Ispaghula (Psyllium)
Plantago ovata seed husk
Also known as: Fybogel · Ispagel · Metamucil · Psyllium · Plantago ovata · Ispaghula husk
Reviewed by the VetSheet Veterinary TeamUpdated Apr 5, 2026Evidence-based veterinary reference
Dosing by species
Dosing data for this drug is not yet available in the VetSheet formulary. Every other section below is complete. Consult the current product label before prescribing.
Overview
Ispaghula (commonly known as psyllium) is a bulk-forming laxative derived from the husks of Plantago ovata seeds. It is utilized in veterinary medicine to manage constipation, improve stool consistency, and increase dietary fiber intake.
Clinical Pearl: Because it absorbs significant amounts of water to form a viscous gel, it is imperative that animals have free access to drinking water to prevent impaction.
Mechanism of action
Acts as a bulk-forming agent that absorbs water in the gastrointestinal tract → increases faecal mass → mechanically stimulates peristalsis. It is moderately fermentable in the colon, and the resultant volatile fatty acids exert an osmotic laxative effect.
Safety & warnings
Contraindications
- Intestinal obstruction
- Fecal impaction
- Dysphagia
- Severe dehydration
Adverse effects
- Flatulence
- Abdominal bloating
- Esophageal or intestinal obstruction (if administered without adequate water)
Precautions
Warning: Must be administered with plenty of water or mixed thoroughly into wet food to prevent choking or esophageal/intestinal obstruction. Do not use in animals with suspected bowel obstruction or severe dehydration.
Drug interactions
May delay or reduce the gastrointestinal absorption of concurrently administered oral drugs. Administer at least 2 hours apart.
Monitoring
- Stool consistency and frequency
- Hydration status
- Signs of abdominal discomfort or bloating
Pharmacokinetics
Half-life
Absorption
Not absorbed systemically. Remains within the gastrointestinal lumen.
Distribution
Confined to the gastrointestinal tract.
Metabolism
Moderately fermented by colonic bacteria into volatile fatty acids.
Elimination
Excreted in feces as unfermented gel and bacterial mass.
Overdose
Overdose is unlikely to cause systemic toxicity as the drug is not absorbed. However, excessive ingestion without adequate water may lead to severe bloating, constipation, or gastrointestinal obstruction.
Available products
Formulations
- Oral granules
- Oral powder
Human-labeled
- Fybogel (UK)
- Ispagel (UK)
Regulatory status
Available Over-The-Counter (OTC) as a human dietary supplement/laxative.
Available as a non-prescription product.
Classified as General Sales List (GSL), available over the counter.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store in a cool, dry place in tightly closed containers to prevent moisture absorption, which can cause the powder to clump and swell.
Client information
Ispaghula (psyllium) is a natural fiber supplement used to help regulate your pet's bowel movements. It can help with both constipation and certain types of diarrhea by normalizing stool consistency.
Important: Always mix the powder or granules with plenty of water or wet food. Never give the dry powder directly, as it can swell in the throat and cause choking. Ensure your pet has access to fresh drinking water at all times.
VetSheet drug reference is intended for licensed veterinary professionals as a clinical decision-support aid, not a substitute for professional judgement or the manufacturer’s current label.