Occurrence of clinical and subclinical mastitis in buffaloes and associated bacterial pathogens

Introduction

Mastitis is one of the most prevalent and economically devastating diseases affecting dairy animals worldwide, posing a major constraint to profitable milk production [1] . In India, where the dairy sector contributes significantly to agricultural GDP and rural livelihoods, mastitis continues to be a persistent problem in both cattle and buffaloes [6] . The disease not only reduces milk yield and alters milk composition but also compromises animal health and welfare, leading to substantial economic losses due to treatment costs, discarded milk, reduced market value of animals, and increased labour requirements [3,4] . Buffaloes contribute more than 45% of India's total milk production and represent a vital component of the dairy industry. Despite being traditionally considered more resistant to mastitis than cattle, buffaloes are increasingly affected due to intensive production systems, poor housing hygiene, hot and humid climatic conditions, and unscientific milking practices. The prevalence of mastitis in buffaloes varies widely across regions and management systems, with subclinical mastitis reported far more frequently than the clinical form. Subclinical mastitis remains a major concern because of its asymptomatic nature, making detection difficult while causing prolonged reductions in milk production and quality [5] . Mastitis is broadly classified into clinical and subclinical forms based on the presence or absence of visible signs in the udder and milk. Subclinical mastitis is particularly significant from an epidemiological standpoint, as it serves as a reservoir for infection and facilitates the transmission of pathogens within herds. Common etiological agents associated with mastitis include Staphylococcus aureus, Escherichia coli, and various Streptococcus species, with their prevalence influenced by environmental and management factors [2] . Understanding the prevalence of mastitis under field conditions is essential for designing effective control and prevention strategies. Accurate prevalence data provide insights into the magnitude of the problem and help in identifying risk factors associated with disease occurrence. Therefore, the present study was undertaken to assess the prevalence of mastitis in buffaloes, with particular emphasis on subclinical mastitis, under local dairy farming conditions.

Materials and Methods

Study area

The present study was conducted in and around the Ayodhya and Amethi region of Uttar Pradesh, India. The area is characterized by a tropical climatic condition with hot summers and moderate to high humidity, which predisposes dairy animals to udder infections. Buffaloes maintained under smallholder and semi-intensive dairy farming systems were included in the study.

Study animals

A total number of 300 lactating buffaloes of different ages, parities, and stages of lactation were screened for mastitis during the study period. Animals were selected randomly from organized and unorganized dairy farms. Buffaloes with a history of recent antibiotic treatment were excluded from the study to avoid diagnostic interference.

Study design

A cross-sectional study was carried out to determine the prevalence of mastitis in buffaloes. The prevalence was assessed at both animal level and quarter level. Mastitis was categorized into clinical and subclinical forms based on clinical examination and milk testing.

Clinical examination

Each buffalo was examined clinically for signs of mastitis such as swelling, pain, heat, and hardness of the udder. Milk from each quarter was examined for visible abnormalities including watery consistency, flakes, clots, or discoloration. Animals showing visible udder and milk abnormalities were recorded as cases of clinical mastitis.

Screening for subclinical mastitis

Milk samples from all apparently healthy quarters were screened for subclinical mastitis using standard indirect diagnostic tests. The Modified California Mastitis Test (MCMT) was employed as a cow-side test to detect elevated somatic cell content indicative of subclinical infection. Quarters showing positive reactions were considered as subclinical mastitis cases.

Milk sample collection

Milk samples were collected aseptically from each quarter after thorough cleaning and disinfection of teats. The first few streams of milk were discarded, and samples were collected in sterile containers for further examination wherever required.

Calculation of prevalence

The prevalence of mastitis was calculated as the proportion of animals and quarters affected with clinical and subclinical mastitis. Animal-wise prevalence was calculated based on the number of buffaloes affected, while quarter-wise prevalence was calculated based on the total number of quarters examined.

Statistical analysis

Data obtained were compiled and analyzed using standard descriptive statistical methods. The prevalence of mastitis was expressed in percentage terms to evaluate the magnitude of the disease under field conditions.

Result and Discussion

A total of 300 lactating buffaloes were screened for mastitis in Ayodhya and Amethi districts. Of these, 128 buffaloes (42.66%) were found positive for mastitis, while 172 animals (57.33%) were recorded as healthy. Among the mastitispositive animals, subclinical mastitis constituted the major proportion, affecting 93 buffaloes (31%), whereas clinical mastitis was observed in 35 buffaloes (11.66%) (Table 4.1). The predominance of subclinical mastitis over the clinical form highlights its epidemiological importance and agrees with earlier reports indicating that subclinical mastitis remains largely undetected under field conditions. District-wise analysis revealed a higher overall prevalence of mastitis in Ayodhya district, where 72 cases (48%) were recorded, compared to 56 cases (37.33%) in Amethi district. Subclinical mastitis was more prevalent in Ayodhya (53 cases; 35.33%) than in Amethi (40 cases; 26.66%). Similarly, clinical mastitis cases were slightly higher in Ayodhya (19 cases; 12.66%) as compared to Amethi (16 cases; 10.66%). The higher prevalence observed in Ayodhya may be attributed to differences in management practices, housing hygiene, climatic conditions, and milking procedures. Hot and humid environmental conditions coupled with inadequate udder hygiene are known to favour the persistence and transmission of mastitis-causing pathogens. The results are depicted in Table 1 and Fig 1. The findings of the present study clearly demonstrate that mastitis, particularly the subclinical form, is widely prevalent in buffaloes and contributes to significant hidden economic losses due to reduced milk yield and compromised milk quality. The observed pathogen profile further emphasizes the need for regular screening of dairy animals, improved hygienic practices, and rational use of antimicrobials based on antibiogram studies. Effective control measures and farmer awareness programs are essential to reduce the burden of mastitis and improve udder health in buffaloes.

Conclusion

The present study concludes that mastitis is highly prevalent among buffaloes in the Ayodhya and Amethi districts, with an overall prevalence of 42.66%. Subclinical mastitis constituted the major proportion of cases, highlighting its significant epidemiological and economic importance due to its asymptomatic nature and prolonged impact on milk production and quality. The higher prevalence observed in Ayodhya district compared to Amethi indicates the influence of management practices, environmental conditions, and hygiene standards on disease occurrence. Microbiological analysis revealed Staphylococcus spp. as the predominant mastitis pathogen, followed by Escherichia coli and Klebsiella spp., suggesting the involvement of both contagious and environmental sources of infection. The findings emphasize the need for routine screening of dairy buffaloes for subclinical mastitis, adoption of improved milking hygiene, and implementation of targeted control strategies based on pathogen profiling. Strengthening farmer awareness and preventive management practices is essential for effective mastitis control and improvement of udder health in buffaloes.

Acknowledgement

AcknowledgmentsThe authors are thankful to the Dean, College of Veterinary Sciences, and the Head of the Department of Veterinary Medicine for providing the necessary facilities and support to carry out this study. Financial SupportNot available

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