Efficacy of fipronil/(S)-methoprene combination spot-on for dogs against shed eggs, emerging and existing adult cat fleas (Ctenocephalides felis, Bouché)

The inhibitory activities of fipronil (10% (w/v) solution), (S)-methoprene (9% (w/v) solution), and fipronil/(S)-methoprene (10 and 9% (w/v) solution, respectively) combination against eggs and emerging adult cat fleas (Ctenocephalides felis) and adulticidal activity were tested on experimentally infested dogs. Thirty-two Beagle dogs were selected for this study and eight replicates of four animals were formed based on body weight within sex. One dog in each replicate was randomly allocated to treatment with: (1) untreated control; (2) fipronil 10% (w/v) solution, (3) (S)-methoprene 9% (w/v) solution, and (4) fipronil 10% (w/v) and (S)-methoprene 9% (w/v) combination solution. Treatments were applied once topically on Day 0 at the rate of 0.067 ml/kg. On Days -12, -1, 21, and weekly to Day 84 each dog was infested with approximately 200 fleas and comb counted approximately 24h later, or 2 days (our 48 h) after in the case of Day -1 infestation. On Days -11, 1, 22, and weekly to Day 85 each dog was again infested with approximately 200 fleas. Flea eggs were collected over approximately 24 h beginning 3 days after infestation. Fleas were combed off of the dogs and counted at the end of the egg collection period (approximately 96 h count). One aliquot of up to about 100 eggs, if available, from each animal at each infestation time was incubated for approximately 72 h to determine larval hatch and the other for 35 days to determine the number of adults that developed. The 10% (w/v) fipronil spot-on provided excellent control (>95%) of adult fleas on dogs for 5 weeks. Similarly, the combination spot-on of 10% (w/v) fipronil and 9% (w/v) (S)-methoprene provided excellent control of adult fleas, i.e., >95% for 5 weeks. From week 6 post-treatment onward, the relatively low inhibition of adult flea emergence substantiated the lack of significant ovicidal/larvicidal activity in the fipronil (10%, w/v) treatment group. However, the combination product provided excellent (>90%) ovicidal activity for 8 weeks and high (91.4%) inhibition of adult flea emergence for 12 weeks. In addition, a synergistic effect of the two compounds in combination was demonstrated with fipronil enhancing the ovicidal and inhibition of adult flea emergence activity of (S)-methoprene against cat flea eggs. When all stages of the life cycle of the cat flea are considered, the combination spot-on product provided a high level of total flea control yielding a curative effect against adult fleas and inhibition of flea development stages with little to no potential reinfestation pressure on the animal or in the environment for 12 weeks.     

Assay of two 10% (w/v) fipronil spot-on formulations against feline infestations with Ctenocephalides felis

A new fipronil-based spot-on formulation was evaluated against experimental flea infestations in cats in two studies. In both studies, eight cats served as negative controls (groups 1 and 4); on day 0, eight cats were treated with a 10% w/v fipronil-based spot-on solution (Effipro Spot-on, 0.5ml per cat, groups 2 and 5) and eight cats served as positive controls (Frontline Spot-on, 0.5ml per cat, groups 3 and 6). Each cat was infested on day - 1 with 50 fleas (study 1) and weekly (day 7-day 56) with 100 fleas (study 2). Geometric mean flea counts obtained 48h after the treatment or each re-infestation were reduced by 99.0 and 98.3% in groups 2 and 3, respectively, on day 2, compared to the negative control group. Cats were protected from re-infestations with an efficacy >99% for 58 days in group 5 and for 37 days in group 6.     

