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.

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.

Effectiveness of transdermal fluralaner in the treatment of Lynxacarus radovskyi (Acari: Listrophoridae) in naturally infested domestic cats.

Mites of the species Lynxacarus radovskyi, which are commonly found on domestic cats in Brazil, can cause discomfort, itching, and alopecia. The development of new, safer and more effective treatments with a broad spectrum of activity, including the use of isoxazolines, is needed. The purpose of this study was to assess the efficacy of transdermal fluralaner in domestic cats naturally infested with L. radovskyi. Twenty cats were evaluated by trichograms and divided into two groups of 10 animals. The control group was not treated, while the treated group was given a single topical dose of fluralaner, as per the manufacturer's instructions. The cats were reassessed for the presence of L. radovskyi eggs and mites on days D+7, D+14, D+28, D+42, D+56, D+70, D+84, and D+98. As of D+42, all the animals (100%) tested negative for mites, and remained parasite-free until the end of the study, while the control group tested positive throughout the experiment. It can be concluded that a single dose of fluralaner applied topically was effective in treating cats naturally infested with L. radovskyi.

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.

Refrigerated modified Knott concentrate enables long-term morphological viability of canine blood microfilariae.

There are several methods of laboratory diagnosis of filarids, the most used are the thick smear and the Knott method. Both are quick to perform, have a low cost and allow observing the presence, quantifying and analyzing the morphological characteristics of microfilariae. Knowing the morphological viability of fixed microfilariae is of practical importance, as it allows the transport of samples to a laboratory, facilitates epidemiological studies , and allows the storage of samples for didactic. Thus, the aim of this study was to evaluate the morphological viability of microfilariae fixed in the refrigerated modified knott test using 2% formalin. To perform the modified Knott technique, 10 samples of microfilaremic dogs aged over 6 months were used. To evaluate the morphological viability time of the microfilariae in the modified Knott concentrate, the evaluations were repeated after intervals of 0, 1, 7, 30, 60, 120, 180, 240, and 304 days. In the present study, we did not verify any difference in the morphology of the microfilariae in any of the analyzed intervals from day 0 to 304 days, and it is possible to conclude that the use of 2% formalin in the modified Knott technique allows the microfilariae to be identified in a period of 304 days. days after processing the sample without changes in its morphology.

Existem diversos métodos de diagnóstico laboratorial de filarídeos, os mais utilizados são a gota espessa e o método do Knott. Ambos são de rápida execução, possui baixo custo e permitem observar a presença, quantificar e analisar as características morfológicas das microfilárias. Conhecer a viabilidade morfológica das microfilárias fixadas tem importância prática, pois permite o transporte de amostras para um laboratório, facilita estudos epidemiológicos, e permite o armazenamento de amostras para fins didáticos. Desta maneira, o objetivo do trabalho foi avaliar a viabilidade morfológica das microfilárias fixadas em teste do knott modificado refrigerado utilizando formalina a 2%. Para realização da técnica de knott modificado foram utilizadas 10 amostras de cães microfilarêmicos, com idade superior a 6 meses. Para avaliar o tempo de viabilidade morfológica das microfilárias no concentrado de Knott modificado, foram repedidas as avaliações após intervalos de 0,1,7, 30, 60, 120, 180, 240 e 304 dias. No presente estudo não verificamos diferença na morfologia das microfilárias em nenhum dos intervalos analisados deste do dia 0 até 304 dias, sendo possível concluir que a utilização da formalina a 2% na técnica de Knott modificada permite que as microfilárias possam ser identificadas em período de 304 dias após o processamento da amostra sem que ocorram alterações na sua morfologia.

Pyothorax caused by Nocardia sp. in a cat - Case report.

Nocardiosis is an infection caused by ubiquitous opportunistic bacteria and is rare in felines. In retrospective studies of the infection in the species, pyothorax was found in only about 5% of the cases described, with the most frequent forms being cutaneous and subcutaneous. This report describes Nocardia spp. as an etiologic agent of pyothorax in a feline leukemia virus (FeLV)-positive female cat. A 10-year-old female mixed-breed cat, positive for FeLV, with chronic kidney disease IRIS stage 2, was examined with a severe dyspneic onset, suspected of pleural effusion. It also had skin lesions in the interscapular region. The patient underwent thoracentesis, and a dense, creamy, fetid, and flocculated liquid was collected. Radiography was performed after draining the pleural fluid, which showed images suggestive of atelectasis of the left lung lobes and pneumonia. The collected material was sent for analysis, which found that it was a septic exudate. In addition, it was referred for bacterial culture in a special medium due to suspicion of nocardiosis. Long-term treatment with amoxicillin + clavulanic acid resolved the clinical case.

