Biomarkers of gastrointestinal nematodes in beef cattle raised in a tropical area.

Biomarkers are specific molecular, histological, or physiological characteristics of normal or pathogenic biological processes and are promising in the diagnosis of gastrointestinal nematodes (GINs). Although some biomarkers have been validated for infection by Ostertagia sp. in cattle raised in temperate regions, there is a lack of information for tropical regions.

Enzootic stability of tick fever in Holstein calves grazing in a tropical region, subjected to strategic cattle tick control with fluralaner.

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.

Efficiency of fluralaner pour-on in different strategic control protocols against Rhipicephalus microplus on Brangus cattle in a tropical area.

Background: The occurrence of higher winter temperatures in Brazilian areas with tropical and highland climates may result in a fifth peak of tick populations during winter in addition to the four generations previously described. Therefore, a strategic control protocol was developed with treatments in two seasons with the objective of controlling the generations of ticks that occur in spring/summer and those that occur in autumn/winter.

Methods: The study was conducted in Mato Grosso do Sul, Brazil, from the beginning of the rainy season, November 2020, to October 2021.

Control of Rhipicephalus microplus on taurine cattle with fluralaner in a subtropical region.

Background: In Rio Grande do Sul, Brazil, a region with a subtropical climate, Rhipicephalus microplus is present in taurine cattle raised for beef and milk. In addition, ticks resistant to multiple acaricides are present in this region. Recently, fluralaner (isoxazoline) was launched on the market.

Toltrazuril + fenbendazole for cattle: Pharmacokinetics and efficacy against Eimeria spp. and gastrointestinal nematodes.

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.

Two protocols using fluralaner for Rhipicephalus microplus strategic control on taurine cattle in a tropical region.

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.

Essential oils and isolated compounds for tick control: advances beyond the laboratory.

Background: Tick control is a worldwide challenge due to its resistance to acaricides. Essential oils (EOs) and isolated compounds (EOCs) are potential alternatives for tick control technologies.

Methods: A review with EOs and EOCs, under field and semi-field conditions, was performed based on Scopus, Web of Science and PubMed databases.

Comparison of the efficacy of different methods to apply acaricides for control of Rhipicephalus (Boophilus) microplus.

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).

Combination of synthetic acaricides with (E)-cinnamaldehyde to control Rhipicephalus microplus.

This work had the objectives to (1) evaluate the susceptibility of various Rhipicephalus microplus populations to commercial acaricides, and (2) select commercial acaricides (50-80% effective) and evaluate the effects of binary combinations of the phenylpropanoid (E)-cinnamaldehyde with selected commercial acaricides to control R. microplus under laboratory and field conditions. Using adult immersion tests with 116 populations and 14 commercial acaricides, products showing 50-80% effectiveness (percent control) with the lowest number of active ingredients were selected.

Effect of the formulation with fipronil and fluazuron on the reproductive biology and ovaries histopathology of Rhipicephalus microplus engorged females.

This study aimed to evaluate the effects of a commercial formulation containing fipronil and fluazuron on the reproductive biology and the morphology of ovaries from Rhipicephalus microplus engorged females. To carry out the study, three calves were artificially infested every 3 days with approximately 5000 larvae. On day 0, the animals were treated with a commercial formulation containing fipronil (1.

Strategic control of cattle co-parasitized by tick, fly and gastrointestinal nematodes: Is it better to use ecto + endoparasiticide or just endectocide formulations?

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.

Infection capacity of Trypanosoma vivax experimentally inoculated through different routes in bovines with latent Anaplasma marginale.

The aim of the present study was to compare the infection capacity of Trypanosoma vivax experimentally inoculated through different routes in calves naturally infected with latent Anaplasma marginale. On Day 0 of the study, 25 calves (breed: Girolando) were divided into five groups. The first four groups of five calves each received approximately 1 × 10 trypomastigotes of T.

Avermectin toxicity in bovines less than thirty days old.

The present study was designed to evaluate possible adverse effects of different dosages of avermectins (abamectin and a combination of ivermectin + abamectin) administered subcutaneously in calves less than one month of age. Clinical as well as biochemical parameters of blood and cerebrospinal fluid (CSF) were evaluated for animals subjected to various treatments. Thirty-five calves were divided into seven groups of five animals each: T01 (control), T02 (abamectin 200 μg/kg), T03 (abamectin 400 μg/kg), T04 (abamectin 600 μg/kg), T05 (ivermectin 450 μg/kg + abamectin 250 μg/kg), T06 (ivermectin 900 μg/kg + abamectin 500 μg/kg) and T07 (ivermectin 1350 μg/kg + abamectin 750 μg/kg).

The effectiveness of a fixed-dose combination pour-on formulation of 1.25% fipronil and 2.5% fluazuron against economically important ectoparasites and associated pharmacokinetics in cattle.

The present work consisted of eight studies to evaluate the ectoparasiticidal spectrum and determine the pharmacokinetic parameters of a pour-on combination of fipronil 1.25mg/kg+fluazuron 2.5mg/kg for cattle against Rhipicephalus microplus, Haematobia irritans and the larvae of Dermatobia hominis and Cochliomyia hominivorax.