Disease Guide

Encephalitis in Dogs & Cats: Seizures, Behaviour Changes & Care [2025]

Encephalitis is inflammation of the brain, which can be caused by infection or immune-mediated conditions. Signs include seizures, altered consciousness, and behaviour changes. Imaging and cerebrospinal fluid analysis are needed to determine the underlying cause.

Last updated: 2026/01/05
Pethealthmap Editorial Team
Sources: WSAVA, AVMA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek Emergency Care Immediately

  • Continuous or repeated seizures that cannot be stopped
  • Sudden loss of consciousness or collapse within a short period
  • Obvious difficulty breathing or gum discoloration

Schedule a Clinic Visit Soon (within 24–72 hours)

  • Persistent and notable decrease in alertness or activity level
  • Intermittent seizures or involuntary muscle trembling
  • Persistent loss of appetite or changes in water intake

01What symptoms indicate something is wrong?

Encephalitis in dogs and cats commonly causes behavioural and neurological changes. Symptoms may appear acutely or intermittently — watch for changes in daily behaviour and coordination.

  • Changes in mental status, such as lethargy or unusual agitation
  • Fever, reduced appetite, or vomiting and diarrhoea
  • Coughing or respiratory symptoms are also worth noting
  • Seizures: generalised convulsions or localised involuntary muscle twitching
  • Unsteady gait, reduced coordination, or head tilt
  • If any of the above changes are noticed, schedule a clinic or specialist consultation

Seek emergency care immediately if you notice the following symptoms:

  • ⚠️ Seizures that are continuous or cluster without stopping
  • ⚠️ Sudden loss of consciousness or collapse within a short period
  • ⚠️ Obvious difficulty breathing or discolouration of the gums

02How to assess your pet at home: key observations and when to go to emergency

Systematic observation and record-keeping at home before your visit helps the vet assess the progression and prioritise tests.

  • Note the date and time symptoms first appeared
  • Track daily changes in alertness, activity level, and behaviour
  • Measure and record body temperature, and monitor whether it is rising
  • Record appetite, water intake, and urination and defecation patterns
  • Film any seizures or abnormal gait on your phone to show the vet
  • Compile your notes and videos to bring to the clinic or neurology referral centre

03How will the vet make a diagnosis? Common tests and examinations

The vet will use blood tests, urine analysis, and imaging to rule out metabolic or infectious causes and assess the extent of brain involvement.

Complete blood count (CBC) to assess for infection or inflammation

Blood biochemistry to evaluate liver, kidney, and metabolic function

Urinalysis to help differentiate metabolic or urinary-related conditions

X-rays to rule out concurrent lesions outside the thorax or skull

Cytology and bacterial culture to identify possible pathogens

Brain imaging (MRI or CT) arranged when necessary

04Treatment and care after diagnosis: medication, dietary adjustments, and home nursing

Treatment depends on the underlying cause. Regular follow-up visits, laboratory monitoring, and home care are essential to ensure effectiveness and safety.

  • If infection is suspected, targeted antimicrobial or antiviral therapy may be prescribed
  • Schedule regular follow-up appointments and neurological assessments as directed by your vet
  • Repeat blood and biochemistry tests to monitor treatment response and side effects
  • Proper nutrition and hydration management support recovery
  • Provide a quiet home environment and avoid stimulation, bright lights, or loud noises
  • For complex cases, referral to a veterinary neurology specialist is recommended

05What to prepare before your vet visit: key information to help the vet diagnose faster

1
Write down when symptoms started, how they have progressed, and any potential triggers
2
Record specific changes in appetite, water intake, and bowel or bladder habits
3
List all current medications, supplements, and vaccination history
4
Bring video or photo recordings of any seizures or abnormal gait
5
Bring previous test reports or imaging studies if available for comparison
6
Call ahead to book at a clinic that can perform the relevant diagnostic tests

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Frequently Asked Questions (FAQ)