Introduction
My rabbit Paco died on June 2, 2011 from complications arising from thymoma, a tumor of the thymus gland, which is located in the chest. When Paco was diagnosed I panicked and did not know what to do. There was very little information available and what was available was conflicting and scattered. I had to make a decision about what to do quickly. It was a very stressful time. I was lucky enough to live in Pittsburgh, PA where there is a very active and strong community of rabbit enthusiasts. My rabbit friends were able to give me a lot of advice and guidance, and I was also able to find help and advice on the internet. The purpose of this page is to gather all the information that helped me into one easily accessible place, with the hope that it might benefit other rabbits and their owners. On this page you will find details about Paco’s life, diagnosis, and treatment, his x-rays, his vets, helpful links, and testimonials from other owners who have dealt with thymoma.
Background
Paco Bunny was born on May 5, 2004. The truth is that date is an approximation, but I have always considered it to be his official birthday. He arrived at my house on June 19, 2004 – a birthday gift from a friend. Let me state here and now that giving people pets as a gift is the last thing I condone. I was a tad bit horrified when I looked into the cardboard box and saw a bunny in there. But at any rate, Paco had arrived and that was that.
Paco was a Netherland Dwarf-type rabbit and weighed about 3.5 pounds at his fattest. From the very moment I got him he was smart and outgoing and friendly and I was just amazed at his fantastic personality. He was very very stubborn and bossy and sometimes drove me insane, but I loved him more than anything. He lived life to the fullest. He always had free roam of my apartment and enjoyed exploring and destroying the walls and baseboards. He loved eating all sorts of terrible things that rabbits should probably not eat. He lived in Virginia and Pennsylvania and traveled to New York City and Connecticut. He made an impression on everyone he met.
For several years we lived in a large apartment building with long, carpeted hallways in the common area. Late at night I would leave my apartment door open as I watched TV or worked on my computer and Paco would go outside and run up and down the hall. He liked running on the carpet because he did not slide around. Sometimes I would forget he was out there and would eventually find him all the way down the hall, totally out of sight. I was always scared he would get on the elevator but he never did. When he had enough of running he liked to just lie in the hall outside my door. The neighbors all got used to him and would stop and say hello on their way in and out of the building.
For 6 of the 7 years we lived together my bedroom was the one place that was off limits. I just needed some space where I could throw stuff on the floor without having to worry about it being chewed on. I used a baby gate to keep Paco out and he literally spent 6 years chewing on that gate, trying to get through. The idea of being forbidden to go somewhere drove him crazy. He never gave up. After 6 years we moved into a loft-style apartment where there was no way to block off the bedroom. And so, finally, Paco got what he wanted. I put his little cardboard house next to my bed and he spent every night in there. We had a regular evening routine. I would tidy up the apartment, load the dishwasher, brush my teeth, and so on. Paco would get a treat. I’d turn off the lights and get into bed. About a minute later I’d hear a crash as Paco jumped into his house and then another crash as he jumped up onto the second floor.
I’m glad he got to sleep with me that last year.
Diagnosis
Paco had never really had any health problems but in late September or early October of 2010 I noticed that his eyes looked strange. For the first time ever I was seeing the whites of his eyes, mostly in the front corners. I also thought I could see glimpses of the third eyelid. Basically, I did not know what I was seeing, but his eyes looked different. It was most noticeable when he was leaning forward and chewing – I first noticed it when he was chewing on a stick that I was holding in front of him near the ground.
I did not think too much of this development at first, but after a few weeks I mentioned it to my friends at Rabbit Wranglers and they encouraged me to take Paco to the vet. Paco had always been seen by Dr. Tom Wiles at Pittsburgh Spay and Vaccination Clinic, but this time I took him to see Dr. Robert Wagner.
On October 21, 2010 Dr. Wagner took an x-ray of Paco’s chest and immediately informed me that Paco had thymoma. A huge tumor was filling his chest, taking up so much space that it was causing his eyes to bulge. I was told that treatment options included radiation, surgery, and chemotherapy, but that the outlook really wasn’t good. I took Paco home, devastated, and set about trying to figure out what to do. It was a horrible time because I had to act quickly, there was no concrete information available, and I had to balance all kinds of important issues such as what I wanted, what was fair to Paco, how much money I could spend, and so on.
