RESUMO
The present study compared the efficacy of different methods to apply an acaricide formulation to control Rhipicephalus (Boophilus) microplus. To compare the methods, an acaricide blend containing three active ingredients (a pyrethroid and two organophosphates) was used. In experiment 1 (farm 1: Goiânia, GO, Brazil), three methods were tested: a backpack sprayer (BS), power sprayer (PS) and spray race (SR). In experiment 2 (farm 2: São José do Rio Pardo, SP, Brazil), two methods were tested: BS and PS. In both experiments, 10 cattle with similar tick burdens were used. On day 0 in both experiments, the animals were treated with the acaricide. On day +1 (only in experiment 1), +3, +7, +14, +21, +28 and +35 (only in experiment 2), tick counts were performed to determine the control efficacy. The time application, pressure (KPa), volume applied (L) and ergonomic aspects of each spraying system were also evaluated. The adult immersion test (AIT) using three different acaricide blends (combinations of pyrethroid + organophosphate) was performed to compare the susceptibility of strains of each farm. In experiment 1, all treatments significantly reduced (p < 0.05) the number of ticks on the animals, and PS resulted in the greatest acaricide efficacy since day +1. In experiment 2, both treatments (PS and BS) reduced (p < 0.05) the tick burden, and as observed in experiment 1, PS resulted in the best reduction. The application times were 4.5, 150 and 330 s, while pressures were 306.8, 4,826.3 and 220.6 KPa for SR, PS and BS, respectively. In the AIT, the efficacy values were between 99.8 and 100% for the tick strain form farm 1 (Goiânia), while for tick strain from farm 2 (São José do Rio Pardo), the efficacy was between 67.2 and 80.9%. We conclude that the sprayer methods chosen influences the efficacy of the acaricide. All sprayer methods were efficient for acaricide application; the best efficacy was obtained using the PS, while the SR resulted in good efficacy and lower application time. The strain from farm 2 was less susceptible to all acaricides tested.
Assuntos
Acaricidas , Doenças dos Bovinos , Piretrinas , Rhipicephalus , Infestações por Carrapato , Animais , Bovinos , Acaricidas/farmacologia , Piretrinas/farmacologia , Organofosfatos , Brasil , Doenças dos Bovinos/prevenção & controle , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterináriaRESUMO
Foot-and-mouth disease (FMD) is a viral disease that affects several animal species, including domestic and wildlife ones. The occurrence of an FMD outbreak can potentially cause a large negative impact on countries or regions' livestock production and economy. Performed over several decades, mass herd vaccination has been the main strategy to control the disease. However, countries are beginning the stage of eradicating FMD, which involves suspending vaccinations. The present study carried out a risk classification for FMD occurrence in Goiás State, Brazil by evaluating and combining multiple risk factors involved in FMD introduction and dissemination. Data from 126,345 rural properties were collected and categorized by municipality. The risk factors were grouped into two modules and then scores for each module were obtained by adding and weighting the risk factors. These combined scores resulted in the final FMD occurrence risk score. Most of the municipalities, as well as the herds were found in the lowest likelihood levels. Variables linked to herd density and animal movement played a key role in the score composition. We believed that this model can be a useful tool in the decision-making process regarding actions and strategies related to FMD eradication.
A febre aftosa (FA) é uma doença viral, febril, aguda e altamente contagiosa que afeta várias espécies domésticas e silvestres. Sua ocorrência resulta em grandes impactos negativos na cadeia pecuária e na economia de um país ou região. A FA está presente na América do Sul desde o fim do século XIX gerando esforços de órgãos oficiais no combate à enfermidade com vistas à erradicação, o que possibilitará futuramente a retirada da vacina, fato previsto no estado de Goiás para o ano de 2021. Neste sentido, o presente estudo objetivou classificar o risco de ocorrência de FA nos rebanhos do estado de Goiás. Para tanto, avaliou-se e combinou-se vários fatores de risco (FR) ligados à introdução e disseminação da FA obtidos de dados de 126.345 propriedades rurais. Estes FR foram agrupados em módulos formados por caminhos de introdução e disseminação da FA. A combinação dos FR se deu por meio de adição, sendo em seguida ponderados por pesos atribuídos por especialistas. Foram gerados os escores de introdução e disseminação de FA em Goiás, possibilitando a classificação do risco de ocorrência da doença no estado. Identificou-se que a maioria do rebanho e do território goiano se encontra em baixos níveis de risco. Foi identificada complexa composição nos níveis de risco obtidos, indicando ampla variação dos fatores que compuseram os escores de risco, especialmente nos municípios de mais alto escore de ocorrência. Variáveis ligadas à densidade de rebanho e trânsito e movimentação de animais apresentaram importante participação na composição dos escores. Acreditamos que os resultados deste trabalho podem compor uma ferramenta importante na tomada de decisão sobre as ações e estratégias de combate à FA em Goiás, ao passo que posteriores avaliações e adaptações poderão ser realizadas para a validação do modelo proposto.
Assuntos
Doenças Transmissíveis , Medição de Risco , Erradicação de Doenças , Febre Aftosa/epidemiologiaRESUMO
Due to the scarcity of information regarding the control of Rhipicephalus microplus on bovines with different tick burdens, tick counts and the efficacy of a commercial spray formulation (aspersion bath with organophosphate + pyrethroid) were evaluated for animals with a low and high tick burdens for 35 days in a stall test. Thirty-two crossbreed Bos taurus indicus x Bos t. taurus experimentally infested with R. microplus larvae were divided into four groups: T01 high infestation control, T02 high infestation treated, T03 low infestation control, and T04 low infestation treated. The bovines were kept individually in pens and R. microplus females were collected daily. All data were statistically analyzed with a significance level of 5% (P ≤ 0.05). For linear regressions, variables with P≤0.05 and the highest coefficients of determination (R2 ≥ 0.70) were considered the best descriptors. The reliability level was 95%. Tick counts differed (P<0.0001) between T01 and T02 (high infestation control vs. treated), except at day 2 (P >0.05) post-treatment, and efficacy ranged from 85.2 to 50.6%. The number of collected engorged females was lower (P<0.0001) for T04 than for T03 (low infestation treated vs. control) animals from day 3 to 29, and efficacy ranged from 95.2 to 69.8%. In addition, tick burden and efficacy were negatively correlated for both the group of animals with a high tick burden (r = -0.5256; p = 0.0012; R² = 0.2762) and the group of animals with a low tick burden (r = -0.9817; p < 0.0001; R² = 0.9638). In conclusion, a high tick burden on bovines decreases the efficacy of the tested spray acaricide.
