selamectin and Ectoparasitic-Infestations

The monthly administration of broad-spectrum heartworm medications can effectively prevent a variety of internal and external parasitic diseases in cats. Although not every parasite can be stopped, many of the common feline parasites are susceptible to these agents. This article discusses the epidemiology and prevention strategies for those parasites that can be controlled by the administration of ivermectin, milbemycin oxime, or selamectin, either alone or in conjunction with an external parasiticide.

Topics: Animals; Antiparasitic Agents; Cat Diseases; Cats; Ectoparasitic Infestations; Helminths; Intestinal Diseases, Parasitic; Ivermectin; Macrolides; Mites; Phthiraptera; Siphonaptera; Ticks

To compare safety and efficacy of spinosad and selamectin and determine effects of those products on flea allergy dermatitis (FAD) in cats.. Randomized clinical trial. Animals-211 client-owned cats.. Cats with ≥ 5 fleas evaluated at 8 veterinary clinics were allocated to receive spinosad (50 to 100 mg/kg [22.7 to 45.5 mg/lb], PO; n = 139) or selamectin (≥ 6 mg/kg [≥ 2.7 mg/lb], topically; 72) once per month. Flea comb counts and FAD scores were determined on day -1, between days 27 and 33, and between days 85 and 95 (evaluations 1, 2, and 3, respectively); day 0 was the first day of drug administration.. The most common adverse event was vomiting (14.3% and 2.4% of spinosad- and selamectin-treated cats, respectively). Evaluation 2 and 3 geometric mean flea counts for spinosad-treated cats were significantly lower than those for selamectin-treated cats. Percentage reductions in flea counts for the spinosad and selamectin groups were 97.5% and 88.8% (evaluation 2) and 99.3% and 97.7% (evaluation 3), respectively. At evaluations 2 and 3, 70.6% and 92.6% of spinosad-treated cats and 29.4% and 64.7% of selamectin-treated cats were free of fleas, respectively. Weighted FAD scores for spinosad- and selamectin-treated cats decreased 94.2% and 80.0% during the study, respectively. Spinosad tablets were successfully administered during 98.1% of treatments.. Results of this study indicated spinosad and selamectin both reduced flea counts and FAD scores for cats, although spinosad was more effective. Monthly oral administration of spinosad may be practical for treatment of flea infestations and FAD in cats.

Topics: Animals; Cat Diseases; Cats; Drug Combinations; Ectoparasitic Infestations; Female; Insecticides; Ivermectin; Macrolides; Male; Siphonaptera; Tablets

To determine pharmacokinetics, efficacy, and adverse effects of topically administered selamectin in flea-infested rabbits.. 18 healthy 5-month-old New Zealand White rabbits.. On day 0, rabbits (n = 6/group) received topically applied selamectin at doses of 10 or 20 mg/kg or received no treatment. Each rabbit was infested with 50 fleas (Ctenocephalides felis) on days -1, 7, and 14. Live and dead flea counts were performed on days 2, 9, and 16, and treatment efficacy was calculated. Blood samples were collected prior to drug administration and at 6 and 12 hours and 1, 2, 3, 5, 7, 10, 14, 21, and 28 days after treatment for determination of plasma selamectin concentrations via high-performance liquid chromatography with mass spectrometry. Pharmacokinetic parameters were determined.. On day 2, efficacy of selamectin against flea populations of rabbits in the 10 and 20 mg/kg treatment groups was 91.3% and 97.1%, respectively, but by day 9, these values decreased to 37.7% and 74.2%, respectively. Mean terminal half-life and maximum plasma concentrations of selamectin were 0.93 days and 91.7 ng/mL, respectively, for rabbits in the 10 mg/kg group and 0.97 days and 304.2 ng/mL, respectively, for rabbits in the 20 mg/kg group. No adverse effects were detected.. Selamectin was rapidly absorbed transdermally and was rapidly eliminated in rabbits. Results suggested that topical administration at a dosage of 20 mg/kg every 7 days is efficacious for treatment of flea infestation in rabbits. Further studies are needed to assess long-term safety in rabbits following repeated applications.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Area Under Curve; Ectoparasitic Infestations; Female; Half-Life; Ivermectin; Male; Rabbits; Siphonaptera

A series of studies was conducted to determine the effect of systemically and topically active insecticides on blood consumption by fleas (Ctenocephalides felis). Infestations were conducted by placing fleas into plexi-glass chambers attached to the lateral rib cage of domestic short-hair cats. After pre-defined periods, fleas and flea feces were extracted using vacuum aspiration and spectrophotometrically analyzed for hemoglobin using Drabkin's reagent. To determine how rapidly nitenpyram kills actively feeding fleas, a single oral treatment was administered 24h after infestation. To determine the effect of nitenpyram on blood consumption of newly acquired fleas, cats were infested with fleas 1h post-treatment and fleas and flea feces from both studies were extracted at 15, 30, 60, 120, 240 and 480min post-treatment or post-infestation. To compare the effects of topically versus systemically active insecticides, 20 cats each with 2 chambers attached, were randomly allocated among groups and were infested with fleas 1h after each of 4 nitenpyram treatments, or at 7, 14, 21 and 28 days after a single application of commercial spot-on formulations of fipronil, imidacloprid or selamectin. Infestations were also completed for untreated (control) cats. Twenty-four hours after infestation, fleas and flea feces were removed for host blood quantification. If at any time, flea blood consumption in a treated group did not significantly differ from that of fleas infesting controls, that treatment group was withdrawn from the study. Nitenpyram effects on actively feeding fleas were first observed at 60min post-dosing when 38% of fleas were dead or moribund, and at 240min 100% were dead or moribund. Nitenpyram produced a significant reduction in flea blood consumption (p<0.05), which appeared to cease 15min after infestation. For the treatment comparisons, significantly more (p<0.05) blood was consumed by fleas taken from imidacloprid and fipronil-treated cats than from the nitenpyram or selamectin groups. Only on nitenpyram- or selamectin-treated cats were there significant reductions (p<0.05) in flea blood consumption on days 21 and 28, with significant difference (p>0.05) between these two groups on day 28. In this study systemically acting insecticides such as nitenpyram, and the topically applied but systemically active insecticide selamectin, were more effective in interfering with flea blood feeding than were imidacloprid and fipronil.

