Paraffin
Liquid paraffin / Mineral oil
Also known as: Katalax · Lacri-Lube · Liquid paraffin oral emulsion · Simple Eye Ointment · Mineral oil · White soft paraffin · Petrolatum
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
Paraffin (also known as liquid paraffin or mineral oil) is a widely used lubricant laxative and ophthalmic tear substitute in veterinary medicine. Orally, it is used to manage constipation and hairballs (especially in cats). Topically, it is used to lubricate the eyes and prevent tear evaporation.
Clinical Pearl: Extreme caution must be used when administering liquid paraffin orally due to the severe risk of aspiration pneumonia. It is tasteless and does not elicit a normal gag reflex, making aspiration highly likely if force-fed.
Mechanism of action
Paraffin has two distinct mechanisms depending on the route of administration:
- Gastrointestinal (Laxative): Acts as an emollient laxative. It coats the feces and intestinal mucosa → interferes with intestinal water resorption → softens stools and facilitates passage.
- Ophthalmic (Lubricant): Acts as a lipid-based tear substitute. It mimics the lipid layer of the tear film → prevents aqueous tear evaporation and protects the corneal surface.
Safety & warnings
Contraindications
- Dysphagia or impaired gag reflex
- Vomiting patients
- Concurrent use with docusate sodium
- Prolonged daily use (due to vitamin malabsorption)
Adverse effects
- Aspiration pneumonia (if inhaled during oral administration)
- Anal seepage / oily perianal soiling
- Decreased absorption of fat-soluble vitamins (with chronic oral use)
- Granulomatous reactions (if absorbed into intestinal mucosa)
Precautions
WARNING: Never force-feed liquid paraffin via syringe. The lack of taste prevents the gag reflex, leading to silent aspiration and severe, often fatal, lipoid pneumonia. Always allow the animal to lick it voluntarily or mix it with food.
Drug interactions
Decreased intestinal absorption of vitamins with chronic paraffin use
May increase the systemic absorption of mineral oil, leading to granuloma formation
Monitoring
- Resolution of constipation
- Signs of respiratory distress or coughing (indicating possible aspiration)
- Fecal consistency
Pharmacokinetics
Half-life
Absorption
Minimal systemic absorption from the gastrointestinal tract under normal conditions.
Distribution
Remains primarily in the GI lumen or on the ocular surface.
Metabolism
Not metabolized.
Elimination
Excreted unchanged in the feces.
Overdose
Overdosage via the oral route primarily results in diarrhea, anal seepage, and profound perianal soiling. Chronic overdosage may lead to deficiencies in fat-soluble vitamins.
Available products
Formulations
- Oral paste (white soft paraffin)
- Oral emulsion (50/50 oil/water mix)
- Ophthalmic ointment (3.5 g, 4 g, 5 g)
Veterinary
- Katalax (white soft paraffin paste)
Human-labeled
- Lacri-Lube (ophthalmic ointment)
- Liquid paraffin oral emulsion
- Simple Eye Ointment
Regulatory status
Available OTC as a laxative and ophthalmic lubricant.
Available as a Pharmacy (P) or general sales list medicine depending on formulation.
Classified as a Pharmacy (P) medicine in the UK.
No regulatory data for: 🇭🇰 HK · 🇹🇼 TW · 🇯🇵 JP · 🇰🇷 KR · 🇦🇺 AU
Storage & stability
Store at room temperature. Keep containers tightly closed.
Client information
Do not force your pet to swallow liquid paraffin from a syringe, as it can easily go down the wrong way and cause severe, life-threatening lung damage. If using for hairballs or constipation, let your pet lick it voluntarily or mix it with food. If using eye ointment, apply as directed and do not let the tube tip touch the eye. Oral use may cause oily leakage from the rectum.
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.