Assuntos
Doenças dos Bovinos , Piretrinas , Rhipicephalus , Infestações por Carrapato , Animais , Bovinos , Doenças dos Bovinos/prevenção & controle , Feminino , Organofosfatos , Reprodutibilidade dos Testes , Infestações por Carrapato/prevenção & controle , Infestações por Carrapato/veterináriaRESUMO
Ticks, flies, and gastrointestinal helminths (GINs) significantly affect cattle productivity; thus, ectoparasiticide, endoparasiticide, and endectocide drugs have commonly been used for their control. The study aimed to compare the technical (parasites counts), productive, and financial effects of a treatment protocol comprising ecto- + endoparasiticides formulations (T01: fluazuron 2.5 mg/kg + fipronil 1.25 mg/kg and fenbendazole 5 mg/kg; n = 15) to a treatment with one formulation of endectocide (T02: ivermectin 450 µg/kg + abamectin 250 µg/kg; n = 15) over 308 days under field conditions in crossbred cattle co-parasitized by Rhipicephalus microplus, Haematobia irritans, and GINs. Bovine weight gain and return on investment (ROI) were also evaluated. Bovines from T01 received four treatments against the cattle tick and two against two GINs. For T02, four treatments were performed. Animals from T01 gained 15.4 kg more than T02 and provided a comparative ROI of 15.8. In cattle co-parasitized with R. microplus, H. irritans, and GINs, the treatment protocol used in this study with ecto- + endoparasiticidal action formulations showed better technical results regarding parasite counts and productive and financial data than the strategic treatment protocol using only an endectocide formulation.
Assuntos
Acaricidas , Doenças dos Bovinos , Muscidae , Nematoides , Rhipicephalus , Infestações por Carrapato , Animais , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Infestações por Carrapato/tratamento farmacológico , Infestações por Carrapato/veterináriaRESUMO
We analyzed Cryptosporidium spp. in fecal samples of wild cervids (Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo) from many Brazilian regions, a fact unprecedented in the literature. Sniffer dogs were used to collect 936 fecal samples of cervids from 14 Brazilian localities. Cervids species were identified using polymerase chain reaction (PCR) performed from genomic DNA extracted from 563 fecal samples of Ozotoceros bezoarticus, Blastocerus dichotomus, Mazama nana, Mazama americana, and Mazama bororo. Cryptosporidium spp. oocyst screening was performed using malachite green negative staining. Nested PCR (nPCR) protocols targeting the 18S rRNA and GP60 genes followed by genetic sequencing were performed for Cryptosporidium spp. detection and Cryptosporidium parvum subtyping, respectively. Nested PCR targeting actin gene and genetic sequencing were performed in samples with non-identified Cryptosporidium species by 18S rRNA amplicon sequencing. The association between the occurrence of Cryptosporidium and the presence of bovines in the same locality was evaluated using Fisher's exact test. The positivity rates of diagnostic methods were compared by McNemar test and the Kappa correlation coefficient. The prevalence rates of Cryptosporidium spp. in cervids were 1.42% (8/563) and 0.36% (2/563) by nPCR and malachite green negative staining, respectively. C. parvum IIaA16G3R1 isolate was identified in three fecal samples from M. americana, two from M. nana and one from B. dichotomus. Cryptosporidium ryanae were found in one sample from B. dichotomus. We identified a new Cryptosporidium genotype, named Cryptosporidium deer genotype BR, from one M. americana fecal sample.
Assuntos
Criptosporidiose , Cryptosporidium , Cervos , Animais , Criptosporidiose/epidemiologia , Cryptosporidium/genética , Fezes , Reação em Cadeia da Polimerase/veterináriaRESUMO
The present study aimed to evaluate the spatial distribution and risk factors for infection by Toxoplasma gondii in sheep in the state of Goiás, located in the central-western region of Brazil. Through the immunofluorescence antibody test (IFAT), the seroprevalence of anti-T. gondii antibodies was analyzed in 1000 blood serum samples obtained from sheep in all macro and micro regions of the state of Goiás. Data related to sex, age of the animals, size of the farm, type of farm, water source, veterinary assistance, replacement of the herd, presence of domestic cats, presence of wild cats and presence of other wild animals were obtained at the sampling time. The differences between the seroprevalences obtained in relation to the variables analyzed were estimated using Pearson's chi-square test (χ2). The odds ratio (OR) values for each risk factor evaluated were statistically analyzed with a confidence interval of 95%. Positivity for IgG anti-T. gondii was observed (titer ≥64) in 34.3% (343/1000) of the samples, which ranged from 26.9% (31/115) to 44.2% (53/120) and from 21.8 (12/55) to 55.2% (16 / 29), respectively in the analyzed mesoregions and microregions. In all investigated regions of the State of Goiás, serum-reactive animals were detected with the age of the animals, the source of water, the form of replacement of the herd and the presence of domestic cats and wild animals risk factors statistically associated with the occurrence of T. gondii in animals.
