How Veterinarians Diagnose Arthritis in Dogs

Why Early Diagnosis Is the Most Important Step in Protecting Your Dog's Mobility

By Dr. Lisa Mason, DVM, CCRT, CVA, CVPP

If you've noticed your dog slowing down, hesitating before jumping into the car, or taking a little longer to get up after a nap, you may be wondering if arthritis is to blame.

One of the most common things I hear from pet owners is, "I think my dog is just getting older." While aging certainly brings changes, pain should never be considered a normal part of growing older. Many of the behaviors we attribute to age are actually subtle signs of osteoarthritis (OA)—a progressive joint disease that affects millions of dogs.

The challenge is that dogs rarely tell us they're painful. They don't complain or point to the joint that hurts. Instead, they adapt. They shorten their stride, shift their weight to healthier limbs, avoid activities they once loved, or simply become less active. These changes happen gradually, making them easy to miss.

As an expert in rehabilitation and pain management, I believe the earlier we identify arthritis, the more opportunities we have to preserve mobility and improve quality of life. Diagnosis isn't simply about confirming arthritis—it's about understanding how the disease is affecting your individual dog so we can develop a personalized treatment plan.

In this article, I'll walk you through how veterinarians diagnose arthritis, what you can expect during an evaluation, and why diagnosis involves much more than taking an X-ray.

Arthritis Doesn't Start With a Limp

One of the biggest misconceptions about arthritis is that dogs suddenly become lame when the disease begins.

In reality, arthritis develops slowly.

Inflammation inside the joint often begins months—or even years—before a noticeable limp appears. During this time, cartilage is gradually damaged, muscles weaken, joint motion becomes restricted, and dogs begin changing the way they move.

Some of the earliest signs include:

• Stiffness after resting

• Slowing down on walks

• Hesitation with stairs

• Reluctance to jump into the car

• Sleeping more than usual

• Difficulty getting comfortable

• Less interest in playing fetch

• Mild muscle loss over the hips or shoulders

• Behavioral changes such as irritability or decreased interaction

These subtle changes often provide the first clues that something isn't right.

Diagnosis Begins at Home

One of the most valuable diagnostic tools isn't found in a veterinary hospital.

It's you.

You spend every day with your dog. You know how they normally move, play, sleep, and interact with your family.

Because arthritis develops gradually, owners are often the first to notice small changes.

I encourage clients to think about questions like:

• Does my dog hesitate before jumping?

• Are walks becoming shorter?

• Does my dog lag behind on hikes?

• Is getting up after resting becoming harder?

• Has my dog stopped using the stairs?

• Does my dog tire more quickly?

• Has my dog become less playful?

Sometimes owners don't recognize these changes until they compare videos taken several years apart.

I often recommend families take short videos of their dogs walking, sitting, standing, climbing stairs, and playing every few months. These videos become incredibly helpful for monitoring progression over time and evaluating how well treatment is working.

The Physical Examination

Once you're at the veterinary hospital, the diagnostic process begins with a thorough physical examination.

This involves much more than simply checking for a limp.

A complete orthopedic examination evaluates:

Joint motion

Your veterinarian gently moves each joint through its normal range of motion, looking for stiffness, decreased flexibility, or discomfort.

Pain

Not every painful dog cries or pulls away.

Sometimes discomfort is much more subtle, such as muscle tension, resistance to movement, shifting weight, or changes in facial expression.

Muscle mass

One of the earliest consequences of arthritis is muscle loss.

Pain causes dogs to use the affected limb less, leading to weakening of the surrounding muscles.

Muscle loss tells us valuable information about how long the problem has been affecting your dog.

Joint thickening

Arthritic joints often develop bony remodeling and thickening that can sometimes be felt during the examination.

Joint stability

Conditions such as cruciate ligament injuries, luxating patellas, or shoulder instability frequently contribute to arthritis and should always be evaluated.

Watching Your Dog Move

One of the most important parts of a rehabilitation evaluation is simply watching your dog walk.

A gait assessment allows us to observe:

• Stride length

• Weight bearing

• Head movement

• Back posture

• Turning

• Sitting posture

• Rising from lying down

• Transitions

• Balance

Many dogs compensate so well that owners don't recognize abnormalities until they're pointed out.

Some dogs shift weight away from painful joints.

Others overload their front limbs because of hip arthritis.

Some simply move differently without ever developing an obvious limp.

Every movement tells a story.

Advanced Gait Analysis

At Florida Veterinary Rehabilitation, we frequently use objective tools to evaluate mobility.

One example is a stance analyzer, which measures how your dog distributes weight among all four limbs.

Dogs naturally shift weight away from painful joints.

Sometimes these changes are too subtle for the human eye to detect, but computerized analysis allows us to identify asymmetry and monitor improvement throughout treatment.

