Publications by authors named "Vando E Soares"

Article Synopsis
  • Trypanosoma vivax infections are prevalent in Africa and were introduced to Latin America in 1919, causing trypanosomosis, with some local cattle breeds (trypanotolerant) showing resilience against the disease.
  • A study evaluated the Curraleiro Pé-Duro (CPD) breed's ability to meet trypanotolerant criteria compared to Holstein/Gyr breeds by assessing their response to T. vivax infection over 532 days.
  • Results indicated that CPD animals maintained normal health without treatment and demonstrated recovery from anemia, while the Holstein/Gyr breed exhibited significant weight loss and required treatment after infection.
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The water can be a significant risk factor for the occurrence of cattle eimeriosis on farms located in tropical climate regions. This study aimed to assess the viability period of sporulated oocysts of bovine Eimeria spp. in water containing organic matter and to evaluate the efficacy of disinfectants against sporulated oocysts of this protozoa.

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Article Synopsis
  • The study assessed the effects of the tick Rhipicephalus microplus on Holstein calves' health and productivity on a tropical dairy farm, focusing on factors impacting tick fever (TF) outbreaks.
  • It involved tracking rectal temperatures and blood sampling of calves to diagnose TF agents like Anaplasma marginale and Babesia species, leading to specific treatment protocols.
  • Results indicated that factors like colostrum quality, embryo transfer status, and weaning weight affected the recurrence of TF, with each recurrence reducing first lactation milk production by over 200 liters.
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This study aimed to verify the number of R. microplus annual generations in irrigated and non-irrigated pastures compared to the constant ideal environment. It also sought to evaluate the biology of the non-parasitic phase of this tick for each generation in these different areas of pasture; assess the larvae population dynamics in the pasture of each tick generation, and evaluate the R.

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This study evaluated the reproductive, productive and financial consequences of chronic Trypanosoma vivax infection in a dairy cattle herd located in a region without the cyclic vector during two years. Animals were categorized as either positive (chronically infected) or negative for T. vivax antibodies using a commercial rapid test.

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Article Synopsis
  • The study assessed the impact of various supportive treatments on improving packed cell volume (PCV) in dairy calves infected with tick fever agents, following specific antibiotic treatments.
  • Five supportive products were tested on Girolando female calves, aged four to six months, which were naturally infected and infested with R. microplus, with evaluations made on days 0, 3, and 7 post-treatment.
  • Results indicated that while oral or intravenous vitamins and minerals improved PCV, certain tonics showed no positive effects, and only Type III iron injections significantly raised hemoglobin and PCV levels, highlighting the need for further research on iron supplementation methods.
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Background: In 2022, fluralaner was launched on the market for use in the control of the cattle tick Rhipicephalus microplus after showing 100% efficacy in registration trials against the causative agents of cattle tick fever (TFAs). The aim of the present study was to determine whether a strategic control regimen against R. microplus using fluralaner (FLU) in Holstein calves grazing in a tropical region would alter the enzootic stability status of cattle tick fever, triggering outbreaks in these animals up to 22 months age.

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Article Synopsis
  • - The study aimed to find the best timing and number of acaricide treatments for controlling cattle ticks in tropical regions, comparing three treatment groups over a year.
  • - The T02 group, which started treatment in early spring during the first tick generation, needed significantly fewer treatments (nine) compared to the T01 group (eleven), and experienced a lower tick burden overall.
  • - Starting the tick control program in early spring proves more effective than autumn, benefiting animal welfare and addressing acaricide resistance concerns.
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This work investigated the mechanical transmission of Trypanosoma vivax by Stomoxys calcitrans to cattle in a region without a cyclic vector. The study involved two experiments, one with calves experimentally infected with T. vivax, in the acute phase of trypanosomosis (Experiment 1) and the other in the chronic phase (Experiment 2).

