What are the common symptoms of arachnoid diverticulum in dogs and cats?

Common signs include recurrent seizures, unsteady gait, localised pain responses, and changes in appetite or energy. If any of these occur, see a vet promptly for further evaluation.

How is arachnoid diverticulum diagnosed?

Advanced imaging such as CT or MRI is the primary diagnostic tool, revealing the location and size of the diverticulum; your vet may also recommend blood work or cerebrospinal fluid analysis for a complete assessment.

Can symptoms be managed with medication alone, without surgery?

In some cases, medication can control seizures and symptoms. Whether surgery is needed depends on the diverticulum's location and clinical impact, and should be assessed by a veterinary neurosurgeon — follow your vet's guidance.

What follow-up care is needed after treatment?

Regular check-ups are generally recommended to monitor neurological function and imaging changes, along with tracking symptoms and body weight. Your vet will determine the specific follow-up schedule based on clinical and imaging findings.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Arachnoid Diverticulum in Dogs & Cats: Seizures, Gait Problems & Imaging [2025]

Spinal cysts compress nerves and may require surgery

Take 1 minute to check the symptoms first

Last updated: 2026/01/06

Pethealthmap Editorial Team

Sources: ACVIM, WSAVA, National Taiwan University Veterinary Hospital

When to See a Vet

Seek immediate veterinary care (emergency)

•Frequent seizures that cannot be stopped or recovered from
•No obvious response or only a very weak response to calling or touching
•Rapid breathing or difficulty breathing that cannot be resolved

Schedule a clinic visit soon (within 24–72 hours)

•Persistent unilateral or bilateral gait instability
•Recurrent trembling or shivering-like tremors that are increasing in frequency
•Noticeably decreased appetite or reduced activity level

01What symptoms indicate something is wrong?

Arachnoid diverticula often cause central nervous system signs including recurrent seizures and gait abnormalities; symptoms may fluctuate, so close monitoring and keeping a seizure diary are important.

Recurrent seizures or epileptic episodes — record the frequency and duration of each episode
Unsteady or ataxic gait, stumbling, or veering to one side
Repeated trembling or shivering unrelated to activity or emotion — pay extra attention if persistent
Signs of pain such as vocalising, avoiding touch, or reluctance to be lifted
Reduced appetite or a notable change in energy levels and willingness to interact
If any of these signs are present, arrange a neurology consultation as soon as possible

Seek emergency care immediately if you notice the following symptoms:

⚠️ Frequent seizures that do not stop — this may be life-threatening
⚠️ Significant change in consciousness or markedly reduced responsiveness — seek emergency care immediately
⚠️ Difficulty breathing or severe respiratory distress — treat as an emergency

02How to assess changes at home — what to monitor and when to go to emergency

Detailed home records help your vet assess the condition and identify triggers — use video and a written diary where possible.

Log the number, timing, and duration of each trembling or seizure episode
Note changes in alertness and willingness to interact with you
Track daily trends in appetite, food intake, and water consumption
Record urination and defecation frequency, any change in consistency, or episodes of incontinence
Film gait, seizures, or unusual behaviour with your phone to share with your vet
Weigh your pet regularly and log any changes to help track disease progression and medication response

03How will the vet diagnose this condition? Common diagnostic tests

At the clinic, the vet will start with a full physical examination and neurological assessment, supplemented by blood work, imaging, and specialist referral as needed to clarify the diagnosis and treatment plan.

Full physical and neurological examination to assess reflexes and gait changes

Baseline blood and urine tests to rule out metabolic or infectious causes

Urine culture if needed to exclude urinary tract involvement

Radiographs to gather supplementary information and rule out head, neck, or thoracic conditions

Advanced imaging (CT or MRI) is the primary method for confirming diverticulum location and extent

Cerebrospinal fluid analysis or referral to a veterinary neurologist when further evaluation is needed

04What treatment and care come after diagnosis? Medications, lifestyle adjustments, and home care

Treatment may involve medication management and surgical assessment; both post-operative and conservative care require long-term imaging follow-up, functional monitoring, and lifestyle adjustments.

Medications to control seizures and symptoms, with regular check-ups to monitor response
For cases where surgery is indicated, a veterinary neurosurgery team evaluation and discussion is required
Post-operative follow-up includes imaging and neurological function assessments
Maintain a low-stimulation environment and adjust diet and daily activity to minimise triggers
During home care, record any symptom changes and report regularly to your vet

05What to prepare before the appointment — helping your vet assess the cause quickly

Write down when symptoms first appeared, how often they occur, and how long each episode lasts

List all current medications, supplements, and vaccination history

Bring or back up videos of seizures and gait abnormalities, ideally from multiple angles

Prepare notes on recent changes in appetite, elimination habits, and body weight for the vet

Bring any previous imaging or diagnostic reports, or provide digital copies

Call ahead to book an appointment and let the clinic know CT or MRI may be required

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.

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