15/10/2026
🐄🦠 BOVINE CONTAGIOUS MASTITIS: CAUSES, SYMPTOMS, TREATMENT & PREVENTION
📚 VET DISEASES & TREATMENT
👨⚕️ By Dr Ismail Salarzai
💚 Protect the udder. Improve milk quality. Save your dairy farm!
Contagious mastitis is an infectious inflammation of the mammary gland that can spread from infected cows to healthy cows, especially during milking. It can cause reduced milk production, poor milk quality, permanent udder damage, and significant financial losses.
🔬 1. CAUSES OF CONTAGIOUS MASTITIS
Major causative organisms include:
🦠 Staphylococcus aureus — may cause persistent infection, abscesses, and chronic udder damage.
🦠 Streptococcus agalactiae — a highly contagious pathogen that can spread rapidly through dairy herds.
🦠 Mycoplasma bovis — may cause severe mastitis affecting multiple udder quarters and often responds poorly to conventional antibiotics.
🦠 Streptococcus dysgalactiae — can spread during milking, although environmental transmission also occurs.
⚙️ 2. HOW DOES THE DISEASE SPREAD?
1️⃣ Bacteria transfer through contaminated hands, milking equipment, teat cups, and reusable towels.
2️⃣ The organisms enter through the teat canal.
3️⃣ Bacteria multiply inside the mammary gland.
4️⃣ Inflammation damages milk-producing tissues and changes milk quality.
5️⃣ The cow develops clinical or subclinical mastitis.
⚠️ Some infected cows show no obvious symptoms but can continue spreading infection.
🔍 3. CLINICAL SIGNS
🔴 Hot, swollen, and painful udder quarters.
🥛 Milk containing clots, flakes, or abnormal discoloration.
📉 Reduced milk production.
🪨 Hardening of udder tissue in chronic cases.
🌡️ Fever and loss of appetite.
🐄 Weakness, dehydration, depression, and reduced rumination in severe cases.
🚨 Severe mastitis can cause shock, inability to stand, and death. These cases require urgent veterinary attention.
🩺 4. DIAGNOSIS
Veterinarians may use:
🔬 Clinical examination of the udder and milk.
🧪 California Mastitis Test (CMT).
🧫 Milk culture to identify the causative organism.
📊 Somatic cell count (SCC).
🧬 PCR testing when indicated and available.
💊 5. TREATMENT
Treatment depends on the pathogen, severity of infection, and lactation status.
✅ Intramammary antibiotics when indicated.
✅ Systemic antibiotics in selected cases, particularly when systemic illness is present.
✅ Supportive treatment, including fluids and appropriate anti-inflammatory medication, when needed.
✅ Milk culture and susceptibility testing to guide treatment when appropriate.
⚠️ Staphylococcus aureus infections can be difficult to cure, while Mycoplasma bovis mastitis often responds poorly to conventional antibiotics.
🚨 Never select antibiotics blindly. A qualified veterinarian should determine the appropriate drug, dosage, route, and duration. Do not delay emergency care for a severely ill cow.
🛡️ 6. PREVENTION
✔️ Milk healthy cows before infected cows.
✔️ Wear clean gloves during milking.
✔️ Use a separate clean towel for each cow.
✔️ Disinfect teats after milking with an appropriate product.
✔️ Maintain milking-machine hygiene and function.
✔️ Monitor udder health using CMT, SCC, and milk culture when appropriate.
✔️ Separate or milk infected cows last when necessary.
✔️ Check udder health before introducing new animals.
✔️ Maintain treatment and mastitis records.
🥛 7. MILK AND MEAT WITHDRAWAL
📌 Follow the medicine label and veterinary instructions.
📌 Observe milk and meat withdrawal periods separately.
📌 Never sell abnormal milk or milk that must be withheld.
💰 8. ECONOMIC IMPORTANCE
Uncontrolled mastitis causes reduced milk yield, increased treatment costs, poor milk quality, permanent udder damage, premature culling, and continued infection throughout the herd.
🎯 THE GOLDEN RULE
Good milking hygiene + Early detection + Appropriate treatment + Effective herd management = Better udder health and higher dairy productivity.
📢 SHARE THIS KNOWLEDGE! Help farmers, veterinary students, and animal-health professionals protect dairy cows and improve milk production.
⚕️ VET DISEASES & TREATMENT
👨⚕️ Dr Ismail Salarzai
Knowledge | Care | Cure
📌 Veterinary disclaimer: This educational post does not replace veterinary diagnosis, laboratory testing, or professional treatment.
