Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Strongylus”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources

Benzimidazole resistance of equine strongyles: critical tests of several classes of compounds against population B strongyles from 1977 to 1981.

From 1977 to 1981, critical tests were conducted on 10 horses naturally infected with population B strongyles. Drugs tested were: oxibendazole (OBZ), 10 mg/kg of body weight (n = 1); albendazole, 10 mg/kg (n = 1); a mixture of thiabendazole (TBZ), 44 mg/kg and trichlorfon, 40 mg/kg (n = 1); a mixture of TBZ at 44 mg/kg with piperazine (PPZ) at 55 mg of base/kg (n = 1); febantel (FBT), 6 mg/kg (n = 3), 12 mg/kg (n = 1), or 24 mg/kg (n = 1); and pyrantel (PRT) pamoate, 6.6 mg of base/kg (n = 1). Large strongyles, Strongylus vulgaris (9 horses) and S edentatus (5 horses), were effectively removed (100%) by each compound and mixture. Five species of small strongyles (Cyathostomum catinatum, Cyathostomum coronatum, Cylicocyclus nassatus, Cylicostephanus goldi, and Cylicostephanus longibursatus), previously singled out in this population as resistant to 5 benzimidazoles (TBZ, mebendazole, cambendazole, fenbendazole, and oxfendazole), but not OBZ, were efficaciously removed by OBZ, albendazole, the mixture of TBZ plus PPZ, FBT (24 mg/kg), or PRT. These 5 small strongyle species were resistant to FBT (6 mg/kg) in 3 foals and Cylicostephanus minutus was also resistant in 2 of 3 foals to FBT (6 mg/kg). Doubling the dose of FBT to 12 mg/kg increased the average removal of the 5 basic species plus Cylicostephanus minutus to 88%. The mixture of TBZ and trichlorfon was relatively ineffective against 3 species (C catinatum, C coronatum, and Cylicostephanus longibursatus), but unexpectedly efficacious (86% to 99%) for 2 species (Cylicocyclus nassatus and Cylicostephanus goldi).(ABSTRACT TRUNCATED AT 250 WORDS)

Albendazole↗

Critical test evaluations of oxfendazole and trichlorfon: effectiveness of a paste formulation in the horse.

Critical tests were performed on 6 horses to evaluate the antiparasitic effectiveness of oxfendazole given in combination with trichlorfon in a paste formulation. Treatments were given orally as a single dose. The rates of active ingredient administration were 2.5 and 40 mg/kg of body weight for oxfendazole and trichlorfon, respectively. The combined activities of the 2 antiparasitic compounds proved 100% efficacious in the removal of adult Strongylus vulgaris, S edentatus, Oxyuris equi, and Parascaris equorum. Fourth stage O equi, and 2nd and 3rd instars of Gasterophilus nasalis also were completely removed. Second and 3rd stage instars of G intestinalis were removed at the rates of 98.1% and 98.8%, respectively. Nematodes of the "small strongyle" category were removed at the combined rate of 97.0%. Pronounced larvicidal effects of the test formulation were demonstrated via culturing fecal nematode eggs during the trial. Untoward effects of treatment were not seen in any of the trial animals.

Animals↗

Cambendazole for strongyle control in a pony band: selection of a drug-resistant population of small strongyles and teratologic implications.

Cambendazole (CBZ) treatments (20 mg/kg) given at 8-week intervals were used for parasite control in a breeding band of ponies (n = 33 to 43) during the period July 1974 to August 1978. Pre- and posttreatment worm egg counts on feces were used to evaluate efficacy of treatments after every 2nd treatment interval by monitoring changes in strongyle egg counts. Initially, effective reductions (expressed as 92% to 96% fewer worm eggs) were lessened to 70% by the 9th treatment (18 months) and to 28% by the 12th treatment, and thereafter, they fluctuated between 0% and 38%. Critical tests on animals culled during the 3rd year revealed that (i) large strongyles (Strongylus vulgaris and S edentatus) were efficaciously removed, (ii) 5 species of small strongyles (Cyathostomum catinatus, Cyathostomum coronatum, Cylicocyclus nassatus, Cylicostephanus longibursatus, and Cylicostephanus minutus) exhibited some degree of resistance, and (iii) 11 species of small strongyles from 6 genera, including the 3 already named, were highly susceptible. Cylicostephanus minutus, in this population exhibited benzimidazole resistance for the first time, whereas Cylicostephanus goldi, previously recognized as resistant in other populations (B and C) in Kentucky, was susceptible to CBZ. A 2-fold increase in the drug-dose rate did not increase efficacy against the CBZ-resistant species of small strongyles, but a 4-fold increase small stronglyles, efficaciously removed 93% of the resistant small strongyles. Foaling rates in the brood band ranged between 38% and 61% for the 5 seasons. Three deformed foals occurred--1 in 1976 and 2 in 1977--among the total of 83 births. Present data did not evidence a probable week of early gestation for possible insult of the fetus by CBZ treatment.