Treatment of dog thelaziosis caused by Thelazia callipaeda (Spirurida, Thelaziidae) using a topical formulation of imidacloprid 10% and moxidectin 2.5%

Canine thelaziosis caused by Thelazia callipaeda infects dogs, cats, foxes, rabbits, and humans resulting in conjunctivitis, pain and excessive lacrimation. T. callipaeda live in the eyes under the nictitating membrane and females release first stage larvae which are ingested by flies which act as intermediate hosts. Control of canine thelaziosis is currently based on the removal of nematodes directly from the eyes of affected dogs or on the local instillation of antiparasitic drugs. With the aim of evaluating the efficacy against T. callipaeda of an association of imidacloprid 10% and moxidectin 2.5% by spot-on formulation administered via dermal application, three groups of naturally infected animals were selected: i.e. group A (21 dogs) received a single dose of imidacloprid 10% and moxidectin 2.5% by spot-on; group B (21 dogs) received a single dose of imidacloprid 10% by spot-on and group C (20 dogs) were left untreated. The efficacy of treatments was established by eye inspection and parasite viability and vitality after 1, 5 and 9 days after animal treatments (groups A and B) and after 9 days only in untreated animals (group C). Imidacloprid 10% and moxidectin 2.5% in spot-on formulation showed to be effective with regards the control of dog thelaziosis within 5 (90.47%) to 9 (95.23%) days after treatment. Only one dog from group A presented nematodes after treatment. The presence of parasites in the eyes of dogs from groups B (imidacloprid 10%) and C confirm that the anthelmintic efficacy against T. callipaeda in animal from group A (imidacloprid 10% and moxidectin 2.5%) was most likely attributable to moxidectin 2.5%. The spot-on formulation containing imidacloprid 10% and moxidectin 2.5% is very easy to apply and helps overcome problems linked to the mechanical removal of parasites or to the restraining of the animals for the local instillation of drugs in the eyes.     

Canine adder bites in the UK: a retrospective study of cases reported to the Veterinary Poisons Information Service

This retrospective study examined cases with follow-up reported to the Veterinary Poisons Information Service (VPIS) between September 1985 and December 2010. Most bites (69.2 per cent) occurred between April and July, particularly between 15:00 and 16:00 hours. Adder bites were more frequently reported in the south-east of England, particularly in Surrey. Swelling to the face and limbs was common, as was lethargy, depression, hyperthermia and tachycardia. About two-thirds of dogs developed both systemic and local effects, while a third developed local effects alone. Initial clinical effects usually occurred within two hours, with full recovery typically occurring five days after the bite. Antivenom was used in 55.9 per cent of cases and appeared to significantly reduce duration of oedema from an average of 94 to 47 hours. Adder bites can cause significant morbidity (97 per cent of dogs were symptomatic), but mortality is low (4.6 per cent died).     

Efficacy of a topically applied formulation of metaflumizone on cats against the adult cat flea, flea egg production and hatch, and adult flea emergence

A spot-on metaflumizone formulation was evaluated to determine its adulticidal efficacy, effect upon egg production, and ovicidal activity when applied to flea infested cats. Eight male and eight female adult domestic shorthair cats were randomly assigned to either serve as non-treated controls or were treated topically with a minimum of 40mg/kg metaflumizone in single spot-on Day 0. On Days -2, 7, 14, 21, 28, 35, 42, 49, and 56, each cat was infested with approximately 100 unfed cat fleas, Ctenocephalides felis felis. On Days 1, 2, and 3, and at 48 and 72h after each post-treatment reinfestation, flea eggs were collected and counted. At approximately 72h after treatment or infestation, each cat was combed to remove and count live fleas. Egg viability was determined by examining hatched eggs after 5 days and adult emergence was determined 28 days after egg collection. Metaflumizone provided >/=99.6% efficacy against adult fleas from Days 3 to 45 following a single application. Following treatment, egg production fell by 51.6% within 24h and 99.2% within 48h. Following subsequent weekly infestations egg production from treated cats was negligible out to Day 38, with >/=99.5% reduction relative to non-treated cats. Where there were eggs to evaluate, metaflumizone treatment did not have any apparent effect on the hatching of eggs or on the development and emergence of adult fleas from the eggs produced by fleas from treated animals.     

