Mastitis in Cattle[1]
Mastitis is an inflammation of the mammary gland, usually from bacterial infection. It causes painful, swollen udders, abnormal milk with clots, flakes or blood, reduced yield, and potential systemic illness. It poses major welfare and economic issues for dairy farms. It presents as clinical or subclinical forms impacting milk quality and cow health, sometimes leading to fatality. Mastitis is controlled through hygiene, proper milking and available prevention / treatment options.
What causes Mastitis?
Mastitis in cows is primarily caused by bacterial infections that enter the udder through the teat canal. Other factors include physical injury to the udder, which may be caused by improper milking machines or trauma, dirty bedding or poor hygiene conditions, and a cow’s low immunity. Occasionally, other organisms like fungi or viruses can also cause Mastitis.
How does mastitis spread in cattle?
Bacterial infection is one of the most common causes of mastitis in cattle, causing an immune response that leads to inflammation. Some of the common bacteria include Staphylococcus aureus, Streptococcus uberis, and Escherichia coli[2].
Apart from infection, poor hygiene and environmental factors may also lead to mastitis. Injury to the udder from accidents, over-milking, or poorly maintained milking equipment can lead to mastitis. Unsanitary conditions in the barn, on the bedding, or around milking equipment create a favourable environment for bacteria to spread to the udder. A cow’s immune system is crucial. A compromised immune system due to poor nutrition or stress can make a cow more susceptible[3].
What are the Mastitis signs to watch for in cattle?
- Clinical Mastitis (Visible Signs):
- Udder Changes: Swelling, heat, redness, hardness, or lumps in one or more quarters.
- Milk Changes: Watery appearance, flakes, clots, pus, or blood.
- Cow’s Behaviour: Reduced milk yield, loss of appetite, fever, rapid breathing, hunched posture, stiffness, or reluctance to move.
- Subclinical Mastitis (Hidden Signs):
- No visible udder or milk changes, but milk has a high somatic cell count (SCC).
What is the impact of Mastitis in cattle?
- Reduced Milk Production: Infected cows produce significantly less milk, with losses varying by pathogen and severity, impacting overall farm revenue.
- Discarded Milk: Milk from treated cows must often be discarded during antibiotic withdrawal periods, leading to direct revenue loss.
- Treatment & Vet Costs: Direct expenses for antibiotics, supportive drugs, diagnostics, and veterinary services add up quickly.
- Culling & Replacement Costs: Cows failing to recover or with chronic issues are often culled prematurely, incurring costs for replacement heifers and lost future production.
- Quality Premiums: High Somatic Cell Counts (SCC) from subclinical mastitis reduce milk quality, leading to lower prices or refusal by processors.
- Labor: Increased labor is needed for special care, treatment, and managing diseased animals.
Prevention, control and treatment of Mastitis in Cattle
Prevention of mastitis in cattle focuses on a multi-layered approach that combines physical barriers, rigorous hygiene, and biological therapies.
- Milking Routine and Hygiene
- Teat Disinfection: Dip teats in antiseptic solutions both before and after milking to kill bacteria on the skin.
- Clean and Dry Preparation: Always wash and thoroughly dry udders using individual disposable paper towels or sanitized cloths before attaching milking units.
- Milking Order: Milk healthy, young cows first and known infected cows last to prevent cross-contamination.
- Operator Hygiene: Milkers should wear clean gloves and wash them frequently during the milking process.
- Environmental Management
- Dry Bedding: Use clean, dry, and comfortable bedding (e.g., sand or fresh straw) and replace it daily to minimize bacterial growth.
- Clean Housing: Regularly scrape alleyways and feeding areas to prevent manure from splashing onto udders.
- Post-Milking Standing: Provide fresh feed immediately after milking to keep cows standing for 30–60 minutes, allowing the teat canal to close before they lie down.
- Pasture Management: Avoid muddy or poorly drained areas and implement fly control measures, especially to prevent “summer mastitis”.
- Equipment Maintenance
- Milking Machine Checks: Ensure vacuum levels and pulsation rates are correctly set; excessive vacuum can damage teat ends and increase infection risk.
- Liner Replacement: Replace teat cup liners on a regular schedule (e.g., every 2,500 milkings for rubber) to maintain effectiveness and hygiene.
- Dry Cow Management
- Dry Cow Therapy (DCT): Use long-acting intramammary antibiotics at the end of lactation to treat existing subclinical infections and prevent new ones during the dry period.
- Teat Sealants: Apply internal teat sealants to create a physical barrier against environmental bacteria. Bismuth subnitrate is the primary active ingredient in non-antibiotic internal teat sealants. It is a viscous, inert paste that forms a physical plug in the teat canal, mimicking the cow’s natural keratin plug to block bacterial entry during the dry period.
- Health and Nutrition
- Balanced Nutrition: Ensure adequate intake of Vitamin E and Selenium, which are crucial for immune function and udder health.
- Vaccination: Administer coliform mastitis vaccines (e.g., J5) to reduce the severity and duration of clinical mastitis, although they may not prevent all new infections.
- Culling: Remove chronically infected cows from the herd to eliminate persistent sources of infection.
References:
- Cheng WN, Han SG. Bovine mastitis: risk factors, therapeutic strategies, and alternative treatments – A review. Asian-Australas J Anim Sci. 2020 Nov;33(11):1699-1713. doi: 10.5713/ajas.20.0156. Epub 2020 May 12. PMID: 32777908; PMCID: PMC7649072.
- https://www.icbf.com/mastitis/
- https://kb.rspca.org.au/categories/farm-animals/cattle/dairy-cattle/what-is-mastitis-in-dairy-cows