Assuntos
Doenças do Gato , Toxoplasmose Animal , Animais , Animais Selvagens , Anticorpos Antiprotozoários , Brasil/epidemiologia , Gatos , Fatores de Risco , Estudos Soroepidemiológicos , Ovinos , Toxoplasmose Animal/epidemiologiaRESUMO
Gastrointestinal nematodes negatively impact the health and productivity of livestock. Macrocyclic lactones (MLs) are the most common class of chemicals used in helminth control programs, however, their intense use is accelerating the development of parasite resistance. For cattle, little is known regarding the relationship between fecal egg counts (FECs) and the helminth population inside the animal's gastrointestinal tract and so this study evaluated the correlation between FEC and worm burden in cattle treated or not with MLs (ivermectin 200 µg/kg, ivermectin 630 µg/kg, abamectin 200 µg/kg, doramectin 700 µg/kg and moxidectin 200 µg/kg). Animals were necropsied to determine if there were any modifications to the proportions of worm species due to chemical treatment. FECs of ML-treated and untreated animals showed significant (p ≤ 0.05 and R2 ≥0.70) positive linear correlations and substantial or perfect strength-of-agreement (LCCC ≥ 0.61) with total worms present, all of which were Haemonchus placei and Cooperia punctata. However, this correlation and strength-of-agreement did not occur when the efficacy of MLs was ≥80 % against these helminths. Among the active MLs tested, moxidectin had the weakest relationship between FEC and worm burden, except for H. placei. Analysis of the helminthological fauna found an increase of H. placei (35.6 % = 95 % CI 35.4-35.6) and a consequent decrease of C. punctata (52.5 % = 95 % CI 52.3-52.6) in untreated animals, when compared to studies carried out over 20-40 years ago, but this proportion was reversed for ML-treated animals (C. punctata 64.5 % = 95 % CI 64.4-64.8; H. placei 30.8 % = 95 % CI 30.6-30.8). It is possible that MLs mitigate this effect in the field and that C. punctata remained prevalent in cattle in different regions of Brazil.
Assuntos
Anti-Helmínticos , Doenças dos Bovinos , Nematoides , Infecções por Nematoides , Animais , Anti-Helmínticos/uso terapêutico , Bovinos , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/epidemiologia , Fezes , Ivermectina/uso terapêutico , Lactonas/uso terapêutico , Infecções por Nematoides/tratamento farmacológico , Infecções por Nematoides/veterinária , Óvulo , Contagem de Ovos de Parasitas/veterináriaRESUMO
This research had as objective to evaluate the occurrence and to characterize genetically the infections by Cryptosporidium in Mazama gouazoubira. By a non-invasive harvest methodology using trained sniffer dogs to locate fecal samples of cervids, 642 fecal samples were obtained from six Brazilian localities. The cervids species responsible for the excretion of each fecal sample were identified by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP), using the mitochondrial cytochrome b target gene (cyst b) and the restriction enzymes Sspl, AflIII and BstN. From this identification, 437 fecal samples of M. gouazoubira were selected for research of Cryptosporidium spp. performed through negative staining with malachite green and polymerase chain reaction (nPCR), with the subunit of 18S rRNA gene, followed by sequencing the amplified products. In the samples that were diagnosed the presence of parasite species with zoonotic potential, genotyping was also performed using nPCR with the subunit of GP60 gene. Statistical analysis consisted of the Fisher exact test to verify the association of the presence of the enteroparasite in relation to the presence of cattle in each locality, and the McNemar tests and Kappa correlation coefficient used to compare the results obtained between the two diagnostic techniques. In the fecal samples of M. gouazoubira the occurrences of Cryptosporidium were diagnosed in 1.6% (7/437) and 1.1% (5/437), respectively, through nPCR and microscopy. Cryptosporidium. parvum was diagnosed in 100% (7/7) of the samples submitted to sequencing (18S gene). The IIaA16G3R1 subtype was diagnosed in five of the C. parvum samples submitted to genotyping (GP60 gene). This is the first world report of C. parvum in M. gouazoubira and subtype IIaA16G3R1 in cervids.
Assuntos
Criptosporidiose/diagnóstico , Cryptosporidium parvum/isolamento & purificação , Cervos , Fezes/parasitologia , Animais , Brasil , Bovinos , Criptosporidiose/parasitologia , Reação em Cadeia da Polimerase/veterinária , Polimorfismo de Fragmento de Restrição , RNA de Helmintos/análise , RNA Ribossômico 18S/análiseRESUMO
This work evaluated tick and flea burdens and the efficacy of a single topical application of 10% fipronil + 9% (S)-methoprene spot-on against experimental infestations of Rhipicephalus sanguineus sensu lato and Ctenocephalides felis felis on dogs that were submitted to regular baths for 56-days post-treatment. Four treatments (n = 24) were evaluated: no chemical treatment and no bathing (T01); no chemical treatment + bathing (T02); chemical treatment and no bathing (T03) and chemical treatment + bathing (T04). Dogs were infested with adult ticks and fleas seven days pre-treatment (-7). The ectoparasites were then counted and removed on day -5, followed by a new infestation on day -2 and treatment on day 0. Ticks and fleas were then counted without removal on day 1 and counted with removal on day 2. The dogs were then repeatedly infested with both ectoparasites on days 5, 12, 19, 26, 33, 40, 47 and 54 post-treatment. Baths and ectoparasite counts with removal were performed every 48 h before and after experimental infestation, respectively. Animals of T04 had lower (P ≤ 0.05) tick burden than animals from T01 and T02 from day 2 to day 28. For fleas, the counts varied among days of the study. Dogs from T03 presented lower (P ≤ 0.05) flea burden than dogs from T01 from day 1 until day 56. The same was true for T04 when compared to T01 from day 1 to day 42. Animals of T02 greater (P ≤ 0.05) flea burden than animals of T04 in all dates post treatment. In addition, dogs from T02 presented higher (P ≤ 0.05) flea burden than T01 from day 7 to day 28 and from day 49 to day 56. In sum, the efficacy of the spot-on formulation used declined over the time against both ectoparasites. The efficacy for ticks ranged from 0.0 to 96.5% and 0.0 to 98.52% for T03 and T04, respectively. While for fleas, the efficacy of the formulation ranged from 67.41 to 100% for T03 and 40.18 to 100% for T04. So, bathing dogs that were not treated increased C. f. felis burden but not R. sanguineus s. l. burden. The residual efficacy of the product had a shorter duration against these ectoparasites for dogs that received subsequent bathing.
