Setaria equina (Abildgaard, 1789) is from the Horse and Donkey of Eurasia (and of America and the coastal stripe of North Africa). 2) Setaria equina theilerae n.sub.sp. is from the Zebra of Africa. 3) Setaria equina defaallai n.sub. sp. is from the Horse and the Donkey of southern Sahara area of the Ethiopean Region of Africa, from the Nile valley till to the western coast. 4) Crossing between S. equina and S. e. theilerae may be possible, as their host spp. does with the resultant bastard offspring experimentally.
The prevalence, relative abundance and site distribution of nematodes of the subfamily Cyathostominae in horses killed in Britain. A total of 21 species of Cyathostominae was found in the lumen of the large intestine of 86 mature horses of various ages and breeds killed in south-west England during 1972-1974. Cylicostephanus longibursatus, C. goldi, C. calicatus, Cyathostomum catinatum, C. coronatum and Cylicocyclus nassatus were found in over 80% of the horses, while 12 of the remaining species were detected in less than 30%. Quantitative studies on 55 horses showed the adult cyathostome burdens to rise to a sharp peak (average over 400,000/horse) in April-June and a lower one in November-December. Parallel fluctuations ...
A practical health programme for prevention of parasitic and infectious diseases in horses and ponies. A scheme of combined anthelmintic treatment and vaccination is described. The seasonal veterinary activities are as follows: March (all horses); parasitological examination of faeces, anthelmintic treatment, immunization against influenza and tetanus (booster dose). June: parasitological faeces examination of foals, anthelmintic treatment of all horses, immunization of foals against tetanus (1st dose). August: anthelmintic treatment of all horses and immunization of foals against influenza (1st dose) and tetanus (2nd dose). October: parasitological faeces examination and anthelmintic treatment...
Studies on the development and chemotherapy of larvae of Parascaris equorum (Nematoda: Ascaridoidea) in experimentally and naturally infected foals. Experimentally induced infections of Parascaris equorum in worm-free pony foals required 14 to 17 days for migration of the larvae through the liver and lungs, and 79 to 110 days to become gametogenically functional. Treatment of experimentally infected or naturally exposed foals during the parenteral phase of development, using levamisole at 8 mg/kg, a mixture of levamisole at 8 mg/kg plus piperazine at 88 mg base equivalent/kg, or dl-tetramisole at 10 mg/kg, was quite efficacious in (1) reducing the number of P. equorum larvae recovered from the small intestines of the foals at necropsy, or ...
Critical tests of anthelmintic activity of a paste formulation of thiabendazole in horses. Critical tests of the activity on large strongyles, ascarids, mature pinworms, and bots were carried out in 11 horses intraorally treated with a paste formulation of thiabendazole. The dose level of 44 mg/kg was administered to 3 horses, and the dose level of 88 mg/kg to 8 horses. Removals of Strongylus vulgaris and mature Oxyuris equi were 100% at the 2 dose levels, and efficacy against Strongylus edentatus varied from 95 to 99% and 89 to 100% for the 44- and the 88-mg/kg dose levels, respectively. Strongylus equinus was completely removed from the 1 infected horse treated at the dose level o...
Observations on the transmission, immunology, clinical signs and chemotherapy of dourine (Trypanosoma equiperdum infection) in horses, with special reference to cerebro-spinal fluid. This paper is a record of observations on the transmission and clinical signs of dourine in naturally infected cases of known duration, and of temporal and quantitative aspects of the immune response in blood and cerebro-spinal fluid. Included in the record are observations on the presence of Trypanosoma equiperdum parasites in these body fluids and methods for their detection. There is evidence that the occurrence of nervous symptoms and lesions in infected horses is associated with the presence of Trypanosoma equiperdum parasites in cerebro-spinal fluid. The suitability of cerebro-spinal flu...
The prevalence of Gasterophilus intestinalis and G nasalis in horses in Ireland. During the months October-May inclusive 90-8% of horses slaughtered at an abattoir near Dublin and 66-9% of those at an abattoir near Belfast were infected with Gasterophilus intestinalis; 28-6% of horses at the former abattoir harboured G nasalis while none of the horses examined at the latter abattoir was found to be infected with this species.
Critical tests with oxibendazole against gastrointestinal parasites of ponies. Twenty ponies were allotted to 4 groups of 5 ponies each, and oxibendazole was orally administered at dose levels of 5, 10, 15, and 20 mg/kg. In the 3 groups of ponies given the largest doses, efficacy against 3 species of Strongylus was between 92 and 100% and that against small strongylids of the genera Cyathostomum, Cylicocyclus, Cylicodontophorus, and Cylicostephanus was more than 99%. All adults and 95 to 100% of larvae of the pinworm Oxyuris equi were removed. In the group of ponies given 5 mg/kg, 86 to 100% of the large strongylids and 84 to 100% of the small strongylids were removed, a...
