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.     

Evaluation of the efficacy of a topically administered combination of imidacloprid and permethrin against Phlebotomus perniciosus in dog

The phlebotomine sand fly Phlebotomus perniciosus is one of the main vectors of Leishmania infantum, responsible for human and canine leishmaniasis in the Mediterranean Basin. The objective of this study was to evaluate the repellent and insecticidal efficacy of imidacloprid 10% (w/v)/permethrin 50% (w/v) spot-on against sand flies (P. perniciosus) on dogs. The dogs used in this trial were laboratory-bred beagles: eight were impregnated with the solution (treated group), while the other eight were left untreated (control group). On day 0 the animals in the treatment group received 0.1 ml/kg body weight of the combination imidacloprid/permethrin spot-on. Dogs were exposed for 1h to about 100 female sand flies at weekly intervals for a period of 4 weeks, on day 1, 7, 14, 21, and 28 after applying the product. The repellency criterion was based on the feeding rate of sand flies in the treated compared to the untreated group. The insecticidal efficacy criterion was based on comparison of the survival rate of sand flies between the two groups. The product had an insecticidal efficacy on female sand flies of 53.2% (day 1), 49.4% (day 7), 15.1% (day 14), 13.2% (day 22), and 2.9% (day 29). The product showed a repellent effect of 97.7% (day 1), 96.3% (day 7), 96.5% (day 14), 92.7% (day 22), and 74.0% (day 29). Within the first week of application the insecticidal effect was significant; however it did not surpass 50%. On the other hand, the product showed a potent anti-feeding effect of over 90% during the first 3 weeks of this trial. Therefore, the application of this product every 3 weeks would be a good tool to significantly reduce sand fly bites over the period of transmission of vectorial diseases such as leishmaniasis and several arbovirosis such as Toscana virus.     

Efficacy of 65% permethrin applied to dogs as a spot-on against Phlebotomus perniciosus

Leishmania infantum is a protozoan parasite causing leishmaniosis, a visceral disease transmitted by the bites of sand flies. As the main reservoir of the parasite, dogs are the principal targets of control measures against this disease, which affects both humans and dogs. Several studies have revealed the usefulness of topical insecticide treatment (collars, spot-ons and sprays) in reducing the incidence and prevalence of L. infantum. The present study was designed to test the efficacy of 65% permethrin applied to dogs as a spot-on against the sand fly vector Phlebotomus perniciosus. The duration of the desired effects was also estimated to help design an optimal treatment regimen. Twelve dogs assigned to treatment (n=6) and control (n=6) groups were exposed to sand flies once a week over a seven-week period. Repellent and insecticidal efficacies were estimated and compared amongst the groups. Our findings indicate satisfactory repellent, or anti-feeding, effects lasting 3 weeks and short-term insecticidal effects lasting 2 weeks after initial application. Accordingly, we recommend the use of this product every 2-3 weeks during the active phlebotomine sand fly period to protect dogs against the bites of P. perniciosus.     

Prevention of sand fly attack by topical application of a permethrin/pyriproxyfen combination on dogs

Dogs are the primary domestic reservoir of Leishmania infantum, the parasite responsible for most cases of human visceral leishmaniasis. A strategy for the control of leishmaniasis would be to inhibit the sand fly bite. A study was designed to measure the prevention of the sand fly attack by spraying a combination of permethrin and pyriproxyfen on dogs artificially exposed to the vector of leishmaniasis. Eight dogs were individually challenged with 100 female sand flies for 1 hour on Days -7, 0, 7, 14, 21, and 28. Four dogs were randomly assigned to a control group and four dogs were treated with topically applied permethrin/pyriproxyfen on Day 0. After each exposure, sand flies were collected, counted, and scored as fed or unfed. Efficacy of the combination for prevention of feeding was based on the number of unfed sand flies (dead or alive). The combination of permethrin/pyriproxyfen demonstrated a significant (P <.05) repellent effect against Phlebotomus perniciosus bites as soon as it was sprayed on the dogs, and its repellent efficacy lasted at least for 28 days. The combination product provided significant (P <.05) knockdown activity against challenge with sand flies for 21 days in adult dogs and 14 days in puppies. These findings indicate that adult animals in endemic areas should be sprayed with the permethrin/pyriproxyfen product at 3- to 4-week intervals, and young dogs should be sprayed at approximately 2-week intervals, to prevent sand fly attack.     

