Environmental enrichment interaction for laboratory beagle dogs used in research.

Experimental animal facilities can have a negative impact on the well-being of animals owing to confinement. To mitigate this, environmental enrichment (EE) is implemented confinement. The purpose of EE is to enhance the complexity of an animal's natural environment. The objective of this study was to identify the types of EE most enjoyed by dogs used in experimental research and housed in individual kennels. A total of six adult Beagle dogs, housed at the Laboratório de Quimioterapia Experimental em Parasitologia Veterinária (LQEPV) at the Universidade Federal Rural do Rio de Janeiro (UFRRJ) were included in the study. The EE tools used included Petball® toys, a grassy outdoor area, interaction with other dogs and with a team member, a "pool" made of plastic bottles, and dog's wet food ice cream. A team member assessed the usage of these tools every 5 min for a 30-min period, six times per day, one day per week, over the course of eight weeks. The study revealed that the grass area was the tool most commonly used for physical enrichment, accounting for 58% of the occurrences (p < 0.05). Social and food enrichment were enjoyed in second and third place, with 23% and 19% of occurrences, respectively. that the study findings suggest that dogs housed in individual kennels enjoy engaging in their natural behaviors.

Os animais de biotério podem viver em situações que afetem o seu bem-estar, como o confinamento. Um dos métodos que buscam para reduzir os impactos negativos é o Enriquecimento Ambiental (EA), o qual objetiva a promoção da complexidade do ambiente dos animais. Foi possível, com esta pesquisa, atingir o objetivo de identificar quais tipos de EA são mais aproveitados por cães utilizados em pesquisas experimentais que viviam em canis individuais. Foram utilizados seis cães adultos, Beagles, oriundos do Laboratório de Quimioterapia Experimental em Parasitologia Veterinária (LQEPV) da Universidade Federal Rural do Rio de Janeiro (UFRRJ). Como ferramentas de EA foram utilizados brinquedos Petball®, área de grama ao ar livre, interação com outros cães e com uma pessoa da equipe, "piscina" de garrafas plásticas e sorvete de ração úmida. Um membro da equipe avaliou o uso a cada 5 minutos, por período de 30 minutos (6 avaliações) por dia, um dia por semana ao longo de 8 semanas. O estudo revelou que a ferramenta mais usufruída pelos cães foi a área de grama através do enriquecimento físico, quantificado em 58% de ocorrência (p<0,05). Os enriquecimentos sociais e alimentar, foram usufruídos em segundo e terceiro lugar, com 23% e 19% de ocorrência, respectivamente. Pode-se concluir que os cães mantidos em canis individuais individualizados mais necessitam exercer seu comportamento natural específico, para que seu grau de bem-estar seja mantido em nível satisfatório e em consequência sua saúde mental.

Ultrastructural characterization and quantification of hemocytes in engorged female Amblyomma sculptum ticks.

Amblyomma sculptum (formerly Amblyomma cajennense) ticks have been implicated in the transmission of pathogens that cause diseases in animals and humans. Their wide geographic distribution and high impact on animal health and zoonotic disease transmission highlight the importance of studying and implementing effective control measures to mitigate the risks associated with this tick species. The aim of this study was to quantify and characterize the morphology and the ultrastructure of different types of hemocytes in the hemolymph in engorged A. sculptum females fed on rabbits. The hemolymph samples were collected by perforation of the cuticle in the dorsal region. Hemocyte types, sizes, and differential counts were determined using light microscopy, while ultrastructural analysis of hemocytes was performed using transmission electron microscopy. The average number of total hemocytes in the hemolymph was 1024 ± 597.6 cells µL-1. Five morphologically distinct cell types were identified in A. sculptum females: prohemocytes (6 % ± 8.8), plasmatocytes (10 % ± 7.7), granulocytes (78 % ± 12.2), spherulocytes (5 % ± 4.48), and oenocytoids (1 % ± 1.6). In general, prohemocytes were the smallest hemocytes. The ultrastructural morphology of A. sculptum hemocytes described in the present study agrees with the findings for other hard ticks. This is the first study to investigate ultrastructural characteristics of hemocytes of female A. sculptum ticks.

Do combinations of fipronil, eugenol and carvacrol have synergistic effects against Rhipicephalus sanguineus?

