moxidectin and Ancylostomiasis

Ancylostoma ceylanicum is a common zoonotic hookworm of dogs and cats, especially in the Asia-Pacific region. The objective of this study was to determine the efficacy of a spot on combination product containing imidacloprid 10% and moxidectin 1% (Advocate(®)/Advantage(®) Multi, Bayer Animal Health) against A. ceylanicum in experimentally infected cats. Sixteen kittens were each subcutaneously injected with 100 infective third-stage larvae of A. ceylanicum. Kittens were stratified by egg count and randomly allocated into control and treatment groups. The kittens in the treatment group were each treated with a spot on combination of 10% (w/v) imidacloprid and 1% (w/v) moxidectin, administered topically at recommended label dose rates. The kittens in the control group were not treated. Egg counts were performed daily until the end of the study period and compared for the treated and control groups. No eggs were detected in the treated group of kittens within 4 days of treatment and faecal samples from this group remained negative throughout the rest of the study, resulting in a treatment efficacy (egg reduction) of 100% (P<0.0001). The egg counts remained high (993 ± 666 epg) in the untreated control group for the rest of the study period. This study demonstrated that based on faecal egg count reduction, the spot on combination containing imidacloprid 10% (w/v) and moxidectin 1% (w/v) (Advocate(®)/Advantage(®) Multi, Bayer Animal Health) given at the recommended dose is highly effective against infection with A. ceylanicum in cats.

Topics: Administration, Topical; Ancylostoma; Ancylostomiasis; Animals; Antinematodal Agents; Cat Diseases; Cats; Drug Combinations; Feces; Female; Imidazoles; Larva; Macrolides; Neonicotinoids; Nitro Compounds; Parasite Egg Count; Skin Diseases, Parasitic; Treatment Outcome

Ancylostoma ceylanicum is a common hookworm of dogs, cats and humans in Asia. More recently, this hookworm was found to infect dogs in Australia. The objective of this study was to determine the efficacy of a spot on combination product containing imidacloprid 10% and moxidectin 2.5% (Advocate/Advantage Multi, Bayer Animal Health) against A. ceylanicum in experimentally infected dogs. Twelve dogs were each subcutaneously injected with 300 infective third-stage larvae of A. ceylanicum. Pups were stratified by egg count and randomly allocated equally into control and treatment groups. The pups in the treatment group were each treated with a spot on combination of 10% (w/v) imidacloprid and 2.5% (w/v) moxidectin, administered topically at the skin surface between the shoulder blades. The dogs in the control group were not treated. Egg counts were performed daily until the end of the study period and compared for the treated and control groups. No eggs were detected in the treated group of pups within 4 days of treatment and faecal samples from this group remained negative throughout the rest of the study, resulting in a treatment efficacy (egg reduction) of 100% (P < 0.0001). The egg counts remained high (4,469 +/- 2,064 eggs per gram, epg) in the untreated control group for the rest of the study period. This study demonstrated that the spot on combination containing imidacloprid 10% and moxidectin 2.5 % (Advocate/Advantage Multi, Bayer Animal Health) given at the recommended dose is highly effective against infection with A. ceylanicum in dogs.

Topics: Administration, Topical; Ancylostoma; Ancylostomiasis; Animals; Anthelmintics; Dog Diseases; Dogs; Drug Combinations; Female; Imidazoles; Macrolides; Neonicotinoids; Nitro Compounds; Parasite Egg Count; Skin Diseases, Parasitic; Treatment Outcome

The aim of the investigation was to examine whether a single topical administration of a combination of imidacloprid and moxidectin to pregnant dogs could prevent neonatal infections with reactivated Ancylostoma caninum larvae. Three pregnant beagles, infected with A. caninum, were treated topically with the combination on day 56 of pregnancy. Three further dogs served as untreated controls. Treatment appeared to prevent neonatal infections in the puppies completely. Neither intestinal stages nor somatic larvae were found in two examined puppies per litter. All puppies and dams of the treatment group remained coproscopically negative. No side-effects in dams or puppies were observed. Two of three untreated dams showed a patent infection after parturition. Necropsy of two puppies of each negative control litter revealed seven intestinal and five somatic A. caninum stages in total. One litter of the untreated dams showed a patent infection 33 days after parturition. In the other two litters, no representative sample sizes could be collected.

