Arthritis in Cows: Causes of Swollen, Painful Joints in Cattle

Arthritis in cows is inflammation of one or more joints. That inflammation can be infectious, such as septic arthritis or "joint ill," or noninfectious, such as traumatic arthritis, osteochondrosis-related joint disease in growing animals, or osteoarthritis in older cattle. In all cases, the joint becomes painful and less able to move normally.

In calves, septic arthritis is especially important because bacteria can reach the joint through the bloodstream after a navel infection, diarrhea, pneumonia, or another early-life infection. Merck notes that septic arthritis is a common cause of swollen joints in young large animals, and that cattle may also develop joint infection after penetrating wounds or, less commonly, after procedures involving the joint. Mycoplasma bovis can also cause polyarthritis, especially in calves with respiratory disease.

For pet parents, the biggest practical concern is that a swollen joint is not the same thing as ordinary stiffness. A cow with arthritis may be in significant pain, may stop bearing weight, and may struggle to stand, nurse, travel to feed, or keep up with the herd. Early evaluation helps your vet sort out whether this is an urgent infection, a traumatic injury, or a more chronic degenerative problem.

The causes of arthritis in cattle fall into a few main groups. Septic arthritis happens when bacteria or other infectious agents enter the joint. Merck describes three major routes: spread through the bloodstream, direct contamination from a wound, and iatrogenic introduction after a joint procedure. In calves, bloodstream spread is especially important and is often linked to navel ill, respiratory disease, or gastrointestinal disease.

Another cause is trauma. A slip, fall, kick injury, or penetrating wound can inflame the joint and may also introduce infection. Hard flooring, poor footing, overcrowding, and long standing times do not directly cause every case of arthritis, but they can increase limb stress, worsen lameness, and make recovery harder.

Developmental and degenerative joint disease also matter. Merck notes that osteochondrosis and degenerative joint disease are seen in young growing cattle, while osteoarthritis is more common in older animals. These cases may start with abnormal cartilage development, repetitive stress, previous injury, or chronic wear over time.

In some herds, Mycoplasma bovis is part of the picture. Merck reports that Mycoplasma arthritis is recognized in calves and may occur alongside pneumonia, with the carpi and tarsi commonly affected. When several calves develop swollen joints, your vet may recommend a broader herd investigation rather than treating the problem as an isolated injury.

Diagnosis starts with a careful history and physical exam. Your vet will want to know the cow's age, when the lameness started, whether the swelling came on suddenly or gradually, and whether there has been a recent navel infection, wound, pneumonia, diarrhea, calving injury, or herd outbreak. Watching the cow walk and examining the limb helps narrow down whether the pain is coming from the foot, soft tissues, or the joint itself.

A swollen, warm, painful joint often points toward arthritis, but your vet may need tests to tell infectious from noninfectious disease. Merck notes that arthrocentesis, or joint tap, can help confirm septic arthritis. Joint fluid analysis can look at cell counts, inflammation patterns, and whether infection is likely. Bloodwork may also be useful if your vet suspects a systemic infection.

Imaging can add important detail. Radiographs may show soft tissue swelling and joint effusion early, and later may reveal bone or cartilage damage. In some cases, ultrasound or referral-level imaging helps assess surrounding tissues or guide procedures. These steps matter because treatment options and prognosis can look very different for a calf with early joint ill versus an older cow with chronic degenerative change.

Because lameness in cattle is common and not every swollen limb is arthritis, your vet may also rule out hoof disease, fractures, tendon injuries, and abscesses before settling on a final diagnosis.

Prevention depends on the type of arthritis. For septic arthritis in calves, the biggest steps are strong newborn care, clean calving areas, prompt navel care, good colostrum management, and fast treatment of diarrhea, pneumonia, and navel infections. Because bacteria often reach the joint through the bloodstream, preventing those early infections can lower the risk of joint ill.

Housing also matters. Cornell resources on cow comfort and calf housing emphasize clean, dry bedding, reduced manure exposure, and comfortable resting areas. For adult cattle, better footing, less overcrowding, and enough lying time can reduce limb stress and help limit injuries that may trigger or worsen joint problems.

For herd health, work with your vet on lameness monitoring, biosecurity, and management review if multiple animals are affected. Repeated swollen joints in calves may point to a larger issue such as hygiene, colostrum transfer, or respiratory disease pressure. In some herds, your vet may also consider Mycoplasma as part of the investigation.

Not every case is preventable, especially when trauma or developmental joint disease is involved. Still, cleaner environments, safer footing, earlier treatment of infections, and regular herd-level review can meaningfully reduce the number of painful joint cases you see.