The efficacy of pyrantel pamoate against ascarids and hookworms in cats

The purposes of this study were to evaluate pyrantel pamoate administered orally at 20 mg/kg body weight for the removal of induced or natural infections of Ancylostoma tubaeformae and Toxocara cati in cats and to compare the efficacy of paste (40 mg base/g) and granule (80 mg base/g) formulations. Thirty cats of mixed breeding and various ages with natural and/or induced infections of A. tubaeformae and T. cati were assigned to one of three treatment groups: (1) non-medicated controls; (2) paste formulation at 20 mg base/kg; or (3) granule formulation at 20 mg base/kg. Infections were induced by feeding the cats on carcasses of infected mice. The study was conducted in replicates of at least one animal per treatment per replicate. The study parameters included clinical observations, physical examinations, faecal egg counts and the numbers, species and stages of worms recovered at necropsy. The paste formulation was 99.3% and 99.7% effective in reducing egg counts of Ancylostoma sp. and Toxocara sp. respectively. The granule formulation was 97.7% and 99.9% effective in reducing faecal egg counts of Ancylostoma sp. and Toxocara sp. respectively. When administered in paste form, pyrantel pamoate was 99.5% effective in removing adult Ancylostoma and 100.0% effective against adult Toxocara. The granule formulation was 97.9% effective against Ancylostoma and 100% effective against Toxocara. No toxic effects of either formulation of the drug were noted.     

Safety study of a beef-based chewable tablet formulation of ivermectin and pyrantel pamoate in growing dogs, pups, and breeding adult dogs.

To determine the safety of a new combination of ivermectin and pyrantel (as pamoate salt) in a novel beef-based chewable tablet formulation, 3 tolerance trials were conducted and included growing dogs, pups, and breeding adult dogs. Growing dogs, given the combination orally for 5 consecutive days at recommended dosages (5 mg of pyrantel/kg of body weight, 6 micrograms of ivermectin/kg) or at twice the pyrantel dosage in combination with the recommended dosage of ivermectin, had no adverse effects. The combination also was administered to 6-week-old pups at 1, 3, and 5 times the recommended dose on 3 successive days for 3 times in 1 month. Compared with age-matched controls, treatment had no effect on clinical status, growth rate, or gross or histologic features. Breeding male and female dogs given the combination at 3 times the recommended dose for extended periods had no adverse effects, and prevalence of abnormalities in the offspring was not greater than that in nonmedicated controls.     

Efficacy of ivermectin and pyrantel pamoate combined in a chewable formulation against heartworm, hookworm, and ascarid infections in dogs.

Eight trials were conducted in dogs to document the efficacy of ivermectin (6 micrograms/kg of body weight) and pyrantel pamoate (5 mg of active pyrantel/kg) in a beef-based chewable formulation against Dirofilaria immitis, Ancylostoma caninum, Uncinaria stenocephala, Toxocara canis, and Toxascaris leonina. Three studies involved induced infection with D immitis, and 5 studies involved induced or natural infection with hookworms and ascarids. In 3 intestinal parasite trials, the efficacy of the combination chewable tablet was compared with each of its components. Results indicated that 1 component did not interfere with the activity of the other. In 1 heartworm and 2 intestinal parasite trials, the efficacy of pyrantel, ivermectin/pyrantel combination, or ivermectin with pyrantel dosage of 10 mg/kg was evaluated. The ivermectin/pyrantel combination was 100% effective in preventing development of D immitis larvae. Efficacy of the combined product against T canis, Toxascaris leonina, A caninum, and U stenocephala was 90.1, 99.2, 98.5, and 98.7%, respectively. In the intestinal parasite trials, each individual component was found not to interfere with the anthelmintic action of the other. Increasing the dosage of pyrantel to 10 mg/kg (2 x that in the combination) did not interfere with the efficacy of ivermectin against heartworm or increase the activity of pyrantel against intestinal parasites.     

Efficacy of an ivermectin/pyrantel pamoate chewable formulation against the canine hookworms, Uncinaria stenocephala and Ancylostoma caninum.