Assuntos
Banhos/veterinária , Doenças do Cão/prevenção & controle , Infestações por Pulgas/veterinária , Inseticidas/uso terapêutico , Metoprene/uso terapêutico , Pirazóis/uso terapêutico , Infestações por Carrapato/veterinária , Administração Tópica , Animais , Doenças do Cão/parasitologia , Cães , Feminino , Infestações por Pulgas/parasitologia , Infestações por Pulgas/prevenção & controle , Masculino , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controleRESUMO
The present study aimed to evaluate biological parameters of Rhipicephalus microplus in the non-parasitic phase in both field and laboratory conditions. It also aimed to assess correlations between duration (in days) of these parameters and climatic variables (humidity, rainfall, and soil temperature) and to estimate the annual number of generations of R. microplus in a tropical region. The non-parasitic phase of R. microplus in field and laboratory conditions was evaluated throughout the course of two years. A pasture was infested with engorged female of R. microplus, and biological parameters, including female pre-oviposition, female oviposition, egg mass incubation, larval pre-hatching phase, larval maturation, and larval longevity, were evaluated concomitantly with the collection of data on climatic conditions. The same parameters were also evaluated in a climatized chamber in the laboratory. The total duration of the non-parasitic phase in the field was longer in the dry season (1st and 4th life-cycle repetitions) than in the rainy season (2nd, 3rd, and 5th repetitions). Tick biological parameters for the non-parasitic phase in the laboratory were similar to those obtained in the field during the rainy season. The evaluated biological parameters were influenced mainly by environmental and ground-level temperatures, which modified egg mass incubation, larval pre-hatching, and larval longevity periods and, consequently, the total duration of the non-parasitic phase of the tick. The annual number of generations for the tick was estimated at five per year, which is alarming because it represents an increase, and so new studies into strategic control are needed.
Assuntos
Clima , Estágios do Ciclo de Vida/fisiologia , Animais , Bovinos , Feminino , Larva , Longevidade , Oviposição , Rhipicephalus/fisiologia , Fatores de TempoRESUMO
The present study attempted to verify the prevalence of and risk factors for diarrhea-causing agents in dairy calves from Brazil. Additionally, ages with a higher risk of occurrence for each agent were verified by means of the receiver operating characteristic (ROC) curve. The collections were performed on 39 farms, belonging to 29 municipalities located in eight states of Brazil. It was possible to conclude that the prevalence of Coronavirus, Rotavirus, Cryptosporidium spp., Eimeria spp., and nematodes was 7.20% (95% CI 4.54-9.78), 6.37% (95% CI 3.85-8.89), 51.52% (95% CI 45.26-55.57), 3.46% (95% CI 2.24-4.67), and 3.46% (95% CI 2.24-4.67), respectively. Ages with higher probabilities of occurrence of these diseases in calves were < 10, > 8, > 6, > 37, and > 36 days, respectively. Diarrhea occurred more significantly (P < 0.0001) in animals less than 21 days old and mainly on those receiving milk through automatic feeders (P < 0.001). Cryptosporidium spp. were a risk factor for the occurrence of Rotavirus, and vice versa (P = 0.0039) and presented a positive correlation with Coronavirus (P = 0.0089). Calves that drink water from rivers, streams, and ponds had a higher chance of being infected by Eimeria spp. (P < 0.0001), as well as developing infection by nematodes (P < 0.0001). The results found in this study highlight the importance of studying the agents of diarrhea together, once they act as coinfection where the losses triggered for the owners will involve some of these agents simultaneously.
Assuntos
Doenças dos Bovinos/epidemiologia , Infecções por Coronavirus/veterinária , Criptosporidiose/complicações , Diarreia/veterinária , Infecções por Nematoides/veterinária , Infecções por Rotavirus/veterinária , Animais , Brasil/epidemiologia , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/virologia , Coronavirus/isolamento & purificação , Criptosporidiose/epidemiologia , Cryptosporidium/isolamento & purificação , Diarreia/parasitologia , Diarreia/virologia , Eimeria/isolamento & purificação , Fazendas , Fezes/parasitologia , Fezes/virologia , Feminino , Infecções por Nematoides/complicações , Prevalência , Curva ROC , Fatores de Risco , Rotavirus/isolamento & purificaçãoRESUMO
This study aimed to investigate the presence of Toxoplasma gondii in semen, testicle and epididymis tissues of cats experimentally infected by this coccidium. A total of 12 male felines without a definite breed that were of reproductive age and serologically negative for T. gondii were selected and distributed to the following three experimental groups: GI, inoculated with 600 tissue cysts of the P strain of T. gondii (isolate III); GII, inoculated with 2×105 tachyzoites of the RH strain (isolate I); and GIII, not inoculated (control group). Prior to inoculation (day -7 and 0) and on post inoculation days (PIDs) 7, 14, 21, 28, 42, 56, and 70, all felines were subjected to assessments of anti-T. gondii IgG by indirect immunofluorescence (IIF) and assessments of parasitemia. Collection of semen (electroejaculation) was performed on the specified dates, followed by nested PCR and bioassays in mice to detect T. gondii. On PID 70, all 12 felines were orchiectomized, and the presence of the parasite in the testicles and epididymides was evaluated by nested PCR, murine bioassay, and histopathological and immunohistochemical analyses. All felines inoculated with T. gondii (GI and GII) seroconverted to the toxoplasmic infection after PID 14; on PID 7, seroconversion of three felines (P4, RH2 and RH4) could observed, and all exhibited detectable titers by PID 64. The GII felines exhibited greater serological titers compared with GI felines. The maximum serological titer (IgG) was observed in feline RH3 (titer 1024), while in other experimental felines, a maximum titer of 256 was detected. Parasitemic peaks were diagnosed in all felines of groups I and II from PIDs 7-42. A total of five parasitemic peaks were diagnosed in GI and nine in GII. In none of the experimental time points was the presence of T. gondii diagnosed in seminal samples collected from the felines or in the testicle or epididymis tissues collected from these animals. Thus, sexual transmission in domestic cats does not appear to be a major route of T. gondii infection, possibly demonstrating the tendency of this protozoan to develop a response directed to the formation and excretion of oocysts in the feces of these definite hosts, which act as its main route of perpetuation in the environment.