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.     

Eco-epidemiology of visceral leishmaniasis in the urban area of Paracatu, state of Minas Gerais, Brazil

The present study was developed in the urban area of Paracatu, an endemic city for the American visceral leishmaniasis in Brazil. A six-month canine survey was performed with 6295 domiciled dogs in 28 districts in that area and showed that 4.2% of those (267 dogs) were positive for VL by ELISA and IFAT serum assays. Prevalence ratios for canine VL varied between 1.2% and 16.1%, depending on the district under investigation. Fifteen dogs - 80% of which were clinically asymptomatic for VL - were submitted to a more detailed study that comprised direct parasitological examination and Leishmania kDNA amplification of tissue samples as well as two PCR-RFLP methods using myelocultures. Leishmania amastigotes or Leishmania DNA were detected in all dogs but one. The infecting species of Leishmania was identified in about 50% (7/15) of the sample dogs: Leishmania (Leishmania) chagasi in two of them and, unexpectedly, Leishmania (Leishmania) amazonensis in the remaining five. Three months after the end of confiscation and elimination of the VL-seropositive dogs in the 28 districts of Paracatu, a systematic entomological survey was performed in five of them. Six hundred and sixty five (665) phlebotomine sand flies were captured in total, from which 89.5% were identified as Lutzomyia longipalpis. The population density of that species increased during the rainy season. Other thirteen (13) species of phlebotomine sand flies were captured at varying percentages from 0.2 to 5.0%. It is worth noting that L. longipalpis females were predominantely intradomicile when compared to males, suggesting that the VL transmission cycle in Paracatu may be occurring inside home.     

Treatment of canine Old World visceral leishmaniasis: a systematic review

Canine visceral leishmaniasis is a systemic disease caused by Leishmania infantum. The aim of this systematic review was to identify and evaluate the evidence of efficacy of interventions for treatment or prevention of canine visceral leishmaniasis, and to propose recommendations for or against their use. Forty-seven articles describing clinical trials published between 1980 and 2004 fulfilled selection criteria. The evaluation of clinical trials provided good evidence for recommending the use of meglumine antimoniate at a minimum dosage of 100 mg kg(-1) daily for at least 3-4 weeks, combined with allopurinol in order to obtain a good clinical efficacy and a reduced relapse rate. The evaluation of the articles also provided fair evidence for recommending the use of pentamidine (4 mg kg(-1) twice weekly) and aminosidine (5 mg kg(-1) twice daily) for 3-4 weeks. There was insufficient evidence for recommending the use of allopurinol alone, amphotericin B, buparvaquone, ketoconazole, enrofloxacin, and the combinations of metronidazole with spiramicyn or metronidazole with enrofloxacin. Fair evidence against the use of aminosidine at high dosages (20-80 mg kg(-1) per day) was proposed due to its side effects. Evaluation of articles on repellent measures against sand fly vectors of leishmaniasis provided good evidence for recommending deltamethrin collars and fair evidence for recommending spot-on permethrin.     

Infectivity of seropositive dogs, showing different clinical forms of leishmaniasis, to Lutzomyia longipalpis phlebotomine sand flies

Visceral leishmaniasis (VL) is a growing zoonosis with an increasing number of new cases and a rapid geographical spreading of the disease. In the present study, a canine survey was carried out in the city of Montes Claros (320,000 inhabitants), an endemic area of American visceral leishmaniasis in the state of Minas Gerais, Brazil. A total number of 4795 dogs were examined by serology, which showed a rate of seropositivity of 5%. Isoenzymatic analysis confirmed Leishmania infantum chagasi as the local aetiological agent of CVL. Canine tissues were assayed for the presence of Leishmania parasite DNA using different techniques. The infectivity of asymptomatic, oligosymptomatic and symptomatic seropositive dogs was tested by xenodiagnosis using laboratory reared Lutzomyia longipalpis. Rates of infection of 5.4%, 5.1% and 28.4% were found for the phlebotomine sand flies that fed in asymptomatic, oligosymptomatic and symptomatic dogs, respectively. Our results indicate that, under experimental conditions, symptomatic dogs are about four times more infective to VL vectors than oligosymptomatic or asymptomatic animals. The lower infectivity rates of dogs displaying any of the last two clinical forms of leishmaniasis, however, must be taken into account in the epidemiology of CVL.     

