Hello . I am Dr. B, a licensed veterinarian and I would like to help you with Sam today.
This is a very common situation we face in our older animals (all species, even people) who suffer from multiple older age issues, like arthritis and kidney insufficiency. Now with Sam we find ourselves needing to treat the discomfort his arthritis (which would be quite likely at his age and potentially exacerbated by this previous fracture/repair) but at the same time wanting to do so while trying to keep any strain drugs may put on the kidneys as low as possible for him.
Unfortunately, in situations like this, there is no single straight forward treatment option. This is because most of our first line 'anti-inflammatory' medications for treating the discomfort associated with arthritis are filtered through the kidney. This includes Pardale, the non-steroidal anti-inflammatory medications (ie Rimadyl, Metacam, Onsior, Previcox, etc), and steroids. Despite this, we do have pure pain relieving medications (ie Tramadol, Bupenorphine, etc). These can sometimes be helpful with animals who are painful with their arthritis but we do sometimes find that the lack of anti-inflammatory relief in these medications can limit their success in these situations.
The reason we do give great consideration to the long term use of any medication that is filtered by the kidney in these situations is because if a dog has kidney insufficiency, this would be an extra 'job' for the kidneys to process. This means that it is possible that with long term treatment, this 'extra workload' (along with all the other daily strains on the kidney of course) could negatively impact the kidneys over time and play a role in the progression of his kidney disease.
Therefore, in these situations, we need to find a balance. If Sam is no longer responding positively to the Pardale, then we do have to consider that his discomfort from arthritis may be progressing to a severity that the Pardale cannot fully relieve. If that is the case, then you may wish to consider discussing other options with his vet. You may even want to speak to your vet about Tramdol or oral bupenorphine preparations as a potential treatment trial. If these work for him, then they'd be an option for long term treatment in his situation. But if you find these do not aid Sam's limp enough (or makes him too drowsy), then you may want to consider using a low dose of an alternative anti-inflammatory medication like one of the non-steroidal anti-inflammatories. And if this route is required to manage Sam's situation, then we may need to support the kidneys while treating (with diet +/- kidney supporting medication or subcutaneous fluids). That said, this would completely depend on his specific kidney blood parameters and urine results specifically.
Finally, while often not enough in advanced arthritic conditions, you might want to also consider using joint support supplements like glucosamine/chondroitin. This is a nutrient supplement that is available at your vets, pet shops, and health food stores (as capsules, liquids, and even treats). There are a range of products on the markets and the ones we typically use for dogs in this situation would be Cosequin (LINK), Seraquin (LINK), and Flexivet (is usually more economical then the others but I have had good results with it). It works by aiding joint suppleness by helping cartilage replenish itself and blocking enzyme destruction of cartilage in the joint. Often we can find this helpful in animals with mild signs, but it could be enough in balance with his current treatments to settle some of the discomfort he has had. Normally we give dogs 300mg glucosamine + 50mg chondroitin a day per 10 pounds of body weight. So, this could be an option along with his current treatment or any future one you may use.
Overall, when we have pets who are suffering from multiple issues of this nature, our goal is to find the least taxing treatment option that gives him adequate relief to carry out those parts of his life that are important to him. Therefore, if the Pardale at this ever increasing dose is not helping, then we do need to consider other pain relief options as well as supporting his kidneys (if required) while using these medications. Because at the end of the day, our goal is to keep him as comfortable, mobile, and happy as long as possible.
I hope this information is helpful.
If you have any further questions, don't hesitate to ask!
All the best,