Efficacy of dinotefuran, permethrin and pyriproxyfen combination spot-on against Aedes aegypti mosquitoes on dogs

A spot-on formulation combining permethrin, dinotefuran and pyriproxyfen (Vectra 3D? spot-on solution for dogs - one 10-25kg pipette contains 196mg dinotefuran, 1429mg permethrin and 17mg pyriproxyfen) was evaluated in adult Beagle dogs in a study designed to measure its efficacy to control Aedes aegypti (anti-feeding effect and mortality effect). The trial was performed according to Animal Welfare and Good Clinical Practice. Twelve dogs (five males and seven female, >3 years old, weighing 8.8-13.0kg) were randomly allocated to treatment groups on pre-treatment mosquito counts: six dogs served as untreated controls, and six dogs were treated with the test formulation. Treatment consisted of applying a combination formulation to deliver at least 46.6mgkg(-1) permethrin, 6.40mgkg(-1) dinotefuran and 0.57mgkg(-1) pyriproxyfen. The combination is designed to control fleas, ticks, sand flies and mosquitoes. Each dog was infested with approximately 100 adult unfed A. aegypti once before treatment (day 6) then at 1, 7, 14, 21 and 28 days post-treatment. Counts and engorgement determination of dead and live mosquitoes were performed after 1h exposure period. In the treated group (group A), the repellency effect of the product based on engorgement status (anti-feeding effect), was 91.5%, 94%, 94.7%, 94% and 87% at 1, 7, 14, 21 and 28 days post-treatment. Mortality effect or insecticidal efficacy calculated at the end of the 1-h exposure was almost identical when calculated 24h after the 1-h exposure and remained above 93% until the end of the in-life phase. No adverse events were observed following treatment, including observations conducted 2, 4 and 24h after the last dog was treated.     

Efficacy of a single application of a 12.5% pyriprole topical solution against laboratory infestations with ticks (Ixodes ricinus, Dermacentor reticulatus, and Rhipicephalus sanguineus) on dogs

In three separate studies, the efficacy of a single treatment with a 12.5% pyriprole spot-on solution was investigated against induced infestation with Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus on dogs (both sexes; Beagles in Studies 1 and 2, mixed-breed in Study 3). For each tick species, one group of 8 dogs left untreated (Studies 1 and 2) or treated with a placebo solution (Study 3) was compared with another group treated once with the spot-on solution at a dose rate of at least 12.5mg/kg. The dogs were infested with 50 unfed adult ticks of the respective species at various time-points before and after treatment and the surviving attached and unattached ticks were recorded 48 h after re-infestation. For each tick species, efficacy was assessed for each time-point and cumulatively for the whole evaluation period. The dogs were submitted to general health observations and clinical assessments during the study. Efficacy against I. ricinus and R. sanguineus was 100% during the whole evaluation period of 30 days. For D. reticulatus cumulative efficacy for the 30 days after treatment was 98.9%. The product was well tolerated by all the animals.     

The influence of topical unsaturated fatty acids and essential oils on normal and atopic dogs

Seven dogs with atopic dermatitis and six normal dogs were treated with a spot-on product containing essential oils and unsaturated fatty acids q 7 days for 8 wk. Seven additional atopic dogs received a daily spray containing similar ingredients to the spot-on. In all dogs, transepidermal water loss (TEWL) was measured before and after treatment using a closed chamber device. In atopic dogs, a validated lesion score (canine atopic dermatitis extent and severity index, CADESI) was determined and pruritus was assessed with a visual analog scale before and after treatment. The mean CADESI scores in atopic dogs decreased with the spot-on (P=0.0043) and with the spray (P=0.0366). Similarly, the pruritus scores decreased with the spot-on (P=0.266) and with the spray (P=0.0177). There was a significant difference between the TEWL values of healthy and atopic dogs on the abdomen (P=0.0181) and back (P=0.0123). TEWL decreased significantly on the back after treatment with the spray (P=0.016), but not on the abdomen (P=0.078). Adverse effects were not observed. The results of this pilot study indicate that topical fatty acids and essential oils are a useful treatment option for canine atopic dermatitis.     