Topics: Animals; Cats; Drug Therapy, Combination; Ectoparasitic Infestations; Feeding Behavior; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Pyridines; Siphonaptera

Twenty adult, domestic short hair cats were randomly allocated into four groups of five cats and housed in separated cages. Each cat was infested with 25 fleas Ctenocephalides felis felis and 25 Ctenocephalides felis strongylus and 2 days later (day 0) the cats in group 1, 2 and 3 received a spot on application of selamectin, imidacloprid or fipronil, respectively, while the cats in group four were not treated. The cats were combed 48 h later, the fleas were removed, counted and their subspecies were determined. All the cats were reinfested with the same number of the two subspecies of fleas on days 7, 14, 21, 29 and 35. The efficacy of each treatment was calculated 48 h after each infestation. The mean number of fleas on the control cats was 16.4 C. f. felis and 13.4 C. f. strongylus. The three treatments were effective for the first 31 days for C. f. felis and for the full 37 days for C. f. strongylus. Over the first 31 days, the efficacy of selamectin ranged from 89 to 100% and 85 to 100% against C. f. felis and C. f. strongylus, respectively, the efficacy of imidacloprid ranged from 76 to 100% and 92 to 100% and the efficacy of fipronil ranged from 98 to 100% and 97 to 100% against C. f. felis and C. f. strongylus. There were no significant differences between the control of C. f. felis and C. f. strongylus by the three products.

Topics: Animals; Cat Diseases; Cats; Cross-Over Studies; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera; Time Factors; Treatment Outcome

A study was conducted to evaluate the efficacy of selamectin and fipronil-(S)-methoprene against adult cat fleas (Ctenocephalides felis), flea egg production, and the viability of flea eggs collected from treated cats. Cats were infested with approximately 50 adult fleas 2 days before treatment and weekly thereafter; flea eggs were collected and counted on days 0, 1, 2, and 3 and 48 and 72 hours after each weekly flea infestation. Live fleas were collected approximately 72 hours after treatment or infestation. Compared with fipronil-(S)-methoprene, selamectin provided significantly greater control of adult fleas from days 24 to 31 and significantly greater reduction in egg production from days 16 to 45. For the most part, both products significantly impacted larval and adult emergence for the entire 6-week study, with fipronil-(S)-methoprene providing significantly greater reduction in larval and adult emergence at week 6.

Topics: Administration, Cutaneous; Animals; Cat Diseases; Cats; Ectoparasitic Infestations; Insecticides; Ivermectin; Larva; Pyrazoles; Siphonaptera; Treatment Outcome

The speed of kill of selamectin, imidacloprid, and fipronil-(S)-methoprene against Ctenocephalides felis infestations on cats for one month following a single treatment was evaluated. Eighty cats were randomly allocated so that there were 20 cats in four different treatment groups. On Days -2, 7, 14, 21, and 28, each cat was infested with 100 adult C. felis from the Kansas 1 flea strain. Following initial application only imidacloprid had caused a significant reduction in adult fleas on treated cats within 6 hours, but by 24 hours all three formulations had killed 96.7% of the fleas. At 7 days post treatment, all three formulations reduced flea populations within 6 and 24 hours by 68.4% and 99.4%, respectively. At 21 and 28 days after treatment, none of the formulations killed significant numbers of fleas as compared to controls within 6 hours of infestation. At 28 days after treatment, selamectin, fipronil-(S)-methoprene, and imidacloprid had killed 99.0%, 86.4%, and 72.6% of the fleas within 48 hours of infestation, respectively. This study demonstrates that the speed of kill of residual flea products on cats decreases throughout the month following application. It also demonstrated that selamectin provided the highest level of residual activity on cats against the Kansas 1 flea strain.

Topics: Administration, Cutaneous; Animals; Cat Diseases; Cats; Chemistry, Pharmaceutical; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera; Time Factors; Treatment Outcome

Speed of kill and percentage kill of nitenpyram (CAPSTAR) was compared to fipronil (Frontline) spot-on), imidacloprid (Bayvantage/Advantage), selamectin (Stronghold/Revolution) and cythioate (Cyflee) against adult fleas on cats and dogs 3 and 8h post-treatment. Selamectin was used on dogs only; cythioate was used on cats only. Groups of eight cats and eight dogs (four males and four females each) were experimentally infested with 100 unfed fleas 1 day prior to treatment with the test products. One group of cats and one group of dogs served as control. Fleas were collected from four cats and four dogs in each group (two males and two females) by combing 3h after treatment, the remaining four cats or dogs were combed 8h after treatment. In cats cythioate treatment resulted in a mean efficacy of 62.4 and 97.4% at 3 and 8h post-treatment, respectively. Imidacloprid efficacy at the same times was 26.9 and 82.8%, whereas fipronil efficacy was 24.3 and 62.6% efficacy, respectively. In dogs mean efficacy 3 and 8h after treatment with selamectin was 39.7 and 74.4%; with imidacloprid efficacy was 22.2 and 95.7%, respectively and 35.9 and 46.5%, respectively after treatment with fipronil. Nitenpyram was 100% effective in cats and 99.1% effective in dogs within 3h of treatment and 100% effective in cats and dogs within 8h.

Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Pyridines; Siphonaptera; Time Factors

To determine whether treatment with selamectin would reduce clinical signs of flea allergy dermatitis (FAD) in dogs and cats housed in flea-infested environments.. Randomized controlled trial.. 22 dogs and 17 cats confirmed to have FAD.. Animals were housed in carpeted pens capable of supporting the flea life cycle and infested with 100 fleas (Ctenocephalides felis) on days -13 and -2 and on alternate weeks with 10 to 20 fleas. On day 0, 11 dogs and 8 cats were treated with selamectin (6 mg/kg [2.7 mg/lb]). Dogs were retreated on day 30; cats were retreated on days 30 and 60. All animals were examined periodically for clinical signs of FAD. Flea counts were conducted at weekly intervals.. Throughout the study, geometric mean flea counts exceeded 100 for control animals and were < or = 11 for selamectin-treated animals. Selamectin-treated cats had significant improvements in the severity of miliary lesions and scaling or crusting on days 42 and 84, compared with conditions on day -8, and in severity of excoriation on day 42. In contrast, control cats did not have any significant improvements in any of the clinical signs of FAD. Selamectin-treated dogs had significant improvements in all clinical signs on days 28 and 61, but in control dogs, severity of clinical signs of FAD was not significantly different from baseline severity at any time.. Results suggest that topical administration of selamectin, even without the use of supplementary environmental control measures and with minimal therapeutic intervention, can reduce the severity of clinical signs of FAD in dogs and cats.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dermatitis, Allergic Contact; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Ivermectin; Male; Siphonaptera; Treatment Outcome

The comparative efficacy of monthly administration of selamectin or lufenuron against Ctenocephalides felis felis on dogs and cats was evaluated over a 5-month period in flea-infested environments. Twenty-four dogs and 32 cats were randomly allocated to receiving a topical treatment with selamectin or an oral administration of tablets containing lufenuron/milbemycin oxime (for dogs) or lufenuron only (for cats). Each product was administered in accordance with the manufacturer's label recommendations. Eight dogs and four cats served as untreated sentinels. Treatments were administered on days 0, 30, 60, 90, and 120. Each animal received an application of 100 fleas on days -28 and -21, and then weekly applications of 20 fleas from days 91 through 147. Flea comb counts were performed on day -6, and every 2 weeks after day 0. From day 29 (dogs) or day 44 (cats) to day 150, geometric mean flea counts for selamectin were < or =0.4. Mean flea counts for animals assigned to treatment with selamectin were significantly lower (P=0.0001) than for animals assigned to treatment with lufenuron at all assessments after day 0.

Topics: Animals; Antiparasitic Agents; Benzamides; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Housing, Animal; Insecticides; Ivermectin; Male; Siphonaptera; Treatment Outcome

Twenty-four beagles were randomly allocated into four groups of six and housed in separate cages. Each dog was infested with 25 Ctenocephalides canis and 25 Ctenocephalides felis felis and two days later (day 0) the dogs in groups 1, 2 and 3 received a spot-on application of selamectin (6 mg/kg), imidacloprid (10 mg/kg), or fipronil (6-7 mg/kg), respectively, while the dogs in group 4 were not treated. The dogs were combed 48 hours later, the fleas were removed, counted and their species were determined. All the dogs were reinfested with the same number of the two species of fleas on days 7, 14, 21, 28 and 35, and the efficacy of the treatments was calculated 48 hours after each infestation. The mean numbers of fleas on the control dogs were 19.8 C. canis and 14.7 C. felis felis. The three treatments were effective for the full 35 days of the trial; over the first 28 days, the efficacy of selamectin ranged from 81 to 100 and 92 to 99 per cent against C. felis felis and C canis, respectively, the efficacy of imidacloprid ranged from 98 to 100 per cent and the efficacy of fipronil was 100 per cent against both species. There were no significant differences between the three treatments.

Topics: Administration, Cutaneous; Animals; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera; Treatment Outcome

Imidacloprid (Advantage, Bayer Corporation, Shawnee Mission, KS) and selamectin (Revolution [United States], Pfizer Animal Health, Exton, PA 19341; Stronghold [European Union], Pfizer Animal Health Ltd, Sandwich, Kent CT 13 9NJ, UK) were tested to assess the speed of flea kill achieved against existing flea infestations and subsequent reinfestations. Thirty-six dogs were infested with 100 unfed adult fleas on day-1. On day 0, 12 dogs (group 1) were treated with imidacloprid at the minimum label dose of 10 mg/kg body weight. Twelve dogs (group 2) were treated with selamectin at the minimum label dose of 6 mg/kg body weight. Twelve dogs (group 3) remained as untreated controls. Four sub-groups (A through D) of three dogs each were designated within each group. All dogs were subsequently reinfested with fleas on days 6, 13, 20, 27, 34, and 41. Live flea counts were performed for subgroups A through D at 6, 12, 24, and 36 hours after treatment/reinfestation. Imidacloprid provided significantly and consistently greater flea kill than selamectin at 6, 12, and 24 hours after treatment and at 6 and 12 hours after each reinfestation. Although both products are commercially labeled for monthly topical use, imidacloprid provided significantly greater 36-hour flea kill at 34 and 41 days after treatment.

Topics: Animals; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Neonicotinoids; Nitro Compounds; Siphonaptera; Time Factors

The topical endectocide selamectin (Revolution, Pfizer Animal Health) was evaluated in seven veterinary dermatology specialty clinics for its ability to control fleas on 75 dogs and 46 cats from single- and multiple-animal households. All animals were treated on days 0, 30, and 60 with a minimum unit dose of 6 mg/kg of selamectin(h) applied to the skin in a single spot at the base of the neck in front of the scapulae. The product was applied according to label instructions, and the use of other topical or environmental flea control products was prohibited during the study. Efficacy was assessed by percentage reductions in geometric mean flea comb counts. The reductions in flea numbers for dogs and cats combined were 90.6%, 97.0%, and 98.0% on days 30, 60, and 90, respectively, compared with day 0. This study demonstrates that selamectin, applied at 30-day intervals to dogs and cats, effectively controls flea infestations without other flea control products in single- and multiple-animal households.

