Understanding Idiopathic Epilepsy in Dogs
Idiopathic epilepsy (IE) is one of the most common causes of recurrent seizures in dogs, affecting up to 5% of certain breeds. By definition, idiopathic epilepsy means there is no underlying structural brain disease or metabolic disorder causing the seizures. Most affected dogs require lifelong anti-seizure medication (ASM) such as phenobarbital, levetiracetam, zonisamide, or potassium bromide to maintain good seizure control.
Even with consistent treatment, some dogs may experience breakthrough seizures or sudden changes in seizure frequency. While it’s easy to assume the medication is “failing” or needs to be adjusted, new research shows there may be another explanation: a urinary tract infection (UTI).
New Research: Looking Beyond Epilepsy Progression
A recent veterinary case series published in Animals (MDPI, 2025) described eight dogs with idiopathic epilepsy whose seizure control worsened unexpectedly. The cause wasn’t progression of epilepsy or medication failure, but rather urinary tract infections with E. coli.
What These Dogs Showed
- An increase in seizure frequency (including cluster seizures)
- Lethargy and weakness
- Worsened coordination (ataxia)
- Incontinence or changes in urination
- Behavioral changes such as panting or restlessness
On average, these changes persisted for about a month before the UTIs were identified.
Diagnostic Findings
- All dogs had significant bacteriuria (>10⁶ CFU/mL of E. coli)
- Urine specific gravity averaged ~1.020
- Signs were at first attributed to epilepsy or medication side effects
Treatment & Outcome
- Dogs improved within 24–72 hours of receiving antibiotics (commonly amoxicillin–clavulanic acid)
- A few dogs relapsed, underscoring the need for follow-up urine cultures
What This Means for Dog Owners
If your dog with epilepsy suddenly has more seizures than usual, don’t assume the medication isn’t working. Sometimes, an underlying medical issue, such as a urinary tract infection, may make seizures harder to control.
Practical tip: If your epileptic dog has breakthrough seizures, especially if accompanied by lethargy, weakness, or changes in urination, ask your veterinarian about checking for a UTI before adjusting anti-seizure medication.
What This Means for Veterinarians
For primary care and referral colleagues:
- Remember that UTIs may contribute to loss of seizure control in patients with idiopathic epilepsy.
- Consider routine urinalysis and culture when seizure control worsens unexpectedly.
- Avoid reflexively adjusting ASM doses until systemic causes of seizure breakthrough are ruled out.
This simple step can prevent unnecessary medication changes and improve patient outcomes.
Key Takeaways
- Idiopathic epilepsy is a common condition in dogs requiring lifelong ASM therapy.
- UTIs can worsen seizure control.
- Clinical signs of infection may mimic medication side effects.
- Pet owners: Report new changes in urination, behavior, or seizure frequency promptly.
- Veterinarians: Always rule out infection before adjusting seizure medications.
Final Thoughts & A Question for Colleagues
This study reinforces an important reminder: not every setback in seizure control is due to epilepsy progression or medication failure. Sometimes, the underlying problem is a urinary tract infection interfering with stability.
👉 To my veterinary colleagues: Have you seen cases where seizure control worsened in epileptic dogs due to a UTI or other systemic illness? How did you approach it?
By sharing experiences, we can better safeguard seizure patients and strengthen the bond between pets and their families.
