Encephalitozoon cuniculi (E. cuniculi)

This is one of the more serious conditions rabbit owners should understand.

What Is It?

E. cuniculi is a microscopic parasite (a microsporidian) that can affect:

  • Brain and nervous system
  • Kidneys
  • Eyes

Many rabbits carry this parasite without symptoms. Stress, illness, or immune suppression can trigger active infection.

How It Spreads

  • Shed in urine of infected rabbits
  • Ingested through contaminated food/water
  • Can pass from mother to babies
  • Spores survive in environment for weeks

Warning Signs

Neurological symptoms:

  • Head tilt (vestibular disease) - sudden or gradual
  • Loss of balance, falling over
  • Rolling (in severe cases)
  • Hind leg weakness or paralysis
  • Circling in one direction
  • Seizures (rare)

Eye symptoms:

  • White spots in the eye (lens rupture)
  • Cataracts
  • Uveitis (eye inflammation)

Kidney symptoms:

  • Increased thirst and urination
  • Weight loss
  • Often no obvious signs until advanced

Important: Head Tilt

Head tilt is alarming but NOT always E. cuniculi!

Other causes of head tilt:

  • Inner ear infection (very common)
  • Stroke
  • Trauma
  • Abscess
  • Tumor

Your vet will need to determine the cause. Don't assume - get a proper diagnosis.

Diagnosis

  • Blood test can show exposure (antibodies)
  • Positive test means exposure, not necessarily active disease
  • Many healthy rabbits test positive
  • Diagnosis often based on symptoms + response to treatment

Treatment

Standard protocol:

  • Fenbendazole (Panacur) for 28 days
  • Anti-inflammatory medication
  • Supportive care (hydration, assisted feeding if needed)
  • Physical therapy for balance issues

Prognosis:

  • Early treatment improves outcomes significantly
  • Some rabbits recover fully
  • Some have permanent head tilt but adapt well
  • Severe cases may not recover

Living With a Head Tilt Rabbit

Many rabbits with permanent tilt live happy lives:

  • Pad their environment (rolled towels, soft surfaces)
  • Low food and water dishes
  • Single-level housing (no ramps)
  • They adapt remarkably well!

Fur Mites (Cheyletiella)

Also called "walking dandruff" - very common and treatable.

Signs

  • Flaky, dandruff-like skin (especially along back)
  • Mild to moderate itching
  • Fur loss in patches
  • "Dandruff" that moves (the mites themselves)

Treatment

  • Revolution (selamectin) - prescription, very effective
  • Ivermectin - injection or oral
  • Treat all rabbits in household
  • Clean environment thoroughly

Prevention

  • Quarantine new rabbits
  • Regular health checks
  • Good hygiene
  • Treat promptly if detected

Ear Mites (Psoroptes cuniculi)

More common in lop-eared rabbits due to ear anatomy.

Signs

  • Dark, crusty debris in ears
  • Head shaking
  • Scratching at ears
  • Strong odor from ears
  • Ear sensitivity/pain

What You'll See

The crusts can be dramatic - thick, brown/black buildup. Do NOT try to remove crusts yourself as this is extremely painful.

Treatment

  • Revolution or Ivermectin
  • Vet may sedate to clean ears safely
  • Pain medication often needed
  • Multiple treatments usually required

Lop Ear Owners

Check ears weekly! The folded ear creates a warm, moist environment where mites thrive. Early detection makes treatment much easier.

Pinworms (Passalurus ambiguus)

Rabbit-specific pinworms - not transmissible to humans.

Signs

Often no symptoms! May notice:

  • Small white worms in feces
  • Increased grooming of rear end
  • Mild irritation

Treatment

  • Fenbendazole (Panacur)
  • Usually clears easily
  • Clean environment to prevent reinfection

Not a Crisis

While unpleasant, pinworms are common and not serious. Many rabbits have them without issues.

Coccidia

A protozoal parasite, more concerning in young rabbits.

Signs

  • Diarrhea (can be severe)
  • Poor growth in young rabbits
  • Weight loss
  • Lethargy
  • Bloated abdomen

Risk Factors

  • Young rabbits (under 6 months) most vulnerable
  • Stress
  • Overcrowding
  • Poor sanitation
  • Weakened immune system

Treatment

  • Sulfa-based antibiotics
  • Supportive care for dehydration
  • Environmental cleaning crucial

Prevention

  • Clean living conditions
  • Prevent fecal contamination of food/water
  • Reduce stress
  • Quarantine new rabbits

Fleas

Yes, rabbits can get fleas!

Signs

  • Scratching
  • Visible fleas or flea dirt (black specks)
  • Fur loss from scratching
  • Restlessness

Safe Treatment

  • Revolution (selamectin) - rabbit-safe
  • Advantage (imidacloprid) - check with vet on dosing

NEVER Use

  • Frontline (fipronil) - TOXIC to rabbits
  • Flea collars
  • Flea baths/dips
  • Most over-the-counter products

Always consult your vet before using any flea product.

General Parasite Prevention

Good Practices

  • Quarantine new rabbits (2-4 weeks minimum)
  • Regular health checks (weekly)
  • Clean living environment
  • Fresh hay from reputable sources
  • Wash vegetables thoroughly
  • Minimize stress
  • Annual vet checkups

When to See a Vet

  • Any neurological symptoms (head tilt, balance issues)
  • Persistent scratching or fur loss
  • Visible parasites
  • Diarrhea
  • Weight loss
  • Behavior changes

Environmental Cleaning

If parasites are diagnosed:

  • Wash all bedding in hot water
  • Replace hay and litter
  • Clean enclosure thoroughly
  • Some parasites require specific disinfectants
  • Follow vet's recommendations

Key Takeaways

  • E. cuniculi is serious but manageable with early treatment
  • Head tilt needs vet diagnosis - don't assume the cause
  • Mites are common and very treatable
  • Prevention is easier than treatment
  • Never use dog/cat flea products without vet approval
  • Regular checkups catch problems early

Most parasitic conditions are treatable, especially when caught early. Know what's normal for your rabbit so you notice changes quickly.