The 8-point health check
Scan your axolotl using these 8 features every few days. Together they catch about 95% of health problems before they become serious.
1. Gills
Healthy
Bushy, branching, bright red or pink
Warning sign
Stringy, curled forward, pale or white
Why it matters: Gills are the first thing to deteriorate in poor water quality. Color and shape change before other symptoms appear.
2. Body color
Healthy
Vibrant, even color matching the morph
Warning sign
Pale, washed-out, splotchy
Why it matters: Color reflects circulation and stress hormones. Pale color often signals chronic stress before behavioral changes.
3. Skin
Healthy
Smooth, slightly slimy, no patches
Warning sign
Dry-looking, white fuzzy patches, sores
Why it matters: Fungal infections (Saprolegnia) show as white cotton-like patches. Catching early treatment is much easier than late.
4. Body shape
Healthy
Plump and well-fed, slightly tapered tail
Warning sign
Thin, visible spine and ribs, swollen belly
Why it matters: Thin axolotls are underfed or sick. Swollen belly indicates impaction or excessive gas.
5. Eyes
Healthy
Clear, bright, normal size
Warning sign
Cloudy, sunken, swollen
Why it matters: Eye changes often indicate water quality issues or age-related changes. Sunken eyes suggest dehydration despite living in water.
6. Tail
Healthy
Symmetric fin, smooth edges, follows body line
Warning sign
Frayed, bitten edges, kinks in spine
Why it matters: Tail damage is often from tankmates (a problem itself) or fin rot from water quality. Spinal kinks indicate calcium issues or breeding stress.
7. Activity level
Healthy
Calm bottom-walking, responsive to food
Warning sign
Constant hiding, refusing food, glass-surfing
Why it matters: Behavior changes are the most reliable early warning. Active axolotls becoming withdrawn means something is wrong before physical signs appear.
8. Breathing
Healthy
Quiet gill movement, occasional surface gulps
Warning sign
Rapid gill panting, constant surface gulping
Why it matters: Frequent surface trips indicate low oxygen (warm water) or gill damage that reduces breathing efficiency.
The fastest health check: gills first
If you only check one thing, check the gills. Healthy axolotl gills are:
- Branching out from the head like a feather duster
- Bright red or pink in color
- Many small filaments visible, looking fluffy
- Moving slightly with water flow
Unhealthy gills:
- Stringy and thin (water quality issue)
- Curling forward toward the head (ammonia or heat stress)
- Pale or white (poor circulation or chronic stress)
- Short and stubby (regenerating from bite damage)
What a healthy axolotl does each day
- Spends 60-70% of time resting or slowly bottom-walking
- Surfaces occasionally to gulp air (a few times per hour)
- Responds within seconds when food enters the water
- Doesn't constantly hide unless visibly stressed
- Doesn't constantly swim laps unless overstimulated
- Maintains stable body color (no rapid color shifts)
Healthy axolotl water parameters
| Parameter | Healthy range |
|---|---|
| Temperature | 60-68°F (16-20°C) |
| pH | 7.4-7.6 |
| Ammonia | 0 ppm |
| Nitrite | 0 ppm |
| Nitrate | Under 20 ppm ideal, under 40 ppm tolerable |
For the complete water parameter breakdown, see water parameters cheat sheet.
Healthy axolotl growth
By age, healthy axolotls reach:
- 0-3 months: Up to 3 inches
- 3-6 months: 3-5 inches
- 6-12 months: 5-8 inches
- 12-24 months: 8-10 inches
- 2+ years: 9-12 inches (mature size)
Significant deviation from these ranges (especially smaller) indicates underfeeding, water issues, or genetic limits. See how big do axolotls get.
How to keep your axolotl healthy long-term
The four pillars of axolotl health:
- Cool stable water (62-65°F sweet spot, never above 70°F long-term)
- Pristine water parameters (test weekly, change 20-25% weekly)
- Varied diet (pellets + earthworms + occasional treats)
- Low stress (no tankmates, dim lighting, minimal handling)
Early warning signs of illness
Catch problems early with these markers:
- Gill color shift from bright red to pale within 1-2 days
- Refusing 2 consecutive meals when normally hungry
- Constant hiding when previously visible
- Sitting still for hours when previously active
- Floating tail-up consistently
- Any visible white patches, sores, or growths
If you see any of these, test water immediately. Most of these resolve with water quality fixes alone.
Frequently asked about axolotl health
What does a healthy axolotl look like?
Healthy axolotls have bushy red/pink gills, smooth slightly slimy skin, plump well-fed bodies, bright clear eyes, smooth tail fins, and exhibit calm bottom-walking with responsive feeding behavior. Pale gills, white skin patches, thin bodies, or constant hiding are warning signs.
How can I tell if my axolotl is healthy?
Daily checklist: bushy red/pink gills, smooth skin with no patches, plump body, eating normally, calm behavior. Weekly: clear water test results (0 ammonia, 0 nitrite, under 20 nitrate). Monthly: stable body weight and no behavioral changes.
What are signs of a sick axolotl?
Stringy or curled gills, white fuzzy patches on skin, refusing food for more than 2 days, floating or drifting (especially belly-up), pale or splotchy color, lethargy beyond normal calm behavior, constant gasping at the surface.
How often should I check my axolotl's health?
Brief daily observation (1-2 minutes) checking gills, color, and behavior. Weekly water testing to verify parameters. Monthly: photograph the axolotl to track gradual color or body changes over time. Vet visit only if specific symptoms emerge.
Should I take my axolotl to the vet for a checkup?
Routine wellness vet visits aren't standard for axolotls (and few vets specialize in them). Only visit a vet if specific symptoms appear: persistent floating despite fasting, fungal patches that don't respond to salt baths, bloody discharge, severe lethargy.
For behavioral health specifically, see axolotl behavior guide. For floating issues (one of the most common health concerns), see why is my axolotl floating. For the broader care routine, see axolotl care guide.