Seek urgent veterinary care if your Papillon collapses, faints, has marked difficulty breathing, shows sudden severe weakness, has a painful or swollen limb, cannot stand, or develops a sudden major change in awareness or behavior. These signs can reflect a serious medical problem and should not be monitored at home.
For changes that are milder but persistent—such as a recurring limp, stiffness, reluctance to jump, lower exercise tolerance, coughing, a change in appetite, or a change in energy—book a veterinary appointment promptly. Your veterinarian can examine your Papillon, review its history, and decide whether any testing is appropriate.
Until you have advice, keep activity calm, prevent jumping or rough play if your dog appears painful, and do not give over-the-counter human medication. Make note of when the signs started, what makes them better or worse, and any family-health information you have.