Vetdrugs 2.0Liquid paraffin, also called mineral oil, is a poorly absorbed lubricant laxative used mainly in large-animal medicine. Its principal role is assistance with passage of intestinal contents in selected constipation or impaction cases, particularly in horses. Clinical usefulness depends on the nature and location of the retained material.
Group
Lubricant laxative
Mechanism of Action
Mineral oil coats fecal material and intestinal surfaces, reducing friction and facilitating movement of luminal contents. It can also limit removal of water from the coated material and help maintain softer feces. These physical effects support passage of selected retained contents without direct stimulation of intestinal smooth-muscle receptors.
Dose Rates
Dogs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | Older oral references list 2-60 mL per dog, with narrower alternatives of 5-30 or 5-25 mL; another source lists 10-50 mL every 12 hours. Oral liquid oil is rarely recommended because of aspiration risk. |
Cats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | Older oral references list 2-10 mL, 2-6 mL, or 5 mL daily mixed with food; another source lists 10-25 mL every 12 hours. These disparate source alternatives are not a universal safe range; avoid oral liquid oil when aspiration is possible. |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | Adults: 1-4 L by stomach tube, with a separate source alternative of 0.5-2 L; calves 60-120 mL. Frequency is not consistently specified. |
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | Adults: 2-4 L by nasogastric tube, repeated daily if needed; a separate alternative is 0.5-2 L. Foals: 240 mL, with a separate 60-120 mL alternative. Individualise to age, diagnosis and response. | |
| Large-colon impaction | Reference only | PO | Older protocol: 2-4 US quarts by stomach tube every 12-24 hours, with warm water to aid administration. The source describes escalation as high as 5 US gallons; this is not a routine dose and requires individual reassessment. | |
| Sand impaction adjunct | Reference only | PO | Study combination: mineral oil 2 L by nasogastric tube daily, with psyllium 0.5 kg mixed into 1 L mash twice daily. Not evidence for oil alone. |
Sheep
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | 100-500 mL by stomach tube; a separate source lists 500-1000 mL. Select an appropriate protocol rather than merging these alternatives. |
Goats
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | 100-500 mL by stomach tube; frequency is not specified. |
Pigs
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | 50-100 mL by stomach tube; another source lists 500-1000 mL. Do not merge the different source alternatives. |
Birds
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Constipation or impaction | Reference only | PO | 5 mL/kg PO once, repeated if necessary; another volume instruction is 1-3 drops per 30 g. Administer cautiously to avoid aspiration. |
Indications
- Adjunctive treatment of selected equine constipation or nonstrangulating fecal impactions.
- Lubricant laxative treatment of selected constipation in other veterinary species.
- Adjunctive treatment of selected equine sand-associated impactions within a supported intestinal evacuation plan, with variable evidence of benefit.
Contraindications
- Do not use orally where aspiration, dysphagia, regurgitation or vomiting is likely.
- Exclude mechanical obstruction before laxative treatment.
Interactions
- Docusate can increase oil absorption.
- Chronic use can reduce absorption of vitamins A, D, E and K.
Adverse effects
- Aspiration can cause severe or fatal lipid pneumonitis.
- Anal oil leakage; long-term malabsorption and tissue granulomas are possible.
Toxicity
There is no specific antidote for aspiration; respiratory support and treatment of pulmonary complications may be required.
Monitoring and Administration
Confirm stomach-tube placement before delivery; never force a drench into a struggling small animal.
Do not convert oil volume to grams without a verified product density. Liquid oil and petrolatum hairball pastes are different preparations.
Monitor faecal passage, pain, hydration and signs of aspiration.