Recently my male MBK (3 months old) has gone off food, his last meal was 2 weeks ago. He doesn’t appear to be in shed, though it’s been about a month since his last shed. He has also been randomly making what sounds like chirping noises. I’ve caught him doing it a couple times, his entire body tenses up when he makes the sound. My biggest concern is a respiratory infection, though he doesn’t seem to have any other symptoms at the moment. When I checked on him today he seemed more sluggish than usual. If it is a respiratory infection, is there any chance that it was caused by a powdery substrate? I use a mix or fir bark, cypress mulch, and reptisoil. His enclosure is rather dry, and the reptisoil is very powdery. Any help is greatly appreciated.
Respiratory infections can be viral, bacterial, or fungal so it’s generally hard to tell the source without knowing the specific pathway of infection. Viruses can also often cause secondary bacterial respiratory infections.
I would suggest a vet visit, it’s concerning to me when a dumpster feeder like an MBK is declining food,
Since he burrows frequently, I was concerned that the dust was getting in his nose, maybe clogging his airways and/or infecting him with an RI. I’ve scheduled a vet visit for next Monday, though I’ve considered also replacing his substrate with something less fine like aspen.
I would remove him from his enclosure right away and put him in a ventilated bin with clean paper towels instead of any other substrate. Of course give him a water bowl and a hide. And of course heat one side.
Also imho I don’t think fir bark is an ideal substrate due to the oil/scent of the bark. Of course someone please correct me if I am wrong! I seem to remember reading this somewhere? 
I am tagging @noodlehaus to verify all of the above and give any other input.
Btw welcome to the forum! I’m sorry you are having this issue with your little one! And most definitely a vet visit is a must! 
Welcome to the community, @ecg_605 . I’m sorry your snake’s causing you worries. I’ve got a couple of questions. How’s his behavior apart from not eating? Have you noticed him holding his head up, and/or holding his mouth open? Have you observed any mucus, or bubbles at his nose or mouth? How is his body tone? How long has this “chirping” been happening, and how frequently does it happen?
It’s possible that what you’re hearing is simply because the snake is soon to shed. Sometimes noisy breathing or whistle-type sounds can occur in the days before a shed occurs.
You’re right about pine and cedar oils being dangerous for herps. Fir trees don’t pose the same problems, though. (I was surprised when I learned this.) Fir bark is used with a lot of herps who like humidity, so this may be potentially problematic in another way. I don’t know.
Ahhh! Now I remember it’s pine and cedar! But I could have sworn fir bark was not ideal for some reason. I will have to do some research! And thank you for clearing that up Caryl!
I never thought about that either! Pre-shed is definitely a possibility! Let’s hope so @ecg_605 Thanks Caryl! I’ve gotta start takin notes! 
Been tagged so I’ll throw my two cents in: the shed interval could be a possibility here. It could also be that the dry substrate is irritating his nose and he’s doing a hard exhale to clean it out. I’d say it might be worth trying aspen to see if that changes anything.
That said, however, you did mention he’s more sluggish than usual, which is a good indicator that a vet visit is the right way to go, just to be sure it’s not something like an RI. Has anything changed in his enclosure recently? Temps stable and within the appropriate range? No drafts or anything?
I have made some changes to the enclosure recently, I removed about half of the substrate and added a lot of fake plants. He is in an enclosure that is way more than large enough for him at this age, 36x18x12. I first put about 8 gallons of substrate in, which was so much that the terrain had hills in it. I removed it because he spent a significant amount of time burrowing, even for a kingsnake. He would just disappear and I would eventually have to dig him out from under 6-8 inches of substrate. He can still burrow with the amount of substrate that is now in the tank, and I added the plants to compensate so that he feels more secure above ground. The temperature has not changed, I have a large heat pad beneath one side of the tank and a thermostat set to 95 F (to compensate for the heat lost through the substrate).
The chirping is something I first noticed about a week ago, but I assumed at first that it was just because I may have startled him. Now I have seen him do it not as a reaction to me, and most often right after he comes out of a burrow. It is concerningly loud for a snake his size, I can hear it clearly from across the room. I am certain the dust from the substrate has at least something to do with it, I just hope that it’s only that and not a RI. I have seen him open his mouth randomly a couple times, but very briefly and it wasn’t obvious that he was mouth breathing. I’ve checked his mouth a couple times for excess saliva/mucus and haven’t seen any. Though with a mouth as small as his it can be difficult to tell for sure.
The reptisoil I think is the issue, it’s mostly topsoil and sand. I think it’s made for higher humidity enclosures, because when it dries out it becomes a very fine dust.
Yes you are probably right. I am a big fan of aspen myself because I just don’t like dealing with “dirt”! 
Please do keep us updated! Sure hope he is all right!
Sounds like the substrate is contributing to the issue, at least. Like @caron, I’m an aspen fan. It comes in varying textures, depending upon the provider, so there’s going to be one which your snake will enjoy. It’s good at for holding its shape for their burrows and tunnels. And sometimes I go in and fluff it all up again after spot- cleaning. That gives the snake something to do; make new tunnels!
That’s what I do! And you are right! It gives them something to do! 
Update: I took him to the vet yesterday, and he was prescribed antibiotics. They said that it was difficult to definitively tell that it is an RI (because he’s so small), but it is almost certain from the symptoms. She gave him a shot there, and showed me how to do it. I’ve also changed out the substrate to aspen, and will be turning up his heating pad’s thermostat. Thank all of you so much for responding!
So glad things are looking up for your little one! Hopefully switching to the aspen substrate will make a big difference! As well as the meds of course! 
Thanks for the update, @ecg_605 . I’m glad that you were able to get the little guy seen and treated. Hopefully he’ll get back to good health soon. Reptiles do take a while to heal; what with their slower metabolism. Warmer temps in his enclosure will be helpful there. He’s lucky that he’s got such a caring human to look out for him.
Update 2, he’s finally decided to eat! I couldn’t get him to take it from the tongs like he was before, but this time I decided to try braining the pinkie and putting him in a small tote with it and leaving him alone for a bit. He is also noticeably more active (not sure if that’s the heat or the aspen). Thanks again to everyone who responded to my post!
Yippee Kai 
Yay! I am so glad your little noodle boodle is eating again! That is a super sign he is on his way to recovery!
Please do keep us updated and there is a service charge for for all the advice: Pictures (at your convenience of course!) And his name too! 
Oh good! Glad your baby ate. That’s a very good sign. And yes please, pics and name when you have a chance! (Edited to fix autocorrect’s incorrect grammar. “you’re baby…” Sheesh! 
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