Research
Over a period of several days I had lengthy discussions with my rabbit-savy friends and I posted a plea for help on EtherBun, asking anyone with thymoma experience to please get in touch. I took Paco to see Dr. Wiles for a second opinion. I googled and googled to try to get as much information as I could. I have posted some of the useful links I found in the “resources” section of this site. Feel free to refer to them. Below I will try to summarize what I learned through my research and the decision process that led me to choose a treatment plan for Paco. Please keep in mind I am not a vet and my intention is not to tell anyone what to do. I am just laying the information out the way I understood it to be and telling you what I decided to do.
Chemotherapy: At least in this context, there are two different types of chemotherapy. One is the traditional kind, and one is herbal or homeopathic. Specifically, there is an herbal substance called neoplasene (google it) that many people have a lot of faith in. I did not consider traditional chemotherapy to be an option because I did not hear from anyone who had used it and there was just no information available. I did consider treatment with neoplasene, but I was personally skeptical that it would help and I wanted to consider more aggressive options.
Surgery: Surgery to treat thymoma is extremely invasive. To access the tumor the chest has to be cracked open. In addition, the tumor is often wrapped around important organs such as the heart, which can make removal difficult. If the surgery is successful, the rabbit still has to recover from the operation itself. I had a consultation with a vet who was a surgical expert who explained to me that rabbits do very poorly after major surgery. Their postoperative mortality rate is very high, even if the surgery itself is a success. I did hear from one individual who chose surgery for her rabbit and had a good result. But after a lot of thought, I came to the personal decision that surgery was just too risky and too invasive and would be unfair to Paco. Overall, my view was that it would be extremely painful for him and I did not think it was my right to force him to go through it.
Radiation: Of the thymoma treatment options available the one that came up most frequently in my research was radiation. I found some decent information online and also received emails from several owners who had chosen radiation for their own sick rabbits. There was simply more data available to me about radiation than about any of the other options. Some people reported bad experiences with radiation in that it caused severe side effects or did not treat the tumor as hoped. Others had positive experiences in that the tumor was successfully treated with minimal side effects. One negative was that everyone I heard from had gone through radiation quite recently, within the past few months. No one was able to say yes, my rabbit was successfully treated with radiation several years ago and remains healthy. Regardless, radiation appealed to me because it was an aggressive option, but not as invasive or painful or risky as surgery. The major downsides of radiation are that it can only be performed at certain facilities that have specialized equipment, that multiple treatments are necessary, and that the patient has to be anesthetized for each treatment, which carries risks of its own. In addition, it is very, very expensive, with absolutely no guarantees. So few rabbits are treated with radiation that there is simply no reliable data available about how well it works.
No treatment: Without treatment, the tumor in Paco’s chest would have continued to grow until eventually he became unable to eat or breathe.
I had a very, very hard time deciding between these options. I was absolutely terrified of being unfair to Paco. I loved him so much and did not want to cause him pain or make him suffer just because I was not ready to let him go. At the same time, I was worried about not doing anything and then regretting it. I was also worried about spending a huge amount of money and having the treatment not even work. It was a terrible, terrible time. And it was made more difficult by the fact that Paco actually seemed OK! Although his eyes were getting worse, he did not seem particularly unwell. He was perhaps eating a bit less but overall seemed happy. Although I knew he would soon start to get really sick, it was hard to think about subjecting him to a treatment that could possibly kill him when he was happily hopping around my living room, going about his usual daily business.
Ultimately, I decided to try radiation, because I thought it struck a good balance between doing nothing and being unfairly aggressive. It seemed radical enough that it might work, but not so painful and invasive that it would be unfair to Paco. I knew there was risk involved in putting him under anesthesia and I knew there was a risk it would not work, but I thought those risks were reasonably balanced by the possible benefits, and I thought the level of discomfort to Paco, in light of the possible benefits, was acceptable. I don’t mean to sound flippant about that last point. I was still really concerned about causing him pain and fear and I spent a lot of time thinking that perhaps I should just keep him happy and comfortable at home for as long as possible. In the end it was something pretty peculiar that helped me make my decision. I thought about Paco and his personality and what he would be like if he were a person. I thought about how bold and outgoing he was, how he was such an optimistic, cheerful little guy. I thought about the baby gate outside my bedroom and how he spent 6 years trying to chew through it. He was obstinate and he never gave up. I think if Paco had a say in the matter he would have wanted treatment. He would not have wanted to just give up and die. I also took into consideration the fact that he was only 6 years old – still a fairly young bunny.
