title: Outbreak of bovine clinical mastitis caused by Mycoplasma bovis in a North Italian herd.
abstract: This report describes an outbreak of Mycoplasma bovis mastitis affecting 45 cows in a herd of 122 dairy cattle in Northern Italy. Clinically, the outbreak was characterized by agalactia, multiple swollen and painless quarters, high milk somatic cell count and unresponsiveness to conventional antibiotic therapy. M. bovis was isolated from the milk samples of all the 32 affected cows tested and from the mammary tissue of three affected cows that underwent necropsy. No other pathogens were isolated from these samples. Lesions in two of the necropsied cows were characterized by mild chronic suppurative mastitis and galactophoritis. The other necropsied cow showed a chronic necrosuppurative and pyogranulamaous galactophoritis, a condition not previously associated with M. bovis. M. bovis was detected immunohistochemically in the lumen of the affected mammary ducts suggesting that ascending infection via the teat canal was the likely route of transmission. No other intralesional pathogens were demonstrated microscopically.
authors.affiliation: Dipartimento di Patologia Animale, Igiene e Sanità Pubblica Veterinaria, Facoltà di Medicina Veterinaria, Università degli Studi di Milano, via Celoria, 10, 20133 Milano, Italy. enrico.radaelli@unimi.it
authors.forename: E
authors.initials: E
authors.lastname: Radaelli
authors.forename: V
authors.initials: V
authors.lastname: Castiglioni
authors.forename: M
authors.initials: M
authors.lastname: Losa
authors.forename: V
authors.initials: V
authors.lastname: Benedetti
authors.forename: R
authors.initials: R
authors.lastname: Piccinini
authors.forename: R A J
authors.initials: RA
authors.lastname: Nicholas
authors.forename: E
authors.initials: E
authors.lastname: Scanziani
authors.forename: M
authors.initials: M
authors.lastname: Luini
mesh_terms: D000818:Animals; D002417:Cattle; D003612:Dairying; D004196:Disease Outbreaks / Q000662:veterinary*; D005260:Female; D007558:Italy / Q000453:epidemiology; D008321:Mammary Glands, Animal / Q000276:immunology / Q000382:microbiology / Q000473:pathology*; D008414:Mastitis, Bovine / Q000175:diagnosis / Q000453:epidemiology* / Q000473:pathology; D008892:Milk / Q000382:microbiology*; D009175:Mycoplasma Infections / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary*; D045682:Mycoplasma bovis / Q000302:isolation & purification*; D016133:Polymerase Chain Reaction / Q000662:veterinary; D013492:Suppuration / Q000175:diagnosis / Q000453:epidemiology / Q000473:pathology / Q000662:veterinary