A survey on canine leishmaniasis and phlebotomine sand flies in central Italy

Zoonotic visceral leishmaniasis (ZVL) is a vector-transmitted zoonosis caused by the parasitic protozoan Leishmania infantum. Bloodsucking sand flies of the subfamily Phlebotominae are the obligatory insect hosts, and the dog is the only domestic reservoir.This study reports data from a survey of canine infection and sand fly phlebotomine monitoring in the province of Perugia in central Italy. The overall seroprevalence in a total of 100 dogs tested was 8% (95% confidence interval: 3.8-15.6%). Data analysis revealed that serological positivity was statistically associated with age (p-value = 0.03) and the area where dogs lived. Standard blacklight traps employed for sampling Culicoides midges in bluetongue disease surveillance were used in phlebotomine monitoring. A total of 5698 sand flies were collected and the two species, Leishmania competent vectors, were identified, Phlebotomus perfiliewi (50%) and Phlebotomus perniciosus (30%).     

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.     

Leishmania (Leishmania) chagasi is not vertically transmitted in dogs.

The most frequent and most important mode of human or canine visceral leishmaniasis (CVL) transmission is through the bite of infected sand flies. This study investigates Leishmania (Leishmania) chagasi vertical transmission in offspring of naturally infected dogs. Thus 63 puppies from 18 female dogs with CVL were used. Parasite presence was evaluated through parasitologic and histopathologic examination of lymphatic organs, as well as polymerase chain reaction (PCR) on samples from adults (milk, uterus, placenta, spleen, liver and bone marrow) and offspring (spleen, liver, lymph nodes and bone marrow). PCR sensitivity and specificity were calculated using a microscope as the gold standard on samples of bone marrow, spleen and liver. Specificity was 100% for all organs and sensitivity was 100% for bone marrow, 71.4% for spleen and 66.6% for liver. Bone marrow smears (n = 63), histopathology and imprint of spleen (n = 25), liver (n = 25) and lymph nodes (n = 25) were performed to evaluate congenital transmission in the 63 offspring. PCR was done on 92 samples collected from 56 of the offspring. No test performed on the offspring was positive. It was not possible to confirm vertical transmission of CVL (95% confidence interval for the observed prevalence), despite positive PCR in the placenta of seropositive adults.     

Risk factors for canine leishmaniasis in an endemic Mediterranean region

Human visceral leishmaniasis is an emergent/re-emergent parasitic zoonotic disease in Europe caused by Leishmania infantum, with domestic dog as its main reservoir host. This study presents the results of a canine epidemiological survey in a mediterranean region where human and canine leishmaniasis (CanL) are endemic - Portugal. The main goal was to identify risk factors, which can be relevant for Leishmania infection control. The national survey was carried out in January 2009 with a screening of 3974 dogs from all 18 districts of mainland Portugal. Direct Agglutination Test was used for the detection of anti-Leishmania antibodies in canine blood. An overall CanL true prevalence of 6.31% was observed. Apparent prevalence at district level ranged from 0.88% to 16.16%, with the highest prevalence in the interior regions. Identified risk factors for positivity were: dogs of 2 years and older (adjusted odds ratio OR=5.39); spending exclusively/most of the time outdoors (OR=2.51); origin from the interior of Portugal in comparison to littoral/coast districts (OR=2.51); not having long fur (OR=2.03); and being pure exotic (OR=1.67). The results confirm the leishmaniasis endemicity in Portugal and the dynamic character of prevalence as new foci emerged and old foci lost their importance. The dog's age, fur size, district and living outdoors as opposed to indoors were more important than dog breeds and insecticide treatment in the transmission of Leishmania infection. The future of CanL prevention and control rely on an integrated approach involving veterinarians, dog owners and health authorities in order to reduce the canine infection risk and consequently, the human zoonotic visceral leishmaniasis.     

