My skink's body is jumping occasionally as if he's hiccuping

[rixusaku]

Like the title says, I'm not sure if this is a behavior to be concerned about or not. Occasionally his whole body will sort of jolt for a quick second and I'm not sure what it is. He doesnt make any noise when he does it and he's not doing anything odd that I can notice before it happens. He seems to be doing fine otherwise.

He has been getting dusty and sneezy though, so I think the coconut fiber substrate I have at the very bottom of the tank has dried up. It's the eco earth stuff from the brick format. I'm going to be replacing all of his substrate here soon toward the end of next week to do the monthly full cleaning and skipped buying the eco earth this time. He'll only be on repti bark and coco husk moving forward, which is currently what's mixed in with the eco earth.

Is it the dried up coconut fibers that's causing the reaction and does anyone think I should do my full cleaning earlier to remove it and replace it with the new substrate?

For more information, he's a 2 year old northern, the hot side of his tank is around 95 with the cool end around 75, and his basking spot is around 100-105 all in farenheit. I started noticing the behavior when I started monitoring him more regularly throughout the day. I brought him home from the shop on the 9th this month and left him be with little check ins for the first few days he's been home. I also got a first initial vet checkup Wednesday last week along with a fecal sample and the vet told me that he was doing very good and was healthy (although they did notice some flatulence in the fecal sample. Not sure how or what's causing that but they ruled it as a low concern). I wasnt there in the room when they checked him out since they had me wait in the parking lot due to covid, so I don't know if he exhibited the behavior while he was in the checkup. I also didn't really think about it at the time since it wasn't on my radar, but it doesn't seem to be going away so I'm starting to get a little worried about it. He does it maybe once or twice every other day that I've noticed.

If you guys think I should take him in for another visit let me know, or if it's just a substrate change that's needed. Thanks!

[rixusaku]

Oh, also, the humidity in his tank is usually around 35-45% and gets to the 50's if I spray it with water. His coloring is looking pretty dull compared to when I got him, so I think he's due for a shedding here soon. His belly scales feel smooth though and not too dry.

[IvanDanko]

Hi Rixusaku,

In the absence of an audible sneeze or other symptoms, what is your skink doing when this usually happens? It sounds fairly infrequent if its only once or twice every other day. Is it usually after it has been sitting in one spot for a while? Potentially it sounds like your skink might be napping and has 'jolted' awake. My skink does this every once in a while, particularly while basking or after sitting in one spot for a long time when being held. If I recall correctly, I think BTS can sleep with their eyes open/one eye open as an evolved mechanism to rest parts of the brain whilst other parts remain active, as can some other animals. I have observed this quite a few times in person myself.

[rixusaku]

He usually looks awake when he does it, but it does resemble an "I just woke up" jolt a lot. Sometimes he'll move his head to look at me when I'm near, pause a moment, then jolt in that manner you described and goes about his business. So it's possible he's partly asleep when he's doing this and then waking up like a kid who falls asleep in class lol.

[splashy07]

More than likely just a sneeze. There is nothing wrong with coco fiber, I have been using it forever. You don't have to necessarily 'see' a sneeze, they are just clearing their air passages.
Northerns seldom have issues, I wouldn't be concerned if he's doing what skinks do otherwise.

[rixusaku]

Ohhh ok! He does sneeze normally too, but that could be it too. Alright, I think I will just continue to monitor him at home to make sure it doesnt turn into something else or get worse and to see if it goes away once I do his monthly cleaning. If it changes or gets worse I think it would be time to call his vet, haha.

Thank you guys for all your help, I feel much much better about it! This morning was also his second time being handled since I got him and he didn't get huffy at all, so I'm very excited about the trust progress right now. He looked like he was enjoying the neck and chin pets too. :D