Topics: Animals; Cat Diseases; Cats; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Insecticides; Ivermectin; Male; Siphonaptera

Topics: Animals; Anthelmintics; Antiparasitic Agents; Cat Diseases; Cats; Dirofilaria immitis; Dirofilariasis; Dog Diseases; Dogs; Drug Evaluation, Preclinical; Ectoparasitic Infestations; Female; Ivermectin; Male; Mice; Models, Chemical; Siphonaptera; Tick Infestations

Selamectin, 25-cyclohexyl-25-de(1-methylpropyl)-5-deoxy-22, 23-dihydro-5-(hydroxyimino)-avermectin B1 monosaccharide, is a novel endectocide with a unique combination of efficacy and safety in dogs and cats following both oral and topical administration. The compound is active against fleas and ticks, intestinal hookworms and ascarids, and immature heartworms. Also it is well tolerated at higher dosages than 22,23-dihydroavermectin B1a (DHAVM) or milbemycin oxime in Collies, which is a breed known to exhibit idiosyncratic sensitivity to avermectins.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Drug Administration Schedule; Ectoparasitic Infestations; Female; Ivermectin; Male; Siphonaptera

Selamectin, a novel avermectin, was evaluated in two controlled studies (one in Beagles, one in domestic shorthaired cats) to determine an appropriate topical dose for efficacy against adult Ctenocephalides felis felis (C. felis) fleas on dogs and cats for 1 month. For each study, animals were allocated randomly to four treatments. One treatment consisted of the inert formulation ingredients (vehicle) administered as a negative control, and the other three treatments consisted of a single topical dosage of 3, 6, or 9mgkg(-1) of selamectin. In each study, selamectin was administered as a topical dose applied to the skin in a single spot at the base of the neck in front of the scapulae. Dogs and cats were infested with 100 viable unfed C. felis (50 males and 50 females) on days 4, 11, 18, and 27. Seventy-two hours (+/-2h) after each infestation, on days 7, 14, 21, and 30, a comb count to determine the number of viable fleas present on each animal was performed. Efficacy of selamectin on day 30 was used to select an appropriate dose. For dogs and cats, percentage reductions in geometric mean flea comb counts for the three selamectin treatments ranged from 94. 6 to 100% on days 7, 14, and 21, compared with the negative-control treatment. On day 30, reductions in flea comb counts were 81.5, 94.7, and 90.8% for dogs, and 79.8, 98.0, and 96.2% for cats treated with selamectin at 3, 6, or 9mgkg(-1), respectively. For day 30 flea comb counts for dogs and cats, analysis of variance showed that the three selamectin treatments resulted in significantly (P< or =0.05) lower counts than did the negative-control treatment. For dogs and cats, geometric mean flea counts for selamectin administered at a dosage of 3mgkg(-1) were significantly (P< or =0.05) higher than those for the 6 and 9mgkg(-1) treatment dosages combined. There were no significant differences in flea counts between the 6 and 9mgkg(-1) treatments. This analysis was confirmed by linear-plateau modeling. Thus, the optimal dose of selamectin for efficacy against adult fleas for both dogs and cats, as estimated by the turning point (plateau) in the dose response curve, was 6mgkg(-1).

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Ivermectin; Male; Siphonaptera

Selamectin was evaluated in eight controlled studies (4 in dogs, 4 in cats) to determine the efficacy of a single topical unit dose providing the recommended minimum dosage of 6mgkg(-1) against Ctenocephalides felis felis and Ctenocephalides canis fleas on dogs and against C. felis on cats. In addition, the effect of bathing on the efficacy of selamectin against C. felis was evaluated. Identical studies were performed in Beagles and domestic shorthaired cats. For each study, animals were allocated randomly to treatments of 8-12 animals each. All studies (dog studies A, B, C, and D and cat studies A, B, C, and D) evaluated the efficacy of selamectin without bathing. In addition, study C in both dogs and cats evaluated efficacy with a shampoo bath at 24h after dosing, and study D evaluated the efficacy of selamectin with water soaking at 2h after dosing or with a shampoo bath at 2-6h after dosing. Dog study B evaluated efficacy against C. canis, whereas all other studies used C. felis. In each study, selamectin was administered on day 0 as a topical dose that was applied directly to the skin in a single spot at the base of the neck in front of the scapulae. Dogs and cats were infested with approximately 100 viable unfed C. felis or C. canis on days 4, 11, 18, and 27. On days 7, 14, 21, and 30, approximately 72h after infestation, a comb count of the number of viable fleas present on each animal was made. For C. felis and C. canis for dogs and cats, compared with controls, selamectin achieved significant reductions in geometric mean adult flea comb counts of > or =98.9% on days 7, 14, and 21 in all eight studies. On day 30, the reduction for C. felis remained at or above 98.0%. This included the dogs and cats that were soaked with water or bathed with shampoo at 2, 6, or 24h after treatment. There were no significant (P>0.05) differences between the flea counts from selamectin-treated animals in these studies, regardless of bathing status. On day 30, a significant reduction of 91.8% was achieved against C. canis on dogs. Thus, these studies demonstrated that a single topical unit dose of selamectin was highly effective against adult fleas on dogs and cats for at least 27 days.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Ivermectin; Male; Siphonaptera; Time Factors

The adulticidal, ovicidal, and larvicidal effects of selamectin against flea (Ctenocephalides felis felis) infestations on dogs and cats were evaluated in a series of seven controlled and masked studies (three in cats, four in dogs). Animals were randomly allocated to treatment with either selamectin at a minimum dosage of 6mgkg(-1) in the commercial formulation or one of two negative-controls (0.9% NaCl solution or the vehicle from the commercial formulation). Treatments were administered topically in a single spot on the skin at the base of the neck in front of the scapulae. Speed of kill, measured by flea comb counts at 12h intervals during the 48h immediately following a single treatment on day 0, was evaluated in two studies. One study was in dogs and the other in cats, and each animal was infested with approximately 100 unfed viable adult fleas prior to treatment. Reductions in geometric mean flea counts for selamectin compared with saline were >98% between 24 and 36h after treatment in dogs, and between 12 and 24h after treatment in cats (P< or =0.0006). Efficacy in reducing flea egg hatch and larval development was evaluated in four studies, in which dogs and cats were treated once on day 0 and then repeatedly infested with approximately 600 fleas. Flea eggs were collected approximately for 72h after each infestation, on days 3, 7, 14, 21, and 30, counted, and cultured to determine their hatchability and subsequent larval development. Compared with the vehicle, selamectin was highly effective in reducing flea egg hatch (>92% in cats) and larval development (> or =95% for dogs and cats), and emergence of adults (97.8-100% for dogs, 85.6-100% for cats) for 30 days. Effects of exposure to hair coat debris were investigated in a study with dogs treated once on day 0 and repeatedly infested with 100 adult fleas. Debris (dander, flea faeces, hair, scales) was collected on days 1, 7, 14, 21, and 30 and added to normal flea eggs or larvae for incubation. Compared with debris from vehicle-treated dogs, debris from selamectin-treated dogs was highly effective in preventing egg hatch (>96%), in killing larvae (>98%) and in preventing larval development to adults (>99%) (P