The tick Rhipicephalus sanguineus is one of the main ectoparasites that affects dogs, causing direct and indirect damage to parasitized animals. Currently, infestation control is mainly carried out by using synthetic acaricidal drugs. However, a decrease in efficacy and an increase in resistance to the main therapeutic protocols against tick infestations have been increasingly reported and confirmed, a factor that has driven research into the potential acaricide activity of natural compounds, including in association with synthetic molecules. The aim of this work was to evaluate whether the combinations of fipronil (FIP) and eugenol (EUG), FIP and carvacrol (CAR), and EUG and CAR would have synergistic effects against immature and unfed adult stages of R. sanguineus through in vitro bioassays. Bioassays were carried out using the larval packet test (FAO 2004) adapted for nymphs and adults. The synergistic activity was explored by combining each solution, based on the estimated LC50, in a 1:1 ratio (FIP: EUG, FIP: CAR and EUG: CAR). CompuSyn software was used to evaluate the various pairwise combinations of FIP, EUG and CAR, checking if there was synergism or antagonism between them. FIP and EUG and FIP and CAR showed combination index (CIn) values above 1.45, indicating antagonism. The synergistic activity between EUG and CAR was verified against all unfed phases of R. sanguineus, since the CIn was below 0.70, a value that indicates synergism. The combination of fipronil with either eugenol or carvacrol presented antagonistic effects against R. sanguineus larvae. On the other hand, carvacrol and eugenol had excellent pharmacological synergism against all tick stages with mortality values in the range of 80 to 100%, including the adult stage, which is less susceptible than immature stages.

In vitro evaluation of the activity of Cinnamaldehyde as an inhibitor of the biological cycle of Ctenocephalides felis felis.

The objective of this work was to evaluate the in vitro activity of cinnamaldehyde as an inhibitor of the biological cycle of Ctenocephalides felis felis. Tests were carried out with six repetitions containing 10 eggs of C. felis felis together with 0.5g of diet and filter paper discs with area of 23.76 cm2 impregnated with different concentrations of cinnamaldehyde (6; 8; 10; 12; 14; 16; 18; 20; 24 and 28 µg.cm-2) in Petri dishes and incubated in a climate-controlled chamber at 27 ± 1 °C and RH 75 ± 10%, for 30 days. The tests included a placebo group containing the diluent (acetone) and a negative control group, without treatment. At the end of 30 days, the percentage of inhibition of adult emergence/mortality was calculated, as well as the LC50 and LC90. Inhibition of adult emergence greater than 50% was observed from a concentration of 10 µg.cm-2 and 100% inhibition from a concentration of 14 µg.cm-2, obtaining LC50 and LC90 results of 8.75 and 13.57 µg.cm-2, respectively. We concluded that the volatile compound cinnamaldehyde is effective in vitro as an inhibitor of the biological cycle of C. felis felis.

O objetivo deste trabalho foi avaliar a atividade in vitro do cinamaldeído como inibidor do ciclo biológico de Ctenocephalides felis felis. Para realização do teste, seis repetições contendo 10 ovos de C. felis felis juntamente 0,5g de dieta e papel filtro de área 23,76 cm2 impregnado com diferentes concentrações de cinamaldeído (6; 8; 10; 12; 14; 16; 18; 20; 24 e 28 µg/cm2) foram armazenados em placas de petri e incubados em câmara climatizada à 27 ± 1°C e UR 75 ± 10%, por 30 dias. Além disso, o teste contou com um grupo placebo contendo o diluente (acetona) e um grupo controle negativo, sem tratamento. Ao final dos 30 dias, com os dados coletados foram calculados o percentual de inibição de emergência de adultos/mortalidade, como também a CL50 e CL90. Com os resultados, foi observado uma inibição de emergência de adultos superior a 50% a partir da concentração de 10 µg.cm-2 e uma inibição de 100% a partir da concentração 14 µg.cm-2 obtendo como resultados de CL50 e CL90 de 8,75 e 13,57 µg.cm-2, respectivamente. Conclui-se que o composto volátil cinamaldeído tem eficácia in vitro como inibidor do ciclo biológico de C. felis felis.

Larvicidal activity in vitro of essential oils against Cochliomyia hominivorax.