The effectiveness of the combination of pyrantel pamoate (5 mg kg-1) and ivermectin (6 micrograms kg-1) against the canine hookworms Uncinaria stenocephala and Ancylostoma caninum was determined. This combination is intended for monthly use as a heartworm preventative and for treatment and control of canine hookworms. The formulation was found to be effective (99.6% reduction in worm burdens) against both species of hookworms in experimentally infected dogs. No adverse effects due to the drug combination were observed in any dog during the course of this study.     

Efficacy of heartworm preventatives against ascarids and hookworms in client-owned dogs: a retrospective case control study

Gates, M.C., Nolan, T.J. Efficacy of heartworm preventatives against ascarids and hookworms in client‐owned dogs: a retrospective case control study. J. vet. Pharmacol. Therap. 34 , 116–119. The efficacy of heartworm preventatives against ascarids and hookworms was assessed in a retrospective analysis of 1329 dogs that received a fecal examination and were surveyed about heartworm preventative use upon presentation to the veterinary teaching hospital at the University of Pennsylvania. To remove confounding due to age, patients under 6 months old were analyzed separately from the remaining population. Although there were no reported cases of ascarids or hookworms in patients under 6 months old receiving monthly heartworm prevention, the prevalence reached 5.2% and 11.7%, respectively, in patients that were not using any products. For patients over 6 months old, there were no apparent associations between parasites and heartworm preventative use. Of the 75.5% of dogs that were administered heartworm preventatives, 16.1% reported seasonal use and 83.9% reported using the products year round. Patients using heartworm preventatives seasonally were no more likely to be harboring nematode parasites than patients using preventatives year round (OR = 0.70, 95% CI: 0.19–2.55). Overall efficacy rates were consistent with prior studies on the active ingredients. Heartworm preventative have the greatest value for controlling nematode endoparasites in patients under 6 months old.     

Efficacy of an ivermectin and pyrantel pamoate combination against adult hookworm, Ancylostoma braziliense, in dogs

A chewable tablet incorporating ivermectin and pyrantel was tested in 12 Beagle dogs for efficacy against the adult hookworm, Ancylostoma braziliense. The dogs were administered infective larvae of A braziliense orally. Twenty-one days after infection the dogs were weighed and allocated randomly to receive either an oral treatment with ivermectin and pyrantel in a beef-based chewable tablet or no treatment. The chewable tablet was a commercially available product, which was made to deliver ivermectin at 6 μg/kg and pyrantel at 5.0 mg/kg to each dog. Seven days after treatment the dogs were euthanased, necropsied, and examined for adult hookworms. At necropsy, no adult A braziliense was observed in any of the 6 treated dogs and all 6 dogs that had been left untreated were infected with adult A braziliense (range, 48 to 161). It was concluded that this combination product is 100% efficacious against adult A braziliense.     

Efficacy of a drug combination of praziquantel, pyrantel embonate, and febantel against helminth infections in dogs.

Tablets containing praziquantel, pyrantel embonate, and febantel were tested for efficacy against helminths in dogs. A single treatment with this drug combination gave 100% reductions in Toxocara canis and Taenia hydatigena in experimentally induced infections in dogs. In dogs with naturally acquired infections, treatment gave > 97 to 98% reductions in fecal egg counts attributable to Toxascaris leonina, T canis, and Uncinaria stenocephala. Efficacy against Trichuris vulpis was > 92%.     

Evaluation of praziquantel against induced Nanophyetus salmincola infections in coyotes and dogs

Efficacy of praziquantel against Nanophyetus salmincola, the trematode vector of salmon poisoning disease, was determined in coyotes (n = 29) and dogs (n = 25). The 10- to 14-week-old animals were fed fish or fish kidneys that contained metacercariae of N salmincola. To prevent salmon poisoning disease, all animals were treated with tetracycline on days 8 and 9 after they were fed fish. Ten days after ingestion of infected fish, 19 coyotes and 12 dogs were treated once with praziquantel, administered SC or IM, at dosages between 6.68 and 38.73 mg/kg of body weight. Within 8 days after treatment, the numbers of trematode eggs in feces and trematodes recovered from the small intestine were reduced by greater than 99% when compared with untreated controls. Signs of drug toxicosis were not observed. On the basis of these results, praziquantel at doses approved for use in dogs against cestodes was highly effective against N salmincola in coyotes and dogs.     

