Hi dvasq,
To help you with your axie, i need to ask a few questions as well as for you to do a few tasks.
1 - What do you feed your axolotl, how often and how much of each?
2 - What are the water parameters (Ammonia, Nitrite, Nitrate, pH)?
3 - What is the water temperature? Does it fluctuate drastically throughout the day?
4 - Are there any excessive water currents?
5 - Do you have any other animals in the same tank?
6 - Have you changed anything in the tank or routine care recently? Did you add a new plant or ornament etc?
7 - What substrate if any do you use?
8 - From your description, your axie displays the following signs of illness - Inappetance, intermittent appearance of red speckling, unusual behaviour (twitching, spasms, stiff hind legs). Does it have any other signs? Please be as thorough. Are there unusual growths or skin/gill discoloration? Any unusual looking faeces? Does the axie's mouth open and close rapidly like 'gurgling'?
9 - If possible, pease take some photograhs and post here.
10 - How do you perform the refrigeration?
My tentative differentials are parasitism, toxicity and neurological illness. It would depend on your answers of the above to give me a better idea, and then i can formulate some plans for you.
Cheers.