Suzanne, I'm sorry that your question wasn't answered in a timely manner. We don't have many avian vets on this site. For immediate pain relief you can dissolve an adult 325 mg aspirin in one pint of drinking water for Petie. For more chronic analgesia to address his arthritis please see this exerpt from the Merck Veterinarinary Manual:
Septic and traumatic arthritis may occur at any age. Septic arthritis is most common in the digits. Osteoarthritis is also common in geriatric birds and can lead to other issues such as pododermatitis if not caught early and treated. The weight of the bird, its general physical condition, previous injuries, and any concurrent medical conditions can all contribute to the onset and severity of arthritis. Concurrent pododermatitis is often present and may be both a cause and result of decreased activity. Malnutrition, which decreases the integrity of the plantar epithelium, and concurrent obesity are often present in affected birds. The cage environment, especially the variety, diameter, and texture of perches, can be important in providing comfort and stability for arthritic birds while preventing or minimizing pododermatitis. If possible, the nails should be left with sharp points to add strength and stability to the grip. Wings should not be clipped, to help with balance.
Clinical signs vary, depending on the location of the arthritis and the severity of disease. Birds may exhibit lameness or be less active. A flighted bird may not want to fly or may not fly as well. The bird may not be perching normally or may fall off perches. Other signs of arthritis are swollen or warm joints, decreased range of motion, feather picking or mutilation, or excessive vocalization.
Diagnosis is based on clinical signs, physical examination findings, and imaging (radiographs or CT scan). Radiographic lesions include narrowing of the joint space, sclerosis of the subchondral bone, misalignment of the joint, and osteophyte formation. CT scans help determine the severity of the bony changes. Commonly affected joints are the tarsus, stifle, and phalangeal joints. The joints of the thoracic limb appear to be less commonly affected.
A multimodal treatment plan is recommended, incorporating both medical and nonmedical modalities. Medical treatment includes the use of NSAIDs, chondroprotectants, and possibly opioids. The most common NSAID used in avian medicine is meloxicam (0.5–1 mg/kg, PO, once to twice daily), a COX-2 inhibitor. Potential adverse effects of NSAIDs are renal ischemia, so they should be used with caution longterm and at the lowest therapeutic dose possible. Anecdotally, glucosamine (20 mg/kg, PO, bid, or 35 mg/kg, PO, once daily or every other day) or polysulfated glycosaminoglycan (5 mg/kg, IM, once weekly for 4 wk then monthly) have been used successfully. The latter should be used carefully, because some birds have had fatal coagulopathies from the injections.
Opioids may be necessary for acute exacerbations of a chronic arthritic condition or for conditions not responding initially to NSAIDs. Tramadol (15–30 mg/kg, PO, bid-qid) or butorphanol (0.5–3 mg/kg, IM, every 4 hr (depending on species of bird), may be used until the NSAIDs take effect.
Additional management includes husbandry changes, a weight loss and exercise plan, a healthier diet (rich in omega-3 fatty acids), and physical therapy. Encouraging flighted birds (without clipped wings) to fly in a safe environment is the best form of exercise. If a safe environment is not possible, encouraging climbing, walking, or even stepping up multiple times can be exercise for parrots. Foraging for food, by putting multiple foraging boxes on opposite sides of the cage or enclosure, promotes exercise. If the bird is overweight, then weight loss is essential, because studies have shown that obesity is a risk factor for osteoarthritis in many species. This may involve converting the bird slowly to a pelleted diet with added essential fatty acids. Fatty acids may have an anti-inflammatory effect and be renal protective. Flax seed oil ( 0.1–0.2 mL/kg/day, PO) is recommended as the best source of fatty acid supplementation for birds. Other husbandry changes, such as changes in perch texture or diameter or padding perches, can be helpful in birds with weak or painful legs or feet.
Articular gout is also common in older birds (see Miscellaneous Diseases of Pet Birds). Differentiation between arthritis and articular gout is critical because of the vast differences in progression, quality of life, and prognosis.
Please respond with further questions or concerns if you wish.