Comparative efficacy of flubendazole chewable tablets and a tablet combination of febantel, pyrantel embonate and praziquantel against Trichuris vulpis in experimentally infected dogs

Fourteen of 23 dogs developing patent Trichuris vulpis infections by 120 days p.i. with 5000 embryonated eggs were allocated into three groups. One group was treated with flubendazole 220 mg chewable tablets (Flubenol) at the recommended dose regimen once daily for 3 days. The second group was given the recommended single treatment with a tablet containing 150 mg febantel, 144 mg pyrantel embonate and 50 mg praziquantel in combination (Drontal Plus). The third group remained untreated. All dogs were necropsied for worm counts 10 or 11 days after (first) treatment. No worms were recovered from the flubendazole treated dogs resulting in a significant worm count reduction of 100%. In contrast, 2 of 5 animals treated with the combination of febantel, pyrantel embonate and praziquantel remained infected; the geometric mean worm burden was reduced by 99.4% as compared to the control group but did not differ significantly from those of the controls.     

Efficacy of fenbendazole granules and pyrantel pamoate suspension against Toxocara canis in greyhounds housed in contaminated runs.

The efficacy of fenbendazole granules against Toxocara canis in naturally infected greyhounds housed in contaminated environments was evaluated. Eight pens, each containing three to seven greyhounds, 3-12 months of age, were randomly allotted into two treatment groups. Greyhounds in Group 1 were treated with fenbendazole granules mixed in their feed at 50 mg/kg/day for 3 consecutive days once a month for 4 months. Greyhounds in Group 2 were treated with pyrantel pamoate suspension at 5.0 mg/kg per os once a month for 4 months. Quantitative fecal examinations were performed on days 0, 10 and then on the first day of each monthly treatment. Greyhounds administered fenbendazole had fecal egg count reductions (FECRs) of 95.8 and 99.8% at 10 and 31 days following initial treatment, respectively. Greyhounds administered pyrantel pamoate had FECRs of 85.8 and 88.3% at 10 and 31 days after the first treatment, respectively. T. canis fecal egg counts conducted from Day 31 through Day 128 were significant lower in those greyhounds administered fenbendazole as compared to greyhounds administered pyrantel pamoate. Fenbendazole produced FECRs in greyhounds from Day 31 through Day 128 by 96.8-99.8%. Pyrantel pamoate reduced fecal egg counts during the same time period 71.4-98.3%.     

Evaluation of the efficacy and safety of two formulations of pyrantel pamoate in cats

The efficacy of paste and granule formulations of pyrantel pamoate against concurrent infections of Toxocara cati and Ancylostoma tubaeforme in cats was examined in a controlled trial. Three groups of 8 cats received either no medication (controls) or pyrantel pamoate in paste or granule formulations at a dosage of 20 mg/kg of body weight. After administration of the paste formulation, fecal egg counts of A tubaeforme and T cati were decreased by 98.6 and 96.4%, respectively, and 100% of hookworms and 93.5% of ascarids were removed from the intestine. After administration of the granule formulation, fecal egg counts of A tubaeforme and T cati were decreased by 99.4 and 78.2%, respectively, and 100% of adult hookworms and 88.9% of ascarids were removed. All reductions of egg counts and worm numbers were significant (P less than 0.01). The clinical safety of pyrantel pamoate was evaluated in 4- to 6-week-old kittens. Three groups of 10 kittens received either no medication (controls) or pyrantel pamoate in paste or granule formulations at the rate of 100 mg/kg for 3 consecutive days. Adverse effects were not observed in young kittens following administration of the high dose of pyrantel pamoate.     