Cochliomyia hominivorax, from the family Calliphoridae, is responsible for causing most myiases in domesticated animals in Brazil. As alternatives to conventional treatments, essential oils (EOs) could possibly be used as natural control of ectoparasites. The aim of this study was to evaluate the in vitro activity of EOs from Salvia sclarea L., Rosmarinus officinalis L., Lavandula hybrida Reverchon, Citrus bergamia Risso, Citrus paradisi L., Juniperus virginiana L., Copaifera reticulata Ducke, Illicium verum Hook f., Pelargonium roseum, Cymbopogon winterianus Jowitt, Cymbopogon flexuosus Steud, Eugenia caryophyllus Spreng, Cinnamomum cassia Presl, Thymus vulgaris L. and Origanum vulgare L. against third-instar larvae of C. hominivorax. To evaluate the mortality rate, filter paper tests were performed at different concentrations and verified after 24 h and 48 h. Essential oils of T. vulgaris, O. vulgare and I. verum induced 100% mortality in the screening test, and their main active components (thymol, carvacrol and anethol, respectively) were also tested alone. In this new test, lethal concentrations (LC50) after 24 h and 48 h, respectively, were 407.1 and 314.2 µg.cm-² for T. vulgaris, 540.9 and 253.8 µg.cm-² for O. vulgare, 314.2 µg.cm-² (after 48 h) for I. verum, 255.6 and 102.3 µg.cm-² for thymol, 970.5 and 931.1 µg.cm-2 for carvacrol and 559.4 µg.cm-2 (after 48 h) for anethol. These results showed the potential of these EOs and their main components for development of ectoparasiticides for veterinary use, especially T. vulgaris EO and thymol.

Prevalence of gastrointestinal parasites in domestic cats (Felis catus) diagnosed by different coproparasitological techniques in the municipality of Seropédica, Rio de Janeiro.

The objectives of this work were to investigate the occurrence of parasites in feces of cats, compare different coproparasitological techniques for their diagnosis and determine associations with parasitism. The samples were processed using three different coproparasitological techniques: centrifugal flotation in sucrose, centrifugal flotation in ZnSO4 and simple sedimentation. The parasitic association between parasitism and variables such as age, sex and fecal consistency was performed using the chi-square test or the G test with a significance level of 5%. A total of 237 samples were analyzed, of which 93 (39.2%) were positive, being Ancylostoma spp. (17.3%), Giardia intestinalis (12.2%), Platynosomum illiciens (8.0%), Cystoisospora spp. (6.3%), Toxoplasma gondii/ Hammondia hammondi (3.4%), Diphyllobothriidae (2.1%), Toxocara spp. (1.7%), Dipylidium caninum (1.3%) and Mesocestoides spp. (0.8%). In the parasitism association analysis, it was possible to verify a statistical difference in the age category for Cystoisospora spp. (p=0.001) observing a strong relationship between parasitism and young animals, the association with sex proved to be important for P. illiciens (p<0.001) with a higher frequency of parasitized females and fecal consistency revealed to be related to the parasites G. intestinalis (p=0.007) and P. illiciens (p=0.033) showing a higher number of positive animals for these parasites with normal fecal consistency. In conclusion, we observed a higher occurrence of Ancylostoma spp. and G. intestinalis in fecal samples from domestic cats received in routine diagnoses and the presence of other parasites with zoonotic potential, as well as the relationship of these diagnosed parasites with the categories sex, age and fecal consistency.

Dogs infected by Dirofilaria immitis: a threat to the health of human and non-human animals in Rio de Janeiro, Brazil.

This study aimed to investigate the presence of Dirofilaria immitis microfilaremia in dogs from two regions of the state of Rio de Janeiro, Brazil, where heartworm infections are highly prevalent. Blood samples were collected from dogs aged > 12 months, independent of the use of preventatives. All samples obtained and analyzed using Knott's modified test by the investigators. A total of 133 blood samples were tested, and D. immitis microfilariae were detected in 29 of them, resulting in an occurrence of 21.8%. The percentage of dogs with microfilaremia detected raises concerns for pet families, one health professionals, and small animal practitioners. Microfilaremic dogs are the richest source of infection for the mosquitoes, increasing the risk of transmission. Therefore, the stakeholders in One Health must raise concerns regarding the health of wild animals, as wild canids and other species of wild animals are exposed to the risk of D. immitis infection. In addition, humans can get infected and develop human pulmonary dirofilariasis. In conclusion, the presence of dogs with microfilaremia potentiates opportunities for D. immitis transmission, exposing all animals, wild or domestic, human or non-human to the disease.

