How To Treat Axolotl Blisters And Axolotl Skin Bubbles? When To Worry?

Axolotl Blisters

Unlike most fish, axolotls don’t have a protective scaly coat. This means they are more prone to skin problems such as axolotl blisters, bumps, lumps, warts and more. It’s often really difficult to establish the cause of these problems which leaves owners in despair what to do with their sick axolotl.

In this article, we are going to explore all the possible causes for axolotl blisters and axolotl bubbles appearing on the skin aswell as recommend the best treatment options.

Axolotl Skin Problems

Tiny bubbles or bumps under the skin can be totally normal as they are just the pores that produce the axolotl’s slime coat. However, it’s good to keep in mind that axolotls are susceptible to various skin diseases.

Most common causes for skin problems such as axolotl blister and skin bubbles include:

  • Poor water quality
  • Water temperature issues
  • Overfeeding can cause cloudy water and an unbalanced tank
  • Faulty filtration systems or crack in piping

Disease introduced from live food especially fish, ornaments that aren’t aquarium safe, plants or objects from another tank that might be carrying disease or pollutants

Poor water quality is one of the most common causes of axolotl blister and skin lesions. Thats why purchasing a water quality test kit is highly recommended. This way you can test the water regularly and keep a diary.

Axolotl Skin Problems – Bubbles And Blisters

The causes for axolotl blisters or skin bubbles depends on the physical appearance and if there are any accompanying symptoms.

With that said, some of the possible causes for axolotl blisters or skin bubbles include:

  • Gas Bubble Disease
  • Ranavirus infection
  • Poor water quality
  • Bloat

However, if your axolotl is showing other symptoms such as floating for long periods of time, refusing to eat, even though skin bubbles like the picture above are completely normal, there can be some other health problem going on. To learn more about why your axolotl is floating, head over here Why Is My Axolotl Floating? 4 Causes For Floating Axolotl

Now, let’s take a look at axolotl blisters and bubbles as a symptom of a health problem.

Axolotl Bubbles – Gas Bubble Disease

axolotl blisters

If you’ve noticed axolotl blisters or bubbles under your axolotl’s skin that are nothing like the ones discussed in the previous section, it can be a sign of gas bubbles disease. This, non-infectious disease is often caused by the following:

  • Sudden additions of cold water to the tank. Sudden changes in the water temperature can cause bubbles. This is because the partial pressure of the gas changes with water temperature. Furthermore, colder water holds more dissolved gases than tropical water, and as it warms, these gases will turn into tiny bubbles, also known as microbubbles
  • Pumps and filtration problems can let too much gas into the water. There shouldn’t be high amounts of bubbles pumped into the water from your filter
  • Air stone malfunctioning

Once the microbubbles enter the blood and tissues of the axolotl, it causes it to swell up, float and the air bubble pockets can even fill with blood in some cases. Then, you’ll start to see axolotl blisters or bubbles like the picture above.

Although, the axolotl won’t die directly from the gas bubble disease, they normally die from a secondary bacterial infection known as Aeromona Hydrophila.


The main symptom of Gas Bubble Disease are bubbles trapped within the axolotl’s eye, gills, or skin. This disease begins as a collection of very small bubbles, known as microbubbles. These bubbles then become larger and more visible.

Another possible symptom is lesion in gills, and the choroid gland of the eye.


Diagnosing Gas Bubble Disease can be difficult without any obvious clinical signs and that is why axolotls can quickly die from it. There are a few ways you can confirm that your axolotl blisters are the result of Gas Bubble Disease:

  • “Candle” the axolotl with a strong light to check for more bubbles or blisters formed
  • Check the water clarity. If it has become cloudy, it means the tiny microbubbles are held in suspension. Collect a sample of the cloudy water and allow it to rest still for 30 to 45 minutes. If it is microbubbles, the water will become clear, and the bubbles will stick to the inside of the glass, like in champagne
  • X-ray or radiograph performed by a vet can confirm the diagnosis

When checking the systems in the tank such as water pumps, filtrations systems, etc., also check for tiny bubbles on plats, decorations and on the tank walls. This can also be a sign that of a problem with the gas released in the water.


If you suspect your axolotl blisters to be a sign of Gas Bubble Disease, follow these steps:

  • Remove the axolotl from the environment that might be causing the problem
  • Place your axolotl in a tub of dechlorinated water with temperature of 41.9°F
  • Put the tub and the axolotl in the fridge. Set the fridge’s temperature at 41.9°F
  • The feeding should be minimal whilst being fridged

After you’ve placed your axolotl in an environment where he can de-stress and starts healing, it’s now time to check the tank. Test and check all the piping thoroughly to find where the air’s getting in from. Possible sources for the microbubbles in the water include:

  • Air stone malfunctioning – remove it temporarily from the tank or replace with a new one
  • Gas supersaturation. If the filtration system is the culprit, you can check this by turning it off and observing if bubbles are still forming

If you establish that one of the systems are malfunctioning, you should immediately remove it from the tank and replace it with a new one.