Assuntos
Doenças do Gato/parasitologia , Epididimo/parasitologia , Sêmen/parasitologia , Testículo/parasitologia , Toxoplasma/isolamento & purificação , Envelhecimento , Angola/epidemiologia , Animais , Doenças do Gato/epidemiologia , Gatos , Feminino , Masculino , Toxoplasmose Animal/parasitologiaRESUMO
The present study had the primary objective of evaluating clinical, hematological and biochemical parameters, as well as observing anatomical and histopathological characteristics of abomasums, from calves prime-infected with Haemonchus contortus or H. placei. Ten male Holstein newborns were subdivided in three groups (GI placebo; GII infected with H. contortus; GIII inoculated with H. placei). Eye mucosa staining was evaluated. Hematological and biochemical tests were performed on animals. The euthanasia of all ten experimental calves was performed on the 42nd day post-inoculation. Fragments were collected from each of all 10 abomasums for histopathological analysis. Discrete submandibular edema was diagnosed in animals from both infected groups (H. contortus or H. placei). However, there were no significant changes (P > 0.05) in the color of the ocular mucosa of calves from all three experimental groups across the entire experimental period. Hematological and biochemical changes diagnosed on animals could not be linked to infections by species of Haemonchus spp. Regarding histopathological exams, it was possible to diagnose hypertrophy, hyperplasia, binucleated cells, inflammatory infiltrate, multifocal hemorrhage and edema in abomasums from calves of both groups infected with H. placei and H. contortus. It can, thus, be concluded that not only are calves susceptible to infections by both Haemonchus species, but they can also present clinical changes and similar anatomic histopathological lesions independent of being infected by Haemonchus placei or Haemonchus contortus. These results reflect a negative effect on helminth control by mixed grazing between sheep and cattle, especially when using calves.
Assuntos
Abomaso/patologia , Doenças dos Bovinos/parasitologia , Hemoncose/veterinária , Gastropatias/veterinária , Abomaso/parasitologia , Animais , Animais Recém-Nascidos , Análise Química do Sangue/veterinária , Bovinos , Doenças dos Bovinos/sangue , Doenças dos Bovinos/patologia , Olho/patologia , Mucosa Gástrica/parasitologia , Mucosa Gástrica/patologia , Hemoncose/sangue , Hemoncose/parasitologia , Hemoncose/patologia , Haemonchus/classificação , Testes Hematológicos/veterinária , Masculino , Mucosa/patologia , Distribuição Aleatória , Gastropatias/parasitologia , Gastropatias/patologia , Aumento de PesoRESUMO
The present study aimed to evaluate Toxoplasma gondii seroprevalence in cattle slaughtered for human consumption from rural properties in the state of Rondônia, North region, Brazil; the seroprevalence was determined using indirect immunofluorescence assays (IFATs). Additionally, spatial distribution and risk factors associated with toxoplasmosis were also analyzed. Of the 1000 cattle serum samples examined, 53 (5.3%) were determined to be seropositive for T. gondii with antibody titers (IgG) ≥64. In regard to results of the studied risk factors (presence of cats, cats with free access to cattle, breeding system, animal's gender, consumption of raw milk by humans on the property and cattle abortion in the last 12 months) and the odds ratio (OR) of each of these factors influencing cattle to acquire toxoplasmosis, only animals raised on a feeder/stocker/backgrounder system presented a higher probability of being seropositive for T. gondii (OR≥1, P=0.04) than cattle raised only in a feeder/stocker system. There was no association between the occurrence of reproductive problems and T. gondii seropositivity. Based on results obtained in the Brazilian state of Rondônia, it could be concluded that the presence of cats and their contact with cattle on each property, cattle breeding purpose and cattle abortion in the last 12 months were not considered risk factors for T. gondii infection in cattle. Considering that the presence of T. gondii was detected in animals slaughtered in the state of Rondônia, consuming raw or undercooked meat from seropositive cattle should be considered a route of transmission of T. gondii to humans. However, the prevalence of toxoplasmosis diagnosed in cattle from this state (5.30%) is lower than the prevalence of toxoplasmosis observed in South, Southeast and Center-West regions of Brazil, which may vary between 48.5% and 71.0%. The low prevalence of toxoplasmosis in cattle is highlighted in Rondônia, which is the sixth largest state for cattle slaughtering in Brazil and is responsible for producing 20% of all cattle meat exported by Brazil.
