Mastitis is a common and economically significant disease in dairy cattle, characterized by inflammation of the mammary gland. It leads to a sudden reduction in milk yield, alters milk quality, and can cause severe economic losses for dairy farmers. If left untreated, the disease can cause permanent udder damage, reducing the cow’s productivity.
This condition is more prevalent in high-yielding cows, particularly in exotic and crossbred breeds, as compared to Indian zebu cows. Mastitis can be caused by various microorganisms, including bacteria, fungi, Mycoplasma, and viruses. Proper hygiene, early detection, and effective treatment are essential for managing and preventing the disease.
Pathology
Mastitis is primarily an inflammatory response of the udder, regardless of the cause. It results in visible changes in milk composition, such as alterations in color, consistency, and odor.
The most notable consequence of mastitis is a sharp drop in milk yield, which can occur suddenly and, if untreated, may lead to chronic udder infections. The infected udder becomes painful and swollen, making milking difficult.
If the inflammation persists, it may affect multiple quarters of the udder, leading to long-term production losses. Mastitis is highly contagious and spreads rapidly, particularly in poorly managed farms with inadequate hygiene and improper milking techniques.
Causes of Mastitis
Mastitis is caused by a variety of pathogens, with bacteria being the most common culprits. Several species are known to cause infections, including Staphylococcus aureus, Streptococcus agalactiae, Escherichia coli (E. coli), Brucella abortus, Klebsiella spp., Pseudomonas pyocyaneus, and Mycobacterium bovis. These bacteria are often found in contaminated bedding, milking equipment, or the environment.
Fungal mastitis, though less common, is also a concern, with Aspergillus fumigatus, Aspergillus nidulans, Candida spp., and Trichosporon spp. being the primary fungal agents. Fungal infections are often associated with poor hygiene, prolonged antibiotic treatments, or contaminated milking systems.
Certain management factors can also increase the risk of mastitis. Unhygienic milking conditions, incomplete milking, udder injuries, and environmental contamination all contribute to the likelihood of infection. Cows kept in damp, dirty bedding or exposed to contaminated water sources are also more vulnerable.
Mode of Transmission
Mastitis is primarily transmitted through the teat canal, where bacteria or fungi enter the mammary gland. Poor hygiene practices, such as contaminated milking equipment and dirty hands, facilitate the spread of pathogens.
The disease can also be spread through direct contact with infected milk, especially when milking healthy and infected cows together. If proper hygiene is not maintained, the milker’s hands, clothes, and milking machines can serve as transmission points.
Additionally, flies and insects act as mechanical carriers, transferring pathogens between cows. Infection can also spread through contaminated bedding and milking areas.
If an affected cow sheds bacteria into the environment, healthy cows lying in the same area may contract the infection. This is why regular cleaning and disinfection of animal housing and milking parlors are crucial in preventing outbreaks.
Symptoms of Mastitis
Mastitis symptoms vary based on the severity and type of infection. The disease can be classified into clinical mastitis (visible symptoms) and subclinical mastitis (no visible signs, but can be detected through milk testing).
- The udder becomes swollen, hard, and painful, making milking difficult.
- Affected teats turn red and hot to the touch.
- The cow reacts aggressively to udder handling, indicating severe discomfort.
- Milk abnormalities such as blood-stained milk, yellow or brown fluid, or milk containing flakes and clots.
- The milk may have a foul smell.
- Sudden drop in milk yield.
In clinical mastitis, the most common signs include swelling and hardening of the udder, which becomes hot and painful to the touch. Affected cows may kick or resist milking due to the pain.
The teats appear red and swollen, and the milk may contain blood, yellow or brown fluid, flakes, clots, or have a foul odor. Affected cows also exhibit a significant drop in milk production.
Subclinical mastitis is more difficult to identify, as the udder may appear normal, but milk quality deteriorates over time. It can only be diagnosed through milk tests, such as the California Mastitis Test (CMT) or somatic cell count (SCC) analysis. If left undetected, subclinical mastitis can spread silently within a herd, leading to long-term economic losses.
Prevention and Management of Mastitis
Preventing mastitis requires strict hygiene measures, proper milking practices, and environmental management. Maintaining clean and dry bedding is essential to reduce bacterial contamination.
Providing proper bedding and hygiene is essential, especially for high-yielding breeds like Jersey cows, which require extra udder care. Ideally, cows should be kept on sand bedding, as it has low bacterial counts compared to other materials. Damp and dirty bedding should be replaced regularly. Milking hygiene is equally important.
The udder and the milker’s hands should be washed with antiseptic solutions before and after milking. Using iodine-based teat dips after each milking session helps prevent bacterial entry into the teat canal. The first few streams of milk should be discarded into a disinfectant container rather than onto the floor to avoid contamination.
Milking healthy cows first and infected cows last is a key strategy to prevent disease spread. All milking equipment, teat cups, and milking machines should be thoroughly disinfected after each use. New cows introduced to the herd should be screened for mastitis before being mixed with healthy animals.
Flies and insects, which contribute to disease transmission, should be controlled through insecticide sprays and fly repellents in the barn and surrounding areas. Additionally, cows that frequently suffer from mastitis should be culled from the herd to minimize infection risks.
First Aid and Treatment
In cases of mastitis, immediate first aid measures can help reduce inflammation and discomfort. Applying ice packs to the swollen udder can ease pain and reduce swelling.
The infected teat should be milked out three times a day to remove bacterial toxins and prevent further accumulation. It is crucial to prevent the calf from suckling from an infected teat, as this can worsen the condition and spread the infection.
A qualified veterinarian should be consulted immediately for proper diagnosis and treatment. Antibiotic therapy is commonly used to treat bacterial mastitis, but it should be based on milk culture and sensitivity tests to ensure effectiveness.
If an udder quarter is non-responsive to treatment, it may need to be permanently dried off to prevent further complications. Infected milk should be disposed of properly to avoid contaminating the environment.
Adding 5% phenol to the milk before disposal helps kill pathogens. The calf should not be allowed to consume infected milk, as it can lead to digestive issues and systemic infections.
In conclusion, mastitis is a major concern for dairy farmers, significantly impacting milk production, quality, and animal health. However, with proper hygiene, preventive measures, and early intervention, the disease can be effectively controlled.
Maintaining clean milking environments, following correct milking procedures, and monitoring cows for early signs of infection are crucial to preventing mastitis outbreaks.
Prompt veterinary treatment and strict biosecurity measures can help minimize economic losses and ensure the well-being of dairy cows. By implementing these best practices, farmers can maintain a healthy, productive herd while ensuring the production of high-quality milk.