In the late stages of Lyme disease in dogs, which organ systems may be affected?

• A. Joints, kidneys, and nervous system
• B. Joints only
• C. Lungs and liver
• D. Skin and eyes

Answer: (B)

In dogs, the late-stage picture of Lyme disease most reliably shows arthritis. Borrelia burgdorferi drives an inflammatory response in the joints, leading to swelling, pain, and shifting leg lameness that can persist even after initial infection. This joint-focused inflammation is the hallmark late manifestation.

Kidney involvement (lyme nephritis) and occasional nervous system signs can occur in some dogs, but they are less common and not the typical late-stage presentation across most cases. That’s why describing the late-stage organ system as joints only best captures what is most consistently observed clinically. If kidney or neurologic problems do show up, they are important to recognize, but they represent less common complications rather than the standard late-stage pattern.