Abnormalities, Drug-Induced↗

Parasites in Kentucky Thoroughbreds at necropsy: emphasis on stomach worms and tapeworms.

A total of 363 Thoroughbreds (62 males, 292 females, and 9 geldings), 1 to 26 years of age, were examined at necropsy for internal parasites for about a 12-month period from February 1981 through February 1982. Emphasis was on examining the stomach for nematodes and the small intestine and cecum for tapeworms. Parasites recovered from the stomach and infection rates were: Habronema spp--immature (24%), H muscae--adult (38%), Draschia megastoma--immature (13%), D megastoma--adult (62%), and Trichostrongylus axei--adult (4%); lesions caused by D megastoma were found upon gross observation in 58% of the stomachs. The tapeworm, Anoplocephala perfoliata, was recovered from 54% of the horses; A magna was not found. There was no obvious difference in infection rates of the stomach worms and tapeworms according to age or sex of the horses. Seasonal differences were apparent only for immature Habronema spp and immature D megastoma for which infection rates began increasing in June, peaking in October, and declining thereafter. Presence of 4 additional species of parasites was recorded, but only a cursory examination was made for them. These were the large strongyles, Strongylus vulgaris, S edentatus, and S equinus, from the cecum and a filariid, Setaria spp (probably S equina), from the abdominal cavity, for which recovery rates from the horses were 8%, 8%, 1%, and 7%, respectively.

Animals↗

Efficacy of ivermectin (22,23-dihydroavermectin B1) against gastrointestinal parasites in ponies.

The controlled test method was used to evaluate the antiparasitic efficacy of IM inoculated 22,23-dihydroavermectin B1 (ivermectin) against gastrointestinal parasites of horses (ponies). Parasite infections were naturally acquired in southern Louisiana. Dose levels of the drug tested were 0.2 mg/kg, 0.3 mg/kg, and 0.5 mg/kg. Ivermectin at all dose levels tested had an efficacy greater than 97% (P less than 0.05) against Gasterophilus intestinalis larvae, Trichostrongylus axei, Oxyuris equi larvae, Strongylus vulgaris, S edentatus, 15 species of small strongyles, and small strongyle larvae. Ponies were less uniformly infected with Habronema sp larvae, G nasalis larvae, Parascaris equorum, O equi adults, Anoplocephala perfoliata, S equinus, and 11 small strongyle species, and statistical analysis was not possible to do. However, observations indicate that the drug was also highly effective against these species. There were no gross or clinical reactions observed in treated animals. Dissections of the injection sites revealed spindle-shaped lesions, 3 to 5 cm long, in a few ponies in all treatment groups, including those given the placebo injection.

Animals↗

Anthelmintic efficacy of ivermectin given intramuscularly in horses.

The anthelmintic activity of ivermectin was evaluated in 18 female horses with naturally acquired parasitic infections. Horses were treated once (IM) with vehicle only (n = 6), 200 microgram/kg of body weight (n = 6), and 300 microgram/kg (n = 6). Efficacy of both dosages of ivermectin was greater than 99% against Gasterophilus spp, 100% against Trichostrongylus axei, Habronema muscae, H majus, and Draschia megastoma, 98% to 99% against adult cyathostomes, 86% to 97% against 4th-stage cyathostomes, and 100% against adult large strongyles. Although ivermectin was incomplete in its activity against arterial stages of Strongylus vulgaris, it was effective against microfilariae of Onchocerca spp. Adverse local or systemic reactions were not observed due to treatment with ivermectin.

Animals↗

Antiparasitic effectiveness of ivermectin in the horse.

