Causes of arthritis in dogs can be broadly divided into developmental or acquired.
First, be reassured that it in both cases is probably not your fault. The information here is essential to minimise progression in your dog, and hopefully prevent/minimise future cases.
Developmental means that they were genetically predisposed to have abnormally formed joints which become apparent as the dog grows.
Certain breeds are more likely to suffer such as labradors and golden retrievers. These joints don’t move smoothly and freely as they were designed to, which results in damage to the structures within the joint. This causes inflammation which eventually leads to signs of arthritis. The resultant developmental abnormality with joint shape can be mild to severe, which can influence the severity of the signs and at what age they appear.
Developmental diseases will happen no matter what you do, but the severity of their end result can be influenced in early life. Dogs that carry too much weight, do too much or not enough exercise, or have to negotiate slippery floors and lots of stairs, will have more severe clinical signs and premature negative outcomes.
Acquired means that they were not born with a likelihood to develop the disease, but circumstances have caused it.
The main causes of acquired arthritis are traumatic injuries to the joint, immune mediated disease targeting the joint, or infections within the joint.
The causes of arthritis in dogs are often out of the owner’s control. However the action taken when a problem is suspected is in your control. Work with your vet to get the best result.