Este estudo objetivou investigar a presença de cães portadores de microfilemia da espécie Dirofilaria immitis em duas áreas do estado do Rio de Janeiro, Brasil onde a infecções por vermes do coração são altamente prevalescentes. Amostras de sangue foram obtidas de cães com mais de 12 meses de idade, independentemente do uso de preventivos. Todas as amostras foram obtidas e analisadas pelo grupo do estudo utilizando-se o teste de Knott modificado. Um total de 133 amostras foi testado e microfilárias de D. immitis foram detectadas em 29 amostras, resultando em uma ocorrencia de 21,8%. A porcentagem de cães com microfilaremia detectada gera preocupações para as famílias de animais de estimação, para profissionais da saúde única e para clínicos de pequenos animais. Cães microfilarêmicos são a mais rica fonte de infecção para mosquitos, aumentando o perigo de transmissão. Assim, atores de todos os segmentos sociais com interesse na saúde única devem incluir a saude de animais selvagens em suas preocupações, uma vez que canideos selvagens e outras espécies de animais selvagens são expostos ao desafio da infecção por D.immitis. Além disso, seres humanos podem se tornar infectados e desevolver dirofilariose pulmonar humana. Em conclusão, a presença de cães microfilarêmicos potencializa as oportunidades de trasmissão de D. immitis, expondo todos os animais, selvagens ou domesticos, humanos ou não humanos à doença.

Evaluation of the susceptibility to fipronil of Rhipicephalus microplus larvae from egg masses incubated at different times of oviposition.

The objective of this work was to evaluate the susceptibility of R. microplus larvae from different oviposition times to fipronil. The LPT was performed in sextuplicate, at concentrations of 18.75, 37.5, 75, 150 and 300 µg.mL-1. The LC50 found for the egg masses incubated with +7, +14 and +21 days were respectively 105.87, 110.71 and 121.22 µg.mL-1. The larvae originating from egg masses from the same group of engorged females, incubated on different days, presented similar mortality rates compared to the evaluated fipronil concentrations, facilitating the maintenance of laboratory colonies of this tick species.

O objetivo deste trabalho foi avaliar a susceptibilidade de larvas de R. microplus oriundas de diferentes momentos da oviposição frente ao fripronil. O TPL foi realizado em sextuplicata, nas seguintes concentrações 18,75; 37,5; 75; 150; 300 µg.mL-1. Não houve diferença estatística entre as mortalidades das larvas oriundas de posturas incubadas nos dias mais sete, +14 e +21, expostas ao fipronil. As CL50 encontradas para as posturas incubadas com +7, +14 e +21 dias foram respectivamente 105,87; 110,71 e 121,22 µg.mL-1. Observou-se que as larvas oriundas de posturas, do mesmo grupo de fêmeas ingurgitadas, incubadas em dias diferentes apresentam taxas de mortalidade parecidas frente as concentrações de fipronil avaliadas, facilitando a manutenção das colônias laboratorias desta espécie de carrapato.

Insecticidal activity in vitro of the essential oil of Pogostemon cablin against Ctenocephalides felis felis.

The aim of this study was to evaluate the in vitro insecticidal activity of the essential oil (EO) of P. cablin against immature and adult stages of C. felis. The chemical composition of P. cablin EO was determined by gas chromatography (GC). To evaluate the insecticidal activity, the egg, larva, pupa, and adult stages of C. felis were exposed to different concentrations of P. cablin EO diluted in acetone and impregnated in filter paper in a concentration range of 25 to 200 µg.cm-2. After exposure, the material was incubated in climatized chambers and mortality assessment was performed after 24 h for the larval and adult stages, 72 h for the egg stage and 15 days for the pupal stage. After GC analysis, the major constituents of the EO of P. cablin were found to be patchoulol (27.4%), α-bulnesene (19.7%) and α-guayene (15.0%). The of mortality percentage was 100% at the concentration of 200 µg.cm-2 for all stages. The LCs50 values were 46.1, 49.2, 60.6 and 62.7 µg.cm-2, respectively for the pupal, egg, larva and adult stages. Based on the results obtained, we can conclude that the EO of P. cablin contained patchoulol, α-bulnesene, and α-guayene as major constituents and had insecticidal activity against the immature and adult stages of C. felis.