There were a few other factors that led to me choose radiation treatment for Paco. First, my rabbit friends put me in touch with a Pittsburgher named Susan who had recently lost her beloved rabbit, Lily, to thymoma. I’m sure everyone involved found it strange that just a few months after Lily died, Paco came down with the same disease. I was very sad to hear about Susan’s loss, but was happy to learn everything I could from her experience. She was gracious enough to email with me extensively and was able to direct me to an animal hospital that had the equipment necessary to treat Paco, MedVet Medical & Cancer Center For Pets near Columbus, OH. Specifically, she referred me to a vet by the name of Deborah Prescott.
Second, several people referred me to an article entitled Radiation Therapy for the Treatment of Thymoma in Rabbits (Oryctolagus cuniculus) (Journal of Exotic Pet Medicine, Volume 15, Issue 2, April 2006, Pages 138-144 D. Guzman Sanchez-Migallon, J. Mayer, J. Gould and C. Azuma). You can read an abstract of this article and purchase it here. Or, feel free to email me (phoebe at somecows /dot/ com) and I can share my copy with you. This article was one of the few things that gave me hope during this period. First of all, it laid out a concrete course of treatment for Paco. And second, although the number of subjects in the article is admittedly small, they all did very well and responded to the treatment. It might not be the strongest science in the world, but at least it was something.
At this point I should say a few words about radiation therapy, at least as it relates to treating thymoma in rabbits. I am not a doctor so please don’t consider my words to be the ultimate truth. I believe the following to be accurate, but please confirm with your vet. Radiation can be given in different strengths, or doses, and has to be given over multiple sessions. The dose and number of sessions you choose depends on what your goal is, and causes different types of side effects. All of these things have to be taken into consideration as you can come up with a treatment plan. One approach (low dose/many sessions) is to give low doses over multiple sessions. Because so many doses are required, certain immediate side effects can occur during the course of treatment. However, the risk of long term serious side effects, such as permanent damage to the tissue and organs near the tumor, is minimal.
Another approach (high dose/few sessions) is to give higher doses over fewer sessions. Because there are only a few sessions, immediate side effects are minimal. However, the strong doses can result in long-term damage. The latter approach (high dose/few sessions) generally does not cure cancer, but it can give an animal additional time and more importantly, increase quality of life. It is considered to be a palliative treatment. Because there are only a few sessions, the animal does not have to suffer through too many trips to the vet and too many risky treatments with anesthesia. The long-term risks are generally not viewed as posing that much of a threat because the assumption is that the animal will probably not be alive in the long term anyway.
I chose the high dose/few sessions course of treatment for Paco for four reasons. First, it was the one outlined in the article (Radiation Therapy for the Treatment of Thymoma in Rabbits (Oryctolagus cuniculus)) and thus had a proven, if limited, track record of success. Second, it would only require three trips to the facility in Ohio and three anesthesia sessions. I did not feel it was fair to subject Paco to more than three treatment sessions. Third, I was impressed by Dr. Prescott and the MedVet facility. After Susan provided me with MedVet’s contact information I called them and told them about Paco. They were extremely helpful and gave me Dr. Prescott’s contact information. I emailed her and even though she was traveling for a conference, she responded immediately. I sent her the article and she agreed that she could follow the treatment plan that it outlined. After speaking with her a few times I was confident that she was on the same page that I was.
The fourth reason I chose the palliative treatment plan had to do with Susan and Lily and what they went through. Lily was treated with the low dose/many sessions approach. She was treated at MedVet by Dr. Prescott 13 times. Despite the enormous effort that was made to save her life, her tumor grew back very soon after her treatments ended and she passed away. Lily was just one case so there is no way of knowing why her treatment was not more successful, but I figured it made sense to take a different approach with Paco. There was no doubt in my mind that the high dose/few sessions treatment course was the right one. So, all the pieces had fallen into place.
