Hi Suffolk axi,
I think the best way to investigate this is to create a problem list and then tackle each issue. Based on my understanding (from your history) as well as observations from the photos, the problem list i have identified is as follows.
- Inappetance
- Forward facing gills
- Possible behavioural change/lethargy (subjective)
- Red face (a bit vague)
- 75% monthly water changes
- Pebbles as substrate
- Dark coloured toe tips
Inappetance, forward facing gills and lethargy can be indicative of stress or the onset of illness. I would recommend you continue monitoring your axie for other signs such as curled tail tip, production of excess mucus on the skin, discolouration or lesion growths on the skin and gills.
The best way to treat and prevent this is to provide optimal conditions in terms of management and husbandry which i would elaborate below. In the event if you notice your axolotl's condition is deteriorating, you may like to consider fridging him. Fridging the axie would destress it and render the conditions less hospitable for opportunistic pathogens to proliferate. Fridging will boost your axie's immune system and buy you some time to work on the underlying problems, be it due to the water in the tank or illness in your axie.
To fridge your axie, adjust your fridge temperature to about 4 degree celsius. You can then place your axie in a container large enough to allow it to stretch out comfortably. Provide a lid (you can perforate it or use a netting) to prevent it jumping out. Water level should be such that it allows the axie to be fully submerged but yet not too much such that it floats. You can continue offering food daily. You should also perform daily water changes with clean dechlorinated water pre prepared by keeping in bottles stored in the fridge. This would prevent temperature related shocks.
Based on the photos, i couldn't really tell what you mean by 'red face'. I see a red streak across its face but i would thought that was a piece of bloodworm. If you refer to 'red face' as increased or darker pigmentation on the head region, i would not be overly concerned. However, if you notice a laceration, wound, bruise, or blood spots (petechial and ecchymoses), there is a possibility there may be a trauma. Again fridging should help in this case. If you notice increasing reddish hue and prominent blood vessels (due to plebitis, vasculitis), there may be a concern for scepticaemia (bacterial toxins in blood). However, i feel this is unlikely in this case as these cases tend to present with other signs of illness such as bloat.
The dark toe tips are indicative of maturity. This is normal and nothing to be concerned about.
I am concerned about the 75% monthly water changes. I would advise on 20% water changes conducted weekly rather than one huge change end of the month. This is because huge water changes would cause fluctuations in temperature and parameters that itself is very stressful to the axolotl. You should also aim to keep the bioslime (slimy layer) on your tank surfaces intact. Do not scrub them off. They are the beneficial bacteria that help in breaking down nitrogenous wastes. You should also use a good quality water ager (dechlorinator) that can effectively remove chlorines, chloramines and heavy metals whenever you change the water. Follow the instructions as directed on the product.
It is this point that i would also recommend you invest in a good colourimetric solution type test kit. There are master kits that contain all the tests you require. It is good practice to perform regular checks on water parameters. This allows you to evaluate when its time to change water and to assess if poor water quality is the cause of illness or stress in the axolotl. Although dipstick type test kits are cheaper, they are highly inaccurate so do not get those.
Another potential problem is the use of pebbles as substrate. Although most of the pebbles seem larger than the axie's head, i am concerned there may be smaller ones that can potentially cause an impaction when ingested. Furthermore the crevices render cleaning the tank difficult and as such translate to difficulty in managing water chemistry. You can use a bare bottomed tank or use sand as a substrate. Suitable sand includes freshwater aquarium sand, pool filter sand and childrens'play sand.
You have done a good job ensuring the axie is kept under minimal water flow, dim conditions and providing a stable 19 degree celsius water temperature. Continue to do so. You are also doing great offering a variety of food. Although you have provided one hiding log, you may like to add another hiding place.
Lastly, i wanted to mention that inappetance itself can also be normal in the sense that a matured axolotl will require less frequent feeds as compared to younger axolotls. Also, temperature plays a large part. If you have recently experience a cold spell or change of seasons, where the temperature has fallen, your axolotl may be reacting to the temperature change by eating less.
Please keep us updated and feel free to message if you have any further queries.
Regards