O objetivo deste estudo foi avaliar a atividade inseticida in vitro do óleo essencial (OE) de Pogostemon cablin frente estágios imaturos e adultos de Ctenocephalides felis. A composição química do OE de P. cablin foi determinada por cromatografia gasosa (CG). Para a avaliação da atividade inseticida os estágios de ovo, larva, pupa e adultos de C. felis foram expostos a diferentes concentrações do OE de P. cablin diluídos em acetona e impregnados em papel filtro com a faixa de concentração de 25 a 200 µg.cm-2. Após a exposição, o material foi incubado em câmaras climatizadas e a avaliação da mortalidade foi realizada após 24 h para os estágios de larvas e adultos, 72 h para o estágio de ovo e 15 dias para o estágio de pupa. Após análise cromatográfica, os constituintes majoritários para o OE de P. cablin foram: patchoulol (27,4%), α-bulneseno (19,7%) e α-guaieno (15%). Foi obtido 100% de mortalidade na concentração de 200 µg.cm-2 para todos os estágios. As CLs50 foram de 46,1; 49,2; 60,6 e 62,7 µg.cm-2, respectivamente para os estágios de pupa, ovo, larva e adultos. Com base nos resultados obtidos é possível concluir que o OE de P. cablin apresentou o patchoulol, α-bulneseno, e α-guaieno como constituintes majoritários e atividade inseticida frente aos estágios imaturos e adultos de C. felis.

Ocimum gratissimum essential oil and eugenol against Ctenocephalides felis felis and Rhipicephalus sanguineus: In vitro activity and residual efficacy of a eugenol-based spray formulation.

Fleas and ticks are among the main ectoparasites that affect pets. The indiscriminate and incorrect use of chemical antiparasitics may be related to increased insect resistance and environmental contamination, requiring prospection for active ingredients that are less harmful to animals, humans and the environment. The use of essential oils and their isolated compounds has been reported as a potential alternative to synthetic antiparasitics, but there is a lack of studies involving the design and development of stable and safe natural products-based formulations. Therefore, the aim of this study was to establish LC50 and LC90 of Ocimum gratissimum essential oil and eugenol on immature stages and adults of Ctenocephalides felis felis and Rhipicephalus sanguineus; and to design and to determine the in vitro efficacy and residual effect of a natural product-based spray formulation for flea and tick control in pets. Bioassays were carried out according to the filter paper impregnation technique for fleas and through the larval packet test for ticks. O. gratissimum essential oil and eugenol presented pulicidal and acaricidal activity in vitro against immature stages and adults of C. felis felis and immature stages of R. sanguineus. The greater potency of eugenol against fleas and ticks led to the choice of eugenol as the active ingredient in the pharmaceutical form developed. The developed eugenol-based sprays presented adequate physical and chemical characteristics and stability, had pulicidal and acaricidal efficacy after 24 h and residual effect against fleas for up to 48 days.

Fluazuron orally administered to guinea pigs: pharmacokinetic and efficacy against Amblyomma sculptum.

BACKGROUND: Brazilian spotted fever (BSF), the most lethal tick-borne disease in the Western Hemisphere, is caused by the bacterium Rickettsia rickettsii and transmitted by the bite of Amblyomma sculptum. Capybaras are considered primary hosts of this tick and amplifier hosts of R. rickettsii, generating new infected lineages of A. sculptum in BSF-endemic areas. To define a possible treatment regimen for controlling the tick A. sculptum in capybaras, the aim of this study was to establish an effective fluazuron (FLU) dose to control A. sculptum larvae in artificially infested guinea pigs. METHODS: In Study I (pharmacokinetic and pharmacodynamic analysis), 24 guinea pigs were divided into four equal groups: control group (CG; untreated) and treated groups receiving FLU administered by gavage in three doses: G1-1 mg/kg, G2-5 mg/kg and G3-10 mg/kg, once a day for 15 days (d0 to d + 14). Blood samples were collected from the animals of the treated groups before and at d + 1, + 2, + 4, + 7, + 15 and + 21. The guinea pigs were artificially infested at d + 7 with A. sculptum larvae, and specimens were recovered at d + 11 to d + 14 and kept in a climatized chamber for 14 days. In Study II (evaluation of pharmacokinetic parameters), one group of eight animals received FLU administered by gavage in a single dose of 10 mg/kg, and blood samples were collected before and on day 0 (8 h after treatment), + 1, + 4, + 7, + 15, + 21 and + 28 after single FLU administration. FLU was analyzed in plasma samples by high-performance liquid chromatography with ultraviolet detection. RESULTS: FLU plasma concentrations increased quickly, indicating rapid absorption, and decreased slowly. Some larvae from all treated groups exhibited morphological and behavioral changes. FLU interfered in molting, and the efficacy obtained was 100% for all treated groups. CONCLUSIONS: The results offer promising perspectives for the development of a palatable feed cube containing FLU for free-living capybaras to control A. sculptum and also to prevent BSF in areas where capybaras have been shown to play a primary role.