The effect of water and shampooing on the efficacy of a pyriprole 12.5% topical solution against brown dog tick (Rhipicephalus sanguineus) and cat flea (Ctenocephalides felis) infestations on dogs

The efficacy of a single treatment with a 12.5% pyriprole spot-on formulation against induced infestations with R. sanguineus ticks and cat fleas (C. felis) as well as its persistence after repeated washing and shampooing was investigated in four separate studies. In a first study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.3%. No engorged ticks, alive or dead, were found in the treated animals. Shampooing 2 days after treatment and weekly washings did not affect the efficacy. In a second study on R. sanguineus involving 32 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation ranged from 100% to 96.8%. Single washing 8h after treatment and single shampooing 24 h after treatment had no negative impact on the efficacy of the product. In a third study on C. felis involving 28 beagle dogs, the efficacy at various time-points during the 30 days that followed treatment assessed 48 h after re-infestation was always 100% and weekly washings did not diminish the efficacy. In a last study on C. felis involving 24 beagle dogs, the efficacy at various time-points during the 5 weeks that followed treatment assessed 48 h after re-infestation ranged from 100% to 99.8%, and shampooing 24 h after treatment did not reduce the efficacy. The product was well tolerated by the dogs.     

Control of cattle grubs with fenthion pour-on and trichlorfon spot-on in Germany

Field tests in northern Germany showed that fenthion pour-on and trichlorfon spot-on are suitable for the control of cattle grubs. The advantage of these two methods of application compared with other methods is the exact, easy, and time-saving applicationField tests indicate that fenthion (Tiguvon) pour-on is highly effective againsts the migrating first instar and the second and third instars. Trichlorfon (Neguvon) spot-on was also highly effective against the migrating first instar but showed a lower efficacy against the second and third instars. It is suggested that the second and third instars are killed more reliably by direct contact with the compound. This contact is easier to achieve by the pour-on than by the spot-on method.Under German conditions, the following treatment plan is suggested: application of fenthion pour-on or trichlorfon spot-on in the autumn and, if required, fenthion pour-on in the spring. Since cattle eliminate trichlorfon faster than fenthion, application of the former may be preferable in certain cases.     

Bioavailability of ascorbic acid in horses

The bioavailability of ascorbic acid administered to thoroughbreds by intramuscular injection was investigated. For intramuscular injection two preparations were studied, and the percentage bioavailability up to 24 h of 10 g of ascorbic acid was 95% +/- 22 in four horses and 60% in two horses with preparations A and B, respectively. Bioavailability at 24 h in three horses injected subcutaneously with 10 g of preparation B was 82%. Intramuscular injection of both preparations was apparently well tolerated while subcutaneous injection of preparation B (pH 6.0) was associated with marked irritancy. In a cross-over trial in seven thoroughbreds the effect of 13 or 15 days of oral administration of crystalline ascorbic acid (20 g) or ascorbyl palmitate (47 g) on plasma ascorbic-acid concentrations was investigated. Marked differences occurred between individuals. There was a greater increase in plasma ascorbic-acid concentration with ascorbyl palmitate compared to ascorbic acid at 6 and 24 h following administration. In two horses there was no increase in plasma ascorbic acid at 6 h following either oral preparation. The finding of lowered plasma ascorbic-acid concentrations following a period of supplementation warrants further investigation to assess its significance.     

Successful management of severe generalized tetanus in two dogs

Objective: To describe the clinical course and successful outcome of severe generalized tetanus in 2 dogs. Case series summary: Two dogs presenting with severe muscle rigidity, opisthotonus, and trismus were diagnosed with tetanus. In both cases, generalized convulsions, respiratory compromise, and autonomic dysfunction necessitated emergent interventions followed by intensive treatment and monitoring. In the second case, transient mechanical ventilation was required. Both dogs survived and were discharged after 19 days (first case) and 18 days (second case) of hospitalization. Although costly and time‐consuming, treatment for severe generalized tetanus was successful in these 2 dogs. New information provided: Severe generalized tetanus with convulsions, respiratory compromise, and autonomic dysfunction can have a successful outcome with intensive care and appropriate treatment.     

