Weaning info?

Keymaster

Hi Tamara,
Excellent questions!
1. Weaning of prednisone is generally based on three criteria. The first is to determine if the dose is leading to severe side effects that are actually worsening the condition of the patient. The second is if the vet has been able to successfully transition the immunosuppression to another drug. So in your case, transitioning to cyclosporine is in place. The third is how successful have you been at halting the hemolytic destruction and is there either a rise in hematocrit (PCV) or have you been able to stabilize at a level that is supportive enough. Since Ashki may not have been destroying red blood cells in circulation, this isn’t a consideration.

2. Our combined experience, as moderators, and combined with the recommendations by Dr. Dodds and other resources such as attending vets has led us to recommend to start the reduction of prednisone as soon as is practicable. The general percent is approximately 25-33% of the current dose (I like to figure this out as a weekly dose and work from there.)

3. The decreases for prednisone should not happen sooner than approx. every 2-3 weeks. Each decrease should be preceded by a complete CBC. If you are feeling unsure about this then you can request a weekly PCV to be spun to ensure you know that Ashki is stable. The next decrease can occur in about 2-3 weeks provided that there has been no negative change. Ideally, the goal is to reduce this values down below what would be considered immunosuppressive. This is obviously different from dog to dog due to considerations such as size! But in general when you start getting down around 5mg a day (unless it is a tiny dog) you are not in the immunosuppressive range. Some dogs may never be able to completely eliminate prednisone in their lifetime, but for others is isn’t necessary.

Decreasing atopica (cyclosporine) should not occur until there is a completely stable HCT (PCV) at least nPCar the lowest normal range of about 37-39%. (And this can occur alternatively with decreases in prednisone.) However, that said, the dosage for this drug should be approximately the same as the normal dosing for a dog with allergies (which is what Atopica is actually prescribed for.) This drug acts differently than prednisone and controls the population of T-cell lymphocytes. At that maintenance dose suppression should be happening properly. Cyclosporine does not need a complex decrease schedule for safety as prednisone does. It needs to be decreased purely by the results you are seeing with the HCT and the reduced numbers of T-cell lymphocytes.

As Chance had bone marrow failure I focused on getting the prednisone dose reduced as much as I could as it was making him ill. Once that dose was lowered significantly, and he had reached a HCT of about 36-37, I began alternating the reduction between atopica and prednisone. I conferred with Dr. Dodds at each step to see if she recommended what I had determined to be the next reduction.

4. A relapse in a dog that has had bone marrow failure is a bit more complicated to examine. The HCT is not the sole value to be looking at. Evaluating at each step in the reduction should also be accompanied by examining the reticulocyte value. A dog or human with a normal HCT (37-45 for normal dogs) should maintain AT LEAST an absolute value of 60,000 circulating reticulocytes (approx. 1 to 1.5%). If a dog’s HCT has declined slightly during recovery to, say, 33% there should be an accompanying increase in the reticulocyte value. It may be small, but it MUST be more than 60,000 absolute and 1-1.5%. There is no wiggle room on this. If you see a decrease in HCT with no accompanying increase in reticulocytes you must consider that the bone marrow has become non-regenerative again. In that case, if it is slight and Dr. Dodds agrees it is slight, you may want to only increase the dosage of the cyclsporine back to the original dosage. Monitoring the value of lymphocytes helps you evaluate how successfully this worked.

If, however, there is a gradual and definitive decline in HCT over say, a period of a month, you may need to once again add back in prednisone. At this point I would have not made any decisions on my own but would have gone back to Dr. Dodds for help. Any choice to begin increasing prednisone introduces the side effects that make a dog’s health suffer.

As always, in dog with significant bone marrow failure, other factors need to be evaluated such as gastrointestinal health, proper nutrition, other conditions that may be impacting such as liver, kidney, thyroid, heart health. A continuous mild anemia can be related to anemia of chronic disease. That would need to be treated and no manner of immunosuppression would alter that.

There are no hard and fast rules, every case is different. The best thing you can do is continue to remain a frequent visitor to the vet’s office, stay in contact with Dr. Dodds and keep scrupulous CBC records. If at any time anyone needs help evaluating the CBC, I can and will do that for you if you need help. I know how to work the math carefully because I did this for Chance for over 6 months.

Do dogs that have had bone marrow failure return to normal? Yes and no. My vet did a study of all the dogs in her treatment memory that had a spleen removed and/or had bone marrow failure. As I had expected most of these dogs never return to a HCT much higher than 36-42. She could not explain that, but indicated that was Chance’s new normal. How did we determine it was his new normal? Simple. His reticulocyte value always remained at 60,000 (1%) which indicated his BODY WAS HAPPY AT THAT HCT. So in the future you will want to use the recticulocyte value as Ashki’s guideline for good health.

Have I answered your questions well enough?
my best, patrice

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