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Housing, Animal; Ivermectin; Life Cycle Stages; Male; Siphonaptera

The efficacy of selamectin, a novel avermectin, in protecting dogs and cats against experimentally induced environmental flea (Ctenocephalides felis felis) infestations, was evaluated in a series of controlled and masked studies. Purpose-bred shorthaired cats and Beagles were randomly allocated to treatment with either selamectin at a minimum dosage of 6mgkg(-1) of body weight in the commercial formulation or the negative control treatment (vehicle only), and housed in controlled simulated home environments capable of supporting the flea life cycle. Day 0 was defined as the first day of treatment. Treatments were administered topically in a single spot on the skin at the base of the neck in front of the scapulae. In environmental challenge studies, which were designed to evaluate the efficacy of selamectin in the treatment and control of established flea infestations, dogs and cats were each infested with 100 fleas on days -28 and -21 and placed in carpeted rooms in order to establish high levels of active flea infestation prior to day 0. Treatments were administered monthly for 3 months. Flea comb counts were performed on days 14, 29, 44, 59, 74, and 90. Reductions in geometric mean flea comb counts for selamectin, compared with vehicle, were >99% from day 14 onwards for dogs, and >92% on day 29 and >99% on days 44, 59, 74, and 90 for cats (P=0.0001). In prevention of environmental infestation studies, dogs and cats were placed in environments capable of supporting flea infestations and given monthly treatments for 2 months, commencing on day 0. Animals were infested with 100 fleas on days 1 and 7, and flea comb counts were performed on days 29, 44, and 60. Reductions in geometric mean flea comb counts for selamectin, compared with vehicle, were >99% on days 29, 44, and 60 (P=0.0001) for dogs and cats. Monthly administration of selamectin to dogs and cats housed in environments highly suited to completion of the flea life cycle was shown to be highly effective in the treatment and prevention of flea infestations, without the need for supplementary environmental control measures.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Housing, Animal; Ivermectin; Male; Siphonaptera

Two controlled and masked multi-centre studies were conducted to examine the efficacy of a novel topical avermectin, selamectin, against natural flea infestations on 418 dogs and 345 cats. Veterinary patients with viable flea infestations were enrolled in the studies, which were conducted in United Kingdom, France, Germany, and Italy. Animals were allocated randomly in a 2:1 ratio to one of two treatments: either selamectin alone at a minimum dosage of 6mgkg(-1) or fenthion at recommended dose rates. Concurrent use of an environmental spray (containing methoprene and either pyrethrins or permethrin) was permitted only for fenthion-treated animals. In-contact cats and dogs (animals living in the same home) received the same treatment as the first animal enrolled from the household, if recommended by the veterinarian. Study day 0 was defined as the day of first treatment. Animals were treated on days 0, 30, and 60, and flea comb counts and clinical evaluations were conducted on days 0, 14, 30, 60, and 90. Analysis of variance of ln(flea count+1) showed that values were significantly lower for selamectin alone compared with fenthion (with or without the concurrent use of an environmental spray) in dogs on days 30, 60, and 90 (P<0.05) and in cats on days 14, 30, 60, and 90 (P<0.01). For selamectin, the reductions in geometric mean flea counts on days 14, 30, 60, and 90, compared with day 0, were 92.5, 90.7, 98.1, and 99.1%, respectively, for dogs and 92.8, 92.7, 97.7, and 98.4%, respectively, for cats. Selamectin was shown to be safe and highly effective in the control of naturally acquired flea infestations on dogs and cats presented as veterinary patients in Europe.

Topics: Animals; Antiparasitic Agents; Cat Diseases; Cats; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Europe; Female; Housing, Animal; Ivermectin; Male; Siphonaptera

A series of randomized, controlled, masked field studies was conducted to assess the efficacy and safety of selamectin in the treatment of flea infestations on dogs and cats, and in the prevention of heartworm infection in dogs. In addition, observations were made on the beneficial effect of selamectin treatment on dogs and cats showing signs of flea allergy dermatitis (FAD). In all studies selamectin was applied topically, once per month, in unit doses providing a minimum dosage of 6mgkg(-1). Dogs and cats with naturally occurring flea infestations, some of which also had signs associated with FAD, were assigned randomly to receive three months of topical treatment with selamectin (220 dogs, 189 cats) or a positive-control product (dogs: fenthion, n=81; cats: pyrethrins, n=66). Selamectin was administered on days 0, 30, and 60. Day 0 was defined as the day that the animal first received treatment. Flea burdens were assessed by flea comb counts and clinical evaluations of FAD were performed before treatment, and on days 14, 30, 60, and 90. On days 30, 60, and 90, mean flea counts in selamectin-treated dogs were reduced by 92.1, 99.0, and 99.8%, and mean flea counts in fenthion-treated dogs were reduced by 81.5, 86.8, and 86.1%, respectively, compared with day 0 counts. Also, on days 30, 60, and 90, mean flea counts in selamectin-treated cats were reduced by 92.5, 98.3, and 99.3%, and mean flea counts in pyrethrin-treated cats were reduced by 66.4, 73.9, and 81.3%, respectively, compared with day 0 counts. Selamectin also was beneficial in alleviating signs in dogs and cats diagnosed clinically with FAD. A total of 397 dogs free of adult heartworm infection from four heartworm-endemic areas of the USA were allocated randomly to six months of treatment with selamectin (n=298) or ivermectin (n=99). Selamectin achieved a heartworm prevention rate of 100%, with all dogs testing negative for microfilariae and adult heartworm antigen on days 180 and 300. Selamectin was administered to a total of 673 dogs and 347 cats having an age range of 6 weeks to 19 years (3954 doses). The animals included 19 purebred or crossbred Collies (Bearded, Border, and unspecified). There were no serious adverse events. Results of these studies indicated that selamectin was highly effective in the control of flea infestations in dogs and cats without the need for simultaneous treatment of the environment or of in-contact animals and also was beneficial in alleviating signs associated

