AUTHOR(S) / AUTOR(I): Jovan Blagojević 
, Svetlana Nedić , Milan Maletić , Slobodanka Vakanjac
Download Full Pdf 
DOI: https://doi.org/10.46793/SBT26.391B
ABSTRACT / SAŽETAK:
Mastitis remains one of the most economically important diseases in dairy cattle and often represents a complex herd-level challenge. This case series describes an investigation conducted on a small family dairy farm with 12 lactating cows, characterized by recurrent mastitis and persistently elevated somatic cell count (SCC). Initial microbiological examination identified Klebsiella oxytoca in one cow and Klebsiella pneumoniae in another, whereas other cultures were negative. Targeted antimicrobial therapy was administered according to antibiogram results. Although subsequent cultures were negative, SCC values remained markedly elevated but demonstrated a gradual decline over three consecutive sampling rounds. Two Klebsiella-positive cows were also diagnosed with reticular foreign bodies, and herd-level interventions included rumen magnet administration in all cows and reinforcement of hygienic measures. No new clinical mastitis cases were recorded during the follow-up period. These findings suggest that Klebsiella mastitis in small dairy herds may reflect substantial environmental bacterial pressure, while persistent SCC elevation indicates ongoing inflammatory and structural alterations of the mammary gland. Integrated management strategies are essential for long-term stabilization.
KEYWORDS / KLJUČNE REČI:
Klebsiella mastitis, somatic cell count, environmental pathogens, hardware disease, dairy herd
ACKNOWLEDGEMENT / PROJEKAT:
The study was supported by the Ministry of Science, Technological Development and Innovation of the Republic of Serbia (Contract number 451-03-136/2025-03/200143).
REFERENCES / LITERATURA:
- Cheng W. N., Han S. G. (2020). Bovine mastitis: Risk factors, therapeutic strategies, and alternative treatments—A review. Asian-Australasian journal of animal sciences, 33(11), 1699.
- Dufour S., Wellemans V., Roy J. P., Lacasse P., Ordonez-Iturriaga A., Francoz D. (2019). Non-antimicrobial approaches at drying-off for treating and preventing intramammary infections in dairy cows. Part 1. Meta-analyses of efficacy of using an internal teat sealant without a concomitant antimicrobial treatment. Animal health research reviews, 20(1), 86-97.
- Klaas I. C., Zadoks R. N. (2018). An update on environmental mastitis: Challenging perceptions. Transboundary and emerging diseases, 65, 166-185.
- Naranjo-Lucena A., Slowey R. (2023). Invited review: Antimicrobial resistance in bovine mastitis pathogens: A review of genetic determinants and prevalence of resistance in European countries. Journal of dairy science, 106(1), 1-23.
- Oltenacu P. A., Broom D. M. (2010). The impact of genetic selection for increased milk yield on the welfare of dairy cows. Animal welfare, 19(S1), 39-49.
- Østerås O., Sølverød L. (2009). Norwegian mastitis control programme. Irish Veterinary Journal, 62(Suppl 4), S26.
- Ruegg P. L. (2017). A 100-Year Review: Mastitis detection, management, and prevention. Journal of dairy science, 100(12), 10381-10397.
- Tong X., Barkema H. W., Nobrega D. B., Xu C., Han B., Zhang C., Gao J. (2025). Virulence of bacteria causing mastitis in dairy cows: A literature review. Microorganisms, 13(1), 167.