Permethrin Spot-On Toxicoses in Cats

Spot-on insecticides are becoming a popular type of flea control for pets. Spot-on products available include those containing fipronil, imidicloprid, methoprene, and permethrin. Currently, over 15 brands of permethrin spot-on products are labeled for "use in dogs only." These products contain high concentrations (45–65%) of permethrin insecticide and are becoming a very popular choice for flea and tick control for dogs. Cats are highly sensitive to permethrin and inappropriate or accidental application of these products would be fatal. Though they have a wise margin of safety when used appropriately on dogs, even small amount of permethrin spot-on products can cause severe clinical signs in cats. Indications of this species sensitivity have been documented by the National Animal Poison Control Center (NAPCC). In most cases, the owner applied the concentrated permethrin-containing poduct to cats accidentally or intentionally. In some situations, the exposure seems to have resulted when the product was used on the dog and cats were playing with dog. (ASPCA, NAPCC, Unpublished data, 1995–1997).     

Efficacy of a combination of 10% imidacloprid/50% permethrin for the prevention of leishmaniasis in kennelled dogs in an endemic area

The efficacy of imidacloprid 10%and permethrin 50% (Advantix; Bayer AG, Germany) in a spot-on formulation was evaluated in the field as a control measure to prevent canine leishmaniasis (CanL) in dogs in an endemic area of southern Italy. In February 2005, out of 845 dogs initially tested for CanL, 631 dogs which tested negative (315 from a kennel in Bari (KB) and 316 from a kennel in Ginosa (KG)) in a serological and a parasitological examination were allocated to one of three groups: Group A-treated with imidacloprid 10% and permethrin 50% once a month; Group B-treated every 2 weeks; and Group C-untreated control animals. All the dogs were examined serologically and parasitologically for CanL prior to the start of the study, in November 2005 (end of the sandfly season) and in March 2006 (end of the study). An initial CanL seroprevalence of 24.7% (209 dogs) was detected in KB and KG. In KB Leishmania infection, inferred by positivity in at least one of the three tests performed at the interim or final follow-up, was found in one animal from Group A and in nine from Group C. No positive animals were detected in Group B, thus giving a final protection efficacy of 88.9% in Group A and 100% in Group B. In KG Leishmania infection was identified in one animal from Groups A and B, respectively, and 11 from Group C (protection efficacy of 90.36% in Group A and 90.73% in Group B). The incidence density rates (IDRs) of infection in both Groups A and B at each kennel were statistically significantly lower than that registered in Group C (KB p<0.05 and KG p<0.01). The results clearly show that a combination of imidacloprid 10% and permethrin 50%, by virtue of its repellent activity against sandflies, is effective under both application regimes in preventing CanL in the field in endemic areas.     

Seroepidemiological survey on canine leishmaniasis among dogs from an urban area of Brazil

A cross-sectional seroepidemiological survey on canine leishmaniasis among pet dogs was carried out in an urban area in the State of Pernambuco (Brazil) where human cases of visceral leishmaniasis have sporadically been reported. Using an indirect fluorescent antibody test, anti-Leishmania antibodies were detected in 130 out of 322 dogs, confirming previous exposure to Leishmania parasites. The overall seroprevalence found was 40.3% (95% confidence interval: 34.9-45.9). Data analysis revealed that serological positivity was statistically associated with male (chi2=20.60, P-value=0.000) and juvenile dogs (chi2=4.24, P-value=0.039). Furthermore, it was observed that 85.3% of all seropositive dogs showed no clinical signs of leishmaniasis. The results showed a high seroprevalence of anti-Leishmania antibodies among dogs from an urban area of Pernambuco - with a large proportion of asymptomatic seropositive dogs - indicating that the prevalence of Leishmania infection in this area has been underestimated.     

