Immune-mediated poly-arthritis is a condition that causes painful inflammation and stiffness of the joints.
Immune-mediated poly-arthritis can be triggered by a multitude of issues. They are classified Type I-Type IV. These types do not include breed association or side effects from drugs or vaccines which are also culprits.
Your vet will perform a full physical exam and medical history questionnaire on your dog. This may be enough to diagnose, however your vet may include bloodwork, x-rays, and other scans to rule out other conditions and to pinpoint the cause of the IMPA.
IMPA is incurable but there are treatments and medications to help alleviate the symptoms. The treatment course will be somewhere around 2-4 months. The likely medications will fall under two categories immunosuppressive and chemotherapeutic. It is important to note that extended use of either of these medications can have negative side effects.
It is likely you will be required to go in for checkups to make sure your dog is progressing appropriately and whatever bloodwork to be sure the medications are not having a negative effect. You will need a controlled taper off these medicines as well.