A nocardiose é uma infecção causada por bactérias oportunistas ubíquas e é rara em gatos. Em estudos retrospectivos da infecção na espécie, o piotórax foi encontrado em apenas cerca de 5% dos casos descritos, sendo as formas mais frequentes a cutânea e a subcutânea. Este relato descreve Nocardia spp. como agente etiológico do piotórax em um gato vírus da leucemia felina (FeLV)-positivo. Um gato mestiço de 10 anos de idade, positivo para o FeLV, com doença renal crônica IRIS estágio 2, foi examinado com dispneia grave, com suspeita de derrame pleural. Apresentava lesões cutâneas na região dorsal entre as escápulas. Após sedação, tricotomia e antissepsia, o paciente foi submetido à toracocentese e coletado líquido denso, cremoso, fétido e floculado. A radiografia foi realizada após drenagem do líquido pleural, que mostrou imagens sugestivas de atelectasia dos lobos pulmonares esquerdos e pneumonia. O material coletado foi encaminhado para análise, que constatou tratar-se de exsudato séptico. Além disso, foi encaminhado para cultura bacteriana em meio especial por suspeita de nocardiose. O tratamento prolongado com amoxicilina + ácido clavulânico foi suficiente para a resolução do caso clínico.

Insecticidal activity of essential oil of Cannabis sativa against the immature and adult stages of Ctenocephalides felis felis.

Essential oil (EO) of Cannabis sativa (C. sativa) was evaluated against the egg, larval, pupal, and adult stages of the flea Ctenocephalides felis felis. The chemical composition of EO was determined by gas chromatography with flame ionization and mass spectrometry. EO mainly comprised γ-elemene (16.2%) and caryophyllene oxide (14.2%) as major compounds. To evaluate the mortality of flea stages in vitro, filter paper tests were performed at different concentrations. EO of C. sativa showed insecticidal activity (100% mortality at the highest concentrations) for flea control at egg, larval, pupal, and adult stages, with lethal concentrations (LC50) of 32.45; 91.61; 466.41 and 927.92 µg/cm2, respectively. EO of C. sativa indicated the potential for the development of ectoparasiticide for veterinary use, especially for fleas in egg and larval stages.

Endoparasites of Leopardus pardalis (Carnivora, Felidae) rescued in the State of Rio de Janeiro.

Wild cats play an important role as top predators in the food chain and act as ecosystem regulators. However, in recent decades, many studies have demonstrated the potential effects of parasitic diseases on wild carnivore populations, including cats. This study reports on the endoparasites found in an injured and rescued specimen of Leopardus pardalis in the state of Rio de Janeiro. Fecal samples were collected and processed using five coproparasitological techniques: a simple flotation centrifugation, a zinc sulfate flotation centrifugation, a formalin-ether sedimentation centrifugation, a conical centrifuge tube technique, and a modified Ziehl-Neelsen staining technique for fecal smears. Helminth eggs belonging to the families Trichuridae and Diphyllobothriidae and the genus Toxocara were found in both sedimentation flotation techniques. Protozoan oocysts belonging to the genus Cryptosporidium were identified by modified Ziehl-Neelsen staining. These findings show that ocelots can harbor potentially zoonotic and pathogenic endoparasites. Further studies on the helminths and protofauna of these animals are necessary.

