My big puppy's hind legs are swollen and getting bigger. What's wrong?

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.

With this amount of pain and swelling he must be seen and assessed by a vet. A tumour or abscess may give such pain and deformity, but it is impossible to diagnose from a picture. There is no appropriate home remedies that can be recommended until the underlying cause is known and it is not fair to delay treatment in such a case

I really feel that Lexi needs to have a full veterinary exam to determine what has happened. From the pictures, one possibility is that she is adjusting how she sits to extend the injured leg out - if she is not putting any weight on that leg then she may have broken it, or injured a ligament. There are also a couple of illnesses that can occur in a young growing dog, thses can be diagnosed with an exam and xrays. If she is limping she should have pain relief - Do not use any human medicines as these may be toxic to her.

Looking at the photo and considering your description of the progression of this, I would suspect that it is a growing mass. It could simply be a fatty lump such as a lipoma. Other possibilities would be a soft tissue swelling due to trauma, but this seems less likely considering the progression. I would head to the vet and get them to test the lump to see exactly what it is. If it is just a lipoma and not causing bother it should not need to be removed.

I'm so sorry to hear that Tabitha isn't feeling well. I don't see any distinctive lesions, but the swelling does appear to be significant. At this point, I would recommend moving on to different diagnostics like a joint tap to test the fluid in the joint as well as a skin scrape or other diagnostic for the skin lesions. It would also help to know approximately how old Tabitha is. I don't know what resources are available to the adoption group/agency, but if she could be evaluated by an orthopedic surgeon that would be ideal. Hope this helps in some small way! Best of luck to you and Tabitha. Sounds like she has found a wonderful, caring forever home with you! I am also happy to answer any other questions via 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.

With Axel I would be worried about swelling due to an abscess, fracture, or tumor if the muscle or bone. Hip dislocation can also cause a bump appearance but usually the bump is actually up above there the hip is located as it dislocates cranially most often. If he is not bearing weight then he is in significant pain and in my book this warrants a vet visit ASAP, including an emergency vet if he seems painful/unable to rest or relax at home. An X-ray of the leg will be needed to further evaluate what is going on.