Cushing's disease is a very serious condition, but it is treatable, much like diabetes in people. Before there was a viable treatment for it, Cushing's used to be a death sentence. Now, it is a serious, but manageable disease that requires careful monitoring and treatment. With proper care, most equines can live a full, happy and useful life regardless of Cushing's. That is certainly what we are aiming for.
There is only one truly viable treatment for Cushing's disease: it is a drug called pergolide. This was originally used in humans to treat Parkinson's disease, but it caused some heart and lung valve problems and was taken off the market. Since it was the only drug available to treat Equine Cushing's, taking it off the market was a huge problem for horse and donkey owners.
After pergolide was withdrawn, the FDA finally agreed to look the other way when compounding pharmacies made pergolide for horse owners. Eventually, a new drug made just for horses came on the market that contains pergolide, it is called Prascend.
Like all new drugs, the big problem with Prascend is that it is horribly expensive. At some point, after the patent expires, a generic version will come out, but until then all of us who own equines with Cushing's disease are stuck paying the devil his due.
Compounded pergolide is still available at a significantly lower price, but the consistency and quality are suspect. We may try it anyway since the Prascend is so expensive and the animal has to be on the drug for the rest of his life. We'll see.
Some people have had success using chaste tree berry to treat Cushing's, but this is generally only effective in the very early stages. Since Cushing's is a chronic, progressive disease, eventually most animals will need pergolide. I did have Ben on chaste tree powder before his diagnosis because it can be helpful for insulin resistance, it is cheap, easy and I had my suspicions about Cushing's. Unfortunately, his ACTH levels were still too high so clearly, the chaste tree was not enough.
The biggest hurdle to treating Cushing's is the expense. The medication is terribly expensive as is the need for routine blood tests to monitor the progress and treatment efficacy. It becomes a real burden because the treatment and testing are required for the rest of the animal's life. There are many owners who simply cannot or will not make such an investment and many cushinoid horses end up at the meat market.
Hawkeye has been on Prascend for about 6-8 weeks now. He had his ACTH levels retested last week and we just got the good news that, after 6 weeks of treatment, his levels are down to normal. After a period of adjustment to the medication, he is feeling much better. This means that he will stay on his current dose of pergolide for the foreseeable future. He will get another blood test next year to see if his dose needs adjustment. Once his levels have been stable for a while, he will likely get retested twice a year to keep them that way.
I will be very interested to see how Hawkeye's feet shape up now that he is being treated. I expect some big changes.
Like all drugs, Prascend is not without its tribulations. Side effects are fairly common during the first couple weeks and the dose needs to be tapered upwards gradually to alleviate this. The most common side effects are lethargy, depression and loss of appetite. A slightly less common issue is diarrhea. In a few animals, pergolide causes anxiety, aggression, restlessness, irritability and not wanting to be touched.
This last is what happened with Ben when I tapered his dose up to 0.5mg.
Donkeys are (of course!) harder to treat. They are more prone to have adverse side effects than horses and their dose needs to be tapered upward even more slowly than in horses. This can be very difficult in small donkeys because it is hard to get the dose low enough. Equines are very sensitive to pergolide and absurdly low doses have a big impact. Treating mini donkeys can be a real challenge because of these dosing issues.
I started Ben, who weighs approx. 850lbs, on 0.25 mg dose (which is far less than a human would get) and he did fine for the first week so I increased the dose to our target of 0.5 mg. This is when I noticed some definite behavior changes.
Ben is generally very laid back, quiet and cuddly. For about a week, he was impatient, irritable, pawing at the gate, uninterested in ear rubs, annoyed with everything and he even chased Emma one day. He got very possessive of me and would not let Emma or Ramsey come close to me. He would come to me for scratches and then walk off in disgust at the first touch.
One afternoon, when I went out to move the fence for their daily bit of strictly rationed grass, I felt a nudge in my back and turned to find Ben giving ME the dragon eye and trying to get me to move faster. I flicked him on the nose and told him drugs or no drugs he better not think about chasing ME unless he really wanted to meet a dragon.
For about a week, my normally happy, harmonious herd was anything but. Emma and Ramsey watched Ben stomp around with wide-eyed disbelief. Emma was still not talking to me. Ramsey HATES the cold and gets very grumpy about it. He was not happy about the rudely abrupt start to winter and was very mad that I had tried to get away with using Emma's lightweight blanket on him since he outgrew his good Rhino Wug. That proved to be a bad idea since he was not warm enough. Ramsey is even more of a wimp about winter than I am and sweet, gentle Ben had turned into a very prickly, irritable, fire-breathing dragon.
I had been hoping to wait until the after Christmas sales to buy Ramsey a new blanket, but I finally broke down and paid full price for a new Rhino Wug, which made Ramsey much happier. Emma finally started talking to me again and we all stayed out of Ben's way until that dragon got used to his new drugs and crawled back into his cave. He will get a new blood test in January and we will go on from there.
Peace and harmony are coming back into my little herd. Between vet bills, Prascend, a new blanket and my new camera, my credit card is now the one crying for mercy and begging for St. George to ride to the rescue.
Vet bill: $248
60 tabs of Prascend: $148
Harmony in the barn: Priceless.