The last step of this process is to perform deaeration of the tank.

As long as the underlying cause is addressed, over time the Gas Bubble Disease should resolve on its own.

On the other hand, if your axolotl still hasn’t recovered after being fridged for 1 to 2 weeks, it’s time to take them to the vet. The vet will then remove the bubbles by aspirating them with a very small needle and syringe. In addition, the vet might prescribe an antibiotic therapy.


To prevent future axolotl blisters forming from Gas Bubble Disease, follow these steps:

  • Are the plumbing and filtration are properly plumbed and sealed?
  • Maintain the water levels at an appropriate height and top off as necessary
  • Keep a diary of the topping off schedule. This will help you notice any leaks early on
  • Record the temperature of the water before and after water changes

Axolotl Blisters/Bubbles – Ranavirus

Axolotl blisters is often a symptom of a type of ranavirus, also known as Ambystoma tigrinum virus (ATV).

An axolotl can get infected with the virus in any of the following ways:

  • Transmitted through direct contact with an infected animal
  • Living in water that contains virus
  • Introduced from live food especially fish, ornaments that aren’t aquarium safe, plants or objects from another tank that might be carrying disease or pollutants

Although, ranaviruses affect axolotl at all life stages, mortality rates are highest if the axolotl contracts the virus during the larval stage.

It’s important to note that ranavirus is not infectious to humans.


Ranaviruses can quickly spread to the liver, kidneys and spleen. Once these organs are infected, the virus can quickly spread to other cells. Common physical symptoms of this virus include:

  • Subtle to severe hemorrhages in the skin, especially at the base of the hind limbs. These hemorrhages can appear from tip of chin to tip of tail ventrally and may be pinpoint or irregular patches
  • Swelling of the legs and body (edema)
  • Necrosis of the integument and internal organs
  • White plaques in mouth
  • Axolotl blisters, skin ulcers or sores
  • Redness of the skin (erythema)

Behavioral changes include:

  • Lethargy
  • Wheezing
  • Loss of weight
  • Erratic swimming
  • Abnormal wasting (emaciation)

It’s important to keep in mind that symptom of renaviruses in axolotls can be quite vague which makes it harder to diagnose.

Diagnosis & Treatment

Unfortunately, this virus is fatal and there is no treatment available. Once properly diagnosed the most humane thing to do is euthanise the sick axolotl.

If there are other pets living in the same tank as the affected axolotl, you need to quarantine them, the infected tank must be cleaned with bleach and all decorations thrown away.


To prevent infections such as renaviruses, good husbandry is key. This includes:

  • Disinfection of supplies
  • Use of gloves can reduce the chances of infection
  • Using 10% bleach solution to disinfect and clean equipment, surfaces, tanks
  • Quarantining new animals to ensure they don’t show any signs of the disease

Axolotl Blisters/Bubbles – Poor Water Quality

Incorrect water perimeters and poor water quality can result in many axolotl health problems. For instance, incorrect nitrate and ammonia levels can lead to skin irritations such as axolotl blisters and bubble-like sores.

So, what are the right water parameters?

  • Ammonia levels should be 0
  • pH levels. The ideal pH is 7.4-7.6
  • Nitrite levels should be 0
  • Chlorine is harmful for axolotls. Therefore, the water must be dechlorinated or left to stand for 24 hours before adding it
  • Water hardness. Axolotls prefer water that is slightly hard. This means that they need a good concentration of dissolved salts in their water. Hard water ensures healthy gills and healthy slime coat production. If you’re worried about the health of your axolotl’s gills, head over to the full guide Guide On Axolotl Gills Problems – What’s Healthy vs Unhealthy (with Pics)

If the water’s ammonia or nitrate are not 0 and you don’t test the water often, this might aswell be the reason for your axolotl’s blisters.

Ammonia Burns
Ammonia Burn

High ammonia levels will result in ammonia burns. Common causes of ammonia spikes include:

  • Overfeeding which leads to increased waste
  • Increased stocking density
  • The biofilter has been damaged (pump has stopped for a significant length of time, filter becomes clogged, filter is washed too thoroughly, chemicals including antibiotics used)

 The symptoms of ammonia burns include:

  • Gasping at the surface for air
  • Red skin patches like burns
  • Floating

To treat ammonia burns, follow these steps:

  • Multiple partial water changes (25–50% each time)
  • Use chemical filtration such as zeolite
  • Add proprietary ammonia-binders
  • Lower the pH closer to 6.5

If the ammonia levels are extremely high and you can’t get it under control within 24 hours, you should fridge your axolotl whilst performing a complete tank cycle.