Efficacy of a dinotefuran, permethrin and pyriproxyfen combination product in the treatment of rabbits (Oryctolagus cuniculus) naturally infested by Psoroptes ovis.

The main of this study was to evaluate the efficacy of dinotefuran, pyriproxyfen and permethrin-combination (Vectra 3D-CEVA) in the topical treatment of rabbits naturally infested with P. ovis. Adult New Zealand rabbits (n = 18) with plaques of crust in both ears were divided into three groups (one control and two treated). On day 0, the animals belonging to the treated groups received a single dose of a commercial ectoparasiticide formulation, recommended for use in dogs. The control group (G1) (n = 6) received no treatment, the treated group (G2) (n = 6) received one drop in each ear, and the remaining volume was applied along the back of the animal in the dorsal midline with the commercial formulation. In the other treated group (G3) (n = 6), animals received the same product used in G2, but all the volumes of 0.5 mL were applied only to the back of the animal (dorsal midline). On days 0, +7, +14, +21, +28 and +35, lesion scores and mites per gram (MPG) of each ear scab were evaluated. Statistical analysis was performed using the statistical software Bioestat 5.01. As the Shapiro-Wilk test determined that the data were nonparametrically distributed, the Kruskal-Wallis test was performed, followed by the Student-Newman-Keuls test, to determine the significance levels among the mean values of mite counts per gram of crusts compared to the three experimental groups. The efficacies for remission of lesion scores were 19.87 % on day +7 to 83.44 % on day +35 for G2 and 70.67 % on day +7 to 92.20 % on day +35 for G3. The efficacies obtained by evaluation of MPG were 100 % on day +7 to 99.86 % on day +35 for G2 and from 93.05 % on day +7 to 99.89 on day +35 for G3. The topical administration of the combination of dinotefuran (4.95 %), pyriproxifen (0.44 %) and permethrin (36 %) on the ears and back or only on the back in rabbits was shown to be effective in naturally controlling mite infestations by P. ovis.

Oral pharmacokinetic profile of fipronil and efficacy against flea and tick in dogs.

Fipronil (FIP) is an ectoparasiticide of the phenylpyrazole class, used in veterinary medicine in topical form. Supported by evidence of uncontrolled human exposure to FIP and environmental damage caused by commercially available formulations, its use by oral administration has become promising. The effectiveness of FIP against the flea Ctenocephalides felis felis and the tick Rhipicephalus sanguineus and its pharmacokinetics and main active metabolite, fipronil sulfone (SULF) were evaluated after single oral administration of tablets in three different doses (2, 4, and 6 mg/kg) in dogs. Through the plasma concentration curves, it was possible to observe that the FIP showed rapid absorption and metabolization and slow elimination. The values of Cmax (ß = 0.7653) and AUC0- t (ß = 0.3209) did not increase proportionally with increasing dose. At 48 h after treatment, doses of 4 mg/kg (AUC0- t  = 442.39 ± 137.35 µg/ml*h) and 6 mg/kg (AUC0- t  = 421.32 ± 102.84 µg/ml*h) provided 100% and 99% efficacy against fleas, and 95% and 98% against ticks, respectively. The estimated EC90 of FIP +SULF was 1.30 µg/ml against C. felis felis and 2.16 µg/ml against R. sanguineus. The correlation between the FIP pharmacokinetic and efficacy data demonstrated its potential for oral administration in the form of tablets for the control of ectoparasites in dogs, as a safer alternative for animals, humans, and the environment, aligned with the One Health concept.

Resistance of Haemonchus contortus to monepantel in sheep: first report in Espírito Santo, Brazil.

The objective of this study was to provide the first report of resistance of Haemonchus contortus to monepantel in sheep in Espírito Santo. The study was conducted in a property with history of monepantel use since 2014 and register of low efficacy in studies conducted over the past few years with fecal egg count reduction test. Lambs born on the property (males and females aged approximately 100 days) were selected and after eggs per gram of feces (EPG) analysis on fecal samples, these were divided into two groups: a group treated with monepantel (2.5 mg / Kg) and a control group without anthelmintic treatment. Seven days later, the animals were euthanized to recover parasites from the gastrointestinal tract. The efficacy of the treatment was 61.35% against H. contortus, thus proving that anthelmintic resistance to monepantel was present.

