Lameness in dogs: causes, grades and diagnosis

In detail

How can I tell if my dog is lame?

Lameness can show in different ways. A dog does not always limp obviously.

Typical signs are:

• Changed head movement: with forelimb lameness, the dog may raise its head more when the affected limb touches the ground.
• Asymmetrical pelvic movement: with hindlimb lameness, the vertical movements of the pelvis may change.
• Uneven steps: stride length or timing differs between the limbs.
• Offloading when standing: the dog shifts its weight or places a limb differently.
• Changed behaviour: the dog may avoid jumping, climbing stairs or longer walks.

Mild lameness in particular often only becomes apparent on close observation or under certain conditions.

Important: not every visible asymmetry automatically means a painful condition is present.

What can cause lameness in dogs?

Lameness can have different causes. Which structure is affected often cannot be determined reliably from the gait alone.

Area	Possible causes
Paws and claws	Foreign bodies, pad injuries, torn claws
Joints	Osteoarthritis, hip dysplasia, elbow dysplasia, patellar luxation
Ligaments and tendons	Cruciate ligament injuries, tendon injuries, overuse
Muscles	Strains, bruises, muscle injuries
Bones	Fractures, growth disorders, inflammatory diseases
Spine and nervous system	Intervertebral disc disease, nerve injuries, neurological diseases
Other causes	Infections, inflammatory diseases or tumours

The exact cause must be determined by a veterinary examination.

When should I take my lame dog to the vet?

Not every lameness is an emergency. Nevertheless, changes in gait should be taken seriously, as their cause often cannot be judged reliably from the outside.

An immediate veterinary examination is necessary in particular if:

• the dog does not bear any weight on a limb,
• the lameness occurs after an accident or fall,
• there is obvious swelling, malalignment or an open wound,
• severe pain or considerable restriction of movement is evident,
• neurological signs such as paralysis also appear,
• the dog seems very lethargic or shows other general symptoms.

With mild lameness and no such warning signs, the dog should first be rested and assessed by a vet promptly, especially if the problem persists or recurs.

Important: never give your dog human painkillers without veterinary instruction.

How is the grade of lameness in dogs classified?

Veterinary medicine uses different scoring scales to assess the severity of lameness. Depending on the system, lameness is classified into four or five grades, for example. The following overview gives a simplified guide based on a five-point scale.

Grade	Description
Grade 1	Very mild lameness, only visible under certain conditions
Grade 2	Mild but consistently visible lameness
Grade 3	Clearly visible lameness with altered movement
Grade 4	Severe lameness with considerable offloading
Grade 5	The affected limb bears no or almost no weight

Note: the exact definition of the grades depends on the scale used. This table is intended only as a general guide and is not a validated scoring scale in its own right.

What are the limits of visual assessment?

Grading is often based on observing the dog in motion. With mild lameness in particular, assessments can vary between examiners. A study by Waxman et al. (2008) showed that agreement in the visual assessment of lameness can be limited. Objective gait analyses can complement this assessment by recording selected movement parameters quantitatively and making them comparable over time.

How is lameness in dogs diagnosed?

Lameness diagnosis begins with a thorough veterinary examination. Depending on the findings, different examination methods are used.

1. History and clinical examination: first, the vet clarifies how long the lameness has been present, whether it appeared suddenly or gradually and in which situations it is most noticeable. The vet then examines the musculoskeletal system, checking joint mobility, pain responses and possible neurological signs, among other things.
2. Gait assessment: the dog is observed standing and at different gaits. Changes in stride length, limb movement and overall movement may become apparent.
3. Diagnostic imaging: X-ray, computed tomography (CT) or magnetic resonance imaging (MRI) can be used to examine anatomical changes or injuries in more detail. Which examination makes sense depends on the suspected cause.
4. Objective gait analysis: an objective gait analysis can be carried out in addition. Sensor-based systems such as LupoGait record movement data and calculate various gait parameters from it, such as stance and swing phases, movement asymmetries and, depending on the system configuration, joint movements.

This information can help document functional changes and compare them across repeated measurements.

Why can objective gait analysis help with lameness?

Not every lameness can be clearly seen with the naked eye. With slight or shifting abnormalities in particular, it can be difficult to assess changes reliably. Objective gait analyses complement the clinical examination with measurable movement parameters. They can document, for example:

• how long a limb is in contact with the ground during the gait cycle,
• how stance and swing phases differ between the limbs,
• whether there are temporal or spatial movement asymmetries,
• how selected joint movements change,
• whether movement parameters change after treatment or during rehabilitation.

With LupoGait, such parameters can be recorded under suitable measurement conditions and compared over time. Particularly valuable is the possibility of comparing several examinations of the same dog, because what matters is not only the condition at a single point in time but also how movement changes over time. The results must always be interpreted together with the clinical examination, as movement asymmetries alone do not allow clear conclusions about pain or the cause of lameness.

What is subclinical lameness?

Subclinical describes changes that do not yet cause clearly recognisable clinical signs. In the context of gait analysis, the term is sometimes used for very slight movement abnormalities that may not be noticed on visual assessment. Objective measurement methods can capture certain asymmetries or changes in movement. However, not every measurable asymmetry is automatically lameness or a sign of pain. Whether an abnormality is clinically relevant must be judged on the basis of the whole examination.