Intra-articular therapy, or joint injections, may help relieve arthritis pain and inflammation.
While there is no cure for arthritis at this time, there are many things you can do to help manage your dog’s arthritis symptoms and the progression of the disease.
One option is joint injections. These are usually recommended when non-invasive therapies (medication, weight loss, supplements, and rehabilitation) are not sufficient to reduce pain.
However, there are some conditions, such as elbow dysplasia, where joint injections may be helpful early in the arthritis management process.
Click here to read how joint injections have been helping Pickles the black lab maintain a “career” as a crisis response dog despite having elbow dysplasia and arthritis.
Types of joint injections
There are 5 general categories for joint injections:
- Orthobiologics: This includes Platelet Rich Plasma (PRP) and “stem cell” therapy
- Hyaluronic Acid (HA)
- Steroids
- Synthetic hydrogels (ArthramidVet, Spryng)
- Synoviorthesis (Synovetin)
No matter what type of injections your veterinarian recommends, your dog will need to be sedated for the procedure to ensure patient comfort and proper placement of the injection inside the joint.
The injections are not surgery, they are just using a needle the same size as that used to deliver a vaccine, but the joint space is small. That means the technique requires a certain level of skill and that the dog has to remain perfectly still.
Platelet Rich Plasma (PRP)
Platelets contain a large number of growth factors and proteins that control inflammation as well as help with healing and the immune system.
With PRP therapy, your dog’s own blood will be collected and the platelets isolated. This generally takes about 20 minutes and happens in the hospital. The technique requires a special collection device, so not all veterinarians can provide PRP.
Studies suggest that clinical effects are usually noticeable between 1-3 months after injection. Several studies have shown significant improvement in weight bearing. Your veterinarian will likely recommend repeating the injections every 6-12 months.
Stem Cell Therapy
Stem cell therapy in dogs uses adult, or mesenchymal, stem cells. The adult stem cells will be collected from your dog’s own fat or bone marrow, either of which requires a minor surgical or invasive procedure performed under anesthesia.
The current evidence suggests that stem cell therapy may provide pain relief through “immunomodulation,” or influencing the role of the immune system in pain and disease progression.
It’s important to note that no stem cell therapy has currently been proven to be regenerative. However, there is a lot of ongoing research in this area.
Hyaluronic Acid (HA)
HA is a normal component of cartilage and joint fluid that provides lubrication. In arthritic joints, the HA molecule is smaller than normal, leading to inadequate lubrication of the joint.
Injecting synthetic HA is believed to alter the metabolism of naturally occurring HA while also decreasing arthritis symptoms.
HA products primarily differ in their molecular weight and are categorized as Low Molecular Weight or High Molecular Weight. The high molecular weight more closely resembles normal HA in non-arthritic joints.
One study compared the two categories of HA products as well as the effectiveness of one injection compared to 3 injections. Results found that both products and both treatment protocols were significantly better than the placebo (saline), but HMW had better results than LMW. The maximum benefit in pain, lameness, function, and range of motion was seen 4-8 weeks after the injection and began subsiding at 6 months.
Steroids (triamcinolone)
Steroid injections are a common treatment for arthritis in both people and animals. However, repeated steroid injections can be detrimental to cartilage.
Steroids can be effective in decreasing inflammation and pain in the joint. Steroids are typically combined with HA when administered. Improvements can often be seen as soon as 1 week after the injection and last for at least 12 weeks.
Most CARE Contributors recommend reserving steroid injections as a last resort for “end-stage” disease when there is little to no cartilage remaining or when quick pain relief is needed.
Hydrogels
These are newer products that have some research in humans and people, but at this time, very little research in dogs.
The goal of these products is for the substance to be taken up into the joint capsule (the lining of the joint) to help restore a healthy synovial membrane and decrease inflammation. More research is needed to know how these products compare to other joint injection products.
Synovetin OA
This is a radioactive molecule that when injected into the joint, is taken up by inflammatory cells in the synovial membrane and causes the inflammatory cells to die off, leading to reduced inflammation in the joint. There are several studies showing improvement in pain and lameness after Synovetin in dogs with elbow arthritis.
Veterinarians have to receive a special licensure in order to administer Synovetin. While these injections are an outpatient procedure and the radioactive material does not cause any harm to the rest of the body, there are some post-injection limitations you will need to discuss with your veterinarian.