Doc, I think she hurts

Bella is your 15 year old feline friend. She’s been with you since you adopted her at the kitty adoption clinic 14 and some odd years ago. Now, you’re starting to notice that she is slowing down a little. Things aren’t the same as they used to be, she seems reluctant to jump onto the counter for her daily treats, and sometimes she will sleep at the floor of her cat tree. This is something she has never done before. You pet her while she lies down one day and wonder what’s going on. Then you remember that you received a post card not too long ago to bring her into the vet for her annual checkup… Maybe it’s time to do this after all.

On your appointment day you package Bella up and bring her to your veterinarian. You mention this concern to the technician and when you get to see the vet you discuss the problem. What’s going on with Bella?

“My technician told me that you feel like Bella has been slowing down quite a bit?” The veterinarian leads off. You describe what you’ve been seeing and that’s when your veterinarian begins the discussion of chronic pain. Chronic pain is a condition that afflicts many of our geriatric pets. There are a variety of causes, but the one that most frequently comes to mind is osteoarthritis or degenerative joint disease. This can afflict many animals and will frequently worse and worse as a patient gets older.
Chronic pain can be caused by essentially any organ in the body, but this blog will focus predominantly on osteoarthritic pain. There are many chronic diseases afflicting the liver, kidneys, hearts, and various other organs of our dogs and cats that can contribute to the whole picture. Future blogs or podcasts will focus more individually on the various organ diseases so I won’t spend more time on this here.

According to the Mayo Clinic (Mayoclinic.org) osteoarthritis is the most common form of arthritis in people. This develops as cartilage at the ends of bones starts to wear down from chronic use. The cartilage serves as a soft sort of cushion to protect the ends of bones form wearing against one another. In people it will commonly affect the hands, knees, elbows, etc. In other words, the joints that endure the most use. In dogs and cats we often see it affecting the hips, stifles (knees) and elbows.

As a result of osteoarthritis you will often begin to see your pet start to “slow down” usually you will notice them being slower to stand up, they may not even come greet you at the door like they used to. This disease process is one that can be diagnosed on x-rays. And what is usually seen will be degeneration or destruction of the normal bone. Cartilage is not visible on x-rays, so a normal x-ray does not completely exclude OA as a potential diagnosis. How your pet acts clinically is more important than what the x-ray shows, as we want to try to manage pain earlier in the process rather than later.

Pain is an incredibly complex process that involves numerous body processes, and to make it more difficult of course, our pets can’t directly tell us when something hurts. So, paying attention to subtle changes is immensely important. Cats are notoriously good at hiding pain and discomfort, so mentioning subtle changes that you’ve seen at home is important so your veterinarian can try to help. Animals rarely show signs of pain in the clinic. Changes in behavior such as unwillingness to jump, play, or even eat can all be a suggestion of pain.

So, in Bella’s case we’ve identified that she likely has pain, and an x-ray reveals that her hips have severe degenerative changes within them. This likely came as a result of her repeatedly jumping onto her cat tree over the years, but what can we do? In cats our pain management options are somewhat limited. The best long term medication we have right now is probably gabapentin. The mechanism by which gabapentin works is not well understood, but it is thought to interact with calcium channels between cells which reduces the release of excitatory molecules. This helps prevent pain. Gabapentin is ideally dosed every 8 hours or three times per day; however, this is not feasible for all owners, so it is frequently given twice a day. It works better if given consistently, and not on an as needed basis. As a side note, many clients when I mention Gabapentin ask if they can just give their own to their pet. This is not advised as the formulation for people frequently contains a substance called Xylitol which can be fatal to dogs especially in high doses. Cats do frequently need the medication compounded due to their size, so this can be done at a local compounding pharmacy. They should have their own prescription made rather than one of their humans’.

For cats there are very limited additional options, there are certain opioid medications that can be useful, such as buprenorphine. However, the cost of this drug in combination with its controlled status often make it a non-realistic option.

Nonsteroidal anti-inflammatories (or NSAIDs) are the mainstay drug for dogs and there are many products. These drugs work to alleviate pain by decreasing inflammation. They are usually well tolerated in dogs and can be used daily for years to help with pain. Some dogs will have difficulty with this drug either causing gastrointestinal side effects, like vomiting or diarrhea, or occasionally there can be problems with their kidneys or liver. The potential adverse effects on the kidneys is one reason they are often avoided in cats, as geriatric cats frequently are afflicted with some level of chronic kidney disease. Currently drugs like Carprofen, or Rimadyl are the most frequently prescribed for dogs as well as things such as Previcoxx and Galliprant. These all work to block inflammation and therefore relieve pain. A drug called Onsior is an NSAID that is labeled for cats; however, it is labeled for only three consecutive days of use in the United States out of concern for the kidneys (It is approved a little longer in the UK). So NSAIDs at this time are not widely used long term for cats.

