RESUMO
The development of new acaricides is a long and very expensive process. Worryingly, there is increasing resistance to available acaricides worldwide leading to the real possibility that our dwindling supply of effective acaricides will be exhausted unless action is taken to increase the number of new acaricidal products and reduce the rate of resistance development. In 1995, eight major animal health pharmaceutical companies formed the Veterinary Parasite Resistance Group (VPRG) to act as an expert consultative group to guide the FAO in resistance management and collaborate in the prudent use of acaricides. In this paper, members of the VPRG discuss the problems and processes in acaricide development, resistance in the field to commonly used acaricides and the different considerations when targeting the cattle and pet market, and give their view of the future for tick control from the perspective of the animal health industry.
Assuntos
Indústria Farmacêutica/normas , Resistência a Inseticidas , Inseticidas/normas , Controle de Ácaros e Carrapatos/normas , Carrapatos , Animais , Indústria Farmacêutica/economia , Indústria Farmacêutica/organização & administração , Inseticidas/economia , Inseticidas/provisão & distribuição , Controle de Ácaros e Carrapatos/economia , Carrapatos/efeitos dos fármacosRESUMO
Laboratory tests were carried out on larvae and adults of the cattle tick Boophilus microplus to determine the toxicity of macrocyclic lactone acaricides (MLs). Technical and commercial MLs were used in larval packet test (LPT), larval immersion test (LIT) and adult immersion test (AIT). In LIT and AIT the toxicity of MLs was much higher than for LPT. In the AIT, diluting the injectable formulation of MLs in water was as effective as dilution in ethanol+Triton X-100. LC50, LC99.9 and 95% confidence limits were determined so that a discriminating dose (DD) could be set for larval and adult tests in order to diagnose potential resistance to MLs in field samples of the tick. These DDs are for Australian strains of B. microplus and may not be suitable for other strains until further work is carried out. The value of these diagnostic tests can only be verified if or when resistance to MLs emerges in ticks.
Assuntos
Antibacterianos , Doenças dos Bovinos/parasitologia , Resistência a Inseticidas , Inseticidas , Infestações por Carrapato/veterinária , Carrapatos , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Feminino , Larva , Dose Letal Mediana , Macrolídeos , Infestações por Carrapato/parasitologiaRESUMO
Três animais de cada espécie (Bos indicus, Bos taurus e Bubalus bubalis) foram inoculados, via oral, com 2x l0 elevada a quinta potência oocistos de Toxoplasma gondii. Seis outros animais, dois de cada espécie, foram mantidos como testemunhas. A resposta de anticorpos avaliada por meio da reaçäo de imunofluorescência indireta iniciou-se a partir do quinto dia pós-inoculação (DPI) nos zebuínos e bubalinos, e no sétimo DPI nos taurinos. Os títulos sorológicos nos taurinos permaneceram elevados até o final do experimento (70§ DPI), alcançando níveis máximos (1:16.384) entre o 42§ e 49§ DPI. Nos zebuínos e bubalinos o maior título de anticorpos anti-Toxoplasma foi de 1:256. A resposta de anticorpos mais ou menos acentuada näo está necessariamente relacionada à sensibilidade ao T. gondii
Assuntos
Animais , Anticorpos Antiprotozoários/imunologia , Toxoplasma/imunologia , Estudos de Casos e Controles , OócitosRESUMO
Three Toxoplasma gondii free bitches (No. 3-5) were fed 15000 sporulated T. gondii oocysts at 56, 40 and 32 day of gestation and the outcome of the pregnancy was monitored. Two of the three dogs infected during pregnancy showed evidence of congenital infection and one aborted. Two control bitches not fed oocysts delivered eight uninfected healthy pups. This study demonstrated that T. gondii can be congenitally transmitted in dogs when bitches are infected during pregnancy.
