Effectiveness of enrofloxacin for the treatment of experimentally-induced bovine anaplasmosis

Abstract

Four groups of six Holstein calves were inoculated with 3.6 × 10 7 erythrocytes parasitized with Anaplasma marginale. The criteria for treatment of calves were increasing A. marginale rickettsemia and 30% reduction of baseline packed cell volume (PCV) of each animal. Group 1 (G1) received 7.5 mg.kg -1 of enrofloxacin in a single dose; Group 2 (G2) 7.5 mg.kg -1 of enrofloxacin twice every three days; Group 3 (G3) 20 mg.kg -1 of long-acting oxytetracycline in a single dose; and Group 4 (G4) a single dose of PBS. Physical examinations, blood smears and PCV were performed daily. On day treatment, G1, G2 and G3 animals had a mean rickettsemia of 17, 23 and 12%, respectively. At 2 days after treatment (DAT) G1 and G2 animals showed a significant reduction of rickettsemia (p < 0.05) compared to G3. G3 animals had high rates of rickettsemia in the first 2 DAT and a slow decrease until stabilization on 9 DAT. The mean PCV in G1 and G2 increased and stabilized after 7 and 8 DAT, respectively. PCV stabilization was achieved in G3 at 13 DAT. Both enrofloxacin and oxytetracycline were effective for the treatment of anaplasmosis, but enrofloxacin was faster reduction of rickettsemia and PCV recuperation (p < 0.05) compared to oxytetracycline Keywords: Anaplasma marginale, enrofloxacin, treatment. ResumoQuatro grupos de seis bezerros da raça Holandesa foram inoculados com 3,6 × 10 7 eritrócitos parasitados com Anaplasma marginale. Os critérios para o tratamento dos bezerros foram aumento da rickettsemia do A. marginale e redução de 30% do valor basal de volume globular (VG) de cada animal. O Grupo 1 (G1) recebeu 7,5 mg.kg -1 de enrofloxacina em dose única; o Grupo 2 (G2), 7,5 mg.kg -1 de enrofloxacina duas vezes a cada três dias; o Grupo 3 (G3), 20 mg.kg -1 de oxitetraciclina de longa ação em dose única; e o Grupo 4 (G4) uma única dose de PBS. Exames físicos, esfregaço sanguíneo e VG foram realizadas diariamente. No dia do tratamento, os animais G1, G2 e G3 apresentaram rickettsemia média de 17, 23 e 12%, respectivamente. Nos primeiros 2 dias após o tratamento (DAT) os animais do G1 e G2 mostraram uma redução significativa de rickettsemia (p < 0,05) em relação ao G3. Animais do G3 tiveram altas taxas de rickettsemia nos 2 DAT e uma diminuição lenta até à estabilização em 9 de DAT. O VG médio no G1 e G2 aumentou e estabilizou após 7 e 8 DAT, respectivamente. A estabilização do VG do G3 foi aos 13 DAT. A enrofloxacina e a oxitetraciclina foram efetivas no tratamento da anaplasmose, mas a enrofloxacina apresentou redução da rickettsemia e recuperação do VG (p < 0,05) mais rápida em comparação com oxitetraciclina.Palavras-chave: Anaplasma marginale, enrofloxacina, tratamento.

Incidência de Anaplasma marginale, Babesia bigemina e Babesia bovis em bezerros no semiárido paraibano

“…Os resultados de PCR deste estudo foram estatisticamente corroborados pelas dosagens de hematócritos dos bezerros, uma vez que houve associação significativa entre PCR positivo para A. marginale ou B. bigemina e menores valores de hematócrito. Tal associação se deve à patogenia da doença causada por esses dois agentes, que se caracteriza fundamentalmente por diminuição expressiva do número de eritrócitos (Bock et al 2004, Facury-Filho et al 2012. Por outro lado, esta diminuição é menos expressiva na doença causada por B. bovis (Bock et al 2004), justificando a ausência de associação significativa entre PCR positivo para este agente e menores valores de hematócrito (Quadro 5).…”

Assessing different chemoprophylactic protocols against bovine tick-borne diseases and their influence on the weight gain of calves

“…Nonetheless, some authors recommend the use of enrofloxacin for the treatment of anaplasmosis (FACURY-FILHO et al, 2012), but this drug has shown little effect in several studies (ATIF et al, 2012;COETZEE et al, 2006). While in Brazil the recommended dose against anaplasmosis is up to 20 mg Kg -1 of long acting oxytetracycline in a sigle application (FACURY-FILHO et al, 2012;SILVA et al, 2007), other countries use the drug in doses as low as 7 mg Kg -1 (ORTIZ et al, 2012). In this light, we believe that not only subclinical, but even mild cases of anaplosmosis could be treated with the dose used in this study (6.7 mg Kg -1 ), allowing full productive recuperation.…”

“…Anaplasmosis can be treated with 20 mg Kg -1 of long-acting oxytetracycline (FACURY-FILHO et al, 2012). Double effect drugs, such as imidocarb dipropionate can also be used in doses from 1 to 3 mg Kg -1 (VIAL; GORENFLOT, 2006).…”

“…Double effect drugs, such as imidocarb dipropionate can also be used in doses from 1 to 3 mg Kg -1 (VIAL; GORENFLOT, 2006). In clinical cases of anaplasmosis, even after treatment, animals will become chronic carriers of the agent, and at greater risk of reoccurrence (FELSHEIM et al, 2010). In 2012, Nizoli et al (2012) showed that reduced doses of an association of oxytetracycline and diminazene diaceturate were able to minimize the production losses associated with subclinical TBD.…”

Development andin vitroevaluation of oxytetracycline‐loaded PMMA nanoparticles for oral delivery against anaplasmosis

“…By that time, there would be a strong possibility that the tetracycline half-life would be terminated and excreted via glomerular filtration [14] by allowing the infectious agent to escape and infect the new red blood cells. Hence, early recognition and treatment is crucial [15]. Generally, when clinical disease is diagnosed, immediate treatment of affected animals with high dosages (10 mg oxytetracycline per pound body weight for 3-5 days) is normally recommended [16].…”