did the vet commit negligence, by not informing me of the original inj

The veterinarian is responsible for informing you of what happens with your dog while under his care. This means that you should have been told that during the first surgery, the femur broke during placement of the prosthesis and had to be repaired with wires. Discharge instructions for a total hip replacement are lengthy, and so it is possible that in their desire to relay all of the important post-operative care instructions that they neglected to tell you about the complications that arose during surgery. However, a fracture is a pretty big complication and seems like something that would have jumped to the forefront of the conversation.
I would say that it is highly probable that the problem that occurred during the first surgery led to the fracture of the leg and caused the prosthesis to slip. This should be fairly easy to tell if the x-ray shows that the fracture discovered on 8/16 was in the same location as the fracture that occurred on 8/2. There are most likely two sets of x-rays, one set from 8/2 following the surgery to assess proper alignment of the prosthesis and reduction of the cortical fracture, and one set from 8/16. You would be on better ground, legally, if you could have a second veterinarian examine the films to see if the same area of the bone was affected. However, you mentioned that you were unable to pay for the second surgery. In most states, legally, that veterinarian does not have to release those x-rays until you compensate him for the services he provided. In that case, your best bet is to deal directly with your state's veterinary board. Compile all the information that you can- beginning with the surgery, your follow-up conversations and visits regarding your dog's pain after surgery, and the actions that were taken by your vet in response to those conversations. Include all medications, dosages, and post-operative instructions you received following the surgery. The state board can review your information as well as information provided by your veterinarian, which should include the x-rays. The board will have member veterinarians who can review the films and the medical care that your dog received. If your veterinarian is found to be at fault, he will be sanctioned accordingly.
An action in small claims court may not be successful since you owe this veterinarian money. But if you have the backing of the state board that your vet acted negligently, your case improves dramatically.
I can't say whether or not your vet was negligent, nor whether the incident that occurred during the first surgery caused your dog to break his leg. Without full review of your dog's file and x-rays I'd only be making assumptions. However, if there was negligence that led to the need for the second surgery than not only should you receive financial compensation, but you should get your dog back as well. By "lost" your dog I do hope that means that he had to be re-homed, not that he had to be euthanized. If it was the latter, then the best the courts can do is try to assign some "price" for him as a pet and companion. Of course no amount is ever appropriate for a friend.
I hope my information was helpful and I'm sorry that you are going through such a difficult time.

i do have the xr taken on 8/16 and the fracture is on the lower third of the femur, while the medial cortex fracture appears to be at the top of the femur as the wires are showing at the top of the femur. unfortunately, because i do not own the dog, i can't get another orthopedic vet to review the notes and the xrs. i just need clarification-since the second severe break was not near the one that occurred during the first surgery, should i infer that the second break could not have been a product of the problems with the first surgery? isn't the vet negligent as to dx when he did not do an xr on 8/9, knowing that there were problems during the first surgery?

It is much less likely, due to their locations, that the fracture that occurred during the first surgery caused the second break. However, it is reasonable to consider that if the prothesis was improperly placed, or if placement caused undue stress on the lower portion of the bone, this could have led to the fracture of the distal (lower) femur.
As to negligence for not taking an x-ray on 8/9- if your vet did a thorough, hands-on physical examination of the leg and did not find evidence of a fracture (displacement of bones), then this is not negligence. Negligence (dictionary definition) is the failure to use reasonable care, or doing something which a reasonably prudent person would not do. If the vet did not examine the dog during this visit and just told you, "oh, that's normal for this type of surgery", than that is negligence. If you bring your dog in for care, he's ethically and legally obligated to actually examine the dog before presenting a diagnosis. Clearly his decision was the wrong one, but it wasn't negligent. If the fracture was not significantly displaced (you didn't have two pieces of bone overriding each other) or if the prosthesis was still within the two halves of the fracture, this might give the impression of an intact bone on palpation of the leg. That may be why he missed it during his exam.
I believe it is still worthwhile to try to get a second, in person, opinion via review of the x-rays and medical records. This may be difficult, as you mentioned, since you no longer own the dog. However, I think if you look around you should find someone willing to help you. You may still have a claim, especially if evidence points to improper placement of the prosthetic leading to the second severe fracture. But I think that if you can garner support for this before spending money on an attorney, you'd be well served to do so.

Edited by Vet help on October 12 2006 at 10:12pm