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The present work evaluated the pharmacokinetics and efficacy of the association of 15cmg/kg toltrazuril +5cmg/kg fenbendazole against Eimeria spp. and gastrointestinal nematodes (GINs) in calves of different regions of Brazil (Center-West, Southeast, and South). A total of seven experiments were carried out, five of which determined formulation efficacy against Eimeria spp.

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Background: The present study aimed to evaluate the effects of different treatment strategies using a new commercial formulation containing pour-on fluralaner on Rhipicephalus microplus infestation in cattle and in pastures in a tropical climate region where up to five generations of this tick species can occur per year.

Methods: Forty-five naturally infested cattle were divided into three experimental groups: T01, treated with fluralaner (2.5 mg/kg) pour-on every 42 days; T02, the cattle received the first treatment with fluralaner on Day 0 but the next treatment involved a weekly visual evaluation; T03, control, received palliative treatment with a spray formulation when the group mean was ≥ 30 ticks.

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Chemoprophylaxis with dipropionate imidocarb (IMD) is a method adopted to prevent cattle tick fever (TF). Sixty weaned dairy heifers (±60 days old), without previous exposure to Rhipicephalus microplus ticks, were housed in Tifton paddocks and were subsequently exposed to R. microplus ticks and monitored up to 315 days old.

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Article Synopsis
  • The study examined the susceptibility of taurine and zebuine cattle to the cattle tick Rhipicephalus microplus, focusing on tick population dynamics within the same herd over two experiments.
  • In the first experiment, researchers analyzed tick burdens in various age groups of cattle, noting that nursing calves reared in groups had higher tick burdens compared to those raised individually and that tick peaks occurred more frequently in weaning calves and lactating cows.
  • The second experiment involved infesting cattle of different ages with tick larvae to measure how many fully engorged females detachment occurred, with the results indicating age and previous tick exposure affected tick burden and treatment needs.
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Rainfall incidence as a risk factor for umbilical myiasis by Cochliomyia hominivorax in newborn beef cattle and the preventive and curative efficacies of injectable and topical products against its larvae were evaluated. The prevalence of navel myiasis did not differ between sex, however, it did differ between seasons of the year, independent of animal sex, with it being higher in the rainy season than in the dry season for both sexes (males 64.6%, females 62.

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Eimeria are ubiquitous parasites and eimeriosis treatment is based on coccidiostats or coccidicides used prophylactically, metaphylactically, or therapeutically. The long-term efficacy of toltrazuril (TZR, 15 mg/kg) against experimentally infected naïve calves was investigated. Seven groups (six treated and one control) of six animals each were formed.

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The present work investigated the presence of Trypanosoma vivax in semen and reproductive tissues of experimentally infected cattle and evaluated changes in seminal parameters. Two groups of cattle were established: T01 - experimentally infected with T. vivax (n = 8) and T02 - not experimentally infected with T.

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Data regarding parasitemia (blood smears), rectal temperature (RT), packed cell volume (PCV) and vaginal mucosa coloration (VMC) of Gyr x Holstein female calves between 3-7mo were accessed to evaluate different techniques for monitoring the bovine tick fever agents (TFA). The 1 experiment determined the correlation between the TFA parasitemia with RT and PCV. The 2, evaluated the associated risk of A.

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It was investigated how many cattle become infected with Trypanosoma vivax by subcutaneous (SC), intramuscular (IM) and intravenous (IV) routes, using the same syringe and needle from an animal with acute T. vivax infection. Besides, the T.

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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.

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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.

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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.

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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).

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Background: A point-of-care device that can provide immediate and reliable hemoglobin (Hb) concentrations and packed cell volumes (PCVs) would be useful in veterinary medicine.

Objectives: We aimed to compare the use of a human device (Mission Plus; MP) with a gold standard (GS) method for measuring Hb concentrations and PCVs in cattle blood.

Methods: Blood samples from clinically healthy cattle (n = 122) were collected with or without an anticoagulant (K EDTA).

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