Assuntos
Anticorpos Antiprotozoários/sangue , Doenças dos Bovinos/epidemiologia , Carne/parasitologia , Toxoplasma/imunologia , Toxoplasmose Animal/epidemiologia , Matadouros , Animais , Brasil/epidemiologia , Gatos , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/transmissão , Demografia , Feminino , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Masculino , Produtos da Carne/parasitologia , Razão de Chances , Prevalência , Coelhos , Fatores de Risco , Inquéritos e Questionários , Toxoplasmose Animal/transmissãoRESUMO
Este estudio tuvo como objetivo evaluar las características clínicas, hematológicas, aspectos parasitológicos, así como la eficacia de oxitetraciclina de larga acción contra Anaplasma marginale en el ganado infectado experimentalmente. Seis animales seronegativos fueron obtenidos por RIFI. En día 9 del estudio, los tres animales fueron esplenectomizados, y de día cero, seis animales fueron inoculados con aproximadamente 1x106 glóbulos rojos parasitados por Anaplasma marginale. La temperatura rectal se midio desde el primero al 35 º día después de la inoculación (DPI). Haga que el volumen celular empacado (VG - microhematocrito ) y el cálculo de la parasitemia, fueron obtenidos a partir de la 10ª a la 35ª DPI. Los animales recibieron un tratamiento específico (oxitetraciclina LA), cuando se presenta inicialmente la hipertermia ( > = 39,2o.C) y la parasitemia > = 2,0 %, y recibir nuevos tratamientos, clínicos y parasitológicos hasta que se produce la estabilización del animal. Analizando los resultados, parece que a los 21 DPI la parasitemia estaba presente en seis animales, en el mismo dia, comenzó el declive de VG en el ganado. La temperatura rectal del ganado alcanzó fiebre > = 39,2 picos del 23 DPI, en este día que la parasitemia de los animales se encontraban en el lugar . En general, el tratamiento específico para A. marginale, se tuvo que realizar unos tres días después de esta [...](AU)
This study aimed to evaluate the clinical, hematological, parasitological aspects and the effectiveness of long-acting oxytetracycline against Anaplasma marginale in experimentally infected cattle. Six 10-month-old animals seronegative by indirect immunofluorescence reaction (IFAT) were obtained. On day -9 of the study, three animals were splenectomized, and on day zero all six animals were inoculated with about 1x106 by Anaplasma marginale parasitized erythrocytes. Rectal temperature was measured from the 1st to the 35th day postinoculation (DPI). The packed cell volume (VG - microhematocrit) and calculation of parasitemia was obtained from 10º to 35º DPI. The experimental animals received first specific treatment (oxytetracycline LA) when they presented hyperthermia (> = 39.2o.C) and parasitemia >= 2.0%, and received new treatments until clinical and parasitological stabilization occurred. The results revealed that on 21º DPI parasitemia was present in the six animals, and from this day on the VG decreased. Their rectal temperature reached > = 39.2oC from 23º DPI on, when the parasitemia was on the rise. In general, the specific treatment against A. marginale had to be performed about three days after the haemoparasite was identified in the blood. The animals received one to four specific treatments against A. marginale to obtain clinical and parasitological stabilization. [...](AU)
O presente trabalho teve como objetivo, avaliar os aspectos clínicos, hematológicos, parasitológicos, bem como a eficácia da oxitetraciclina longa ação, contra Anaplasma marginale, em bovinos experimentalmente infectados. Seis animais soronegativos foram obtidos pela RIFI. No dia 9 do estudo, três animais foram esplenectomizados, e no dia zero, os seis bovinos foram inoculados com aproximadamente 1x106 hemácias parasitadas por Anaplasma marginale. A temperatura retal foi aferida do 1º ao 35º dia pós-inoculação (DPI). Já o volume globular (VG - microhematócrito) e o cálculo da parasitemia, foram obtidos do 10º ao 35º DPI. Os animais receberam tratamento específico (oxitetraciclina LA), quando apresentaram, inicialmente, hipertermia (> = 39,2ºC) e parasitemia > = 2,0%, e receberiam novos tratamentos, até ocorrer estabilização clínica e parasitológica do animal. Analisando os resultados, verifica-se que no 21º DPI a parasitemia foi presente nos seis animais, neste mesmo dia, iniciou o decréscimo no VG dos animais. A temperatura retal dos bovinos atingiu picos febris > = 39,2, a partir do 23º DPI, dia este em que a parasitemia encontrava-se em ascensão. De um modo geral, o tratamento específico contra A. marginale, precisou ser realizado cerca de três dias após o hemoparasita ter sido identificado na corrente sanguínea periférica dos animais. Os animais tiveram de receber de um a quatro [...](AU)
Assuntos
Animais , Bovinos , Anaplasma marginale , Oxitetraciclina/administração & dosagem , Oxitetraciclina/uso terapêutico , Anaplasmose/terapia , Parasitemia/terapia , Parasitemia/veterináriaRESUMO
Este estudio tuvo como objetivo evaluar las características clínicas, hematológicas, aspectos parasitológicos, así como la eficacia de oxitetraciclina de larga acción contra Anaplasma marginale en el ganado infectado experimentalmente. Seis animales seronegativos fueron obtenidos por RIFI. En día 9 del estudio, los tres animales fueron esplenectomizados, y de día cero, seis animales fueron inoculados con aproximadamente 1x106 glóbulos rojos parasitados por Anaplasma marginale. La temperatura rectal se midio desde el primero al 35 º día después de la inoculación (DPI). Haga que el volumen celular empacado (VG - microhematocrito ) y el cálculo de la parasitemia, fueron obtenidos a partir de la 10ª a la 35ª DPI. Los animales recibieron un tratamiento específico (oxitetraciclina LA), cuando se presenta inicialmente la hipertermia ( > = 39,2o.C) y la parasitemia > = 2,0 %, y recibir nuevos tratamientos, clínicos y parasitológicos hasta que se produce la estabilización del animal. Analizando los resultados, parece que a los 21 DPI la parasitemia estaba presente en seis animales, en el mismo dia, comenzó el declive de VG en el ganado. La temperatura rectal del ganado alcanzó fiebre > = 39,2 picos del 23 DPI, en este día que la parasitemia de los animales se encontraban en el lugar . En general, el tratamiento específico para A. marginale, se tuvo que realizar unos tres días después de esta [...]
