Control of fleas on naturally infested dogs and cats and in private residences with topical spot applications of fipronil or imidacloprid

Thirty-four flea-infested dogs and cats residing in 20 homes in Tampa, FL were randomly placed into 1 of 2 treatment groups during the summer of 1997. Pets were treated topically with either 10.0%w/v imidacloprid or 10%w/v fipronil spot-on on day 0, then once for every 28-30 days for 90 days. Flea populations were assessed in the environment using an intermittent-light trap, while pet flea burdens were assessed using visual area counts. A single application of imidacloprid was 95.3 and 97.4% effective in reducing flea populations on pets at 7 and 28 days, respectively. A single application of fipronil was 97.5 and 97.0% effective in reducing flea populations on pets at the same time points. Following 3 monthly applications of either imidacloprid or fipronil, flea burdens on pets were reduced by 99.5 and 96.5%, respectively. In addition, flea numbers in the in-home environment were reduced by 99. 0 and 98.6% in homes, where pets were treated with imidacloprid or fipronil, respectively.     

Efficacy of dinotefuran-pyriproxyfen, dinotefuran-pyriproxyfen-permethrin and fipronil-(S)-methoprene topical spot-on formulations to control flea populations in naturally infested pets and private residences in Tampa, FL

Thirteen cats and 7 dogs living in 14 homes were treated topically with either a dinotefuran (22%, w/w)/pyriproxyfen (3.00%, w/w) (DP) or dinotefuran (4.95%, w/w)/pyriproxyfen (0.44%, w/w)/permethrin (36.08%, w/w) (DPP) topical spot-on, respectively. Twenty cats and 7 dogs living in 16 homes were treated topically with either a fipronil (9.8%, w/w)/(S)-methoprene (11.8%, w/w) or fipronil (9.8%, w/w)/(S)-methoprene (8.8%, w/w) topical spot-on (FM), respectively. All products were applied according to label directions by study investigators on day 0 and again between days 28 and 30. Flea populations on pets were assessed using visual area counts and premise flea infestations were assessed using intermittent-light flea traps on days 0, 7, 14, 21, 28-30, 40-45, and 54-60. A single application of the DP-DPP and FM formations reduced flea populations by 87.35% and 88.44%, respectively within 7 days. Following two monthly applications of either the DP-DPP or FM formulations, pet flea burdens were reduced by 95.24% and 95.47%, respectively. Flea numbers in the indoor-premises were also markedly reduced by days 54-60, with 98.05% and 96.15% reductions in intermittent-light flea trap counts in the DP-DPP or FM treatment groups, respectively.     

Field efficacy of a 10 per cent pyriproxyfen spot-on for the prevention of flea infestations on cats

The clinical application of a new method for using the insect growth regulator, pyriproxyfen, for controlling flea populations in cat-owning homes is evaluated for the first time. In a multicentric, controlled and randomised trial, 107 flea-infested cats were treated with a minimum dose of 10 mg/kg bodyweight pyriproxyfen as a 10 per cent spot-on application on two occasions, with a three-month interval between doses. For comparison, 99 cats received lufenuron suspension orally, once a month, for six months. Flea counts decreased significantly over time in each group and were significantly lower in the pyriproxyfen group than in cats treated with the reference product. The percentage of 'zero-flea' cats increased from 49 per cent on day 30 to 88 per cent on day 180 in the pyriproxyfen group and from 30 to 71 per cent in the lufenuron group at the same time points (P<0.05). Appropriately timed topical applications of pyriproxyfen, therefore, offer a method of flea control in the domestic environment.     

Evaluation of the comparative efficacy of selamectin against flea (Ctenocephalides felis felis) infestations on dogs and cats in simulated home environments

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.     

Efficacy and safety of selamectin against fleas and heartworms in dogs and cats presented as veterinary patients in North America

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 with FAD. Selamectin also was 100% effective in preventing the development of canine heartworms and was safe for topical use in dogs and cats.     

Control of immature stages of the flea Ctenocephalides felis (Bouché) in carpets exposed to cats treated with imidacloprid

Fleas cause allergic dermatitis in cats and dogs and therefore warrant control. It has been demonstrated previously that there is marked inhibition of the development of the immature stages of the cat flea Ctenocephalides felis on fleece blankets exposed to cats treated with imidacloprid. This study reports on the efficacy of imidacloprid in suppressing adult flea emergence in carpet exposed to treated cats. Circular discs of carpet pre-seeded with flea eggs and larvae were exposed to 6 untreated control and 6 topically treated (imidacloprid 10% m/v) cats 1 to 2 days after treatment and subsequently fortnightly for 6 weeks. Exposure times on alternate days were either 1 or 6 hours. Adult flea yield from carpets was determined 35 days after exposure. Differences between flea yield on control carpets and those exposed for 1 hour were significant only for days +1 and +14. For the 6-hour exposure, differences were significant at all times except on Day +43. The ability of imidacloprid to suppress the yield of adult fleas on carpets (6-hour exposure) steadily declined from 82 % (Day +2) to 12% (Day +43). For the 1-hour exposure it varied inconsistently between 0 and 83% over the 6-week study period.     