Effective treatment and control of biting lice, Felicola subrostratus (Nitzsch in Burmeister, 1838), on cats using fipronil formulations

The efficacy of 0.25% fipronil spray (Frontline Spray, Merial), 10% fipronil spot-on (Frontline Spot-on for Cats, Merial) and 10% fipronil/12% (S)-methoprene (Frontline Plus for Cats, Merial) against the biting louse Felicola subrostratus on cats was assessed and confirmed under laboratory conditions. A field study evaluated the efficacy of a single topical application of Frontline Spray, and spot-on against the parasite on cats. In the laboratory studies, animals were allocated based on pre-treatment louse counts to the treatment groups: (1) untreated control and (2) 10% fipronil spot-on in the exploratory study or (1) untreated control, (2) 0.25% fipronil spray, at 6 ml/kg; (3) 10% fipronil spot-on as per label and (4) 10% fipronil/12% (S)-methoprene as per label in the confirmation study. Cats in treatment groups 2-4 were treated twice topically on Days 0 and 28. No live F. subrostratus were found on cats treated with fipronil formulations at any post-treatment examination. The difference from controls was significant (P < 0.01) for each product at each examination. Based on whole body counts at Day 42, the efficacy of each product was determined to be 100%. In the field study, cats were allocated in strict order of presentation. Cats were randomly allocated to one of the three treatment groups: (1) propoxur collar (Bolfo, Bayer); (2) 0.25% fipronil spray, at 6 ml/kg and (3) 10% fipronil spot-on as per label. Cats were treated once topically on Day 0. Louse counts of cats treated with fipronil formulations were not different than those of cats receiving the propoxur collar. The efficacy was determined to be > 98% on Day 2 and 100% on Days 28 and 42 in all treatment groups. The results of these studies demonstrate that fipronil in topical formulations is effective for treatment and control of biting lice (F. subrostratus) infestations on cats.     

Repellency and efficacy of a 65% permethrin spot-on formulation for dogs against Aedes aegypti (Diptera: Culicidae) mosquitoes

A topically applied 65% permethrin spot-on (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health) used for flea and tick control on dogs was evaluated for repellency and efficacy against the yellow fever mosquito, Aedes aegypti, a vector of canine filariasis. Six dogs were randomly assigned to receive a single application of 65% permethrin on Day 0 (n=3) or to remain untreated as controls (n=3). Dogs were anesthetized and exposed to 100 unfed, female mosquitoes in screened cages for 2 hours on Days -6, -4, -1, 0, 1, 7, 14, 21, and 28. Mosquito landing rates, engorgement rates, and mortality were determined for each mosquito challenge. Cages were thoroughly cleaned after each mosquito challenge. Treatment of dogs with 65% permethrin reduced the mosquito landing rates by 96.3% 6 hours after treatment and by 82.5% on Day 1. Mosquito mortality, relative to the control group, was 28.2% 6 hours after treatment, ranged from 84.0% to 90.9% through Day 21, and declined to 50.3% 28 days after treatment. Successful feeding by mosquitoes was significantly (P=.05) reduced on Days 1 through 28. The 65% permethrin spot-on treatment killed and repelled significantly (P =.05) more mosquitoes on treated dogs versus untreated dogs for 28 days after treatment.     

Efficacy and safety of imidacloprid/moxidectin spot-on solution and fenbendazole in the treatment of dogs naturally infected with Angiostrongylus vasorum (Baillet, 1866)

A randomized, blinded, controlled multicentre field trial study was conducted to evaluate the efficacy and safety of imidacloprid 10%/moxidectin 2.5% spot-on solution and fenbendazole in treating dogs naturally infected with Angiostrongylus vasorum. Dogs were randomly treated either with a single dose of 0.1 ml/kg bodyweight of imidacloprid 10%/moxidectin 2.5% spot-on solution or with 25 mg/kg bodyweight fenbendazole per os for 20 days. The study period was 42 days with dogs being examined on days 0, 7 and 42. The primary efficacy parameter was the presence of L1 larvae in faecal samples evaluated by a Baermann test from three consecutive days. Thoracic radiographs performed on each visit were being taken as a paraclinical parameter to support the results of the Baermann test. Twenty-seven dogs in the imidacloprid/moxidectin group and 23 dogs in the fenbendazole group completed the study according to protocol. The efficacies of the two treatment protocols were 85.2% (imidacloprid/moxidectin) and 91.3% (fenbendazole) with no significant difference between treatment groups. On radiographic evaluation pulmonary parenchyma showed similar improvement in each group. No serious adverse effects to treatment were recorded: most of the minor adverse effects were gastrointestinal such as diarrhea (nine dogs), vomitus (eight dogs) and salivation (three dogs). In general, these adverse effects were of short duration (1-2 days) within the first few days after treatment start and required little or no treatment. This prospective study demonstrates that both treatment protocols used are efficacious under field conditions, that treatment of mildly to moderately infected dogs with either of these protocols is safe and yields an excellent prognosis for recovering from the infection.     