This study aimed to evaluate the clinical, hematological, parasitological aspects and the effectiveness of long-acting oxytetracycline against Anaplasma marginale in experimentally infected cattle. Six 10-month-old animals seronegative by indirect immunofluorescence reaction (IFAT) were obtained. On day -9 of the study, three animals were splenectomized, and on day zero all six animals were inoculated with about 1x106 by Anaplasma marginale parasitized erythrocytes. Rectal temperature was measured from the 1st to the 35th day postinoculation (DPI). The packed cell volume (VG - microhematocrit) and calculation of parasitemia was obtained from 10º to 35º DPI. The experimental animals received first specific treatment (oxytetracycline LA) when they presented hyperthermia (> = 39.2o.C) and parasitemia >= 2.0%, and received new treatments until clinical and parasitological stabilization occurred. The results revealed that on 21º DPI parasitemia was present in the six animals, and from this day on the VG decreased. Their rectal temperature reached > = 39.2oC from 23º DPI on, when the parasitemia was on the rise. In general, the specific treatment against A. marginale had to be performed about three days after the haemoparasite was identified in the blood. The animals received one to four specific treatments against A. marginale to obtain clinical and parasitological stabilization. [...]
O presente trabalho teve como objetivo, avaliar os aspectos clínicos, hematológicos, parasitológicos, bem como a eficácia da oxitetraciclina longa ação, contra Anaplasma marginale, em bovinos experimentalmente infectados. Seis animais soronegativos foram obtidos pela RIFI. No dia 9 do estudo, três animais foram esplenectomizados, e no dia zero, os seis bovinos foram inoculados com aproximadamente 1x106 hemácias parasitadas por Anaplasma marginale. A temperatura retal foi aferida do 1º ao 35º dia pós-inoculação (DPI). Já o volume globular (VG - microhematócrito) e o cálculo da parasitemia, foram obtidos do 10º ao 35º DPI. Os animais receberam tratamento específico (oxitetraciclina LA), quando apresentaram, inicialmente, hipertermia (> = 39,2ºC) e parasitemia > = 2,0%, e receberiam novos tratamentos, até ocorrer estabilização clínica e parasitológica do animal. Analisando os resultados, verifica-se que no 21º DPI a parasitemia foi presente nos seis animais, neste mesmo dia, iniciou o decréscimo no VG dos animais. A temperatura retal dos bovinos atingiu picos febris > = 39,2, a partir do 23º DPI, dia este em que a parasitemia encontrava-se em ascensão. De um modo geral, o tratamento específico contra A. marginale, precisou ser realizado cerca de três dias após o hemoparasita ter sido identificado na corrente sanguínea periférica dos animais. Os animais tiveram de receber de um a quatro [...]
Assuntos
Animais , Bovinos , Anaplasma marginale , Anaplasmose/terapia , Oxitetraciclina/administração & dosagem , Oxitetraciclina/uso terapêutico , Parasitemia/terapia , Parasitemia/veterináriaRESUMO
The present study aimed to evaluate the population dynamics of Rhipicephalus (Boophilus) microplus over a period of 13 months on a rural property located in the state of Minas Gerais in southeastern Brazil. Animals were treated for ticks indoors by whole body spraying when R. (B.) microplus had an average count equal or more than 30 ticks. The study also evaluated the possibility of a partial selective treatment for bovines to control R. (B.) microplus in which only a percentage of the population would be treated (specifically those bovines with tick counts of ≥20. Moreover, we examined the percentage of the population of R. (B.) microplus present on experimental bovines that did not come into contact with the chemical compounds used in the partial selective treatment. We concluded that in this particular region of Brazil, the crossbreed steers support up to five R. (B.) microplus generations per year and that the number of generations was primarily affected by the pluviometric precipitation. We sprayed the bovines with chemicals seven times during the course of the study. The results of the partial selective treatment method revealed that during the rainy and the dry periods, 42.1% to 60.0% and 61.9% to 79.2% of the animals, respectively, fulfilled the criteria to receive a chemical treatment to reduce the number of cattle ticks. In consideration of the need to slow the development of tick resistance with the chemical compounds used in the spraying treatment, the results showed that the percentage of animals that did not require treatment is not relevant. This was evidenced by the result that bovines that presented tick counts of ≥20 during the dry and rainy periods represented 91.5% and 90.6% of the total recorded R. (B.) microplus populations, respectively. Only 8.7% of the tick population remained free from exposure to acaricides during the 13 months of the study, which is an important point when considering the adoption of the partial selective treatment method. Future studies with larger herds must be conducted on these topics; however, our results suggest that the partial selective treatment method most likely will not slow the development of resistance in this R. (B.) microplus population against the chemical compound used in this study.
Assuntos
Acaricidas/administração & dosagem , Doenças dos Bovinos/tratamento farmacológico , Doenças dos Bovinos/parasitologia , Controle de Doenças Transmissíveis/métodos , Controle de Doenças Transmissíveis/normas , Rhipicephalus/fisiologia , Infestações por Carrapato/veterinária , Animais , Brasil , Bovinos , Carga Parasitária , Dinâmica Populacional , Estações do Ano , Infestações por Carrapato/parasitologiaRESUMO
Using field trials, artificial infestations (Stall tests) and in vitro adult immersion tests, the present study evaluated the acaricidal efficacy of 12.5% amitraz administered via whole body spraying against a Rhipicephalus (Boophilus) microplus population that did not have any contact with chemical products belonging to this acaricide family for 10 years (approximately 40 generations). Two natural infestation trials, two artificial infestation trials (Stall tests) and two adult immersion tests were performed in two different stages in 2005 and 2015. Between 2002 and 2015, the bovine herd of this property was formed by approximately 450 animals from the Simmental breed that were divided into nine paddocks formed by Cynodon dactylon (L.) Pers. For the natural infestation experiments in 2005 and 2015, we selected nearly 70 animals naturally infested with ticks from the same herd that belonged to the "São Paulo" farm located in São José do Rio Pardo, São Paulo, Brazil. Field studies were performed in the same paddock (9). To evaluate anti-R. (B.) microplus activity in the artificially infested cattle (Stall tests) and adult immersion tests, two experiments of each methodology were performed at CPPAR (the Center of Research in Animal Health located on the FCAV/UNESP campus in Jaboticabal, São Paulo, Brazil) in 2005 and 2015. R. (B.) microplus used in the artificial infestation, and adult immersion test experiments were obtained from paddocks 1-9 in 2005 and 2015 from the commercial farm where the field studies were performed. Based on the obtained results, it was possible to conclude that amitraz use in rotation with pyrethroids every 28 days for three consecutive years (2002-2004) previous to the beginning of the first trial (2005) was sufficient to generate a R. (B.) microplus strain resistant to amitraz. Moreover, using field trials, artificial infestations (Stall tests) and adult immersion tests, we verified that 40 generations of the tick species with no contact to the aforementioned compound (amitraz) were not sufficient to revert or modify the efficacy/resistance of amitraz for this analyzed R. (B.) microplus strain. The reversion of amitraz efficacy values in R. (B.) microplus may only occur when resistance of the field strain is incipient. Alternatively, the differences in the results may be due to differences in the Rhipicephalus spp. species between current study locations. Therefore, future studies must be performed to prove this hypothesis.