Treatment
Paco was diagnosed by Dr. Wagner on October 21. On November 9 we made our first trip to the MedVet facility in Ohio. It was a three hour drive and I was so nervous about how Paco would do, but things went pretty well. One of my friends came with us which was great, because one of us could let Paco sit on our lap while the other drove. Paco hated being in his carrier and was much happier having a bit of freedom. We met Dr. Prescott and talked at length. She examined Paco and determined he was healthy enough for treatment. In order to minimize the number of trips we would have to make to Ohio, MedVet had agreed to schedule Paco’s first treatment for the same day as our initial visit and so, after our meeting, treatment began.
Paco was anesthetized and given a CT scan to precisely pinpoint the tumor. A CT scan is expensive, but it is the most accurate method of figuring out exactly where the tumor is. Dr. Prescott needed this precise information so that she could focus the radiation as much as possible, thus minimizing damage to surrounding tissue. After the CT scan, the radiation was administered.
While all of this was going on my friend and I waited in the waiting room and after an hour or two Paco was returned to us, packed into his little carrier. He was very wobbly and bleary eyed and his back was shaved, but they told me he had done well. We headed off for the long drive home, being careful to keep the car as warm as possible. Paco would not eat during the car ride, but he was very thirsty. We stopped a few times and let him drink as much water as he wanted.
When we got home, even though 3 hours had passed, Paco was still very wobbly and disoriented. When I let him out of his carrier he lurched around so much I was worried he would get hurt. I put him back in his carrier a little longer to give him time to recover, and then let him out. He was clearly distressed and it was very upsetting. I tried to follow him around and get him to lie down and I tried to put blankets and a hot water bottle near him so he did not get too cold. Eventually he settled down and went into his little cardboard house. He stayed in there all that night and I was so worried.
I paid very close attention to him while he was recovering and did everything I could to get him to eat. It is of course very dangerous when rabbits don’t eat, so I put little pieces of hay and little pieces of his favorite veggies into his house, right in front of his nose. I found that if I did this, he would nibble. He spent most of the following day in his house, but eventually he did come out. I was in the living room watching TV and I remember being so relieved when he came hopping down the hall and lay down on the rug. I knew then he had made it through that first treatment and would be OK.
My memory fails me here in regards to the specific details of each of Paco’s treatments and recoveries. I can tell you that although the process was difficult, it was not as bad as I thought it would be. It was bearable. Each time we drove to Ohio, Paco did OK and would eat hay and hop around while we were waiting for his appointment. Each time he got through the treatment without too many problems, and each time he was all wobbly and disoriented when we got home. He would generally go rest in his little house and after a day or two he would come out and things would go back to normal.
There are a few things that I think were very important in allowing Paco to get through the radiation treatments successfully. First, I kept him eating and drinking up until the last possible moment. I brought hay with me to all the sessions and offered him choice tidbits, trying to get him to eat as many strands as possible while we were in the waiting room. Check with your vet to make sure, but everyone I have consulted with has agreed that it is okay for rabbits to eat right before undergoing anaesthesia – they don’t need to fast the way other animals do. Second, after each treatment I made sure he had a quiet, warm place to rest and recover where he felt safe and secure. And third, I went to enormous lengths to get him to eat during his recovery period. I put little bits of hay and veggies right next to his nose and also offered him Oxbow Critical Care mixed with apple sauce, banana, or pumpkin as well as pieces of fruit and even treats. I took the view that anything I could get him to nibble on would make him stronger and keep his digestive system moving. I would also periodically offer him a small dish of water.
The effect of the radiation on the tumor was immediate and drastic. Paco’s eyes were back to normal the day after his first session. Each time we returned to Ohio the tumor was smaller than it had been on the previous visit. Aside from the day or two that it took for him to recover from each treatment, he did great. He seemed happy and healthy and energetic and it was so nice to have him back to his normal self.
Paco was treated on days 1, 7, 21, and 35. That is, he had his first treatment on November 9, his second treatment a week later on November 16, his third treatment two weeks after that on November 30, and a fourth treatment two weeks after that on December 14. Each time he was administered 8 Gy for a total of 32 Gy (4 fractions at 8 Gy each = 32 Gy). I had originally only planned on three treatments but Dr. Prescott said she strongly recommended four treatments as that was a standard palliative approach. I had wanted to stick to the plan outlined in the article, but deferred to her judgment. Over the course of the four treatments Paco had two CT scans to help pinpoint the tumor, and two x-rays. The CT scans are more accurate but also much more expensive, so Dr. Prescott suggested using x-rays for a few of the visits just to save money.