Effect of topical application of fipronil in cats with flea allergic dermatitis

OBJECTIVE: To determine whether topical application of a 10% fipronil solution would control signs of flea allergic dermatitis in cats housed under natural conditions. DESIGN: Multicenter open clinical trial. ANIMALS: 42 client-owned cats with flea allergic dermatitis. PROCEDURES: Study cats along with all other cats and dogs living in the same houses were treated with 10% fipronil solution topically on days 0, 30, and 60. Flea counts and clinical assessments were performed on study cats on days 0, 14, 30, 60, and 90. RESULTS: Percentage reductions in geometric mean flea counts on days 14, 30, 60, and 90, compared with day-0 geometric mean count, were 75, 73, 85, and 94%, respectively. Pruritus score was significantly improved at each examination after day 0, and pruritus was reduced or eliminated in 31 of 40 (78%) cats at the final examination. Similarly, scores for severity of miliary dermatitis and alopecia were significantly improved at each examination, except for alopecia score on day 14. Overall treatment efficacy, assessed on day 90, was excellent for 28 (70%) cats, good for 6 (15%), moderate for 3 (7.5%), and poor for 3 (7.5%). CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that monthly topical application of fipronil is effective for treatment of flea allergic dermatitis in cats housed under natural conditions.     

Dose titration of an injectable formulation of lufenuron in cats experimentally infested with fleas

OBJECTIVES: To identify the lowest single dose of lufenuron injected s.c. that results in a 90% disruption of the flea (Ctenocephalides felis) life cycle for 6 months in cats. ANIMALS: 40 domestic shorthair cats (20 males, 20 females) between 5 and 7 months old. PROCEDURE: Cats were randomly assigned to 1 of 5 eight-cat groups and experimentally infested with C. felis on days -8, -7, -6, and -4. On day 0, cats in the 4 treatment groups were treated with an injectable formulation of lufenuron at doses of 2.5, 5, 10, or 20 mg/kg of body weight, respectively. Control cats received the injectable formulation without lufenuron. Experimental infestations were repeated and flea eggs collected at various intervals for 196 days after treatment. Eggs were placed in media and incubated in an insectary for 28 days to determine effects of injectable lufenuron on egg and larval development. Number of adults that emerged from eggs were compared among groups. RESULTS: Lufenuron injected once at a dose of 10 or 20 mg/kg, but not at 2.5 or 5 mg/kg, resulted in a 90% decrease in number of adult fleas emerging from eggs for 196 days after treatment. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicate that control of flea egg and larval development for at least 6 months can be achieved in cats with a single s.c. injection of lufenuron (10 mg/kg). The injectable formulation may provide veterinarians and cat owners an alternative to the tablet formulation of lufenuron.     

Imidacloprid/moxidectin topical solution for the prevention of heartworm disease and the treatment and control of flea and intestinal nematodes of cats

Sixteen controlled laboratory studies, involving 420 kittens and cats, were conducted to evaluate the efficacy and safety of topically applied formulations of imidacloprid and moxidectin for the prevention of feline heartworm disease, treatment of flea infestations and treatment and control of intestinal nematodes. Unit-dose applicators and the dosing schedule used in these studies were designed to provide a minimum of 10mg imidacloprid and 1mg moxidectin/kg. Treatments were applied topically by parting the hair at the base of the skull and applying the solution on the skin. Imidacloprid treatment alone did not display activity against Dirofilaria immitis or intestinal nematodes and moxidectin treatment alone provided little or no activity against adult Ctenocephalides felis infestations. The formulation containing 10% imidacloprid and 1% moxidectin was 100% efficacious against the development of adult D. immitis infections when cats were treated 30 days after inoculation with third-stage larvae. A single treatment with this formulation also provided 88.4-100% control of adult C. felis for 35 days. Imidacloprid/moxidectin was 100% efficacious against adult Toxocara cati and 91.0-98.3% efficacious against immature adults and fourth-stage T. cati larvae. The formulation provided 98.8-100% efficacy against adult Ancylostoma and immature adults and third-stage A. tubaeforme larvae. Monthly topical application with 10% imidacloprid/1% moxidectin is convenient, efficacious and safe for the prevention of feline heartworm disease, treatment of flea infestation and for the treatment and control of intestinal nematode infections of cats.     