Assuntos
Doenças dos Bovinos/tratamento farmacológico , Resistência a Inseticidas , Rhipicephalus , Infestações por Carrapato/veterinária , Toluidinas , Acaricidas/administração & dosagem , Acaricidas/normas , Animais , Brasil , Bovinos , Piretrinas/administração & dosagem , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/tratamento farmacológico , Toluidinas/administração & dosagem , Toluidinas/farmacologia , Toluidinas/normasRESUMO
This present study aimed to evaluate the deleterious effects of some commercially available spray formulations (15% Cypermethrin+25% Chlorpyriphos+1% Citronellal and 8% Cypermethrin+60% Ethion) on the reproductive parameters of engorged Rhipicephalus (Boophilus) microplus females that detached from experimentally infested cattle. The following reproductive parameters of engorged female ticks were analyzed: female weight, egg mass weight, percentage of hatchability, percentage of reduction in oviposition, percentage of reduction in hatchability, reproductive efficiency and percent control/efficacy of formulations for reproductive parameters. Our findings showed that although the strain R. (B.) microplus used in both experiments was thought to be sensitive to the test compounds because of the acaricidal efficacy observed throughout these trials, it was not possible to observe overall deleterious effects on the reproductive parameters of this tick species with both spray formulations. However, the 8% Cypermethrin+60% Ethion showed short-term significant effects on the weight of female ticks between the 14th and 16th days post-treatment and the weight of female and the egg mass weight between the 20th and 22nd days post-treatment. New studies should be conducted to show if these results regarding the reproductive parameters of fully engorged R. (B.) microplus females, combined with the acaricidal efficacy can be sufficient to reduce the number of chemical treatments administered to cattle.
Assuntos
Acaricidas/farmacologia , Doenças dos Bovinos/prevenção & controle , Rhipicephalus/efeitos dos fármacos , Infestações por Carrapato/veterinária , Monoterpenos Acíclicos , Aldeídos , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Clorpirifos , Feminino , Monoterpenos , Compostos Organotiofosforados , Piretrinas , Distribuição Aleatória , Reprodução/efeitos dos fármacos , Infestações por Carrapato/parasitologia , Infestações por Carrapato/prevenção & controleRESUMO
Between January 2007 and September 2013, 71 sheep belonging to 12 farms in the Umuarama microregion, State of Paraná, were evaluated regarding presence of Oestrus ovis larvae, during necropsies. The farms from which these animals originated were visited and the owners and employees were interviewed. Occurrences of O. ovis parasitism in sheep were diagnosed for the first time on this microregion. Of the 71 animals, 12 (16.9%) were parasitized by O. ovis, with mean intensity of 2.25 larvae per infested head (1 to 8 larvae/infested head). There was a high correlation (0.81, p=0.0346) between the number of larvae and the macroscopic lesions observed in these animals nasal cavities, such that sheep with more than 3 larvae may contain mucupurulent secretions or epistaxis. From the interviews conducted, it was found that all the farm owners were applying chemical parasite control methods (helminths and/or O. ovis), administered to all animals in the herds every 30 days (91.6% of the producers), using derivatives of macrocyclic lactones and/or benzimidazoles/imidazothiazoles. Further studies need to be conducted in this particular region, in an attempt to elucidate the prevalence of O. ovis parasitism in herds.(AU)
De janeiro de 2007 a setembro de 2013, foram avaliados, durante a necropsia, 71 ovinos pertencentes a 12 propriedades rurais da microrregião de Umuarama, Paraná, Brasil, quanto à presença de larvas de Oestrus ovis. Entre outubro e dezembro de 2013, as 12 propriedades de onde os animais eram provenientes foram visitadas, e os proprietários e funcionários foram entrevistados. A ocorrência do parasitismo por O. ovis em ovinos foi constatada pela primeira vez em propriedades rurais da microrregião de Umuarama, Estado do Paraná. Dos 71 animais, 12 (16,9%) estavam parasitados por O. ovis, com intensidade média de parasitismo de 2,25 larvas por cabeça infestada (1 a 8 larvas). Foi possível verificar correlação elevada (0,81, p=0,0346) apenas entre o número de larvas versus lesões macroscópicas observadas na cavidade nasal desses animais, de modo que ovinos com mais de 3 larvas continham secreção mucopurulenta ou epistaxe na cavidade. Quando da entrevista constatou-se que todos os proprietários fazem controle químico contra parasitas (helmintos e/ou O. ovis) e esse. controle é feito a cada 30 dias por 91,6% dos produtores, que utilizam derivados de lactonas macrocíclicas e/ou benzimidazóis/imidatiazóis. Futuros estudos ainda precisam ser realizados nesta região, na tentativa de elucidar a prevalência de parasitismo por O. ovis nos rebanhos.