• Discussions taking place within this forum are intended for the purpose of assisting you in discussing options with your vet. Any other use of advice given here is done so at your risk, is solely your responsibility and not that of this forum or its owner. Before posting it is your responsibility you abide by this Statement

Overactive Thyroid

popcornpiggles

Junior Guinea Pig
Joined
Nov 1, 2018
Messages
63
Reaction score
67
Points
220
Hi everyone. I recently posted this thread about my guinea pig Merlin and his issue with lice and sudden weight loss (though please be aware that the title is incorrect, I mistakenly referred to the parasite as static lice when they are in fact just lice, sometimes referred to as running lice).

Two weeks of ivermectin shampoo and the lice are almost eradicated. Only found a single louse on Merlin last time I inspected his fur! However, Merlin's weight has dropped to just 600g, and in his increasingly frail condition, it seemed unwise to bathe him for the final treatment, so the shampoo has been put on hold until his condition is less critical.

As the previous post details, I took him to the vet to be examined, and was told there was nothing obviously wrong that they could see without performing further testing, so I was advised to treat the lice and see if the weight loss was merely a result of the parasite making him uncomfortable. Unfortunately, and as I suspected, he only continued to drop in weight.

I had been supplementally feeding him, but lay off this as it was obvious that he was eating and drinking - in fact, he has been eating and drinking far more than usual, and lately I have had to refill the water bottle twice a day as opposed to just once. He is very excited by food, which is, of course, quite normal guinea pig behaviour, but the level of excitability is extremely out of character for Merlin. He is standing upright begging for treats every time I pass by the cage, and when I have him out to feed vegetables, pea flakes, or extra pellets, there is just no point where he seems to have finally had enough.

His excitement does not seem to be limited to food, however - he is uncharacteristically lively, nearly always at the front of the cage looking to interact with us, and when he's not doing that, he is usually pestering his girlfriends or at the water bottle. Now, obviously none of this sounds like the behaviour of an unhealthy guinea pig, but knowing Merlin's personality, this is extremely odd. Since we got him at 6 months old, he has always been a lazy lump of a piggy, more interested in having a nap on your shoulder than exploring the carpet. During floor time, he is consistently the only guinea pig of the herd that chooses not to leave the cage.

So, imagine my surprise when my girlfriends comes up stairs and tells me that Merlin is in the hallway 🫣

We have absolutely no idea how he escaped, but the trail of poops across the living room into the hall don't lie! Of course, she put him straight back, and we pig-proofed the living room and kept the door shut overnight to ensure that he was safe if he escaped again. But I cannot stress enough quite how out of character this is for Merlin!

With all of these symptoms, my mind jumped to hyperthyroidism, and after a vet trip this afternoon, the vet also brought this up as a likely candidate, as well as one of the most treatable of potential diagnoses. She also mentioned his heart beating very fast, which can be another symptom, but then he was also likely anxious at the vet and his heart will be under a lot of strain from the effects of the weight loss. Drawing blood to test for thyroid issues, however, was unfortunately not possible with quite how stressed and overactive Merlin was, and after an hour of trying and taking breaks so as to not upset him too much, they were only able to draw enough to test glucose levels, which were normal.

The vet then offered two options for the next step: either, he could be put under anaesthesia in order to draw enough blood without him becoming anxious, which would also be an opportunity to test for multiple other potential issues, or we could start him on a medication to regulate his thyroid and see if that helps him improve. Now, both options have potential risks, but, ultimately, I was not comfortable with the idea of him going under anaesthesia while so underweight, so I opted to start him on 1mg Thiamazole daily and see if he improves.

Of course, he is not definitively diagnosed, and I will update on his progress, but I thought I would share this anyway, as there seems to be a lack of information regarding hyperthyroidism in guinea pigs (well, guinea pig health in general!), so I thought it might be helpful in case anyone has a guinea pig experiencing these symptoms!

I will update soon! Fingers crossed that Merlin recovers 🩷
 
Thank you for sharing your experience. I hope the Thiamazole helps him and Merlin is showing signs of improvement very soon and there will be no need for him to be sedated for blood to be drawn.
 
I had a piggie with hyperthyroidism, Tomie, diagnosed via blood work. Her main symptoms were weight loss despite having a very good appetite and a LOT of water consumption (she was actually initially suspected to be diabetic because she was so thirstly.) Eventually blood tests showed hyperthyroidism (her thyroxine levels were about 11, normal was under 7.) So she was started on methimazole for us to gradually up-titrate until we found a balance where she gained weight or at least stayed even (we also started at 1 mg twice daily, we were told that 1 to 5 mg twice daily was the acceptable dose.) We had to keep up-titrating until about 4 mg twice daily, at which point she did start putting on some weight. From my understanding hyperthyroidism is not very well-studied in guinea pigs, but I am more than happy to share my experience with Tomie if you have any questions or if it helps you navigate this in any way. Unfortunately Tomie is no longer with us, she developed a URI, seemed to be improving, and then passed away really suddenly (we think it was probably heart-failure related in some way and it's hard to say how much her thyroid condition played a role in that or not.) I would be really happy if her experience could be used to help other piggies!
 
Thank you for the comments on this post and apologies for not responding. Unfortunately Merlin did not make it. I think his body had already deteriorated too much for the medication to make a difference. I hope that this information can help others recognise symptoms in their piggies, and from what I have learned from this, I think it is really important to catch these things before there is too much bodily deterioration to come back from, which is hard because all of this happened within the frame of a month. Acting quickly could be life saving!
 
Back
Top