Platynosomum illiciens (Trematoda: Dicrocoeliidae) in a hybrid marmoset (Callithrix sp.) in the Municipality of Seropédica, RJ, Brazil - Case report.

Platynosomum illiciens is a liver trematode encountered infecting mainly felids although it has also been reported in birds and in additional mammalian species, including non-human primates. The current study reports a natural P. illiciens infection primate of the genus Callithrix. The diagnosis was made using a combination of copro-parasitological techniques, morphological evaluation of adult specimens recovered from the liver during necropsy, and molecular analyses. Eggs were brown in color, oval, operculated, and contained a miracidium. Adult specimens recovered during necropsy were measured and showed dimensions compatible with P. illiciens. Molecular characterization of the trematode involved amplification by polymerase chain reaction (PCR), in combination with nucleotide sequencing, of an approximately 900 base pairs fragment corresponding to 18S-ITS1-5.8S ribosomal DNA. Sequenced amplicons showed 100% nucleotide identity with sequences deposited in the GenBank database as derived from specimens of P. illiciens recovered from cats in Malaysia and Brazil. It was concluded that the morphological and molecular analyses presented herein, confirmed the identification of the trematode recovered as P. illiciens.

Resistance of Haemonchus contortus to monepantel in sheep: first report in Espírito Santo, Brazil / Resistência de Haemonchus contortus ao monepantel em ovinos: primeiro relato no Espírito Santo - Brasil

Abstract The objective of this study was to provide the first report of resistance of Haemonchus contortus to monepantel in sheep in Espírito Santo. The study was conducted in a property with history of monepantel use since 2014 and register of low efficacy in studies conducted over the past few years with fecal egg count reduction test. Lambs born on the property (males and females aged approximately 100 days) were selected and after eggs per gram of feces (EPG) analysis on fecal samples, these were divided into two groups: a group treated with monepantel (2.5 mg / Kg) and a control group without anthelmintic treatment. Seven days later, the animals were euthanized to recover parasites from the gastrointestinal tract. The efficacy of the treatment was 61.35% against H. contortus, thus proving that anthelmintic resistance to monepantel was present.

Resumo O objetivo deste estudo foi fornecer o primeiro relato de resistência de Haemonchus contortus ao monepantel em ovinos no Espírito Santo. O estudo foi conduzido em uma propriedade com histórico de uso de monepantel, desde 2014, e registro de baixa eficácia em estudos conduzidos nos últimos anos, utilizando-se testes de redução de contagem de ovos por grama de fezes (OPG). Cordeiros nascidos na propriedade (machos e fêmeas com idade aproximada de 100 dias) foram selecionados e, após contagem de OPG, foram divididos em dois grupos: um grupo tratado com monepantel (2,5 mg / kg) e um grupo controle, sem tratamento com anti-helmíntico. Após 7 dias, os animais foram eutanasiados para a recuperação dos parasitos no trato gastrointestinal. O tratamento apresentou eficácia de 61,35% para H. contortus, comprovando que a resistência anti-helmíntica ao monepantel foi presente.

In vitro acaricidal activity of different ectoparasiticide classes against Amblyomma sculptum larvae.

Zoonoses are major causes of morbidity and mortality worldwide. Among them, Brazilian Spotted Fever (BSF) is an important one that occurs in some regions of South America and can be transmitted by the "star tick" Amblyomma sculptum. Application of acaricides against the larval stage is important as strategy of population control. However, there is still a deficiency of studies on chemical control of A. sculptum and the present work aims to evaluate the in vitro acaricidal activity of cypermethrin, flumethrin, deltamethrin, fipronil, coumaphos and chlorpyrifos against A. sculptum larvae. Bioassays were performed using the larval immersion test method. A discriminatory analysis between the antiparasitic classes most used for tick control was carried out, which made it possible to determine the classes with higher potential for controlling A. sculptum larvae. Our results showed that A. sculptum larvae present highest sensitivity to the synthetic pyrethroid group, followed by the phenylpyrazole, organophosphate and macrocyclic lactone groups. These findings may support studies on improvement of tick control as in animals as in the environment.

