Documentation of Cushing's Disease in Syrian Hamster

[Kikya]

Around August of 2021, I started to notice some signs of strange behavior. I suppose you wouldn't notice unless you spend as much time with Dipper as I do. I noticed he had been more active/hyper lately (more wheel activity, more hyper when I handle him) and I noticed he'd been hungrier and more thirsty. Getting up more during the day to eat and drink. He had started losing some hair which I had initially attributed to getting older, as my best guess of his age was 1.5 years. His brother Nibbler who I also adopted had some hair loss though not as much as Dipper. I noticed there was more urine when I sifted his sand bath. So I decided to do some digging and I came with a idea of what I thought the cause might be and I message MissPxy, who confirmed what I had been thinking. Endocrine/thyroid issue.

So I found an animal hospital more experience in hamster care and we did some tests. Here are the notes from the first visit

On physical exam, Dipper was bright, alert, responsive and his vital parameters (heart rate and respiratory were within normal limits. He was 125 grams. Auscultation of his heart and lungs was normal. His abdomen was soft and non-painful on palpation and there was no obvious evidence of organomegaly or an abdominal mass. He had some mild hair loss around his neck, which could be normal age related change or secondary to an underlying endocrine disease or dermatologic disease. The remainder of his exam was unremarkable.

The combination of Dipper’s signs that you have been noticing at home may be due to an endocrine disease, such as Cushings disease (or hyperadrenocorticism), hyperthyroidism and/or diabetes. Laboratory hamsters have a high incidence of increased growth of the adrenal glands that produce cortisol (increased cortisol causes Cushings disease). However, there is very little published literature on clinical cases of Cushings disease in hamsters (only 4 cases in Syrian Hamsters have actually been reported). Even less is reported about hyperthyroidism in hamsters. Given Dipper’s age, we also cannot rule out the possibility that his signs are due to some form of neoplasia (cancer).

Dipper was anesthetized for x-rays and a blood draw. He did well under anesthesia once we gave him injectable sedation ahead of time and recovered uneventfully. His x rays revealed no obvious signs of abnormalities. His complete blood count and chemistry were largely unremarkable. One of his white blood cells (lymphocytes) were decreased, which is often seen in stressed patients and is unconcerning for Dipper. His creatinine kinase was elevated – creatine kinase is an enzyme that is expressed by various tissues, primarily muscle cells. We often see an elevated creatine kinase in patients that are stressed and very active during exams due to muscle exertion. His glucose level was normal so we can rule out diabetes at this time. The remainder of his CBC and chemistry were normal, however, we cannot rule out Cushings disease or hyperthyroidism or neoplasia based off these findings. We are still waiting for his T4 level to come back, and we will contact you with that result once it returns.

One thing they didn't mention in the report was, when they put Dipper under just normal anesthesia, Dipper started to have tachycardia and an arrhythmia, they undid the regular anesthesia and woke him back up and then called me to suggest doing the injectable sedation with much lower dose of anesthesia. This worked and Dipper's heart was fine. Injectable sedation takes long to wake up from and recover from but its much less stressful on the heart. Consider that as an option for your hammy if you think he might have a heart condition.

After that, I took him home and they called me to tell me xrays and bloodwork were mostly normal and they wanted to send out for a T4 test. A thyroxine test measures the level of thyroxine (T4) in the blood. Too much or too little T4 can indicate thyroid disease. This took about a week to come back and it was normal meaning his thyroid (which is in the throat area) was functioning.

The next step of diagnosis was to do an ultrasound of his adrenal glands. He was sedated again and they shaved his little belly and they found that his his adrenal glands looked slightly enlarged. They did tell me they didn't have much of a size comparison to go by but that they looked slightly larger than a few other sources. The one on the right being slightly larger than the left. So the provisional diagnosis is that he has Cushings disease.

So now they said we can either do more testing (a CT scan) to try to confirm more certainly (though they said it may not be more certain than with the ultrasound) or they could try to get enough blood from him to do a more bloodwork for a cortisol test or that they could start him on some trilostane (brand name is Vetoryl) to see if he has any noticeable improvement from the medication.