Topics: Administration, Topical; Ancylostoma; Ancylostomiasis; Animals; Animals, Newborn; Anthelmintics; Dog Diseases; Dogs; Female; Imidazoles; Infectious Disease Transmission, Vertical; Intestines; Larva; Macrolides; Neonicotinoids; Nitro Compounds; Pregnancy; Pregnancy Complications, Parasitic; Pregnancy, Animal; Treatment Outcome

The efficacy of milbemycin oxime was evaluated at dosages of 0.25, 0.50, and 0.75 mg/kg of body weight in dogs naturally infected with mature Ancylostoma spp, at a dosage of 0.50 mg/kg in dogs with experimentally induced immature and mature A caninum, and at dosages of 0.55 to 0.86 mg/kg in dogs naturally infected with mature Trichuris vulpis. Milbemycin oxime was 95 and 99% effective against mature Ancylostoma spp at dosages of 0.50 and 0.75 mg/kg, respectively, but only 49% effective at a dosage of 0.25 mg/kg. Efficacy was 49% against pulmonary L3-L4 stages of A caninum (36 hours after inoculation), greater than 80% against L4 (120 hours after inoculation) and early L5 stages (216 hours after inoculation), and greater than 90% against experimentally induced mature stages (360 hours after inoculation). Milbemycin oxime was also 97% effective in the removal of mature Tr vulpis from naturally infected dogs. Adverse reactions were not observed following treatment in any of the dogs.

Topics: Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Dog Diseases; Dogs; Feces; Female; Intestinal Diseases, Parasitic; Macrolides; Male; Parasite Egg Count; Trichuriasis

Twenty-six mixed-breed (14 males, 12 females) dogs were used in a double-blind study to evaluate the effect of milbemycin oxime against naturally acquired infection with Ancylostoma caninum. Dogs were ranked and paired, on the basis of number of hookworm eggs/g of feces, and treatment was randomly assigned. Each dog was given either the study drug or placebo (1 tablet/11.4 kg [0.5 mg/kg] of body weight). Eggs per gram of feces enumeration was done on days 3 and 7 after treatment, and dogs were euthanatized on day 7. On day 3, 5 of the 13 dogs in the milbemycin-treated group had hookworm eggs in the feces (results of the McMaster test). In these dogs, mean number of eggs per gram of feces had decreased markedly (from 5,289 to 452) and, by day 7, was 114. At necropsy, 16 A caninum adults were recovered from 2 of the milbemycin-treated dogs. On day 3, 12 of the 13 dogs in the placebo-treated group had hookworm eggs in the feces. Mean number of eggs per gram of feces in these dogs decreased slightly (from 5,243 to 2,646), but did not decrease further by day 7. A mean number of 54.4 A caninum adults was recovered from 12 of the 13 placebo-treated dogs at necropsy. Milbemycin oxime had 97.8% efficacy against A caninum. Results also indicated that milbemycin oxime may be effective against Trichuris vulpis, but not against Dipylidium caninum.

Topics: Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Dog Diseases; Dogs; Double-Blind Method; Feces; Female; Macrolides; Male; Parasite Egg Count

Endoscopic capsules and endoscopy were used to assess the speed of kill and the clearance of hookworms in dogs experimentally infected with Ancylostoma caninum. A total of four adult dogs were inoculated in two separate cohorts comprised of two 4-year-old females and two 7-year-old males. Dogs were treated topically with Advantage Multi(®) for Dogs 13 days (Cohort 1) or 16 days (Cohort 2) after infection. Endoscopic imaging of the small intestine was carried out both pre- and post-treatment. Examination of the first cohort revealed that the worms had been cleared and the hookworm-induced lacerations were markedly diminished within 48 h of treatment. In the second cohort, endoscopic capsules were given the day of, the day after, and two days after treatment; within 24h of product administration, the worms had been removed with a concurrent reduction in observed lesions. Topical application of Advantage Multi(®) for Dogs rapidly removed worms from the small intestine of the dogs in this study as early as 24h post-treatment, with a marked reduction in the number of mucosal lesions seen.

Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Cohort Studies; Dog Diseases; Dogs; Endoscopy; Female; Hookworm Infections; Imidazoles; Kinetics; Macrolides; Male; Neonicotinoids; Nitro Compounds; Time Factors

The aim of this investigation was to examine whether reactivated Ancylostoma caninum larvae can be eliminated by the administration of moxidectin to pregnant bitches. Four pregnant bitches infected experimentally with 20,000 third-stage larvae of A. caninum were treated subcutaneously with 1 mg moxidectin/kg body weight on day 55 of the pregnancy (5-8 days before parturition). Another four experimentally infected pregnant bitches served as controls. The single moxidectin treatment completely prevented lactogenic infections in the puppies. Neither intestinal stages nor somatic larvae could be found. The administration of moxidectin caused no local or systemic side-effects in the bitches. All 22 puppies of the treated bitches were born healthy and remained so during the whole trial period. Beginning during the third week after birth, all 20 puppies of the untreated bitches developed a severe microcytic, hypochromic anaemia and they revealed a total of 8649 intestinal stages of A. caninum after autopsy.