Topics: Animals; Anthelmintics; Antiparasitic Agents; Cat Diseases; Cats; Dirofilariasis; Dog Diseases; Dogs; Drug Administration Schedule; Ectoparasitic Infestations; Female; Ivermectin; Male; North America; Siphonaptera

The efficacy of selamectin in the treatment and prevention of naturally acquired Toxocara canis infections and experimentally induced flea (Ctenocephalides felis felis) infestations in dams and their suckling pups was evaluated by administering selamectin to the adult females only, approximately 40 and 10 days before parturition and 10 and 40 days after parturition. Unit doses of the commercial formulation of selamectin were administered to the dams to provide at least the minimum recommended dosage of 6mgkg(-1) (range, 6-12mgkg(-1)). Dams and their pups were housed in carpeted environments able to support the flea life cycle. Flea infestations were established initially by experimental infestation before treatment administration and by repeated re-infestation of dams at approximately weekly intervals throughout the study, which was completed 45 days after parturition. There were no adverse drug experiences related to treatment with selamectin and no treatment-related mortalities. Percentage reductions in geometric mean T. canis faecal egg counts for the selamectin-treated dams, compared with those receiving the negative-control treatment (vehicle only) were 99.7% at the end of the study (P=0.0001). Geometric mean faecal egg counts in pups from selamectin-treated females were reduced by > or =96% on the 24th and 34th days after birth (P=0.0001), and the number of adult worms recovered from the gastrointestinal tract of pups from selamectin-treated dams was reduced by 98.2% (P=0.0001), compared with that for pups from dams treated with the vehicle only. Percentage reductions in geometric mean flea counts for selamectin-treated dams and their pups, compared with vehicle-treated dams and their pups, were > or =99.8% (P=0.0001) and 100% (P=0.0001), respectively, throughout the study. Thus, selamectin administered topically at a minimum unit dosage of 6mgkg(-1) to dams with naturally acquired T. canis infections and experimentally induced C. felis infestations was safe and highly effective in the treatment, control, and prevention of adult T. canis infection and C. felis infestation affecting both the dams and their pups.

Topics: Administration, Topical; Animals; Anthelmintics; Antiparasitic Agents; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Housing, Animal; Ivermectin; Larva; Male; Parasite Egg Count; Pregnancy; Siphonaptera; Toxocara canis; Toxocariasis

Selamectin is a broad-spectrum avermectin endectocide for treatment and control of canine parasites. The objective of these studies was to evaluate the clinical safety of selamectin for topical use in dogs 6 weeks of age and older, including breeding animals, avermectin-sensitive Collies, and heartworm-positive animals. The margin of safety was evaluated in Beagles, which were 6 weeks old at study initiation. Reproductive, heartworm-positive, and oral safety studies were conducted in mature Beagles. Safety in Collies was evaluated in avermectin-sensitive, adult rough-coated Collies. Studies were designed to measure the safety of selamectin at the recommended dosage range of 6-12mgkg(-1) of body weight. Endpoints included clinical examinations, clinical pathology, gross and microscopic pathology, and reproductive indices. Selected variables in the margin of safety and reproductive safety studies were subjected to statistical analyses. Pups received large doses of selamectin at the beginning of the margin of safety study when they were 6 weeks of age and at their lowest body weight, yet displayed no clinical or pathologic evidence of toxicosis. Similarly, selamectin had no adverse effects on reproduction in adult male and female dogs. There were no adverse effects in avermectin-sensitive Collies or in heartworm-positive dogs. Oral administration of the topical formulation caused no adverse effects. Selamectin is safe for topical use on dogs at the recommended minimum dosage of 6mgkg(-1) (6-12mgkg(-1)) monthly starting at 6 weeks of age, and including dogs of reproducing age, avermectin-sensitive Collies, and heartworm-positive dogs.

Topics: Administration, Oral; Administration, Topical; Animals; Anthelmintics; Antiparasitic Agents; Dirofilariasis; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Ectoparasitic Infestations; Female; Fetus; Ivermectin; Male; Pregnancy; Reproduction

The safety of the avermectin, selamectin, was evaluated for topical use on the skin of cats of age six weeks and above, including reproducing cats and cats infected with adult heartworms. All studies used healthy cats. Acute safety was evaluated in domestic cross-bred cats. Margin of safety was evaluated in domestic-shorthaired cats, starting at six weeks of age. Reproductive, heartworm-infected, and oral safety studies were conducted in adult, domestic-shorthaired cats. Studies were designed to measure the safety of selamectin at the recommended dosage range of 6-12mgkg(-1) of body weight. Assessments included clinical, biochemical, pathologic, and reproductive indices. Selected variables in the margin of safety study and the reproductive studies were subjected to statistical analyses by using a mixed linear model. Cats received large doses of selamectin at the beginning of the margin of safety study when they were six weeks of age and at their lowest body weight, yet displayed no clinical or pathologic evidence of toxicosis. Similarly, selamectin had no adverse effect on reproduction in adult male and female cats. There were no adverse effects in heartworm-infected cats. Oral administration of the topical formulation, which might occur accidentally, caused mild, intermittent, self-limiting salivation and vomiting. Selamectin is a broad-spectrum avermectin endectocide that is safe for use in cats starting at six weeks of age, including heartworm-infected cats and cats of reproducing age, when administered topically to the skin monthly at the recommended dosage to deliver at least 6mgkg(-1).