After our fourth visit we were discharged from MedVet with a much-shrunken tumor and instructions to get a checkup at our local vet within a month or two, depending on how Paco seemed to be doing. It took Paco a while to recover from that fourth treatment but within a few days he was healthy and happy and vibrant with a big appetite, and we were ready to see what the new year would bring.
Follow Up
During the month or so after Pacos’s last treatment I was so nervous. I was constantly staring at his eyes, constantly worrying that the tumor was going to come back. On January 24, 2011 we went to see Dr. Wagner for our first checkup. He took an x-ray of Paco’s chest and gave us the good news that the tumor looked really small! The x-ray was sent to Dr. Prescott in Ohio for confirmation. I was thrilled. Paco continued to do well so I waited three months before taking him in for another x-ray on April 25, 2011. Once again, the tumor was very small. Dr. Wagner said it did not appear to have grown at all and that, knock on wood, Paco might be able to go back to being a regular bunny. Dr. Prescott reviewed the x-ray, agreed that it looked good, and gave me instructions to continue having Paco checked periodically.
During this time I administered the herbal chemotherapy neoplasene to Paco on an off-again, on-again basis. Neoplasene is inexpensive and Paco did not mind eating it if I sprinkled it on a treat. Dr. Wagner said he did not know if it would help, but that it would probably not hurt. So I figured what the heck. The problem I had was that whenever Paco seemed under the weather, I became convinced it was the neoplasene that was making him feel sick and I stopped giving it to him. I have absolutely no reason to believe the neoplasene was affecting him in a negative way. I have several friends who administer it to sick rabbits on a regular basis with no problem. It was just something I was paranoid about and I am mentioning it here for the sake of being totally thorough in my description of Paco’s treatment.
On May 5, 2011 Paco celebrated his seventh birthday. I was so thrilled that he had made it to that critical date. Back when he first got sick I assumed he’d be gone before he turned seven.
Everything seemed great.
But then everything very suddenly went downhill.
On May 12, 2011 I woke up and Paco seemed fine. He was energetic, running around the apartment, chewing on things and digging at the couch. A half hour later when I got out of the shower, he was hiding in his house. It was so sudden. I could tell right away something weird was going on. He did not seem to be in distress, but he would not eat, not even treats. When things had not changed by the following evening, we took a trip to the ER. They administered subcutaneous fluids and pain meds. He still would not eat. The following morning I made another panicked trip to the vet, just looking for answers. They x-rayed him and listened to his heart and lungs, which seemed fine.
The next few weeks are really just a blur. Paco had what I considered to be a case of stasis. He was off his food and had bouts of obvious pain. At different points he was on metacalm for pain and reglan and cisapride for gut mobility. He had good days and bad days. I hated force feeding him, but I periodically (depending on how much he had eaten that day) fed him Oxbow Critical Care with a syringe. I bought every possible kind of vegetable and herb I could think of and literally chased him around the apartment trying to get him to eat. As always when he was sick, I found that if I offered him single pieces of hay by hand, he would sometimes eat them, and the same was true if I offered him small pieces of kale, basil, and so on. I offered him fruit, dry oatmeal, and treats. I figured whatever I could get him to eat, it would be worth it. There were a lot of ups and downs. One day he would seem fine, and the next he would seem distressed again.
Despite the stress of all this I always just thought it was stasis and that he would get over it. I didn’t think it had to do with the cancer, and I just assumed that since he had successfully battled a tumor, he could get past stasis, too. And he did slowly get better. By the time about two weeks had passed things were sort of back to normal. He was eating and seemed happy and I was not too worried.