New methods and strategies for monitoring susceptibility of fleas to current flea control products

A flea larval bioassay was developed by an international team of scientists to monitor the susceptibility of fleas (Ctenocephalides felis) to imidacloprid (Advantage, Bayer HealthCare). The assay was validated using laboratory and field isolates of C. felis. Flea eggs representing different field isolates of C. felis were collected by veterinarians in the United States, United Kingdom, and Germany. Of the 972 flea isolates obtained during the 5-year study, 768 contained sufficient numbers of eggs to conduct the larval bioassay. Greater than 5% survival occurred for only six of the field isolates evaluated. Further evaluation and analysis of these isolates demonstrated that they did not differ significantly in their susceptibility to imidacloprid from the reference strains used to develop the assay. Collections of field flea isolates will continue in an attempt to detect and document any change in the susceptibility of field flea populations to imidacloprid.     

Questionnaire on the incidence and control of fleas in dogs and cats presented to German small animal practices

2590 small animal practitioners in Germany have been asked by a questionnaire from which 1694 (65.4%) replied. 1186 of these veterinarians (70%) often see ectoparasite infestation. Fleas are predominant and occur on cats (1016/60%), followed by dogs (424/25%), small mammals and birds (254/15%). Flea infestations on dogs and cats are observed throughout the year, but the prevalences are generally higher during the summer season. The results reveal that topically administered spot-on formulations is the most popular method used for flea control. The most common applied antiparasitic substances both in dogs and in cats were fipronil (535/31.6%; 690/40.7%), imidacloprid (290/17.1%; 417/24.6%) and selamectin (267/15.8%; 319/18.8%). Due to 771 (45.5%) of the answering veterinarians the animal owner himself, and according 694 (41%) respectively 229 (13.5%) of the replies the veterinarian or the veterinary technician applies the antiparasiticide onto the skin. 1457 veterinarians (86%) administer compounds against adult fleas and their developmental stages also in the animal's environment.     

Flea blood feeding patterns in cats treated with oral nitenpyram and the topical insecticides imidacloprid, fipronil and selamectin

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.     

Comparative speed of kill of selamectin, imidacloprid, and fipronil-(S)-methoprene spot-on formulations against fleas on cats

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.     

Clinical field study of the safety and efficacy of spinosad chewable tablets for controlling fleas on dogs

Preliminary Studies showed spinosad to be rapidly effective and safe in controlling fleas on dogs. To validate these studies, a clinical trial was undertaken using 470 flea-infested client-owned dogs allocated to receive three monthy treatments with either beef-flavored chewable spinosad tablets (30-60 mg/kg) or selamectin applied to label instructions. Flea counts 15 days after enrollment were reduced by 98.6% and 90.9% for spinosad- and selamectin-treated dogs, respectively; at 90 days, flea count reductions were 99.9% and 98.9%, respectively. Compared with baseline, all flea reductions were significant (P less than .001) for both products and spinosad was significantly (P less than or equal to .0172) more effective than selamectin at each postenrollment flea count.     

Prevalence of Staphylococcus aureus and Methicillin-Resistant Staphylococcus aureus Carriage in Three Populations

Background: A higher prevalence of methicillin-resistant Staphylococcus aureus (MRSA) colonization is reported in healthcare workers compared with nonhealthcare workers.
Hypothesis: The prevalence of MRSA colonization differed in people and pets in households with healthcare workers as compared with households without healthcare workers.
Subjects: A person and 1 dog or cat from 586 households defined as either a nonhealthcare (n = 213), veterinary healthcare (n = 211), or human healthcare (n = 162) worker household.
Methods: Prospective cross-sectional study. Samples from humans and pets were cultured in vitro. Staphylococcus aureus was identified as methicillin sensitive (MSSA) or MRSA with mec A polymerase chain reaction. Pulsed-field gel electrophoresis and spa -typing were used to characterize relatedness of S. aureus and MRSA and assign USA types.
Results: The prevalence of MSSA and MRSA in humans was 21.5% (126/586) and 5.63% (33/586), respectively, and 7.85% (46/586) and 3.41% (20/586), respectively, in pets. There were no differences in prevalences of either MSSA or MRSA between household types. The proportion of MRSA among all S. aureus isolates in humans and pets was 20.8% (33/159) and 30.3% (20/66), respectively. In <1.0% (4/586) of households, the same strain of MRSA was found in both a person and a pet.
Conclusions and Clinical Importance: There were no differences in the prevalences of MSSA or MRSA between healthcare worker and nonhealthcare worker households. Pets and people colonized with S. aureus were as likely to be colonized with MRSA. Colonization of a person and their pet with the same strain of MRSA was rare.     

Evaluation of efficacy of selamectin, fipronil, and imidacloprid against Ctenocephalides felis in dogs

OBJECTIVE: To evaluate efficacy of monthly administration of selamectin, fipronil, and imidacloprid against Ctenocephalides felis in dogs. DESIGN: Randomized controlled trial. ANIMALS: 44 healthy dogs. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL RELEVANCE: 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.     

