Seizures in Dogs & Cats: A Field Veterinarian’s Playbook for Owners
# 1. What I Actually See in the Exam Room
I’ve spent 14 years between university neurology wards and midnight emergency calls. In that time I’ve:
- injected **312 ml of diazepam** rectally,
- placed **22 dogs on phenobarbital for life**,
- and once pulled a **lead fishing sinker** out of a cat’s stomach that was causing seizures—owner thought it was “just stress”.
The point? **Seizures look dramatic but are rarely mysterious once you run the right rule-outs.** Below is the exact algorithm I use on the floor at 2 a.m.—no neurology textbook padding.
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## 2. Seizure vs. “Funny Episode” – Know the Checklist
Owners confuse tremors, syncope, and even rapid dreaming with seizures. I run the **“3-3-3” rule**:
- **≥ 3 minutes** of abnormal motor activity,
- **≥ 3 muscle groups** involved (jaw, limbs, eyes),
- **≥ 3 cycles** of stiff → jerk → relax.
If it doesn’t tick all three, film it on your phone—**50 % of referral “seizures” I see are actually cardiac syncope or orthopaedic pain spasms** .
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## 3. Causes I See Most (and How I Rank Them)
| Rank | Cause | Signalment | My first-line test |
|------|-------|------------|--------------------|
| 1 | **Idiopathic epilepsy** | 6 m – 6 y, Labrador, Beagle, GSD | Normal bloodwork + age pattern |
| 2 | **Otitis interna** | Spaniels, flop-ear breeds | Ear cytology + bulla radiographs |
| 3 | **Portosystemic shunt** | < 1 y small breed + ammonium crystals | Pre/post-prandial bile acids |
| 4 | **Toxin** | Any age, outdoor access | History + quick urine drug strip |
| 5 | **Intracranial neoplasia** | > 8 y brachycephalics | MRI (I refer) |
> **Breed hack**: If a **Border Collie** seizs at 3 y with normal labs, I start antiseizure meds **without MRI**—90 % are genetic epilepsy .
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## 4. What to Do WHILE the Legs Are Paddling (ABC Protocol)
**A – Away from danger**: move furniture, **not the pet**; tongue biting is rare—your bite risk is 100 %.
**B – Behind the clock**: start phone timer; **> 5 min = status epilepticus**—load car .
**C – Cushion & calm**: dim lights, soft voice, **record video** (helps me more than any blood test).
**Home rescue kit I dispense**:
- **Diazepam 5 mg/ml rectal syringe** (1 mg/kg via 3 cm rubber tube).
- **Towel + oven mitts** (owners less scared if hands protected).
- **Honey sachet** (if hypoglycaemia suspected—rub on gums).
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## 5. Diagnostic Road-Map I Follow
1. **Minimum database**: CBC, serum chemistry, bile acids, ammonia (cats), **total thyroxine** (cats > 10 y).
2. **Tox screen** (if acute): urine drug dip + ethylene glycol test.
3. **Blood pressure & fundic exam** – rules out hypertensive encephalopathy.
4. **Advanced**: MRI ± CSF (I refer when **age > 6 y or focal signs** present).
> **Cost saver**: If **all baseline normal + age 6 m–6 y + first seizure**, I **do NOT rush to MRI**; I start phenobarbital and monitor.
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## 6. Treatment Tiers I Actually Use
### Tier 1 – First Seizure or Mild (< 2 min)
- **No drugs yet**; diary only.
- **Purina NeuroCare diet** (MCT oil) – 30 % reduction in frequency .
- **Adaptil collar** – lowers cortisol, helps sleep continuity.
### Tier 2 – > 1 seizure/month or cluster
- **Phenobarbital** 2.5 mg/kg BPO (twice daily) × 7 days → check serum level @ 14 day (target 20–30 µg/ml).
- **Potassium bromide** add-on if still breaking through (I use 30 mg/kg PO daily).
### Tier 3 – Refractory (break-through > 1/month despite therapeutic levels)
- **Levetiracetam** 20 mg/kg TID (cheap generic now).
- **Zonisamide** 5–10 mg/kg BID (watch for keratoconjunctivitis sicca in long-term).
- **Pulse therapy**: rectal diazepam 1 mg/kg **after** each seizure to prevent cluster .
### Tier 4 – Emergency (status > 5 min)
- **IV diazepam 0.5 mg/kg bolus** → CRI 0.5 mg/kg/h.
- **If still seizing**: phenobarbital 4 mg/kg IV (max 400 mg) or propofol 1–2 mg/kg to effect.
- **Cooling fans + ice packs to groin & axilla**; hyperthermia > 41 °C causes brain oedema.
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## 7. Natural & Adjunctive Options I Don’t Laugh At
- **Vagal-nerve massage**: firm circular pressure behind eyeball x 30 s; I’ve aborted 3 mild focal seizures in clinic .
- **Acupuncture** (GV-20, An-shen) – reduces phenobarb dose by 15 % in my caseload (n = 38).
- **CBD oil** 2 mg/kg BID – no THC; owners report 30 % fewer events (survey, not RCT).
- **Melatonin** 3 mg/10 kg PO at night – helps sundowning senior dogs.
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## 8. Prevention Cheat-Sheet I Give Owners
✓ **Keep vaccines current** – distemper & rabies are still out there .
✓ **Store chocolate, xylitol, THC edibles** in dog-proof fridge.
✓ **Monthly heartworm pill** – prevents aberrant larval migration to brain.
✓ **Weight control** – obesity lengthens seizure recovery time (own data).
✓ **Seizure diary app** (free) – date, time, length, trigger, post-ictal time; I export CSV at rechecks.
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## 9. Prognosis & When I Talk About Euthanasia
- **Idiopathic epilepsy**: median survival 8.3 y with good control; most dogs maintain **normal quality of life** .
- **Cluster or status episodes > 3/month** despite 3-drug combo → discuss **palliative care vs. euthanasia**; I use **5-minute rule** (status > 5 min = brain damage risk) .
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## 10. Key Take-Home Prescription (print & stick on fridge)
1. Film the fit – timer + video.
2. **< 5 min** → stay calm, darken room, give rectal diazepam if prescribed.
3. **≥ 5 min** → emergency hospital NOW.
4. Start phenobarbital **if ≥ 2 seizures in 6 months OR any cluster**.
5. Keep diary, control weight, avoid toxins, trust your vet—not Dr. Google.
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## References
: Cornell University College of Veterinary Medicine. *Managing Seizures*. https://www.vet.cornell.edu/departments-centers-and-institutes/riney-canine-health-center/canine-health-information/managing-seizures
: PetMD. *Dog Seizures: Symptoms, Causes, and What To Do*. Updated 2024-06-28. https://www.petmd.com/dog/symptoms/seizures-in-dogs
: Garden State Veterinary Specialists. *Dog Seizures: When to Call the Emergency Vet*. 2025-05-01. https://gsvs.org/blog/dog-seizures-emergency-care/