Abstract
Background:
Mastitis is a significant and economically burdensome disease in dairy cattle, leading to considerable production losses. Generally, it has been divided into two types, called clinical and subclinical. Clinical type of mastitis is easily recognizable, while subclinical type need improved laboratory tests for its detection.

Aim:
This study aimed to evaluate the prevalence of subclinical mastitis in dairy farms of Kabul city, Afghanistan.

Methods:
A cross-sectional study was conducted from August to October 2023 to estimate the prevalence and identify the major etiological agents of subclinical mastitis in dairy farms. A total of 258 lactating cows were randomly selected from 12 different farms. Diagnostic methods, including the California mastitis test (CMT), somatic cell count (SCC), and bacteriological culture, were employed for detection of subclinical mastitis.

Results:
Among 258 cows and 1,032 quarters, 63 cows (24.41%) and 86 quarters (8.33%) tested positive for subclinical mastitis using CMT. CMT-positive samples were further analyzed for SCC and subjected to bacterial culture for etiological identification. From 63 cows and 86 quarters, 55 cows (21.32%) and 74 quarters (7.17%) tested positive for SCC. The mean SCC was highest for Staphylococcus aureus, followed by Streptococcus agalactiae, Bacillus spp, coagulase-negative staphylococci CNS, other Streptococcus spp, other Staphylococcus spp, coliforms, and Escherichia. coli (E. coli), 56 cows (21.70%) and 74 quarters (7.17%) were positive for bacterial culture. The predominant bacterial isolates were Staphylococcus aureus (36.48%), CNS (16.21%), and other Staphylococcus spp (5.40%). It is followed by Streptococcus agalactiae (22.97%) and other Streptococcus spp (10.81%). Other isolates included Bacillus spp. (4.05%), Coliforms (2.70%), and Escherichia coli (1.35%).

Conclusion:
It can be concluded that subclinical mastitis is highly prevalent among lactating cows in Kabul, posing a significant challenge to dairy farming.

Key words: Bacteriological culture; California mastitis test; Dairy cows; Prevalence; Subclinical mastitis.