Cestrum parqui (green cestrum) poisoning in cattle

SUMMARY Naturally occurring cases of poisoning of cattle by Cestrum parqui were characterised by ataxia, depression, recumbency, convulsions and death. Three cattle were dosed experimentally by intrarumenal administration of fresh plant material. One calf died 48 h after receiving 30 g (wet weight) of plant /kg body weight. Doses of 11 and 17 g/kg caused only mild intoxication, with dullness and anorexia lasting 2 days. In natural and experimental cases the main lesion was hepatic periacinar necrosis. Elevated levels of plasma aspartate transaminase and prolonged prothrombin times were demonstrated in experimental cases. Haemorrhage beneath the serosa and into the intestinal lumen occurred in field cases, but not in the experimental. It is concluded that C. parqui poisoning in cattle is a primary hepatotoxicity.     

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations of brown dog ticks (Rhipicephalus sanguineus) on dogs

Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6-8 male and 6-8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48 h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18 h, following post treatment infestations was maintained for at least 35 days.     

Efficacy of a novel combination of fipronil, amitraz and (S)-methoprene for treatment and control of tick species infesting dogs in Europe

Four studies were conducted to show the effectiveness of a novel combination of fipronil, amitraz and (S)-methoprene in a spot-on formulation (CERTIFECT?, Merial Limited, GA, USA) for the therapeutic and preventive control of Ixodid tick species affecting dogs in Europe: Ixodes ricinus, Dermacentor reticulatus and Rhipicephalus sanguineus. In each, untreated control dogs were compared to others treated with the novel combination. All dogs were infested with 50 adult, unfed ticks prior to treatment and at 7-day intervals after treatment. Ticks on all dogs were counted at 18, 24 and 48 h after treatment (therapeutic efficacy) or infestation (preventive efficacy). Therapeutic efficacy of fipronil, amitraz and (S)-methoprene was excellent as shown by significant (p<0.05) and greater than 97% and up to 100% reductions in the 48 h tick counts and significant (p<0.05) detachment/death of ticks evident at 18-24h after treatment for all three tick species. Preventive efficacy was demonstrated by significant (p<0.05) and greater than 93% and up to 100% reductions in tick counts at 48 h after repeat infestations out to 35 days after treatment for I. ricinus and out to 42 days after treatment for D. reticulatus and R. sanguineus. The time to substantial disruption of establishment of new tick infestations after treatment was less than 18-24h and was maintained for up to 28 days after treatment of I. ricinus and D. reticulatus infestations, and 4h to at most 18 h and maintained up to 35 days after treatment of R. sanguineus. Similar preventive efficacy profiles for each of the Ixodid species tested suggest that CERTIFECT kills all Ixodid species starting 4h after contact as demonstrated for R. sanguineus.     

Evaluation of 65% permethrin spot-on and deltamethrin-impregnated collars for canine Leishmania infantum infection prevention

During the 2004 and 2005 sand fly seasons, we evaluated the efficacy of a 65% spot-on solution of permethrin (Exspot, Schering & Plough) and deltamethrin-impregnated collar (Scalibor, Intervet) in reducing Leishmania infantum infection, in a canine leishmaniasis (CanL) endemic region (Liguria) in Italy. Immunofluorescent assay (IFA) revealed that three of 120 dogs (2.5%) treated with a 65% spot-on solution of permethrin, as three of 119 dogs (2.5%) treated with deltamethrin-impregnated collar have shown seroconversion after sand fly season. On the contrary, seroconversion was 15% in 188 untreated control dogs. Treatment reduced the risk of infection by 84%. The difference in treated dogs and control ones is highly significant (chi2 = 12.4; P = 0.0004). Our results show that treatment with 65% spot-on solution of permethrin and the deltamethrin-impregnated collar are effective in reducing the risk of acquiring L. infantum infection.     

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.