Evaluation of the safety of ivermectin administered in a beef-based formulation to ivermectin-sensitive Collies

Twenty-four Collies sensitive to the toxic effects of ivermectin, when administered at high dosages, were studied to evaluate the effects of repeated monthly treatment with an ivermectin beef-based formulation at amounts up to 10 times the dosage recommended for heartworm prevention in dogs. Collies were treated 3 times at 30-day intervals at rates of 12, 36, or 60 micrograms of ivermectin/kg of body weight, or with vehicle. Complete physical and neurologic examinations were performed on all dogs prior to the first treatment and after the final treatment. Clinical observations and ivermectin reaction scores were recorded daily for each dog throughout the study. Clinical or neurologic signs characteristic of ivermectin toxicosis were not observed for any dog during the study. Single episodes of vomiting were recorded for 2 vehicle-treated dogs and 2 dogs treated with ivermectin at 12 micrograms/kg from 6 to 21 days after treatment. At the end of the study, all dogs were challenge-exposed with ivermectin at 120 micrograms/kg to reconfirm their sensitivity to this class of compounds. All dogs developed signs typical of ivermectin toxicosis during the subsequent 48- to 72-hour period. Results of this study demonstrated that ivermectin can be administered repeatedly without adverse effects at rates up to 60 micrograms/kg (10 times the recommended use level) to Collies known to be sensitive to this drug.     

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 animals each or incomplete sets of fewer than four animals. Within sets comprising of two to four horses, one animal was randomly allocated to receive placebo vehicle paste and the remaining horse(s) received pyrantel pamoate paste administered orally at a minimum dosage of 13.2 mg pyrantel base/kg b.w. on Test Day (TD) 0. Single animal sets received pyrantel pamoate paste. Fecal samples of horses were collected and examined for equine tapeworm (Anoplocephala spp.) eggs a minimum of four times (once or thrice between TD -28 and -14, twice between TD -14 and -7, and once on TD 0) prior to treatment on TD 0. Fecal samples of horses that were positive for cestode infection pre-treatment were examined for cestode eggs on TD 7, 8, 9, 14, 15 and 16. Cestode-negative pre-treatment horses were not sampled again after treatment. A total of 241 horses (141 mares, 16 stallions and 84 geldings; 6 months-30 yrs of age; 173-646 kg; 13 recognized breeds and various crossbreds) were evaluated. The prevalence of Anoplocephala spp. determined by pre-treatment fecal examination ranged from 38.3% in Idaho to 68.1% in Tennessee with an overall prevalence of 52.3%. Ninety cestode-positive and 88 cestode-negative horses were treated with pyrantel pamoate paste, 36 cestode-positive and 27 cestode-negative horses were treated with placebo vehicle paste. Overall, 178 horses were treated with pyrantel pamoate paste, and 63 horses were treated with placebo paste. Of the 178 horses treated with pyrantel pamoate paste, no drug related, adverse clinical or neurological health events were observed. No doses of pyrantel pamoate paste were refused or lost during dosing. At each post-treatment time sampling interval, significantly fewer cestode eggs (P < 0.0115) were passed by cestode-positive horses treated with pyrantel pamoate paste compared to cestode-positive horses that received placebo paste. Efficacy of the pyrantel pamoate paste treatment ranged from 92 to 96% from TD 7 to TD 16 with an overall efficacy of 95%. The results of these trials demonstrated that pyrantel pamoate paste (19.13%, w/w, pyrantel base) administered orally at a dosage of 13.2 mg pyrantel base/kg b.w. is highly efficacious (95%) against Anoplocephala spp. and safe for use in horses with no adverse clinical or neurological health events observed under field use conditions.     

