Why is my dog's knee swollen if the X-ray was clear? Is it cancer?

If I read this correctly your dog's leg was swelling to this size within a few hours. If your vet took x-rays and found bone lesions then there is indeed a possibility of bone cancer. However only a biopsy of the bone or the tissue of the swelling will prove that there is cancer. Without the possibility of examining the leg myself I can only give you possibilitites of why there is a swelling: 1) Check for puncture wounds or an injury. this could be a peracute infection of the joint. 2) this may be an injury of the joint such as a fracture or tendon injury, You should take your dog back to a veterinarian for an exam, especially since this is painful.

This appears to be swelling in the knee joint. What we would consider the "ankle" is much lower in the leg. There can be a pocket of joint fluid on the inside of the leg. It is possible this is a skin lump at the exact spot of this fluid pocket, but I doubt it. I suspect she is not putting weight on the leg because she injured the knee, and now as the swelling increases it is becoming more and more painful. I recommend she be seen by a veterinarian to check the stability of the knee to determine if she ruptured her crainial cruciate ligament or CCL (which is like a human's ACL).

Thank you for submitting your question regarding Rufus. I would recommend that he sees his veterinarian for x-rays for the swollen area of the affected limb. Unfortunately bone cancer is a common cause of swelling in the shoulder area. Hopefully this is not the case and he just sustained a soft tissue injury, but you will need the x-rays to know. In the meantime, keep him quiet to allow that limb to rest and do not give any over-the-counter pain medication as these can be toxic to dogs. I hope this information helps.

I cannot give you a definitive answer to your question just by looking at the is one x-ray. I can't get a good look at the x-ray as it won't enlarge enough for me to see what I need to see. Regardless, I think I see a lucent area on the calcaneous. That could be cancer but it could be osteomyelitis (bone infection) or even a fungal infection. It does not appear to involve the joint. The calcaneous is not at typical area to get bone cancer if that is any consolation. It is not impossible, just not common. This could be a hygroma (inflammation of the bursa) but without examining her myself it is too hard to say. I think your vet needs to aspirate the mass and look at the fluid under the microscope - usually you can see if there is bacteria in there (I would be worried about this so she really should be on some antibiotics) or cancer cells or just inflammation, etc. ( https://www.drsfostersmith.com/pic/article.cfm?articleid=2847 ) Hope this helps. Best wishes.

I can see the swelling from the pictures you posted. It appears the swelling goes form the foot all the way to the knee. I see that you live in an area where snake bite is possible. I would check thoroughly for any punctures along the entire leg and see if Diamond is painful in any particular area. If not, other causes of swelling like this could include infection, allergic reaction, trauma, cancer, among others. Sometimes swelling in an entire limb can be caused by decreased lymphatic flow - this can be caused by damage to lymph nodes or a structure under the skin or inside the body that is impinging on the lymph flow. I have also seen swelling like this with a flare-up of a mast cell tumor elsewhere on the body. I agree with your vet; if the medications prescribed to not make a difference, additional diagnostics are warranted. They may include bloodwork, abdominal x-rays, tick testing, or sampling of any small masses found.

Hi there and thank you for your post! I am sorry to hear Sasha is in pain with her left leg. The left ankle being swollen does not make me think an ACL tear, especially if the xrays and physical examination were normal with the knee joint. However, that being said, sometimes when dogs are worked up and energetic in the clinic setting, it can be difficult to assess the knee joint with them awake. These cases I sedate for the xrays and examine the knee joint further under sedation. This may be something to consider with Sasha if she is not improving. Another possibility that I would want to rule out is Valley Fever. The area that you are in certainly does have Valley Fever present (a fungal infection) and this can cause lameness in animals. I would certainly have a Coccidioidomycosis titer performed with your veterinarian to be on the safe side. This also may be a soft tissue injury such as a strain or sprain and may take some time to heal. If there is no improvement, after the directed course of treatment, I would suggest seeing an orthopedic specialist for a second opinion. A CT scan of the ankle joint may help pinpoint the problem as well and this can be done with most orthopedic specialty clinics. Please do not hesitate to call me with further questions / concerns. My main area of interest is orthopedics and if you would like to discuss this further by phone, I am available by consultation.

The most common condition causing this symptom in this breed is called patelar luxation which is basically displacement of the knee cap. you will need to get it checked by your vet to assess the severity of the condition, it might require surgery depending on the level of pain and lameness.