By way of a controlled trial, the anthelmintic efficacies of the injectable and paste formulations of ivermectin were evaluated in the horse. Treatment was given at the rate of 200 microgram/kg of body weight. Regardless of formulation, 100% removals were demonstrated for Strongylus vulgaris (intestinal), S edentatus, 2nd and 3rd instars of Gastrophilus nasalis and G intestinalis, "small strongyles," Triodontophorus serratus and T tenuicollis. Adult Cylicocyclus insigne populations were eliminated at the rates of 99.9% and 96.3% by the injectable and paste formulations, respectively. Levels of 4th-stage Cylicocyclus spp larvae, as detected in the luminal contents of the colon, were reduced by 88.3% and 33.2% by the injectable and paste formulations, respectively. There were no adverse tissue or behavioral reactions induced by either preparation of ivermectin.

Animals↗

Efficacy of injectable and oral paste formulations of ivermectin against gastrointestinal parasites in ponies.

A controlled test was used in ponies to compare the antiparasitic efficacy of ivermectin (22,23-dihydro-avermectin B1) in an injectable micelle solution administered IM with the efficacy of the same drug in an oral paste formulation. Parasite infections were naturally acquired in southern Louisiana. The drug was tested in both formulations at a dosage level of 0.2 mg/kg of body weight. Ivermectin in both formulations tested had an efficacy greater than 98% against Gasterophilus intestinalis and G nasalis larvae. Trichostrongylus axei, Habronema spp, Strongylus vulgaris, S. edentatus, and species of small strongyles present. Efficacy of ivermectin against Oxyuris equi larvae was 100% in the paste formulation and 93% in the injectable formulation. The ponies were less uniformly infected with S equinus, Draschia megastoma, Parascaris equorum, O equi adults, Anoplocephala perfoliata, and A magna. However, observations indicated that the drug in either formulation was also effective against these parasites, except Anoplocephala spp.

Administration, Oral↗

Critical tests of the anthelmintic febantel in the horse: activity of a paste formulation alone or with a trichlorfon paste.

Critical tests were carried out in 10 horses to evaluate the antiparasitic activity of febantel given alone or with trichlorfon. Paste formulations were administered intraorally at dose levels of 6 mg of febantel (active ingredient)/kg and 35 mg of trichlorfon (active ingredient)/kg. In 5 tests with febantel alone, removal of 100% was recorded for mature or immature Parascaris equorum from 2 infected horses. Strongylus vulgaris from 4 infected horses, S edentatus from 5 infected horses, and mature Oxyuris equi from 1 infected horse; and removal of 96% was recorded for small strogyles from 1 horse tested, and bots in 5 infected horses were not affected. In 5 horses treated with both compounds, removal of 100% was recorded for mature P equorum from 2 infected horses, immature P equorum from 1 infected horse, S vulgaris from 5 infected horses, Sedentatus from 5 infected horses, mature O equi from 2 infected horses, immature O equi from 1 horse tested, 2nd Gasterophilus intestin-equi from 1 infected horse, 2nd-instar C nasalis from 1 infected horse, and 3rd-instar C nasalis from 4 infected horses. Removal of 98% was recorded for small strongyles from 1 horse tested, and removal of 65% to 100% for 3rd-instar C intestinalis from 5 infected horses. In the aggregate, removal of 3rd-instar C intestinalis was 99%. Untoward effects of treatment were quite limited. Only a transient softening of feces in 1 of 5 horses given the trichlorfon paste plus the febantel paste was recorded.

Acetanilides↗

Controlled evaluation of ivermectin in Shetland ponies.

Ivermectin was injected IM into 12 yearling Shetland ponies. The following reactions in percentages of parasites recovered from ponies given 200 microgram/kg or 300 microgram/kg, as compared with the parasitic population in those given the vehicle at 1 week after injection, were as follows: Otobius megnini nymphs--no reduction; Gasterophilus intestinalis--100% and 99.9%; G nasalis--100% and 99.9%; Parascaris equorum adults--100% and 96%; Strongylus vulgaris adults--100% and 100%; S edentatus adults--100% and 100%; cyathostome adults of the genera Gyalocephalus, Cylicocyclus, Cyathostomum, Cylicostephanus, and Poteriostomum--99.9% and 100%; 4th-stage larvae--97.3% and 96.8%; Oesophagodontus robustus adults--100% and 100%; Triodontophorus spp--adults--100% and 100%, 4th-stage larvae--95.1% and 100%; and Oxyuris equi adult males--66.7% and 77.7%, adult females--96.5% and 100%, and 4th-stage larvae--94.1% and 96.9%. Other parasites encountered were too few in number to estimate drug efficacy.