Activity of Syzygium aromaticum essential oil and its main constituent eugenol in the inhibition of the development of Ctenocephalides felis felis and the control of adults.

The aim of this study was to evaluate the in vitro activity of Syzygium aromaticum essential oil (SAEO) and its main constituent eugenol (EG) against adult fleas and their action in the maturation of eggs into adults of Ctenocephalides felis felis. In order to evaluate the pulicidal activity, 10 adult fleas were exposed to a filter paper impregnated with SAEO and EG at increasing concentrations of 0.047; 0.094; 0.188; 0.375; 0.750; 1.50; 3.00; 6.00; 12.00 and 24.00 µg cm-2. Flea mortality was evaluated 24 and 48 h after exposure. In order to evaluate the inhibition of the maturation of eggs into adults, 10 eggs were exposed to filter paper impregnated with SAEO and EG at the same concentrations used in the pulicidal test, and the evaluation was performed 30 days after incubation. Untreated repetitions were maintained in both studies (control group). The lethal concentration 50 (LC50) of pulicidal activity to SAEO was 5.70 µg cm-2 in 24 h and 3.91 µg cm-2 in 48 h. The LC90 was 16.10 µg cm-2 and 15.80 µg cm-2 in 24 and 48 h, respectively. The LC50 of inhibition of the maturation of eggs into adults was 0.30 µg cm-2 and the LC90 3.44 µg cm-2. The LC50 of pulicidal activity to EG was 2.40 µg cm-2 in 24 h and 1.40 µg cm-2 in 48 h; the LC90 was 8.10 µg cm-2 and 3.70 µg cm-2 in 24 h and 48 h, respectively. The LC50 of inhibition of the maturation of eggs into adults was 0.10 µg cm-2 and the LC90 0.68 µg cm-2. Based on the results obtained, it is possible to conclude that the both SAEO and EG have in vitro pulicidal activity as well as acting as inhibitors of the maturation of eggs into adults of the flea C. felis felis.

Injectable eprinomectin for cattle: Tick efficacy and pharmacokinetics.

The aims of the present study were to evaluate the pharmacokinetic profile and efficacy of eprinomectin (EPM) against Rhipicephalus microplus in cattle of a new injectable form of EPM (Voss Performa®). The product was administered subcutaneously at a dose of 200 µg EPM/kg, in a single dose. The efficacy of EPM against R. microplus in cattle was evaluated through field and stall tests. Studies were performed to estimate the pharmacokinetic parameters of EPM with the purpose of better understanding the kinetics of the formulation. The formulation was effective in controlling R. microplus in both naturally and artificially infested cattle, providing efficacy greater than 95%. The results of pharmacokinetic study were Cmax of 47.15 ± 22.20 ng/ml, Tmax of 1.33 ± 0.492 days, T1/2 of 2.96 ± 1.212 days, AUC0-t of 228.08 ± 57.30 ng day ml-1 , and AUC0-∞ of 240.50 ± 58.44 ng day ml-1 . Therefore, the new injectable EPM formulation becomes an important alternative for the control of cattle tick in Brazil.

Fipronil Tablets: Development and Pharmacokinetic Profile in Beagle Dogs.

Increased human-pet interactions have led to concerns related to the prevention and treatment of ectoparasite infestations. Fipronil (FIP) is a widely used ectoparasiticide in veterinary medicine available for topical administration; however, its use may cause damage to the owners and the environment. The aim of the study was to develop immediate-release tablets of FIP, as well as to determine its pharmacokinetic properties after oral administration in beagle dogs. The prepared FIP tablets were evaluated for pre-compression (angle of repose, speed flow, and Carr's index) and post-compression (weight variation, friability, thickness, hardness, disintegration time, and dissolution rate) parameters. Orally administered FIP at a dose of 2 mg/kg was rapidly absorbed with Cmáx of 3.13 ± 1.39 µg/mL at 1.83 ± 0.40 h post treatment (P.T.) and metabolized with 1.27 ± 1.04 µg/mL at 2.33 ± 0.82 h P.T. for fipronil sulfone (SULF) (the primary metabolite). The elimination of FIP and SULF occurred slowly and had maintained quantifiable plasma levels in the blood for up to 28 days P.T. The goal of the study is aligned with the concept of One Health, which aims to collaboratively achieve the best health for people, animals, and the environment. Therefore, the use of FIP tablets for the control of ectoparasites in dogs may be a safer alternative for owners and the environment.