Prevalence and etiology of mastitis in dairy cattle in El Oro Province, Ecuador

Said Amer, Fernando Lenin Aguilar Gálvez, Yasuhiro Fukuda, Chika Tada, Ivan Ludeña Jimenez, Wunster Favian Maza Valle, Yutaka Nakai

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25 Citations (Scopus)


This study described the occurrence of clinical and subclinical forms of mastitis in 250 cattle from 5 dairy farms around the cities of Santa Rosa and Machala, El Oro Province, Ecuador. Clinical mastitis (CM) was determined based on obvious changes in milk (mild), signs of inflammation in the udder (moderate), and/or generalized clinical symptoms (severe). Subclinical mastitis (SCM) was assessed using the California mastitis test. CM and SCM were detected in 30 (12.0%) and 150 (60%) of the 250 tested cattle, respectively. Prevalence at the udder quarter level was 57.7% (577/1,000), which was higher among forequarters (369/577; 63.9%) than hindquarters. Of the 577 mastitic milk samples subjected to microbiological analysis, 35 were excluded due to contamination and 20 tested negative. Identification of bacterial isolates revealed that 33.3% of the 93 CM samples contained coliforms, 25.8% coagulase-positive staphylococci, 20.4% coagulase-negative staphylococci (CNS), 9.7% streptococci, 7.5% Bacillus spp., and 3.2% Klebsiella spp. Bacterial profiling of the 429 SCM milk samples showed that 55.4% contained CNS, 22.1% Bacillus spp., 9.3% streptococci, and 6.1% coagulase-positive staphylococci. In vitro antibiotic susceptibility testing of the obtained isolates indicated that all were susceptible to amoxicillin, ampicillin, cefotaxime, enrofloxacin, sulfamethoxazole-trimethoprim, gentamicin, and neomycin. No multidrug-resistant strains were observed.

Original languageEnglish
Pages (from-to)861-868
Number of pages8
JournalJournal of Veterinary Medical Science
Issue number6
Publication statusPublished - 2018


  • Bacillus spp
  • Ecuador
  • Mastitis
  • Staphylococci
  • Streptococci


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