Evaluation of the efficacy of an epsiprantel/pyrantel combination against gastrointestinal helminths of dogs

Trials were conducted to evaluate the anthelmintic effect of a combination of epsiprantel at a dose rate of 5-5 mg/kg bodyweight and pyrantel pamoate at 5 mg pyrantel base/kg against Toxocara canis in prenatally infected unweaned greyhound pups, Toxascaris leonina, Uncinaria stenocephala, Trichuris vulpis and Dipylidium caninum in naturally infected adolescent greyhounds and Ancylostoma caninum, U stenocephala. Taenia hydatigena and Taenia pisiformis in artificially infected laboratory beagles. The product was well accepted and produced no obvious side effects. Percentage efficacy values based on post mortem worm counts were: T hydatigena 100; T pisiformis 100; D caninum 100; adult T canis 84-0; adult T leonina 96-5; immature T leonina 99-8; U stenocephala 99-0 and 87-7; A caninum 92-7; and T vulpis 43-3.     

Efficacy of a chewable formulation of ivermectin against a mixed infection of Ancylostoma braziliense and Ancylostoma tubaeforme in cats.

The efficacy of a beef-based, chewable formulation of ivermectin against a mixed infection of Ancylostoma braziliense and A tubaeforme was determined in cats. Ivermectin administered orally at approximately 24 micrograms/kg of body weight was 92.8% effective against adult A braziliense and 90.7% effective against adult A tubaeforme. The number of eggs per gram of feces had decreased 98.1% by 7 days after treatment. Clinical signs of hookworm disease also decreased after treatment. Location of adult parasites within the small intestine, percentage of infecting larvae that developed to the adult stage, and egg size in cats with infections of A braziliense and A tubaeforme were similar to those reported for cats with separate infections of either species.     

Effects of milbemycin oxime on adult hookworms in dogs with naturally acquired infections

Previous work indicated that adult Ancylostoma caninum can be removed from experimentally infected dogs, using a formulation of milbemycin oxime at dosage of 0.5 mg/kg of body weight. To determine the efficacy of this treatment in dogs naturally infected with adult hookworms, 24 mixed-breed dogs with patent hookworm infections were purchased from an out-of-state vendor, and 6 male and 6 female dogs were assigned to either a control group or a group that would be treated. Dogs were treated 10 days after their arrival and were euthanatized 1 week after treatment. Beginning 3 days before treatment, fecal samples were collected daily from all dogs, and the number of Ancylostoma eggs per gram of dry weight of feces was determined from each sample. By 1 week after treatment, the mean number of eggs being passed by the treated dogs had dropped from 12,700 to 10 eggs/g of dried feces; there was no apparent change in fecal egg counts for dogs of the control group. At necropsy, the mean number of adult A caninum in dogs of the treated and control groups was 1.3 and 56, respectively; in these naturally infected dogs, efficacy of treatment was calculated to be 97.8%. The mean number of adult Trichuris vulpis recovered in dogs of the control and treated groups at necropsy was 24 and 0, respectively, which yielded treatment efficacy of 100%. Although Uncinaria stenocephala and Toxocara canis appeared also to be removed by use of this dosage, too few dogs were in the study to calculate meaningful efficacies.(ABSTRACT TRUNCATED AT 250 WORDS)     

Evaluation of oxfendazole against natural infections of gastro-intestinal nematodes and lung-worms in calves.

The anthelmintic activity of oxfendazole (Syntex) was tested in calves at dosages of 2-5 and 5-0 mg per kg. At both dose levels, oxfendazole showed 100 per cent efficacy against adult Ostertagia ostertagi, O lyrata, O cremensis, fifth stage Ostertagia spp and adult Haemonchus spp. Against adult Cooperia oncophora, efficacy was 99.8 per cent and 100 per cent at doses of 2.5 mg per kg and 5.0 mg per kg respectively while at both dose levels 100 per cent activity was recorded against C surnabada and fourth and fifth stage Cooperia spp. One hundred per cent efficacy was obtained with both dose levels against adult and fifth stage Dictyodaulus viviaprus; against Trichuris spp, percentage efficacy was 92 and 100 per cent at doses 2.5 and 5.0 mg per kg respectively. Oxfendazole showed higher efficacy than levamisole against Ostertagia spp but against the other species encountered, both anthelmintics possessed similar efficacy. Both anthelmintics significantly increased the calves' weight gains.