title: Aetiology and histopathology of bovine mastitis of espontaneous occurrence.
abstract: Infectious bovine mastitis is responsible for serious economic losses in dairy cattle breeding. Information about the damages caused by micro-organisms is of great interest and importance. The purpose of the present study was to report on the microbiological and histopathological aspects of the mammary parenchymas of slaughtered dairy cows. A total of 184 mammary glands were examined and samples of mammary parenchyma were collected for microbiological and histopathological examinations. Micro-organisms were isolated from 69.6% samples; 23 (12.5%) of the 184 samples did not show histological changes; inflammatory response was observed in 56 (30.4%) samples; inflammatory response and repair were present in 82 (44.6%) samples; repair process was verified in 23 (12.5%) of the mammary glands. Coagulase-negative Staphylococci were observed in 53.8% of the samples followed by coagulase-positive Staphylococci (7.6%), Prototheca sp. (2.2%) and Streptococcus dysgalactiae (1.6%). Coagulase-negative Staphylococci and coagulase-positive Staphylococci were associated mainly to chronic inflammatory response and chronic inflammatory response and repair. Samples from which no micro-organisms were isolated (n = 56) had no histological changes in 82.6% of the cases. These results were higher (P < 0.05) when compared to the samples with micro-organisms and without histological changes (17.4%).
authors.affiliation: Research Nucleus on Mammary Gland and Milk Production, Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Brazil. benites@usp.br
authors.forename: N R
authors.initials: NR
authors.lastname: Benites
authors.forename: J L
authors.initials: JL
authors.lastname: Guerra
authors.forename: P A
authors.initials: PA
authors.lastname: Melville
authors.forename: E O
authors.initials: EO
authors.lastname: da Costa
mesh_terms: D000818:Animals; D001938:Brazil / Q000453:epidemiology; D002417:Cattle; D003030:Coagulase; D003612:Dairying; D005260:Female; D008414:Mastitis, Bovine / Q000453:epidemiology* / Q000382:microbiology* / Q000473:pathology; D011525:Prototheca / Q000302:isolation & purification; D013210:Staphylococcus / Q000145:classification / Q000302:isolation & purification; D013291:Streptococcus / Q000145:classification / Q000302:isolation & purification
chemical_list: D003030:Coagulase