Topics: Administration, Oral; Animals; Anthelmintics; Antiparasitic Agents; Cats; Dirofilariasis; Dog Diseases; Dogs; Dose-Response Relationship, Drug; Ectoparasitic Infestations; Female; Fetus; Ivermectin; Male; Pregnancy; Reproduction

To evaluate efficacy of monthly administration of selamectin and fipronil against Ctenocephalides felis in cats.. Randomized controlled trial.. 36 healthy cats.. Cats known to be free of fleas were infested with 100 unfed adult fleas on days -28 and -21. On days 0, 30, 60, 90, and 120, sixteen cats (8 pairs/treatment group) were treated by topical administration of selamectin (6 mg/kg [2.7 mg/lb] of body weight) or fipronil (7.5 mg/kg [3.4 mg/lb]). Four control cats (2 pairs) were not treated. On day -6 and every 2 weeks after initial treatment, comb counts were performed to detect fleas. Flea counts were recorded, and fleas (< or =50) that had been removed were replaced onto the cat. On day 89, fleas were not replaced. On day 91 and every 7 days until the end of the study (day 150), cats were challenged with 20 adult fleas. Flea counts were compared between and within treatments.. 14 days after treatment, geometric mean flea counts were reduced by 71.2% by fipronil treatment and 35.3% by selamectin treatment. Both treatments resulted in 97 to 98% reduction in flea counts on day 29 and 99.8 to 100% reduction from day 44 to the end of the study.. Selamectin is as effective as fipronil in treating infestation in cats housed for 3 months in a flea-infested environment under conditions known to support the flea life cycle and in protecting against subsequent weekly challenges with C felis for an additional 2 months.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Cat Diseases; Cats; Ectoparasitic Infestations; Female; Ivermectin; Least-Squares Analysis; Male; Pyrazoles; Siphonaptera

To evaluate efficacy of monthly administration of selamectin, fipronil, and imidacloprid against Ctenocephalides felis in dogs.. Randomized controlled trial.. 44 healthy dogs.. Dogs known to be free of fleas were infested with 100 unfed adult fleas on days -28 and -21. On days 0, 30, 60, 90, and 120, dogs (12/group) were treated by topical administration of selamectin (6 mg/kg [2.7 mg/lb] of body weight), fipronil (7.5 mg/kg [3.4 mg/lb]), or imidacloprid (10 mg/kg [4.5 mg/lb]); 8 untreated dogs were used as controls. On day -6 and every 2 weeks after initial treatment, comb counts of viable adult fleas were made, and fleas (< or =50/dog) were replaced onto the dog from which they were removed. On day 89, fleas were not replaced. On day 91 and every 7 days until the end of the study, dogs were challenged with 20 adult fleas.. 14 days after initial treatment, geometric mean flea counts were reduced by 97.5 to 99.1 % for all treatments, compared with pretreatment counts on day -6. Selamectin, fipronil, and imidacloprid reduced geometric mean flea counts by 99.7 to 100% from day 29 to the end of the study.. Selamectin is as effective as fipronil and imidacloprid in reducing C felis infestation in dogs housed for 3 months in a flea-infested environment under conditions known to support the flea life cycle, and in protecting against subsequent weekly challenges with C felis for an additional 2 months.

Topics: Administration, Topical; Animals; Antiparasitic Agents; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Least-Squares Analysis; Male; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera

Topics: Administration, Topical; Animals; Antiparasitic Agents; Azetidines; Cat Diseases; Cats; Drug Therapy, Combination; Ectoparasitic Infestations; Ivermectin; Japan; North America; Parasitic Diseases, Animal; Spiro Compounds

Topics: Animals; Antiparasitic Agents; Azetidines; Cat Diseases; Cats; Ectoparasitic Infestations; Europe; Ivermectin; Parasitic Diseases, Animal; Spiro Compounds

Ticks are hematophagous ectoparasites which can transmit several diseases to the host during their feeding process. When ticks mechanically damage the tissue, they eventually induce inflammatory responses on the skin spot where they are fixed. One of the alternatives to control these ectoparasites is the use of chemical substances like selamectin-the active principle of Pfizer's antiparasitic Revolution-a macrocyclic lactone capable of doing neurotoxic damage to the tick and eventually eliminating infestation in dogs and cats. The purpose of this study was to analyze, using histological and histochemical techniques, the occurrence of morphophysiological alterations in the skin of the host rabbits exposed to selamectin and infested with Rhipicephalus sanguineus (Acari: Ixodidae). Histologically, the exposed and infested rabbits showed a partial and/or total decrease in the stratum corneum and the epithelium decreased in the number of cell layers, consequently reducing the stratification (thinning) and quite pronounced formations of sub-epidermal edemas with consequent disorganization of collagen fibers in the dermal layer's connective tissue. Histochemical tests showed strong periodic acid-Schiff-positive reaction in the hair follicle and some regions of the dermis, besides resynthesis of collagen fibers detected by Mallory's trichrome technique. The obtained results showed that selamectin acts like a toxicant agent when in contact with the skin of the rabbit infested with ticks, inducing morphophysiological alterations in the acute inflammatory process in the animal's tegument. Selamectin is a chemical substance which has a dose-dependent action since higher concentrations cause greater morphophysiological damage in the skin of rabbits.

Topics: Acaricides; Animals; Disease Models, Animal; Ectoparasitic Infestations; Histocytochemistry; Ivermectin; Rabbits; Rhipicephalus sanguineus; Skin

Ticks of Rhipicephalus sanguineus species have great medical and veterinary importance for being a vector of various diseases. In an attempt to minimize their action on the host, people have resorted to chemical control by using various acaricides, such as selamectin. Although previous studies have demonstrated its toxic action in domestic animals, no studies focused on the detection of cell death when exposed to selamectin. For this reason, the technique for detecting autophagic cell death was used in order to demonstrate the responses of rabbits' skin tissues pre-infested with R. sanguineus and exposed to different concentrations of selamectin. The obtained results when exposed to 100 and 80% concentrations of selamectin showed a strong mark of acid phosphatase on the cells of the connective tissue of the dermis and hair follicles, whereas the ones exposed to the 50% concentration had a weak mark on the cells of the connective tissue of the dermis and moderate staining in hair follicles. It became clear that, when used at high concentrations (100 and 80%), selamectin is capable to induce a large scale occurrence of the autophagic cell death process. On the other hand, the concentration of 50% causes minor morphophysiological changes in the skin of rabbit hosts when evaluated the cell death process. Therefore, the data confirms that selamectin is a powerful dose-dependent toxic agent causes increased activity of the enzyme acid phosphatase.

