Cow Fever: Causes, When to Worry & What to Do
- A normal rectal temperature for an adult beef cow is about 98.0-102.4°F (36.7-39.1°C). A reading above that can mean infection, inflammation, heat stress, or another serious illness.
- Fever is a symptom, not a diagnosis. Common causes include respiratory disease, mastitis, metritis after calving, salmonellosis, foot infections, and other systemic infections.
- Call your vet the same day for any confirmed fever in a cow that is depressed, off feed, dehydrated, lame, recently calved, producing abnormal milk, or showing cough, diarrhea, or nasal discharge.
- Emergency signs include temperature around 105°F (40.5°C) or higher, collapse, labored breathing, recumbency, severe dehydration, neurologic signs, or a rapidly worsening condition.
- Typical same-day farm-call evaluation and basic treatment cost range is about $150-$600, while intensive hospitalization, IV fluids, lab work, or herd-level diagnostics can raise costs into the $800-$3,000+ range.
Common Causes of Cow Fever
Fever in cattle is usually a sign that the body is responding to infection or inflammation. In adult cows, common causes include mastitis, metritis after calving, pneumonia or bovine respiratory disease, salmonellosis, and painful infections such as foot rot. In calves, fever may also be seen with septicemia, pneumonia, or severe infectious diarrhea. A normal adult beef cow rectal temperature is about 98.0-102.4°F (36.7-39.1°C), so a reading above that deserves attention.
The cause often becomes clearer when you look at the whole picture. A fresh cow with a foul uterine discharge and fever may have metritis. A dairy cow with abnormal milk, udder swelling, and fever may have mastitis. A coughing cow with nasal discharge and a temperature of 104-108°F may have respiratory disease. Sudden lameness with swelling above the hoof can point toward foot rot.
Not every high temperature is a classic infectious fever. Heat stress or hyperthermia can also raise body temperature, especially in hot weather, transport stress, or poor ventilation. That matters because treatment is different. Your vet will help sort out whether the problem is true fever, heat-related illness, or another condition that is making the cow sick.
When to See the Vet vs. Monitor at Home
See your vet immediately if the cow is down, weak, not drinking, breathing hard, has severe diarrhea, shows neurologic signs, has a temperature near or above 105°F (40.5°C), or recently calved and now seems toxic or depressed. These signs can go along with septicemia, severe mastitis, metritis, pneumonia, salmonellosis, or other fast-moving disease.
You should also call your vet promptly if fever lasts more than a few hours, returns after seeming to improve, or comes with a drop in milk production, abnormal milk, foul-smelling discharge, cough, nasal discharge, marked lameness, or dehydration. Young calves deserve extra caution because they can decline quickly, and septicemia may be life-threatening even before diarrhea becomes severe.
Careful monitoring at home may be reasonable only while you are arranging veterinary guidance and only if the cow is still bright, standing, drinking, and has no major breathing, neurologic, or calving-related concerns. Recheck temperature, appetite, manure, milk, hydration, and attitude. If anything worsens, contact your vet right away.
What Your Vet Will Do
Your vet will start with a physical exam and history, including the cow's age, production stage, recent calving status, herd exposure, appetite, manure, milk changes, and any coughing, lameness, or discharge. They will confirm the temperature and look for the source of illness by checking the udder, lungs, uterus if recently fresh, feet, hydration status, and rumen function.
Depending on the findings, your vet may recommend targeted diagnostics such as milk testing, fecal testing, bloodwork, culture, ultrasound, or herd-level infectious disease testing. In unexplained fever cases, veterinarians may also consider blood culture or other sampling to look for systemic infection.
Treatment depends on the cause and severity. Options may include fluids, anti-inflammatory medication, supportive nutrition, and condition-specific therapy that is appropriate for food animals. Your vet will also consider milk and meat withdrawal times, biosecurity, and whether other cattle in the group need monitoring.
Treatment Options
Spectrum of Care means you have options. Here are treatment tiers at different price points.
Budget-Conscious Care
- Farm-call or clinic exam
- Temperature confirmation and focused physical exam
- Basic supportive care plan
- Targeted first-line medication choices when appropriate for the suspected cause
- Home or on-farm monitoring instructions
- Recheck plan if appetite, milk, manure, or attitude worsens
Recommended Standard Treatment
- Complete veterinary exam
- Cause-directed diagnostics such as milk, fecal, or blood testing
- Anti-inflammatory treatment and fluid support as needed
- Condition-specific therapy selected by your vet
- Fresh-cow, mastitis, respiratory, or lameness workup as indicated
- Short-term follow-up or recheck
Advanced / Critical Care
- Emergency stabilization
- IV fluids and intensive supportive care
- Expanded lab work and herd-level infectious disease testing when needed
- Ultrasound or additional imaging in select cases
- Frequent reassessment for recumbent, toxic, or severely dehydrated cattle
- Referral or hospital-level care when available and practical
Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.
Questions to Ask Your Vet About Cow Fever
Bring these questions to your vet appointment to get the most out of your visit.
- What temperature is concerning for this cow's age and stage of production?
- Based on her signs, what are the most likely causes of this fever?
- Does this look more like mastitis, metritis, pneumonia, foot infection, heat stress, or something else?
- What diagnostics would help most right now, and which ones are optional if I need a more conservative plan?
- What supportive care should I provide today for fluids, feed, shade, bedding, and monitoring?
- What changes would mean I should call back immediately or move to emergency care?
- Are there milk or meat withdrawal times I need to follow with this treatment plan?
- Do other cattle in the group need to be checked, isolated, or monitored for similar signs?
Home Care & Comfort Measures
Home care should support your vet's plan, not replace it. Keep the cow in a clean, dry, low-stress area with easy access to fresh water and palatable feed. In hot weather, provide shade, airflow, and cooling measures that are safe for cattle. Watch for manure changes, milk changes, coughing, lameness, and whether the cow is still chewing cud and getting up normally.
Take the temperature again only if your vet recommends it and you can do so safely. Write down the exact reading, time, appetite, water intake, milk production, and any new signs. That record can help your vet decide whether the cow is improving or needs a different plan.
Do not give leftover medications, extra doses, or products not labeled or prescribed for that animal without veterinary guidance. In food animals, treatment choices must account for diagnosis, safety, and withdrawal times. If the cow becomes weak, stops eating, lies down and will not rise, or develops breathing trouble, severe diarrhea, or neurologic signs, contact your vet immediately.