Preliminary studies on the effectiveness of the novel pulicide, spinosad, for the treatment and control of fleas on dogs

Spinosad is a novel mode-of-action insecticide produced from a family of natural products derived from fermentation of the actinomycete, Saccharopolyspora spinosa. Separate studies were undertaken to determine the minimum effective dose of spinosad given orally for the treatment of experimentally induced flea infestations (Ctenocephalides felis) on dogs, and to assess any potential impacts of feeding canned or dry food at the time of dosing. Both were randomized block (blocked by gender and pre-treatment flea counts), blinded parallel-arm studies, with dogs selected on health and ability to maintain pre-treatment flea populations. For dose selection, 48 dogs were allocated among six groups (8 dogs/group; 4 males, 4 females): placebo-treated negative control, spinosad in gelatin capsules at 15, 20, 30 and 40 mg/kg administered per os; and topical imidacloprid (10 mg/kg) as a positive control. Placebo and spinosad treatments were administered on Days 0, 30 and 60, imidacloprid only on Day 0. In a second study to assess the impact of food type at the time of dosing, three groups were formed: placebo-treated control (8 dogs; 4 males, 4 females), spinosad (30 mg/kg) administered with canned food (8 male dogs, 8 females); and spinosad (30 mg/kg) with dry food (8 males, 8 females). Treatments were administered on Days 0 and 30. To assess post-treatment persistent efficacy, flea infestations were repeated at regular post-treatment intervals, beginning on Day 5 through Day 89 in the dose selection study and Day 58 in the impact of food type and dosing study. Flea counts were performed 48 h post-infestation by study personnel who were blinded to treatments. In the dose selection study, compared to geometric mean live flea counts in the control group, each spinosad dose was highly effective (99.8–100%) at 7, 14 and 21 days after treatment. Only the 30 and 40 mg/kg doses maintained high efficacy (97.2–100%) until 30 days after treatment, with no difference between the two. Imidacloprid was highly effective at Day 30, with significant difference only from the 15 mg/kg spinosad group. Because there was no significant difference between the higher spinosad rates, 30 mg/kg was selected as the optimal minimum effective dose. In the second study, spinosad was highly effective at all post-treatment flea counts (98–100%). Taken together, these studies demonstrate that repeated monthly oral treatments with spinosad at 30 mg/kg provide sustained control of C. felis on dogs. There were no treatment-related adverse events in either study, indicating that spinosad has potential to be used monthly as a safe and effective flea adulticide, providing sustained activity that matches that of currently used topical products.     

Evaluation of efficacy of selamectin and fipronil against Ctenocephalides felis in cats

OBJECTIVE: To evaluate efficacy of monthly administration of selamectin and fipronil against Ctenocephalides felis in cats. DESIGN: Randomized controlled trial. ANIMALS: 36 healthy cats. PROCEDURE: 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. RESULTS: 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. CONCLUSIONS AND CLINICAL Relevance: 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.     

A survey of fleas on dogs in southern Italy

A survey aimed at studying the presence and distribution of fleas on dogs was conducted in an area of southern Italy. Between February 2005 and 2006, dogs were examined for fleas at four private veterinary clinics, with a twice-weekly frequency. Fleas were detected on 246 (17.9%) out of the 1376 tested dogs. A total of 960 fleas were sampled and two species were identified, namely Ctenocephalides felis felis (16.3% of the tested dogs) and Ctenocephalides canis (1.5% of the tested dogs). The results of the logistic regression model showed a significant association between the flea positivity and the following independent variables: housed with other dogs or cats and utilization, i.e. increasing prevalence from pets to guard, hunting, and stray dogs. Clinical symptoms (pruritus, alopecia, and flea allergic dermatitis) were also observed in some of the flea positive dogs. Flea infestation was detected throughout the year, although the prevalence was higher during the period between June and October.     

Imidacloprid treatment of marsupials for fleas (Pygiopsylla hoplia).

Two eastern barred bandicoots (Perameles gunnii), two eastern quells (Dasyunrus viverrinus), four fat-tailed dunnarts (Sminthopsis crassicaudata), a Leadbeater's possum (Gymnobelideus leadbeateri), a yellow-bellied glider (Petaurus australis), and a ring-tailed possum (Pseudocheirus peregrinus) were treated with imidacloprid (10.7 +/- 0.6 mg/kg topically, minimum dose 0.5 mg) after observation of fleas (Pygiopsylla hoplia) on animals and in their nest boxes. No live fleas or adverse reactions to imidacloprid were observed for 27 days following treatment. The ease of application, absence of toxicity, and long residual effect makes imidacloprid a useful drug for treating flea infestations in these marsupials.