Is My Axolotl Sick? 10 Warning Signs Every Keeper Should Know

By The Bognook Team · written & researched by amphibian keepersJul 24, 2026🔍 Keeper-reviewed for accuracy

A hand-drawn monochrome info-comic titled 'Too thin, just right, or bloated? - Axolotl' comparing three axolotls — too thin (a narrow body, thin tail and short gills), just right (a rounded body, broad tail and full fluffy gills), and bloated (a swollen belly, labelled 'not fat - fluid or impaction', a vet sign). — Judge an axolotl by its gill fullness and body/tail width: narrow with short gills is underfed or unwell, rounded with full fluffy gills is healthy — and a swollen belly is a vet visit (fluid or impaction), not overfeeding.

First: if you’re reading this because something looks off, take a breath. Axolotls are hardy, most problems are caught in time, and the fact that you’re checking makes you a good keeper. Here’s the honest checklist.

🔧 Worried about a symptom? Our free symptom checker takes you from what you’re seeing to watch · adjust · see-a-vet in about a minute.

The 30-second version

A healthy axolotl has full, forward-facing fluffy gills, all four legs and toes, clean unbroken skin, a steady appetite, and calm resting on the bottom. If you notice any of the signs below, don’t panic — do these three things first, because they fix the majority of issues:

Test the water — ammonia and nitrite should both read 0.
Check the temperature — it should be 16–18°C (60–64°F). Warmth is the #1 hidden cause.
If in doubt, tub — move them to a clean container of cool, dechlorinated water with daily 100% changes while you sort the tank.

Now the signs, roughly from “monitor” to “act now.”

The 10 warning signs

1. Gills curling forward or shrinking 🟡

The classic stress signal. Usually water that’s too warm, too much filter flow, or an ammonia/nitrite spike. Do: test water, check temp, reduce flow. Shrinking gills over time = chronic bad water.

2. Not eating for over a week 🟡

A day or two off food is normal. A week-plus usually means the water is too warm or dirty. Do: check temp and parameters, then tempt with a live earthworm at night.

3. Floating or unable to stay upright 🟡

Usually trapped gas or constipation, often linked to heat. Do: cool the water, reduce stress; a short fridging/tubbing period is the common first step. Persistent or with a swollen belly → vet.

4. Cotton-like white fuzz (fungus) 🟡→🔴

Fluffy white tufts on gills or body, usually after stress. Do: improve water, keep it cool, tub. Mild often clears; if it spreads, see a vet.

5. Red, irritated, or unusually pale skin (or bright red gills) 🔴

Often an ammonia burn or poor water quality. Do: immediate water test + large water change (or tub in clean cool water). This one climbs the ladder fast.

6. Frantic swimming or gulping at the surface 🔴

A distress signal — bad water, heat, or low oxygen. Do: test and change water now, cool the tank, add gentle surface movement for oxygen.

7. Curled tail tip or a hunched, tense posture 🟡

Ongoing stress. On its own it’s a “check everything” flag. Do: review temp, params, flow, and hiding spots.

8. Skin sores, open wounds, or a “melting”/degrading look 🔴

A real emergency — infection and/or severe water problems. Do: pristine cool water immediately and contact an exotics vet. Don’t wait this one out.

9. Weight loss (very thin) or a swollen, bloated belly 🔴

Thin = not eating/illness; bloated = possible impaction (often from swallowed gravel) or internal issue. Do: remove any gravel, review feeding, and get vet advice if the belly is distended.

10. Lethargy + hiding + refusing food, together 🔴

Any one alone can be minor; all three together points to a systemic problem. Do: full water test, cool the tank, tub, and call a vet if it doesn’t turn around quickly.

See a vet now if…

Open wounds or “melting” tissue · spreading fungus · a badly swollen belly · anything that doesn’t improve after you’ve cooled the water and fixed the parameters. A vet call is never the wrong move.

The pattern to remember

Notice how often the fix is the same three things — cool water, clean water, less stress. That’s not a coincidence: the vast majority of axolotl “illnesses” are really water problems wearing a costume. Aquatic veterinarian Jessie M. Sanders, DVM, CertAqV puts the target plainly — “The ideal temperature for Axolotls is between 60-64° F (16-18° C)“¹ — noting you need no heater, and in warm climates a chiller. That cool, stable water is exactly what keeps most of this list from ever appearing.

💚 You don’t have to figure this out alone or feel silly for asking. Cool the water, keep it clean, and reach out to an exotics vet or a kind keeper community. Most problems, caught early, are completely fixable.

Go deeper: the complete Axolotl Care Guide · axolotl questions answered · the printable care sheet · Is my amphibian okay? — the all-species check.

Sources & further reading

This checklist was written and fact-checked against these authorities. It’s kind, general guidance — not a diagnosis or a substitute for an exotics vet:

Caudata Culture (caudata.org) — axolotl health: gill/stress signs, fungus (saprolegnia), tubbing and fridging, and the cool, cycled-water husbandry these problems trace back to.
¹ PetMD, “Axolotl — Ambystoma mexicanum” — by Jessie M. Sanders, DVM, CertAqV (Certified Aquatic Veterinarian). The quoted cool-water target (16–18°C, no heater, chiller in warm climates).
Merck Veterinary Manual — amphibians — fungal and bacterial skin infection, gut impaction, and edema.
Standard aquarium water-quality science (the nitrogen cycle) — why ammonia 0 / nitrite 0 and 16–18°C matter.
Association of Reptilian & Amphibian Veterinarians (ARAV) — a find-an-exotics-vet directory.

Written and fact-checked by The Bognook Team against veterinarian-authored sources — open wounds, “melting” tissue, or spreading fungus need an exotics vet.

Common questions

How do I know if my axolotl is sick?

Watch for these warning signs: gills curling forward or shrinking, not eating for over a week, floating or unable to stay upright, cotton-like fungus, red or irritated skin, frantic swimming or surface gulping, curled tail, skin sores, weight loss or a bloated belly, and lethargy with hiding. Almost every one traces back to water quality or temperature, so test the water and check the temperature first.

Are curled gills on an axolotl serious?

Gills that curl forward are a common early stress signal, usually from water that is too warm, too much filter flow, or an ammonia or nitrite spike. It is not an emergency on its own, but it is a clear sign to test the water and check the temperature (16 to 18C / 60 to 64F) right away.

When should I take my axolotl to the vet?

See an exotics vet promptly for open sores or wounds, tissue that looks like it is melting or degrading, spreading fungus, a badly swollen belly, or any symptom that does not improve after you cool the water and correct the parameters. When in doubt, a vet call is never the wrong move.

Why is my axolotl not eating?

The most common cause is water that is too warm or a water-quality problem, since stress suppresses appetite. Check that the temperature is under about 20C and that ammonia and nitrite are both 0, then offer a wriggling earthworm at night. A few days off food is not an emergency, but a week or more combined with poor water is.

What does axolotl fungus look like?

Fungus appears as white, cotton-like or fuzzy tufts on the gills or body, usually after stress, warmth, or poor water. Improve water quality, keep it cool, and consider tubbing (daily 100 percent water changes in a clean container). Caught early it is very treatable; if it spreads, see a vet.