Animals↗

Anthelmintic treatment of equids: capabilities and limitations. Critical tests of nine anthelmintic agents on ponies.

A number of good anthelmintic drugs are currently available which eliminate gastrointestinal nematodes of equids with over 90% success. This is shown by comparing results of critical tests conducted with 9 anthelmintic agents on ponies using the following dosages: 19 mg/kg for Pyrantel embonate, 10 mg/kg for Oxfendazole, 10 mg/kg for Mebendazole, 5 mg/kg for Albendazole, 40 mg/kg for Dichlorvos, 44 mg/kg for Thiabendazole, 7.5 mg/kg, for Fenbendazole, 20 mg/kg for Cambendazole and 7 mg/kg for Parbendazole. From 6 to 9 ponies were treated with each of these anthelmintic agents. Based on total activity of various parasites involved, there was no significant difference in activity of any of the nine agents. With respect to Trichonema spp., or small strongyles, which are most numerous and most common in equids, statistical analysis enabled all nine products to be classified into three groups as follows: group 1, with the most active being Oxfendazole and Pyrantel embonate; group 2; including Thiabendazole, Mebendazole, Albendazole and Cambendazole; group 3, with Parbendazole, Fenbendazole et Dichlorvos. Results with large strongyles sometimes vary quite significantly. Dichlorvos and Pyrantel embonate should be recommended against Strongylus spp.; Mebendazole and dichlorvos against pinworms; Cambendazole against Strongyloïdes westeri; Pyrantel embonate, Cambendazole and Dichlorvos against Parascaris equorum; and Dichlorvos, Mebendazole with Trichlorfon and Pyrantel embonate with Trichlorfon against bots. No activity against Trichostrongylus axei, Anoplocephala spp. was noted with any of the nine agents tested.

Animals↗

Retropulsion-propulsion in equine large colon.

The circular and longitudinal muscle coats of equine "midcolon" were found to be directly electrically coupled. They appear to act in concert, in healthy animals, as a pacemaker in the area of the large colon pelvic flexure, for retropulsive-propulsive myoelectrical events. The retropulsive events keep the cecum and right ventral and left ventral divisions of the colon filled, imposing a delay time for fermentation of cellulose and for bacterial protein synthesis. Point-to-point involvement of adjacent colon sections was slowed by cooling the intestinal contents with no adverse clinical signs. Diminution of the blood flow to this regulatory area was achieved in 12 weanling foals (raised parasite-free) by parasitic cranial mesenteric arteritis, using Strongylus vulgaris larvae. Four of the 12 developed clinical signs of abdominal pain, but on necropsy 3 of these 4 had no gross lesions in the gastrointestinal tract. Dissociation of the left ventral and left dorsal colon divisions, as regards intraluminal pressure events and their antecedent myoelectrical action potentials, was induced in 7 of 8 adult animals given an acaricide which under field conditions is associated with progressive large colon obstruction and colic.

Animals↗

Seasonal incidence of helminths in the Burchell's zebra.

Ten Burchell's zebras were culled in conjunction with the Kruger National Park's game management programme. The colts ranged in age from 9-17 months and the stallions from 2 1/2-23 years. The gastro-intestinal tract and the abdominal cavity were examined for helminths. The principal families of nematodes recovered included the Atractidae, Strongylidae and Spiruridae. The Atractidae included Crossocephalus and Probstmayria; the Strongylidae 2 subfamilies, Cyathostominae and Strongylinae, and the genera of the Cyathostominae were Cyathostomum, Cylicocyclus, Cylicodontophorus, Cylicostephanus, Cylindropharynx and Poteriostomum. Craterostomum, Oesophagodontus, Strongylus and Triodontophorus represent the Strongylinae. The last of the 3 principal families, the Spiruridae, included Draschia and Habronema. Total worm burdens ranged from 0-1 947 474. Despite the fact that the 3 families have life-cycles that differ greatly, their seasonal incidence over the 11-month period showed similar trends.

Animals↗

Anthelmintic efficiency of fenbendazole in equines.

