What are the signs of a respiratory infection in a ball python?

YMYL note: this is veterinary territory

Respiratory infection (RI) in reptiles is a serious veterinary condition with real mortality risk. This article describes recognition and husbandry-side prevention so a keeper can act early — it is not a substitute for a reptile-experienced vet, and nothing here should be read as treatment advice. If your snake shows any of the signs below, book a vet within 1–3 days. Bring a written husbandry log (temperatures, humidity, last shed, recent feeding, age).

What RI looks like — the signs

Per the Merck Veterinary Manual, captive ball pythons present with a consistent pattern:

• Open-mouth breathing — the snake holds its mouth open at rest, not just during a yawn or after a defensive strike.
• Audible breath sounds — wheezing, whistling, clicking, or a raspy quality on each breath. Healthy ball pythons breathe silently.
• Mucus or bubbles at the nostrils or in the mouth — bubbles can appear after a long drink and resolve in minutes; persistent mucus is the warning sign.
• Head raised, neck extended — the snake tilts its head up to open the airway. Sometimes called "stargazing position" in early RI, though true stargazing (neurological) is different and worse.
• Lethargy and refused food — snake won't strike at offered prey and remains in one place for days.
• Skin colour or shedding changes — secondary signs of chronic poor husbandry that often coexist with RI.

A single brief bubble after drinking is not RI. Any combination of two or more of the above, especially audible breathing + refusal to eat, is RI until proven otherwise.

What causes respiratory infection

Most ball python RI cases trace to one (or both) of two husbandry problems, with a smaller minority caused by infectious disease:

1. Chronic under-heating. A warm-side surface that sits below 27 °C (80 °F) for sustained periods suppresses immune function and lets opportunistic bacteria flourish. This is the single most common root cause. Verify with an infrared gun on the actual basking surface, not a stick-on dial — see the temperature guide.

2. Sustained excess humidity + poor ventilation. Humidity above 70 % in a sealed enclosure with no airflow creates ideal conditions for bacterial respiratory growth. Cross-ventilation matters as much as the humidity reading itself — a tub at 80 % with no ventilation is much worse than an open enclosure at 70 %. See humidity setup for the correct band.

3. Viral or parasitic disease — paramyxovirus, nidovirus, snake mites carrying secondary infection. Less common but worth ruling out with a vet, especially in collections with recently introduced animals or any quarantine breach. Quarantine new snakes 30+ days.

4. Chronic stress — overhandling, no secure hides, exposure to loud noise or constant disturbance — weakens immune function the same way it does in mammals.

What to do RIGHT NOW

If you suspect RI in your ball python, the same-day steps:

1. Verify temperatures with an IR temperature gun. Warm-side surface should read 30–32 °C (86–90 °F). If it's below, raise the thermostat setpoint or check the heat source.
2. Verify humidity — drop to 55–60 % if it's been chronically higher, and open ventilation in tubs/PVC enclosures.
3. Don't handle the snake. Handling stresses an already-stressed respiratory system.
4. Don't offer food. A snake fighting RI shouldn't be digesting.
5. Book a reptile-experienced vet within 1–3 days. General- practice vets often don't have experience with reptile dosing or the right antibiotics. Find an exotics specialist if possible.
6. Bring a written husbandry log — current temperatures (warm side, ambient, cool side, night), humidity, last shed date, last feeding, age, time in current setup, recent changes.

When to see a vet — non-negotiable

Respiratory infection is a YMYL (health-or-life) situation. There is no DIY treatment that beats a vet appointment, and several common keeper interventions actively make things worse:

• Don't raise humidity to 90 % "to clear the lungs" — high humidity worsens bacterial RI.
• Don't use over-the-counter antibiotics meant for fish. Wrong dose, wrong spectrum, wrong route, risk of resistance.
• Don't wait a month to see if it clears. RI hides progression.

A reptile vet will typically: examine the snake, listen to respiratory sounds, optionally take a tracheal wash for culture and sensitivity testing, prescribe targeted injectable antibiotics (commonly ceftazidime or enrofloxacin, depending on culture), sometimes recommend nebulisation. Treatment runs 7–14+ days; complete the full course even if the snake looks better in days.

For the broader cross-species illness pattern, see "is my reptile sick?".

How to prevent recurrence

Once the snake is recovered, the husbandry audit:

Pair the audit with monthly deep cleans (full décor/substrate change), weekly weight tracking and a yearly reptile-vet wellness check. Most RI recurrences in well-kept ball pythons trace to a slow temperature drift over winter — log temperatures monthly and you'll catch it before the next infection.

For other refusal-to-eat causes that look like RI but aren't, see the not-eating diagnostic guide.