# Bovine Mastitis

> Bovine Mastitis (Mastitis (dairy cattle)) is a mammary condition of cattle. Key signs are abnormal milk: clots, flakes, watery, blood-tinged, swollen, hot, painful quarter and drop in milk yield; diagnosis rests on California Mastitis Test and Bulk-tank or quarter milk somatic cell count. Good for mild cases caught early.

Source: https://vetmasterji.com/diseases/bovine-mastitis · Last reviewed: 2026-10-01

## At a glance

- **Species:** Cattle
- **Body system:** Mammary
- **Also known as:** Mastitis (dairy cattle)

## Key clinical signs

- Abnormal milk: clots, flakes, watery, blood-tinged
- Swollen, hot, painful quarter
- Drop in milk yield
- Elevated somatic cell count (SCC)

## Other signs

- Systemic signs (fever, anorexia, recumbency) in peracute coliform mastitis
- Hard / fibrotic quarter in chronic cases
- Gangrenous (cold, blue-black) quarter — Staph aureus, clostridial

## Differential diagnoses

- Mammary contusion / trauma
- Mammary neoplasia (rare)
- Udder oedema (peri-parturient)
- Teat-end lesions

## Diagnosis

- California Mastitis Test (CMT)
- Bulk-tank or quarter milk somatic cell count
- Aseptic milk sample for culture and sensitivity
- PCR panel for major pathogens

## Treatment outline

Strip the affected quarter frequently. Intramammary antibiotics (e.g. ceftiofur LC, cloxacillin, amoxicillin–clavulanate intramammary) per culture. Systemic antibiotics + NSAID (flunixin or meloxicam) for moderate–severe / coliform cases. IV fluids and supportive care for peracute toxic mastitis. Dry-cow therapy at end of lactation. Adhere to label withdrawal periods.

- [Amoxicillin — doses and monograph](https://vetmasterji.com/drugs/amoxicillin)
- [Ceftiofur — doses and monograph](https://vetmasterji.com/drugs/ceftiofur)
- [Meloxicam — doses and monograph](https://vetmasterji.com/drugs/meloxicam)
- [Flunixin Meglumine — doses and monograph](https://vetmasterji.com/drugs/flunixin)
- [Cloxacillin — doses and monograph](https://vetmasterji.com/drugs/cloxacillin)

> An outline, not a prescription. Check each drug’s dose for the species, the patient and the product in the drug calculator before use.

## Prognosis

Good for mild cases caught early. Guarded for peracute coliform / gangrenous mastitis. Chronic Staph aureus often unresponsive — culling of persistent shedders may be required.

## Related

- [Rank differentials from clinical signs](https://vetmasterji.com/diagnose)
- [Foot-and-Mouth Disease](https://vetmasterji.com/diseases/foot-and-mouth-disease)
- [Bovine Ruminal Tympany (Bloat)](https://vetmasterji.com/diseases/bovine-ruminal-tympany)
- [Bovine Respiratory Disease Complex](https://vetmasterji.com/diseases/bovine-respiratory-disease)

## Frequently asked questions

### What are the signs of bovine mastitis in cattle?

Abnormal milk: clots, flakes, watery, blood-tinged, swollen, hot, painful quarter, drop in milk yield and elevated somatic cell count (scc). Less specific signs include systemic signs (fever, anorexia, recumbency) in peracute coliform mastitis, hard / fibrotic quarter in chronic cases and gangrenous (cold, blue-black) quarter — staph aureus, clostridial.

### How is bovine mastitis diagnosed?

California Mastitis Test (CMT), Bulk-tank or quarter milk somatic cell count, Aseptic milk sample for culture and sensitivity and PCR panel for major pathogens. Differentials to rule out include mammary contusion / trauma, mammary neoplasia (rare), udder oedema (peri-parturient) and teat-end lesions.

### How is bovine mastitis treated?

Strip the affected quarter frequently. Intramammary antibiotics (e.g. ceftiofur LC, cloxacillin, amoxicillin–clavulanate intramammary) per culture. Systemic antibiotics + NSAID (flunixin or meloxicam) for moderate–severe / coliform cases. IV fluids and supportive care for peracute toxic mastitis. Dry-cow therapy at end of lactation. Adhere to label withdrawal periods.

### What is the prognosis for bovine mastitis?

Good for mild cases caught early. Guarded for peracute coliform / gangrenous mastitis. Chronic Staph aureus often unresponsive — culling of persistent shedders may be required.

## Sources

- Merck Veterinary Manual, 11th edition

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