A single oral dose of fenbendazole (FBZ) at 10mg/kg body mass was given to 5 donkeys. A further 5 donkeys were dosed with a medicated lick (1 mg FBZ/g lick) until the oral consumption was 10mg/kg body mass. In both trials FBZ was highly effective against adults of the following genera: Cyathostomum, Cylicocyelus, Cylicostephanus, Cylicodontophorus, Poteriostomum, Cabellonema, Craterostomum and Triodontophorus; similarly high efficiency was obtained against the following species: Habronema majus, Habronema musca, Strongylus vulgaris and Oxyuris equi and worms identified as belonging to the subfamily Cyathostostominae. These results were confirmed in horses and in addition FBZ at 10mg/kg was highly effective against Gyalocephalus capitatus, Oesophagodontos robustus and Parascaris equorum.

Animals↗

Haloxon: critical tests of antiparasitic activity in equids.

Critical tests were conducted in 14 naturally infected equids (13 horses and 1 pony) to evaluate the antiparasitic activity of haloxon. Single doses were administered by stomach tube to 3 horses and 1 pony (60 mg/kg of body weight), by addition to the feed of 3 horses (60 mg/kg), and intraorally by powder gun to 7 horses (65 mg/kg). Haloxon was efficacious (99% to 100%) against infections of Parascaris equorum, Oxyuris equi (mature and immature), and Strongylus vulgaris at both dosage levels. Probstmayria vivipara parasites were removed in 1 horse treated at 60 mg/kg by stomach tube and S equinus was removed (1 specimen) in 1 horse treated at 65 mg/kg with the powder gun. Removal activity against small strongyles varied from 67% to 92%, and averaged 88% in ther aggregate. Removal of S edentatus fluctuated from 2% to 100%, and was 49% in the aggregate. Haloxon was generally ineffective against Gasterophilus intestinalis and G nasalis, except that it seemed active against 2nd instar G intestinalis when administered at the 60 mg/kg dosage rate in feed and at the 65 mg/kg dosage rate by powder gun. The compound was inactive against Trichostrongylus axei, Habronema muscae, Draschia megastoma, Anoplocephala perfoliata, and A magna. Clinical signs of toxicosis were not observed after treatment. Problems were not encountered in administration of haloxon directly into the back of the mouth with the powder gun.

Animals↗

Tioxidazole: evaluation of antiparasitic activity of a micronized formulation in horses by the critical test method.

Antiparasitic activity of a micronized formulation of the benzothiazole compound, tioxidazole, at the dose rate of 11 mg/kg, was evaluated by the critical test method. Drug was given by stomach to 3 horses and on feed to 3 horses. Excellent removal activity was found for Strongylus vulgaris (100%) in 5 naturally infected horses, S edentatus (91% to 100%) in 5 horses, small strongyles (88% to 99%) in 6 horses, immature Oxyuris equi (100%) in 5 horses, and Parascaris equorum (100%) in 5 horses (a 6th horse had 10 small specimens present at necropsy). There was no measurable activity against bots, tapeworms, or stomach worms. Tioxidazole, administered in the feed, was palatable. Signs of toxicosis were not observed.

Animals↗

Recovery of helminths postmortem from equines. I. Parasites in arteries, subperitoneum, liver and lungs.

The entire gastro-intestinal tract and viscera of the abdomen and thorax, including the heart, aorta and its branches to the viscera, are removed from the carcass. All the branches of the aorta, with the exception of the A. gastrica sinistra, are dissected from the intestinal tract, and subsequently each branch is isolated from the mesentery, fat, pancreas, kidneys, etc. Usually, the A. ileocolica is grossly enlarged due to chronic arteritis with thrombus formation caused by 4th stage larvae, 4th moult and 5th stage Strongylus vulgaris. Descriptions of methods to examine the subperitoneal tissues, liver and lungs are included.

Animals↗

Equine verminous arteritis; efficiency and speed of larvicidal acitivty as influenced by dosage of albendazole.

Albendazole was effective in destroying Strongylus vulgaris larvae in verminous lesions of the cranial mesenteric artery when administered as a 20% suspension by stomach tube to ponies. Fifty mg/kg body weight administered twice a day for 2 days caused death and gradual disintegration of larvae over a period of 3 to 6 weeks with mild toxic signs appearing in 3 of 11 ponies. Higher total doses of albendazole (50 mg/kg twice a day for 4 days and 25 mg/kg three times a day for 5 days) lead to more rapid disintegration of the larvae but fatal toxicity was observed in 3 of 6 ponies so treated. In all cases, resolution of verminous arterial lesions was delayed until larva remains had disappeared from the lesions. A non-parametric analysis was applied to combined radiographic, pathologic and parasitologic observations and data for testing their statistical significance

Administration, Oral↗