Topics: Acaricides; Acid Phosphatase; Animals; Autophagy; Disease Models, Animal; Ectoparasitic Infestations; Ivermectin; Rabbits; Rhipicephalus sanguineus; Skin

This case report is presumed to be the first case of infestation of a cat by springtails which are small arthropods closely related to insects. The organisms, found by skin scrapings, were identified as Proisotoma spp. (Collembola: Isotomidae). The cat presented with dermatological lesions (itchy, furfuraceous dermatitis), and we speculate that they were due to this infestation. The pathogenic role of the Collembola was hypothesized because of the large number of organisms, the presence of eggs indicating an active reproduction cycle, the lack of other pathogens (fleas, mites or lice) and the clinical recovery accompanied by the disappearance of Collembola following treatment. The owner seemed to be affected by the infestation, because a few days after having purchased the cat, she developed a pruriginous papular dermatitis on the neck and the arms, which disappeared shortly after treatment of the kitten and a careful washing of all of its toys and other accoutrements.

Topics: Animals; Antiparasitic Agents; Cat Diseases; Cats; Ectoparasitic Infestations; Insecta; Ivermectin; Male

Four active ingredients--imidacloprid selamectin, fipronil-(S)-methoprene, and metaflumizone--were tested to assess the speed of flea kill against existing flea infestations and subsequent reinfestations. Thirty flea-infested cats were allocated to four treatment groups and one untreated control group. Flea counts were performed 6, 18, and 48 hours after treatment (day 0) and 2, 4, and 24 hours after weekly flea reinfestations. Cats were also reinfested with fleas after the 6- and 18-hour counts on day 0 and after the 2- and 4-hour counts on subsequent count days. Imidacloprid provided significantly greater flea kill at diverse time points. At the 24-hour counts, all compounds showed expected and similar high efficacies. On study day 34, imidacloprid showed the highest efficacy at 24 hours after reinfestation, with 90.8% flea reduction compared with 55.7% to 67.4% in the other treatment groups. A single topical application of imidacloprid provided a high efficacy in the early elimination of adult fleas, limiting the risk of pathogen transmission and flea allergy dermatitis.

Topics: Administration, Topical; Animals; Cat Diseases; Cats; Ectoparasitic Infestations; Female; Imidazoles; Insecticides; Ivermectin; Male; Methoprene; Neonicotinoids; Nitro Compounds; Parasite Egg Count; Pyrazoles; Random Allocation; Semicarbazones; Siphonaptera; Time Factors; Treatment Outcome

The activity of selamectin, fipronil and imidacloprid against larval cat fleas (Ctenocephalides felis felis) was evaluated in an in vitro potency assay system. One hundred microliters of each compound at various concentrations in acetone were added to glass vials (1.5 by 3 cm) to which had been previously added 20 mg of sand and 10 mg of flea feces. Vials were then ball milled to allow the acetone to evaporate. Selamectin and fipronil were tested at 0.001, 0.003, 0.005, 0.01, 0.03, 0.05, 0.11, 0.3, and 0.5 microg of active compound per tube. Imidacloprid was tested at 0.01, 0.03, 0.05, 0.1, 0.3, 0.5, 1.0, 3.0, and 5.0 microg of active compound per tube. Thirty first instar C. felis larvae were added to each vial. The number of larvae remaining alive in each vial was determined once daily for 72 h. With selamectin, reductions of >/=93.5% were achieved at 24 h after exposure at doses of >/=0.3 microg. In contrast, at 24 h neither fipronil nor imidacloprid reached 90% reduction, even at the highest doses tested (0.5 microg for fipronil and 5.0 microg for imidacloprid). Selamectin was significantly (P/=0.03 microg. A similar pattern of activity was observed at both 48 and 72 h, but higher percentages of larvae were killed for each of the compounds as the incubation time increased. At 72 h selamectin was significantly (P

Topics: Animals; Antiparasitic Agents; Cat Diseases; Cats; Ectoparasitic Infestations; Imidazoles; Ivermectin; Larva; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera

The effects of three insecticides (fipronil, imidacloprid and selamectin) on developmental stages of cat fleas (Ctenocephalides felis) were studied in vivo, in vitro and by means of light and electron microscopy. The results were documented by video. Adult fleas were attached to the skin of dogs that had been treated 7 days before with one of the three compounds. Furthermore, adult fleas were exposed exclusively to the hair and skin debris of such treated dogs or were placed on filter papers that had been impregnated with one of these three compounds or with the blood of treated dogs. Larval fleas were exposed to hair of treated dogs, to debris obtained by combing treated dogs, to dried blood samples of treated dogs or were placed onto filter papers impregnated with one of the three compounds. In these experiments with adult and larval fleas, it was noted that none of the three insecticides had a repellent effect on adult or larval fleas. Imidacloprid was the only compound that acted exclusively by body contact, and was apparently taken up by adult and larval fleas via the thin, non-sclerotized intersegmental membranes of the flea's body, shown when flea stages were exposed to hairs taken from dogs treated with one of the compounds or placed onto drug-impregnated filter papers. Imidacloprid killed larvae and adult fleas within 1 h, while it took at least 24 h until all adult fleas had died on fipronil- or selamectin-treated dogs, thus allowing longer feeding periods, increasing the risk of transmission of flea-derived diseases. Flea larvae covered with debris from dogs topically treated 7 days before with fipronil, imidacloprid or selamectin died, like the untreated control, within 16-28 h after exposure. This was, however, probably mainly due to a drying effect. Adult and larval fleas exposed to filter papers impregnated with the blood of treated dogs survived longer than 7 days, as did the untreated controls. All three drugs apparently acted on nerves and muscles and thus stopped motility.

Topics: Animals; Cats; Dog Diseases; Dogs; Ectoparasitic Infestations; Female; Imidazoles; In Vitro Techniques; Insect Control; Insecticides; Ivermectin; Male; Microscopy, Electron; Neonicotinoids; Nitro Compounds; Pyrazoles; Siphonaptera