Nitrate Poisoning

Nitrate is the result of organic and inorganic waste. If you’re not looking after your axolotl’s tank properly, the nitrate will build up in the tank over time. This happens much quicker in tanks without real plants.

Nitrate level should be below 50 mg/L. If your axolotl gets exposed to high levels of nitrate for long periods of time, it will lead to nitrate poisoning. Some of the symptoms include:

  • Exophthalmia and corneal opacity
  • Diffuse film of mucus

You can treat nitrite poisoning by following these steps:

  • Stop feeding
  • Multiple partial water changes (25–50%)
  • Add methylene blue at a rate of 1–2 mg/L. This will reverse the process of methaemoglobin formation (predilute the chemical, and avoid the biofilter intake)
  • Increase the Salinity (NaCl) by up to 2 mg/L, to competitively inhibit nitrite uptake by the gills
  • The pH of the water can be gradually raised to 8.5, and the water temperature reduced to 41°F to reduce to the toxic nitrate levels
  • Provide supplemental aeration, and additional nitrifying bacteria for the biofilter

If the nitrate levels are extremely high and you can’t get it under control within 24 hours, the next step is to fridge your axolotl whilst performing a complete tank cycle.


Axolotl Bloat

In some cases, what looks like there an air bubble stuck in your axolotl’s belly, it might be bloat instead. As axolotl’s skin is transparent, you will be able to see whatever is in your pet’s belly. Seeming as an air bubble at first sight, it can actually be a bubble filled with liquid which is what axolotl bloat is.

To read the full guide on axolotl bloat, head over here Axolotl Bloated Belly? Causes And Treatment For Bloated Axolotl

How To Treat Sick Axolotl?

Axolotl blisters and most skin conditions (not including fungus) can be treated in similar ways. The best thing you can do is fridge your axolotl whilst you investigate if their environment is what’s caused the problems in the first place.

Follow these steps:

  • Place your axolotl in a tub of dechlorinated water in the fridge. The water and the fridge should be the same temperature of roughly 41°F to 41.9°F. This will immediately de-stress the axolotl and provide them with an environment where they can start healing
  • Feeding should be minimal whilst fridged
  • Perform multiple daily water changes for the fridged tub

For the original tank:

  • Test the water of the main tank using a water test kit such as this one
  • Clean the tank and all decorations with bleach
  • Make sure all the equipment is working properly and there are no leaks
  • Complete 100% water change
  • Test the water again

Perfect Tank Water Perimeters

You want the perimeters of the tank water to always be the following:

  • Ammonia levels should be 0
  • pH levels. The ideal pH is 7.4-7.6
  • Nitrite levels should be 0
  • Chlorine is harmful for axolotls. Therefore, the water in their tank must be either dechlorinated or left to stand for 24 hours before adding it
  • Water hardness. Axolotls prefer water that is slightly hard. This means that they need a good concentration of dissolved salts in their water. Hard water ensures healthy gills and healthy slime coat production

Once your axolotl has improved, you can return them to the original tank. However, you should ensure it’s gradual as any sudden temperature change can really harm your axolotl’s health. This can be done reducing the water temperature in the original tank to the temperature in the fridged tub. Once the temperatures match as much as possible, you can return the axolotl to their original home.

Make sure to keep observing your axolotl and provide good husbandry.

Final Thoughts

Although, skin problems such as axolotl blisters are quite common, many times the cause is unclear. Most skin problems such as axolotl blisters are caused by poor husbandry and can be resolved by fixing the underlying cause.

If your axolotl is visibly sick, the first thing to do is always check the water perimeters and ensure their environment is not making them sick.

If you have tried everything suggested in this article but your axolotl is not improving, you should take them to a specialised vet.

Frequently Asked Questions Q&A

What Does Deaeration Mean?

Performing deaeration to your axolotl’s tank means removing the air that has mixed with water. Deaeration improves the quality of the water and reduces contamination.

You can purchase deaerator tank from the link below

The purpose of this device is to remove harmful impurities from water, such as nitrogen, ammonia or even oxygen that can cause toxicity and lead to axolotl illness.

Why Is My Axolotl Red?

Red skin in axolotls can be a sign that something is wrong in their care such as high levels of ammonia. If the ammonia levels are anything but 0, it will result in ammonia burns which present with a number of symptoms aswell as red skin patches.

To learn more about all the possible causes for your axolotl turning red, head over here Why Is My Axolotl Turning Red? Is Red Axolotl Skin A Concern?



My name is Iliyana and I'm a passionate animal lover and pet owner. As there is significantly less information online about unusual and exotic pets, I decided to found this website and recruit expert writers to help pet owners.

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