Efficacy of two 65 % permethrin spot-on formulations against canine infestations of Ctenocephalides felis and Rhipicephalus sanguineus

The efficacy of two formulations of a topically applied 65% permethrin spot-on for dogs (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health Corp.) was evaluated against experimental infestations of the cat flea, Ctenocephalides felis, and the brown dog tick, Rhipicephalus sanguineus. Thirty dogs were randomly allocated to treatment with 65 % permethrin in diethylene glycol monomethyl ether (original formulation), 65 % permethrin in propylene glycol monomethyl ether (test formulation), or to an untreated control group. Dogs assigned to treatment with a permethrin formulation received either 1 or 2 ml of the formulation in accordance with label directions on Day 0. One hundred unfed, adult cat fleas and 50 unfed, adult ticks were placed on each dog on Days -1, 5, 12, 19, 26, 33, and 40. Live fleas and ticks were counted on each dog on Days 2, 7, 14, 21, 28, 35, and 42. Treatment of dogs with either formulation of 65 % permethrin significantly (P <.05) reduced the number of live fleas and ticks from Days 2 through 42. No statistical differences were noted between the formulations regarding efficacy against C. felis or R. sanguineus.     

Efficacy of two 65% permethrin spot-on formulations against induced infestations of Ctenocephalides felis (Insecta: Siphonaptera) and Amblyomma americanum (Acari: Ixodidae) on beagles

The efficacy of two formulations of a topically applied 65% permethrin spot-on (Defend Exspot Treatment for Dogs, Schering-Plough Animal Health) was evaluated against experimental infestations of the cat flea Ctenocephalides felis and the lone star tick Amblyomma americanum in dogs. Eighteen dogs were randomly assigned to treatment with 65% permethrin in either diethylene glycol monomethyl ether (DGME; original formulation) or propylene glycol monomethyl ether (PGME) or to be untreated as a control. Treated dogs received either 1 (body weight < 15 kg) or 2 ml (body weight > or =15 kg) of the assigned formulation on Day 0. One hundred unfed, adult C. felis were placed on each dog on Days -6, -1, 4, 11, 18, 25, and 32. Fifty unfed, adult ticks were placed on each dog on Days -1, 3, 9, 16, 23, and 30. Live fleas and ticks were counted and removed on Days 3, 7, 14, 21, and 28. Treatment of dogs with the 65% permethrin in DGME reduced flea numbers by 90.4% to 99.9% from Days 3 through 21 (P < or =.05) and by 48.2% 28 days after treatment. Treatment of dogs with 65% permethrin in PGME reduced flea numbers by 93.7% to 99.7% from Days 3 through 28 and by 78.4% 35 days after treatment (P < or =.05). Treatment with 65% permethrin in DGME reduced tick numbers by 90% or more only on Day 7, whereas treatment with 65% permethrin in PGME reduced the number of live ticks by 90%or more on Days 7 and 14 and approached 90%(87.9%) on Day 21. Efficacy against fleas and ticks for the PGME formulation was significantly better (P < or =.05) than for the DGME formulation on Day 28. Findings in this study indicate that both the DGME and PGME formulations of 65% permethrin performed well in reducing numbers of live C. felis and A. americanum on laboratory beagles; however, the PGME formulation was effective approximately 1 to 2 weeks longer than the DGME formulation.     

Participation of Rhipicephalus sanguineus (Acari: Ixodidae) in the epidemiology of canine visceral leishmaniasis