Os felinos selvagens desempenham um papel importante como predadores de topo na cadeia alimentar e atuam como reguladores do ecossistema. No entanto, nas últimas décadas, muitos estudos demonstraram os efeitos potenciais de doenças parasitárias em populações de carnívoros selvagens, incluindo gatos. Este estudo relata os endoparasitos encontrados em um espécime ferido e resgatado de Leopardus pardalis no estado do Rio de Janeiro. Amostras fecais foram coletadas e processadas usando cinco técnicas coproparasitológicas: uma centrifugação por flotação simples, uma centrifugação por flotação com sulfato de zinco, uma centrifugação por sedimentação com éter de formalina, uma técnica de tubo de centrífuga cônica e uma técnica modificada de coloração de Ziehl-Neelsen para esfregaços fecais. Ovos de helmintos pertencentes às famílias Trichuridae e Diphyllobothriidae e ao gênero Toxocara foram encontrados em ambas as técnicas de flotação por sedimentação. Oocistos de protozoários pertencentes ao gênero Cryptosporidium foram identificados pela coloração de Ziehl-Neelsen modificada. Esses achados mostram que jaguatiricas podem abrigar endoparasitas potencialmente zoonóticos e patogênicos. Mais estudos sobre os helmintos e a protofauna desses animais são necessários.

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.

Feline Heartworm in Clinical Settings in a High Canine Prevalence Area.

Heartworm (HTW) infection in cats is associated with persistent pulmonary pathology, even when clinical signs are absent. Treatment options for cats are limited once infected, making prevention an important topic for discussion with cat owners. In Brazil, tests to detect feline HTW infections are unavailable, likely leading to an underestimation of its impact on the wellbeing of cats. The present study investigated the seroprevalence of HTW antigen in cats living in an area with high canine HTW prevalence and investigated risk factors and clinical signs associated with HTW disease in cats from Rio de Janeiro, Brazil. Clinical examinations were conducted, and serological evaluations performed with a point-of-care test (SNAP® Feline Triple® Test, IDEXX Laboratories, Inc.). A total of 586 cats were examined. The HTW antigen seroprevalence was 1.2%. Heartworm positive results were significantly associated with vomiting and abnormal lung sounds. Results from this study indicate that cats residing in areas of high canine HTW prevalence should have HTW disease as a differential diagnosis when presenting with compatible clinical signs. Veterinarians should prioritize client education and promote regular use of effective prophylaxis to protect feline health.

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.

Efficacy and residual effect of Illicium verum (star anise) and Pelargonium graveolens (rose geranium) essential oil on cat fleas Ctenocephalides felis felis.

The essential oils (EOs) of Illicium verum and Pelargonium graveolens were evaluated for lethality, inhibition of development and residual efficacy against the flea Ctenocephalides felis felis. Their chemical composition was characterized by means of gas chromatography with a flame ionization and mass spectrometry detection. Mortality at different immature stages and among adult fleas was measured through in vitro filter paper tests at different concentrations of EOs. The chemical characterization of I. verum volatile oil showed that E-anethole (79.96%) was the major constituent, while the major compounds in P. graveolens were citronellol (29.67%) and geraniol (14.85%). Insecticidal activity against both immature and adult flea stages were observed. The EO of I. verum had insecticidal activity for approximately 18 days, while the EO activity of P. graveolens lasted for 13 days. The pulicidal activity of I. verum remained above 70% for up to 9 days, while the activity of P. graveolens was 41.7% for up to 2 days. Essential oils, especially that of I. verum, showed insecticidal activity for flea control at different life cycle stages and have potential for the development of ectoparasiticides (biopesticides) for veterinary use.

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.

Efficacy and residual effect of Illicium verum (star anise) and Pelargonium graveolens (rose geranium) essential oil on cat fleas Ctenocephalides felis felis / Eficácia e efeito residual dos óleos essenciais de Illicium verum (anis-estrelado) e Pelargonium graveolens (gerânio rosa) em pulgas de gato Ctenocephalides felis felis

Abstract The essential oils (EOs) of Illicium verum and Pelargonium graveolens were evaluated for lethality, inhibition of development and residual efficacy against the flea Ctenocephalides felis felis. Their chemical composition was characterized by means of gas chromatography with a flame ionization and mass spectrometry detection. Mortality at different immature stages and among adult fleas was measured through in vitro filter paper tests at different concentrations of EOs. The chemical characterization of I. verum volatile oil showed that E-anethole (79.96%) was the major constituent, while the major compounds in P. graveolens were citronellol (29.67%) and geraniol (14.85%). Insecticidal activity against both immature and adult flea stages were observed. The EO of I. verum had insecticidal activity for approximately 18 days, while the EO activity of P. graveolens lasted for 13 days. The pulicidal activity of I. verum remained above 70% for up to 9 days, while the activity of P. graveolens was 41.7% for up to 2 days. Essential oils, especially that of I. verum, showed insecticidal activity for flea control at different life cycle stages and have potential for the development of ectoparasiticides (biopesticides) for veterinary use.

