---
title: "Wet Tail in Hamsters — UK Vet Advice"
description: "Wet tail (proliferative ileitis) is a life-threatening hamster emergency. UK guide to symptoms, same-day vet care, causes and hygiene prevention."
url: "https://pethealth.org.uk/health/hamster-wet-tail-uk"
canonical: "https://pethealth.org.uk/health/hamster-wet-tail-uk"
date_published: "2026-07-18"
date_modified: "2026-07-18"
source: "PETHEALTH+"
---

# Wet Tail in Hamsters — UK Vet Advice

Wet tail — severe diarrhoea usually caused by the bacterium **Lawsonia intracellularis** (proliferative ileitis) — is a genuine hamster emergency. **See a vet immediately, the same day** symptoms appear: untreated wet tail can kill within 24–48 hours, and young hamsters are most at risk.

## What is wet tail?

According to UK-Vet Companion Animal, "wet tail" is the colloquial name for **proliferative ileitis**, a serious intestinal infection caused by the bacterium *Lawsonia intracellularis*, spread through contaminated droppings (the faeco-oral route).

A UK VetCompass study of nearly 4,000 pet hamsters under primary veterinary care found wet tail was the **most commonly diagnosed disorder** — and the **most common recorded cause of death**. It is not a minor tummy upset.

## Symptoms

| Symptom | What you see |
|---------|--------------|
| Diarrhoea | Watery, sometimes bloody droppings |
| Wet, soiled rear | Matted fur around tail and belly, foul smell |
| Lethargy | Sleeping far more than usual, limp when handled |
| Appetite loss | Refusing food and water |
| Posture | Hunched body, folded ears, dull or hazy eyes |
| Dehydration | Sunken eyes, skin that stays tented when pinched gently |
| Behaviour change | Unusual irritability or aggression when touched |
| Rectal prolapse | Tissue protruding from the rear — an immediate emergency |

## Why it is an emergency

According to UK-Vet Companion Animal, acute cases can deteriorate and die within **24–48 hours**, and mortality in young hamsters may approach 90%. Hamsters are tiny and dehydrate extremely fast, so there is no safe "wait and see" period.

**See a vet immediately — the same day.** Phone ahead so the practice knows a small furry with diarrhoea is coming.

## What to do right now

- **Phone your vet immediately** — describe the wet rear and diarrhoea
- **Isolate** the sick hamster from any others straight away
- **Keep them warm** — a quiet, warm room, with bedding to burrow into
- **Fresh water** available at all times — dehydration is the killer
- **Do not** give human medicines, anti-diarrhoeals or home remedies
- **Wash your hands** after every handling and **disinfect the cage**, bowl and bottle

Note when symptoms started and what your hamster has eaten — this helps your vet.

## Causes and risk factors

According to UK-Vet Companion Animal, wet tail is strongly linked to **stress and immune suppression**:

- **Young age** — most common around weaning, roughly 4–8 weeks old
- **Transport and rehoming** — the classic "new pet shop hamster" presentation
- **Overcrowding and poor cage hygiene**
- **Sudden diet changes** or nutritional stress
- **Other illness** — including dental disease — weakening the immune system

Adult hamsters are less often affected but can carry and shed the bacteria.

## Prevention

- **Settle new hamsters quietly** — minimal handling for the first few days while they adjust
- **Spot-clean daily**, and do a full cage clean and disinfection regularly
- **Quarantine new arrivals** from existing hamsters until you're confident they're healthy
- **Wash hands** between handling different hamsters
- **Check before you buy** — the rear end should be clean and dry, and the enclosure clean
- **Avoid sudden diet changes** — according to the PDSA, a balanced hamster pellet or mix should form the staple diet, changed only gradually

For everyday setup, diet and handling, see [Hamster care UK](/health/hamster-care-uk). Cold stress is another major UK hamster risk — read [Hamster hibernation & torpor](/health/hamster-hibernation-uk) before winter.

## FAQs

### Can a hamster survive wet tail?

Yes, but only with fast veterinary treatment — antibiotics, fluids and warmth. Without treatment, wet tail can kill within 24–48 hours, so see a vet the same day you spot symptoms.

### Is wet tail contagious?

Wet tail spreads between hamsters through contaminated droppings, cages and hands. Isolate a sick hamster immediately, disinfect the cage, and wash your hands after every handling.

### Can I treat wet tail at home?

No. Home remedies and shop-bought diarrhoea treatments are not a cure. Keep your hamster warm, isolated and hydrated only while arranging an urgent vet appointment.

### What does wet tail look like?

Watery diarrhoea with wet, matted, foul-smelling fur around the tail and rear, plus lethargy, a hunched posture, folded ears and refusal to eat.

### Which hamsters are most at risk?

Young hamsters around weaning age (roughly 4–8 weeks) are most commonly affected, especially after the stress of transport and rehoming. Long-haired Syrian hamsters are often reported as higher risk.

## Sources

- [UK-Vet Companion Animal — Gastrointestinal conditions in pet hamsters](https://www.ukvetcompanionanimal.com/content/clinical/approaches-to-common-conditions-of-the-gastrointestinal-tract-in-pet-hamsters)
- [VetCompass — Pet hamster health under UK primary veterinary care](https://pmc.ncbi.nlm.nih.gov/articles/PMC9796486/)
- [RSPCA — Hamsters](https://www.rspca.org.uk/adviceandwelfare/pets/rodents/hamsters)
- [PDSA — Your hamster's diet](https://www.pdsa.org.uk/pet-help-and-advice/looking-after-your-pet/small-pets/your-hamsters-diet)

Canonical HTML: https://pethealth.org.uk/health/hamster-wet-tail-uk
Last modified: 2026-07-18