One ongoing concern I had was that Paco was having trouble with his teeth. As rabbits get older their teeth can develop spurs, or sharp spots, which need to be filed down. Dr. Wagner had given Paco a dental exam and said that we needed to “keep an eye” on the situation. Just to be on the safe side, I made an appointment with Dr. Wagner to have Paco’s teeth checked one more time, to see if they might have contributed to the stasis. The appointment was on May 24, 2011 and I really considered canceling it. Paco was doing better and I did not want to stress him out with a trip to the vet. But in the end I figured that having his teeth checked was important, so we got in the car and went. I really, really regret that decision. The vet’s office was extremely crowded that day and we had to wait for ages. It really upset Paco. Dr. Wagner did not find anything wrong with his teeth. He tested his urine and said that his kidneys were not performing well, but that it was not necessarily a huge concern.
After that trip to the vet, things were pretty bad. Whatever steps Paco had taken towards recovering from his stasis seemed to have been erased. He did not seem unhappy, but he would not eat. I force fed him critical care and medicine, something I swore I would never get in the habit of doing. I did not want to force feed him just to keep him alive if there was no chance of him getting better and starting to eat on his own. However, even though the fact that he was dying seems obvious in retrospect, at the time I thought I was treating stasis and that he would recover. I guess I just did not want to see the truth.
On June 1, 2011 I got home from work and Paco was obviously not doing well. For the first time ever he was breathing very rapidly and seemed to be in distress. I sat with him on the living room floor and pet him and he seemed to calm down. We both went to bed that night in our usual spots.
The next morning his breathing was still very rapid and I called Dr. Wiles in an attempt to get an emergency appointment. We arrived at his office around noon and as there was a long wait to be seen, we were ushered into a private waiting room. I was able to spend a lot of time with Paco on the floor, both of us sitting on a towel. Dr. Wiles was finally able to see us and said we needed to get a chest x-ray to see what was going on. He put Paco in an oxygen tank for a while to make him more comfortable and then took the x-ray. The finding was that Paco’s chest was filled with fluid, compressing his heart and lungs and making it hard for him to breathe. Dr. Wiles said there were numerous reasons why the fluid might have accumulated, including heart failure, infection, and so on. He recommended a chest tap to drain the fluid, which would make Paco more comfortable, and would allow us to get a sample for testing.
I found myself once again in the position of having to make an important decision about Paco’s treatment. Would performing the chest tap be taking things one step too far? Was it just too much to subject him to? On the other hand, did it make sense, after all we had been through, to give up now? Dr. Wiles told me that in his opinion, doing the chest tap was reasonable. He said it was not terribly invasive, that it would provide immediate relief for Paco, and that it would allow us to determine the cause of the fluid. If it was caused by something easily treatable, we could treat it. If it was caused by something very serious that would not get better, I could have Paco put down. I spoke with Dr. Prescott in Ohio and she agreed. It seemed like a reasonable course of action, and so I authorized it.
Paco died during the chest tap. Dr. Wiles said that he suddenly and unexpectedly went into cardiac arrest. They tried to revive him for several minutes but his heart had totally stopped beating and did not resume.
Dr. Wiles offered to perform a mini autopsy – nothing too invasive, just basic enough to take a look at the tumor. I wanted this done because I wanted to know if the tumor had started to grow back. He found that the tumor was still very small. The nature of the fluid in the chest, along with the physical condition of the heart, led Dr. Wiles to believe that Paco had been suffering from congestive heart failure.
A lot of questions remain. The radiation was obviously successful at shrinking the tumor. It started shrinking after the first treatment and never grew back. But something else obviously went wrong. If Paco really had heart failure, why? Was it just a coincidence that he should have heart failure and cancer? Was the stasis caused by the heart failure, or was it unrelated? Why was his chest filled with fluid on the day he died, but clear just a few weeks before?
My best guess is that the radiation damaged Paco’s heart. The tumor and the heart were so close together – they were virtually indistinguishable on the x-rays – it makes sense that they both would have absorbed some of the radiation, even though it was only meant for the tumor. I never had a chance to discuss Paco’s death with Dr. Wagner but heard second hand that he had the same suspicion I did. He speculated that the radiation could very well have caused damage to the heart that gradually worsened over time. The condition could have built up gradually yet expressed itself very suddenly. I explained everything that happened to Dr. Prescott and would really like to hear her opinion on why Paco died. I have not heard from her yet but if I do, I will update this site.
I feel terrible that Paco died at the vet’s office. I feel terrible that I forced him to eat and forced him to take medicine for the last few weeks of his life. But I was just trying to help, and I think he knew that.
