14 Mar, 2018
Dr. Debra Primovic - DVM
Overview of Polyethylene Glycol 3350 (MiraLAX®) for Canines and Felines
Polyethylene glycol 3350, commonly known as MiraLAX® as well by many other trade names (see below), is used as a laxative to treat constipation for dogs and cats. It is also used to empty the intestines prior to diagnostic procedures. It is commonly used in humans before diagnostic procedures such as colonoscopy.
Polyethylene glycol 3350 belongs to the class of drugs known as osmotic laxatives. Polyethylene glycol works by creating and environment where water is retained in the stool. There are versions of Polyethylene glycol that contain electrolytes used primarily for preparation for colonoscopy in humans including the product “Golytely®”.
The recommendations in this article are for the Polyethylene Glycol 3350 Powder for solution is available in either pre-measured 17 gram packets or bulk powder such as MiraLax®, Dulcolax Balance®, and various generic names.
Polyethylene glycol 3350 is available without a prescription but should not be administered unless under the supervision and guidance of a veterinarian. Some pets will appear to strain which can look like constipation but is actually a urinary obstruction or colitis.
This drug is not approved for use in animals by the Food and Drug Administration but it is prescribed legally by veterinarians as an extra-label drug.
Brand Names and Other Names of Polyethylene glycol 3350 (MiraLAX®)
Human formulations: There are several different trade name products for docusate. Common names include Clearlax, Colyte, Dulcolax, Easylax, EZ2GO, Gavilax, Gavilyte, Gialax, Glycolax, Golytely, Healthylax, Laxaclear, Miralax, Moviprep, Natura-Lax, Nulytely, Pegylax, Powderlax, Purelax, Smooth lax, and Trilyte.
Veterinary formulations: None
Uses of Polyethylene glycol 3350 for Dogs and Cats
Polyethylene glycol 3350 is used to stimulate bowel movements in animals with constipation or when there is a need to empty the large intestine such as before a diagnostic procedure to examine the intestine.
Precautions and Side Effects
Polyethylene glycol 3350 should not be used in animals with known hypersensitivity or allergy to the drug.
While generally safe and effective when prescribed by a veterinarian, Polyethylene glycol 3350 can cause side effects in some animals. Some pets will experience lethargy, nausea, vomiting, and/or increased thirst. Longer-term use can cause electrolyte imbalances including high potassium and/or low sodium or cause dehydration.
Polyethylene glycol 3350 should not be used in animals with gastrointestinal obstructions, rectal bleeding or a tear in the intestinal wall (bowel perforation), or toxic colitis. It is also not approved for breeding, nursing or lactating dogs or cats but is considered safe by many veterinarians.
Polyethylene glycol 3350 may interact with other medications. Consult with your veterinarian to determine if other drugs your pet is receiving could interact with Polyethylene glycol 3350. Such drugs include certain other laxatives and stool softeners.
How Polyethylene Glycol 3350 is Supplied
Polyethylene Glycol 3350 Powder for the solution is available in either pre-measured 17-gram packets or bulk powder such as MiraLax®, Dulcolax Balance®, and various generic products.
Polyethylene glycol 3350 is available in various solutions that have added electrolytes primarily used in humans as preparation for colonoscopy diagnostic procedures. Products include CL® Solution; CoLyte®; GoLYTELY®; NuLytely®, TriLyte®, MoviPrep®.
Dosing Information of Polyethylene Glycol 3350 for Dogs and Cats
Medication should never be administered without first consulting your veterinarian.
In dogs, the dose of Polyethylene Glycol 3350 Powder for solution varies with the size of the dog:
Small dogs – 1/8 to ¼ teaspoon every 12 hours (twice daily)
Medium sized dogs – ¼ to ½ teaspoon every 12 hours (twice daily)
Large dogs – ½ to ¾ teaspoon every 12 hours (twice daily)
In cats, the dose of Polyethylene Glycol 3350 Powder for the solution most commonly used is as a laxative is 1/8 to ¼ teaspoon every 12 hours on food.
The duration of administration depends on the condition being treated, response to the medication and the development of any adverse effects. Be certain to complete the prescription unless specifically directed by your veterinarian. Even if your pet feels better, the entire treatment plan should be completed to prevent relapse.
References for Canine and Feline Use of Polyethylene glycol 3350:
American Society of Hospital Pharmacists. Polyethylene glycol. In: AHFS drug information 2010. Bethesda, MD, USA: American Society of Health-System Pharmacists; 2010.
ASPCA Pet Poison Hotline
Carr A, Gaunt M. Constipation resolution with the administration of polyethylene-glycol solution in cats. In: 2010 ACVIM Forum Proceedings. Anaheim, CA, USA.
Current Veterinary Therapy XV, Bonagura and Twedt.
Leib MS. Colonoscopy. In: 80th Annual Western Veterinary Conference Notes (WVC 2008). Las Vegas, NV, USA; 2008.
Ogbru O. Polyethylene glycol 3350 .San Clemente, CA, USA: Medicinenet.com; 2015.