Topics: Ancylostoma; Ancylostomiasis; Animals; Animals, Newborn; Anthelmintics; Anti-Bacterial Agents; Antibodies, Helminth; Dog Diseases; Dogs; Feces; Female; Macrolides; Mice; Pregnancy; Pregnancy Complications, Parasitic

Third-stage larvae of the major human and canine Ancylostoma hookworm species have the capacity to undergo developmental arrest in the somatic tissues of an infected host. Arrested larvae reactivate at opportune periods such as pregnancy, which results in the transmammary transmission of infection to the nursing neonates. Using murine paratenic hosts to focus specifically on tissue-arrested stages of Ancylostoma caninum, the present study found that neither recommended nor elevated doses of commonly used anthelmintics were effective in eliminating latent infections at the accepted standard of greater than 90% reduction in parasite burden. Of the drugs tested, i.e., pyrantel, fenbendazole, ivermectin, and milbemycin, ivermectin was the most effective and engendered an 80% reduction in the burden of tissue-arrested A. caninum larvae but only if administered repeatedly or at elevated doses. Studies in 2 inbred mouse strains, BALB/c (H-2b) and C57BL/6 (H-2d), that typically display divergent immune responses to various infections showed no significant differences in the efficacies of the drugs tested. The results of this study indicate that there is still a need for effective strategies of eradicating latent infections with tissue-arrested hookworm larvae.

Topics: Ancylostomiasis; Animals; Anti-Bacterial Agents; Antinematodal Agents; Disease Models, Animal; Dogs; Female; Fenbendazole; Humans; Ivermectin; Macrolides; Male; Mice; Mice, Inbred BALB C; Mice, Inbred C57BL; Pyrantel Pamoate; Random Allocation

Twenty-eight helminth-naive Beagles, 16 to 26 weeks old, were inoculated with 200 third-stage larvae each of Ancylostoma caninum and Uncinaria stenocephala 5 times at weekly intervals. Dogs were randomly allocated to 4 groups of 7 on the basis of fecal egg counts, and treatments were randomly assigned. Groups 1 and 3 were given milbemycin oxime at a dosage of 500 micrograms/kg of body weight, PO, on day 0 and on days 0 and 30, respectively; groups 2 and 4 were nontreated controls. Fecal egg counts were evaluated before and after treatments. Feces were collected daily for 7 days after the final treatment for recovery of worms passed, and all dogs were euthanatized 7 days after the final treatment for recovery of worms retained. A 65.7% reduction from the pretreatment value for geometric mean hookworm egg count was found 7 days after the first treatment, and a 97.1% reduction 7 days after the second treatment. Although milbemycin oxime had 96.5% and 99.5% controlled efficacy against A caninum after 1 or 2 treatments, respectively, it lacked efficacy against U stenocephala. The geometric mean number of U stenocephala and the total number of hookworms retained after 1 or 2 treatments were not significantly different from the numbers retained by the corresponding control groups.

Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Dog Diseases; Dogs; Feces; Female; Hookworm Infections; Intestine, Small; Macrolides; Male; Parasite Egg Count; Random Allocation

Anthelmintic efficacy of milbemycin D was evaluated against Toxocara cati and Ancylostoma tubaeforme in domestic cats. Twelve cats naturally infected with each nematode species were allocated among 2 groups of 6 animals each, and milbemycin D was orally administered to the 2 groups of cats in doses of 0.05 mg/kg and 0.1 mg/kg body weight, respectively. In all the cats infected with T. cati, fecal egg counts decreased followed by their disappearance from the feces and 2-35 worms were excreted into the feces after the medication in both doses of 0.05 mg/kg and 0.1 mg/kg. At postmortem of these medicated groups, no worms were detected from 4 cats of each group, but 1 and 2 immature worms were recovered from the other 2 cats respectively. In the cats infected with A. tubaeforme, fecal egg counts decreased followed by the disappearance from the feces and 2-62 worms were excreted into the feces in all the cats of the 2 groups, no nematodes remaining at postmortem. These results indicate that milbemycin D is fully effective against T. cati and A. tubaeforme in cats in a dose of 0.05-0.1 mg/kg.

Topics: Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Cat Diseases; Cats; Feces; Female; Macrolides; Male; Parasite Egg Count; Toxocariasis

Topics: Ancylostoma; Ancylostomatoidea; Ancylostomiasis; Animals; Anthelmintics; Anti-Bacterial Agents; Dog Diseases; Dogs; Feces; Female; Hookworm Infections; Macrolides; Male; Parasite Egg Count

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)

Topics: Ancylostomiasis; Animals; Anti-Bacterial Agents; Dogs; Feces; Female; Macrolides; Male; Parasite Egg Count; Random Allocation; Toxocariasis; Trichuriasis