I decided to forgo more diagnostic testing to save Dipper the stress (since they weren't sure it would help anyway and they would end up recommending the same medication) and see if he improves on the medication. I plan to take careful notes on his behavior and perhaps will start bowl feeding him for a while to measure how much he eats and of what and weighing him weekly. I hope this will help some hammy in the future on here or at the hospital that I will be sending the notes to at the request of the vet. Also, I will edit this post more as we go along to document everything I can.

Notes from second visit:

Dipper originally presented on 9/21/21 for signs including weight loss, increased appetite, increased thirst, increased frequency of urinations, mild hair loss and hyperactivity/hyperexcitability. At the time, we were most suspicious of Dipper’s signs potentially being due to an underlying endocrine disease, such as Cushings disease, hyperthyroidism and/or diabetes. During his initial visit, we performed bloodwork (CBC, Chemistry and T4 level) and x-rays and the results of all of those diagnostics came back unremarkable so we could not rule out Cushings disease or less likely neoplasia at that time.

On physical exam today, Dipper was bright, alert, responsive and his vital parameters (heart rate and respiratory rate) were in normal limits. He weighed 126 grams (vs 125 on 9/21/21). Auscultation of his heart and lungs was normal.

Dipper was sedated for an abdominal ultrasound. We used a similar combination of injectable medications compared to his last visit and he did very well. He was stable throughout the entire ultrasound, and we never heard any arrhythmias or murmurs. His ultrasound revealed a mildly enlarged right adrenal gland compared to the left and they were both mildly enlarged compared to measurements of hamster adrenal glands in histology paper. There was also a cystic structure within the caudal abdomen that we believe to be an incidental finding (shouldn’t effect Dipper’s health or wellbeing). The enlarged right adrenal gland may be suggestive or a benign process called hyperplasia, a benign neoplasia called an adenoma or it may be due to adrenal dependent Cushings disease.

Given the ultrasound finding of mildly enlarged adrenal glands based on the paper we found, in combination with all of Dipper’s other signs you’ve been seeing at home, we are most suspicious of Dipper having Cushings disease. This disease causes the body to produce too much cortisone, which is a stress hormone, or related hormones in the body. Long term elevations in these hormones can have debilitating impacts on the body over time. We recommend initiating treatment for this condition with a medication called Trilostane, which is an adrenal steroid synthesis inhibitor.

Two weeks later, Dipper had been on the medication about 2 days:
Well, so far he's gained 5gs. I was told that if there were side effects or a response, I would see them within in a couple of weeks. I haven't noticed any change as far as side effects, which is good. But no regrowth of hair yet and he still seems to be very hungry. But not getting worse!

Month and half later, Dipper had been on the medication about 1 month:
We started a medication protocol of 0.1ml of Trilostane, once a day, which I administer with a small amount of baby food mixed it on a spoon. He licks his spoon clean, and we never have any issues regarding his intake of medicine.

Update:
Dipper has been on Trilostane for about a month and a week. Started on 10/11, Dipper has been doing great on the Trilostane. I have not seen any side effects that I can tell. He’s calmed down (not as jumpy or hyperactive) though still very positively active (running on wheel, digging tunnels). His hair is growing back! Before I could see his pink skin through his hair, and it was very stringy. Now it’s growing back, he has little butt floofs (which he had lost before) as he is a long-haired male. I no longer see the pink skin underneath, it’s thicker and the color is coming back to him. He had started losing color to the point where I couldn’t see much orange on him. He’s orange and white banded. He just looks more energetic like he feels better!

Update 2:
1 year later, Dipper has been on a continuous medication regimen of Trilostane:
Dipper has grown back much of his lost hair. It's not the same full mane he had before but I cannot easily see through to his skin and he is not getting cuts or losing hair. He's done very well on the trilostane and had no noticeable side effects. I rotate between baby food and oatmeal mixed with his medicine, because sometimes the baby food is too wet and gives him soft poops. His energy levels have stayed good and he's a very happy hamster. He was very unhappy before the medication so I am very happy that I've had a whole other year with him.

If anyone has any questions regarding Cushing's disease, I am happy to help.