Resumo Os óleos essenciais (OE) de Illicium verum e Pelargonium graveolens foram avaliados quanto à letalidade, inibição do desenvolvimento e eficácia residual contra a pulga Ctenocephalides felis felis. Sua composição química foi caracterizada por meio de cromatografia gasosa com detector de ionização de chama e espectrometria de massas. A mortalidade entre os diferentes estágios imaturos e pulgas adultas foi avaliada por meio de testes in vitro em papel filtro, contendo diferentes concentrações de OEs. A caracterização química do óleo volátil de I. verum mostrou que o E-anetol (79,96%) foi o constituinte majoritário, enquanto os principais compostos de P. graveolens foram citronelol (29,67%) e geraniol (14,85%). Foi observada atividade inseticida contra os estágios imaturos e adulto da pulga. O OE de I. verum teve atividade inseticida por aproximadamente 18 dias, enquanto o de P. graveolens durou 13 dias. A atividade pulicida de I. verum permaneceu acima de 70% até o 9º dia, enquanto a atividade de P. graveolens foi de 41,7% até o 2º dia. Os óleos essenciais, principalmente de I. verum, apresentam atividade inseticida para o controle de pulgas em diferentes estágios do ciclo de vida e têm potencial para o desenvolvimento de ectoparasiticidas (biopesticidas) de uso veterinário.

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.

Development of Ctenocephalides felis felis (Siphonaptera: Pulicidae) in different substrates for maintenance under laboratory conditions.

The aim of this study was to evaluate the efficiency of different substrates for larval development of Ctenocephalides felis felis during its biological cycle. Eight hundred eggs of C. felis felis from a flea maintenance colony were used. Different diets were formulated, in which the main substrates were meat flour, powdered milk, sugar, lyophilized bovine blood, tick metabolites and lyophilized egg. The flea eggs were placed in test tubes (10 per tube) and approximately 2 g of the diet to be tested was added to each tube. There were 10 replicates for each substrate. After 28 days, each tube was evaluated individually for the presence of pupae and emerged adults. The following percentages of the larvae completed the cycle to the adult stage: 67% in diets containing tick metabolites; 55%, meat flour; 39%, dehydrated bovine blood; 14%, powdered milk; and less than 1% in diets containing sugar, lyophilized bovine blood, lyophilized egg or wheat bran. It was concluded that among the diets tested, the one constituted by tick metabolites as the substrate was shown to be the most satisfactory for maintaining a laboratory colony of C. felis felis, followed by the one containing meat flour.

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.

In vitro activity of essential oils against adult and immature stages of Ctenocephalides felis felis.

Essential oils (EOs) are considered a new class of ecological products aimed at the control of insects for industrial and domestic use; however, there still is a lack of studies involving the control of fleas. Ctenocephalides felis felis, the most observed parasite in dogs and cats, is associated with several diseases. The aim of this study was to evaluate the in vitro activity, the establishment of LC50 and toxicity of EOs from Alpinia zerumbet (Pers.) B. L. Burtt & R. M. Sm, Cinnamomum spp., Laurus nobilis L., Mentha spicata L., Ocimum gratissimum L. and Cymbopogon nardus (L.) Rendle against immature stages and adults of C. felis felis. Bioassay results suggest that the method of evaluation was able to perform a pre-screening of the activity of several EOs, including the discriminatory evaluation of flea stages by their LC50. Ocimum gratissimum EO was the most effective in the in vitro assays against all flea stages, presenting adulticide (LC50 = 5.85 µg cm-2), ovicidal (LC50 = 1.79 µg cm-2) and larvicidal (LC50 = 1.21 µg cm-2) mortality at low doses. It also presented an excellent profile in a toxicological eukaryotic model. These findings may support studies involving the development of non-toxic products for the control of fleas in dogs and cats.