The vectorial competence of the tick Rhipicephalus sanguineus is discussed in relation to the epidemiology of canine visceral leishmaniasis, taking into account its strict association with dogs and the low indices of natural infection presented by its known vector, the phlebotomine sand fly Lutzomyia longipalpis. In order to evaluate natural infection by Leishmania chagasi and the infectivity of these parasites in the tick, 39 specimens (6 females, 11 males and 22 nymphs) of R. sanguineus were removed from 21 dogs showing diverse symptoms of zoonotic visceral leishmaniasis (ZVL). Six ticks (15.4%) gave positive results for the genus Leishmania using the PCR technique. To determine the infectivity of the parasites, 36 hamsters were inoculated orally and peritoneally with macerates of ticks removed from nine dogs symptomatic for visceral leishmaniasis. After 6 months the hamsters were sacrificed and necropsied. Serum was removed for IFAT, as well as spleen and liver fragments to make imprint smears and for PCR. Eight (88.9%) of these dogs presented ticks that were infective for 14 hamsters (41.2%), 12 (85.7%) of them infected peritoneally and two (14.3%) orally. PCR revealed 27 smears (40.9%) to be positive, 20 (62.5%) of them infected peritoneally and seven (20.6%) orally. IFAT showed 14 positive animals (41.2%). Based on these findings, we suggest that the vectorial capacity of R. sanguineus for L. chagasi should be evaluated further, opening new perspectives in the epidemiology of ZVL.     

Repellency and efficacy of 65% permethrin and selamectin spot-on formulations against Ixodes ricinus ticks on dogs

Two topically applied spot-on products used for flea and tick control on dogs, 65% permethrin (Defend EXspot Treatment for Dogs, Schering-Plough Animal Health Corp., Union, NJ) and selamectin (Revolution [United States] or Stronghold [Europe], Pfizer Animal Health, New York, NY), were evaluated for repellency and efficacy against Ixodes ricinus, the primary vector of Lyme disease in Europe. Eighteen dogs were evenly and randomly allocated to the following treatments: 1) 65% permethrin, 2) selamectin, 3) untreated control. Dogs were treated by topical application of the assigned product in accordance with product label directions on Day 0. At 7, 14, 21, 28, and 35 days after treatment, each dog was exposed for 2 hours to 50 unfed, adult ticks in a cage with a carpet that covered approximately 70% of the floor area. After the exposure period, dogs were removed from the cages and live and dead ticks were counted on the dogs and in the cages. The number of live ticks recovered was reduced by 90.3% to 99.5% for dogs treated with 65% permethrin (P <.0001 versus controls and selamectin), compared with 10.9% to 31.1% for dogs treated with selamectin (P >.05 versus controls). The repellency of 65% permethrin was 63.4% to 80.2% against I. ricinus ticks (P <.0001 versus controls, P <.0007 versus selamectin), compared with 0% to 10.9% repellency for selamectin (P >.05 versus controls).     

Characterization of widespread canine leishmaniasis among wild carnivores from Spain

Visceral Leishmaniasis (VL) is an emerging zoonotic parasitic disease caused by Leishmania infantum in Mediterranean countries, with sand flies (Phlebotomus spp.) as vectors and dogs as the main domestic reservoir. The role of wild carnivores in the epidemiology of leishmaniasis is still controversial. In order to determine the prevalence of natural infection with L. infantum in wild carnivores from Spain, we analyzed 217 samples by PCR and western blotting and used restriction fragment length polymorphism (RFLP) to compare the patterns present in wild carnivores with those of domestic dogs from the same areas. DNA of the parasite was detected in spleen or blood samples from 35 (16.12%) analyzed wild carnivores, including 8 of 39 (20.5%) wolves (Canis lupus), 23 of 162 (14.1%) foxes (Vulpes vulpes), 2 of 7 (28.6%) Egyptian mongooses (Herpestes ichneumon), 1 of 4 genets (Geneta geneta), and 1 of 4 Iberian lynxes (Lynx pardinus). No significant sex or age differences in prevalence were observed in wolves and foxes (P>0.05), but there was a significant difference among regions in foxes (P<0.05). A total of 12 PCR-RFLP patterns were found in foxes, 6 in wolves, 4 in dogs, 2 in Egyptian mongooses and 1 in lynx and genet. RFLP patterns differed between dogs and foxes in the two areas where they could be compared. This is the first study of canine leishmaniasis in wild canids and other carnivores from different regions of Spain by PCR. The prevalence of infection indicates the existence of natural infection in apparently healthy wild carnivore populations, and our results are suggestive of a sylvatic cycle independent of dogs.