Axolotl not eating but can't work out why

[mothEar]

I'm posting as I'm at a bit of a loss as to why my 9yr old axolotl has stopped eating.

He stopped when warm weather caused a spike in tank temperature to about 22 degrees celsius. I think the nitrate was also a little high as a friend looking after him for a few days while we were away left some old pellets in the tank. Nothing that couldn't be brought back down with a water change, but it had that nitratey smell. For a week or so, the temp came down to about 19-20 and the water parameters were fine again but he kept spitting out pellets so I assumed it was too warm for him to be hungry still.

Whilst the temp. slowly went back down we put him in the fridge too in case he had any digestive problems. He didn't regurgitate anything else in the 5 days he was in the fridge. He's been back in the tank for about 5 days and still doesn't want to eat. Since he's been back in the tank the temp. has been 17 degrees ish and pH, nitrate, nitrite and ammonia are all perfect. He's taken one pellet but spit it out again. We've tried tiny pieces of prawn and leaving frozen bloodworm cubes inside a jar in the tank, both of which he's usually keen on. It's getting close to 4 weeks that he's not eaten anything now.

He doesn't seem to be losing weight dramatically - although if anything he was a bit on the chunky side before. His skin looks super healthy and he's pretty active but his gills have got paler since he stopped eating.

Any advice would be greatly appreciated as I'm running out of ideas!

 

[wolfen]

pictures would help.
although you say parameters are perfect what are they?
the part about being chunky is a concern.
fridging slows down the metabolism including digestion, because fridging slows the metabolism it can also cause organ shut down so fridging should only be done as a last resort.
what do you mean by nitratey smell? is it a slight eggy smell or like a pond smell?
do you use substate, if so what ie.. sand etc..
apart from lack of appetite are there any other symptoms?
because of the lack of weight loss and pale gills use 100% holtfreters + 0.2g/l magnesium sulphate, if you can test kh gh.
info on holtfreters.. Axolotls - Requirements & Water Conditions in Captivity

 

[mothEar]

Thanks for your reply. Here's a picture of him from above.

Parameters are pH 7.5, Nitrate 0-1 ppm (test kit is scaled in increments of 2.5 ppm), Nitrite 0, ammonia 0-0.1ppm. Temp is currently 17 degrees.

By nitratey I mean like a pond smell, but that's gone now. He's on sand and has been for about 7 years or so. No other symptoms apart from lack of appetite. He's lost a tiny bit of weight, but as you can see isn't thin.

 

[wolfen]

the nitrate are unusually low, make sure your air-stones are clean and working, as well as regularly turning the sand over to prevent anoxic areas .
his arms aren't overly chunky although using holtfreters would still be helpful.
keep an eye on his size, without him feeding if he continues to put girth on (even whilst using 100% holtfreters + magnesium sulphate) he will need to see a vet.