Objective measurements also help owners see progress that may otherwise be difficult to appreciate.

Do Dogs Always Need X-rays?

This is probably one of the most common questions I receive.

The answer is not always—but they are often very helpful.

Radiographs (X-rays) allow veterinarians to evaluate changes such as:

• Bone remodeling

• Osteophytes (bone spurs)

• Joint narrowing

• Joint incongruity

• Previous injuries

• Hip dysplasia

• Elbow dysplasia

• Degenerative joint disease

However, it's important to understand that X-rays do not measure pain.

Some dogs with significant arthritic changes remain surprisingly comfortable.

Others experience considerable pain despite relatively mild radiographic findings.

That is why we never treat an X-ray—we treat the dog.

The best treatment plans combine imaging findings with your observations, physical examination, gait analysis, and overall function.

The COAST Staging System

Once arthritis has been identified, one of the most helpful tools available is the Canine Osteoarthritis Staging Tool (COAST).

Rather than simply labeling a dog as "arthritic," COAST helps veterinarians determine:

• Where your dog is in the disease process

• How arthritis is affecting daily life

• Which treatments are most appropriate now

• How to monitor progression over time

One of the things I appreciate most about COAST is that it reminds us arthritis develops gradually.

There is tremendous value in identifying dogs during the earliest stages, when interventions can help preserve joint health before significant damage occurs.

(Learn more in our guide: Understanding the Stages of Arthritis in Dogs.)

Looking Beyond the Joints

As a rehabilitation veterinarian, I rarely focus on the joints alone.

Arthritis affects the entire body.

During an evaluation we also assess:

• Muscle strength

• Flexibility

• Balance

• Core stability

• Endurance

• Functional movement

• Ability to perform everyday activities

This comprehensive assessment helps explain why two dogs with similar X-rays may have completely different treatment plans.

One may need to rebuild muscle.

Another may need better pain control.

A third may primarily benefit from weight loss and therapeutic exercise.

There is no one-size-fits-all arthritis treatment.

Why Early Diagnosis Matters

One of the biggest mistakes I see is waiting until a dog is severely lame before seeking help.

Unfortunately, by that point arthritis has often been progressing for years.

Early diagnosis allows us to:

• Slow disease progression

• Maintain muscle mass

• Improve joint stability

• Reduce inflammation

• Preserve mobility

• Delay disability

• Improve quality of life

The earlier we begin treatment, the more options we have available.

What Happens After Diagnosis?

Receiving an arthritis diagnosis isn't the end of the conversation.

It's the beginning of a long-term partnership.

Most dogs benefit from a multimodal treatment plan, which may include:

• Rehabilitation therapy

• Therapeutic exercise

• Weight management

• NSAIDs when appropriate

• Adequan®

• Joint injections

• Acupuncture

• Extracorporeal shockwave therapy

• Laser therapy

• Home exercise programs

• Environmental modifications

Rather than relying on a single treatment, we combine therapies that work together to reduce pain, improve function, and maintain mobility.

Our goal isn't simply to make dogs feel better today.

It's to help them stay active for years to come.

Frequently Asked Questions

Can arthritis be diagnosed without X-rays?

Sometimes. A dog's history, physical examination, gait assessment, and orthopedic findings may strongly suggest arthritis. Radiographs often provide valuable confirmation and help identify the underlying cause, but they are only one part of the diagnostic process.

Should I wait until my dog is limping?

No. Many dogs experience arthritis long before they develop an obvious limp. Stiffness, slowing down, reluctance to jump, or changes in activity level are all good reasons to schedule an evaluation.

Are all stiff dogs arthritic?

Not necessarily. Neurologic disease, soft tissue injuries, muscle strains, spinal conditions, and other orthopedic problems can produce similar signs. A veterinary examination is the best way to determine the underlying cause.

How often should dogs with arthritis be rechecked?

Every dog is different, but arthritis should be monitored regularly. Follow-up examinations allow us to evaluate mobility, adjust medications, progress rehabilitation exercises, and modify treatment as your dog's needs change.

Final Thoughts

One of the greatest advances in veterinary medicine has been recognizing that we no longer have to wait for arthritis to become severe before taking action.

Early diagnosis allows us to change the course of the disease.

If you've noticed your dog moving differently—even if the changes seem small—I encourage you to schedule an evaluation. Those subtle signs may be your dog's way of asking for help.

At Florida Veterinary Rehabilitation, our goal is to identify arthritis as early as possible, understand how it affects your dog's daily life, and develop a personalized treatment plan that supports lifelong mobility. Through a combination of careful examination, advanced diagnostics, rehabilitation, and multimodal pain management, we work to keep dogs doing what they love for as long as possible.

Because when we diagnose arthritis early, we don't just treat joints—we help preserve the moments that matter most between dogs and the families who love them.