Aspirin is also technically an NSAID drug that has been used for many years in dogs and cats for anti-inflammatory processes. It is not labeled as a drug to be used for dogs and cats by the FDA and so its use is actually “off label.” Unfortunately, many drugs that we use in veterinary medicine are not well studied in dogs and cats and so many of them are off label. There are numerous factors that affect that including FDA approval processes, cost of approval, and obtaining sample sizes for studies. Aspirin can be used daily to twice daily for dogs for pain, and usually will be dosed two to three times per week for cats. Aspirin may be more likely in some animals to cause gastrointestinal upset especially if accidentally dosed too high, so its use should be judicious. Aspirin also affects platelets which are clotting cells in the body. So some cats or dogs will be placed onto aspirin in order to disrupt excessive clotting of blood or what is called a pro-coagulant state. These patients may have heart disease, certain immune mediated disorders, or certain hormone based disorder. These dosages may vary from what I’ve presented here at the discretion of the clinician you are working with.

Additional options in dogs are drugs such as Tramadol. Tramadol is an opioid type drug that works by blocking mu receptors in the central nervous system. It also inhibits reuptake of serotonin and norepinephrine which potentially contributes to its pain relief and potential sedative effects. This drug has been used for quite a long time in dogs for chronic pain control; however, more recent research is suggestive that it may not be quite as effective as once thought. Additionally, it appears that dogs benefit most from Tramadol for shorter clinical courses rather than for long term use as would be the case for osteoarthritis. Anecdotally for some dogs; however, Tramadol seems to provide quite a bit of benefit, so it is still somewhat commonly used for long term indications. The final thing I’ll say about Tramadol is that it has a bitter taste which can make administration difficult. Cats do not have much research at all surrounding the use of Tramadol for pain relief and the bitter taste alone is probably enough to avoid use of this drug in pain management for cats.

Glucosamine and Chondroitin Sulfate are two nutritional supplements that have been widely used as an adjunctive treatment for arthritis in both dogs and cats as well as humans. These appear to be very safe; however, like with many of our pain control options their efficacy is unclear. These drugs also are not direct pain medications, they seek to help with the inflammation that is present in OA conditions. With long term use we can often see positive response from patients in combination with other pain medications.

There are numerous supplements available nowadays for management of a wide variety of conditions. Since research is extremely variable on these substances I will not cover them here; however, there is an injection that can be helpful for dogs with OA called Legend. This contains hyaluronic acid which is an important component to joint health. It is given by an intravenous injection on a monthly basis. This requires a trip to the veterinarian every month to receive the injection which is not feasible for all owners, but it can be useful for canine companions that are hurting. The drug is thought to be most beneficial before degeneration of the joint gets to severe stages.

Some alternative pain management options also exist at this time. Acupuncture can be anecdotally useful for some animals. Acupuncture has large bodies of research about it both for and against its efficacy. It does seem useful in certain patients and so it is absolutely an option to explore if you are interested. Additionally, laser therapy can be used to help with osteoarthritic pain. Laser therapy uses a beam of light (laser) to inhibit inflammation in body tissues. It can be helpful to some patients and is becoming more widely available. Depending on your area you likely already have a veterinarian nearby with the ability to do this.

There are two main types of laser, the one that is helpful in managing pain is often referred to as cold laser or low level laser. The “high powered” laser is used for surgical procedures not for pain management so this is the distinction. There are again a wealth of studies surrounding laser, so the full extent of the benefit of this procedure is not well known, but many patients seem to have a good response to it. The laser experience itself is nonpainful causing mild warming to the tissue and light pressure. You will have to wear eye protection if you are with your pet when they are receiving laser therapy as will they ideally, but the veterinarian or technician performing the procedure will be able to explain that to you at the time of treatment. Laser and acupuncture can be administered to both dogs and cats.

As you can see, the world of chronic pain in dogs and cats is not a straight forward one. There are many options and quite a bit of variability in terms of how patient will tolerate medications and how effective said medications will be. The complexity should not discourage one from trying to get pain as managed as possible as this can make dramatic improvements to the quality of life of your furry friend. I hope that you enjoyed listening to or reading this episode of Paws Press Play, this has been Dogtor S. Don’t forget to comment or respond to the website with requests for topics.