A range of factors causes effusion in the joints, and the cause is crucial in determining the treatment. One of the most important indications is whether the onset of the effusion is sudden or gradual. Effusion refers to fluid collecting around the dog's joints, in this case the knee joint. You may notice the dog's leg swelling, or it may become obvious that the dog is trying to avoid bearing weight on one leg.
Treatment for Trauma
The collection of fluid around the joint may be caused by trauma somewhere in the surrounding area. The treatment for this will depend on the extent of the damage. If there is damage to the tissue in the surrounding area, the vet will advise that the dog should be kept as quiet as possible to rest the leg and will also prescribe painkilling medication.
Treatment for Arthritis
Dogs may develop arthritis, and more than one joint may be affected. This is more common in older dogs and usually develops fairly slowly. You may notice a difference in the dog's gait and walk, as well as some swelling around the joint. An anti-inflammatory pill may be prescribed by the vet, who will weigh the dog to determine the dosage.
Effusion of the knee is a symptom rather than a disease, so the vet will have to investigate the cause. X-rays will be taken. If there is a tumour in the surrounding area, it may be possible to have this removed. Blood tests will be taken. If these indicate any underlying illness, like a kidney problem or immune disorder, treatment may the prescription of steroid medication for the dog.