Get

In Your Inbox

Dogster is reader-supported. When you buy via links on our site, we may earn an affiliate commission at no cost to you. Learn more.

Castor Oil for Dogs: Our Vet Discusses Uses, Safety & Potential Risks

seeds and castor oil on the wooden table

Castor oil is a natural substance that was used as far back as 4000 BC for medicinal purposes. It is an old remedy for constipation in dogs. Although it’s okay to use under explicit directions from your vet, we don’t recommend castor oil as a first-line treatment for any ailments.

The risks of giving castor oil without veterinary advice outweigh the benefits in most cases. Read on to learn more about the historic use of castor oil, the risky side effects, and safer alternatives for your dog.

divider single dog paw oct 2024

What is Castor Oil?

Castor oil is made by cold-pressing castor beans from the castor oil plant (Ricinus communis). Castor beans in their natural form are highly toxic to dogs due to the ricin content, which causes illness within 12–48 hours of ingestion.1

Castor oil doesn’t contain ricin since it is removed and deactivated during processing. It is composed mainly of ricinoleic acid, which is responsible for its efficacy as a cathartic agent. Only food-grade castor oil produced by reliable manufacturers should be used medicinally. It should be stored in a cool, dry place and used before the expiration date.

Castor oil is an outdated remedy for constipation in dogs, but it has been shown to stimulate peristalsis of the colon, leading to defecation.2 Think of peristalsis as a stadium wave of colon muscle contraction; the contraction moves along the colon to guide feces toward the exit.

Due to the bitter taste and side effects, castor oil has fallen out of favor in veterinary medicine, with preference being given to other, less noxious laxatives. There is little evidence for other uses of castor oil in dogs or people.

Despite that, it is sometimes used as a topical remedy for minor skin wounds or irritations. In people, it may be used as an alternative treatment for arthritis, headaches, menstrual cramps, labor induction, or dry eye; however, these uses aren’t supported in dogs.

woman holding a dropper with an oil product bottle
Image Credit: Matevz Kosterov, Shutterstock

How Is Castor Oil Given?

Castor oil is a liquid that can be drawn up with a medication syringe. With veterinarian approval, you can give castor oil orally. The best way to do this is to mix the castor oil with wet food.

The dose and frequency can be adjusted to produce the desired effects in your dog, but we recommend starting with small doses, especially in smaller dogs. Your veterinarian can advise you how much castor oil is appropriate for your dog, but a general guide can also be found here.

For topical use, you can make a castor oil pack to place on your dog.3 We don’t recommend using external heat on the castor oil pack, as your dog won’t be able to tell you if they are getting burnt by it. You should also start with just a drop of castor oil on the skin and monitor for allergic reactions before using a castor oil pack.

What Happens if You Miss a Dose?

If you miss a dose of castor oil, your dog will not be harmed, besides the reduced laxative effects. You should only use castor oil under the instructions of your veterinarian. If you miss a dose, contact your veterinarian for advice regarding the next dose.

If you need to speak with a vet but can't get to one, head over to PangoVet. It's our online service where you can talk to a vet online and get the advice you need for your dog — all at an affordable price!

PangoVet_Mention-in-Content Savings V1

Potential Side Effects of Castor Oil

Castor oil has a horrible taste and aftertaste. For this reason, it can be hard to administer to animals. When it’s syringed directly into dogs’ mouths, there is a risk that they may inhale the oil, leading to aspiration pneumonia, which can be severe and life-threatening.

Castor oil ingestion can cause vomiting and diarrhea, especially in larger doses. Vomiting and diarrhea can lead to dehydration and electrolyte imbalances, which can make dogs very sick. In cases of gastrointestinal obstructions, perforations, and inflammatory bowel disease, using castor oil may make things worse for your dog.

Humans using oral castor oil report abdominal pain and dizziness. Castor oil is thought to stimulate uterine contractions, so it’s not safe during pregnancy. It is unknown if castor oil enters breast milk when it’s used during lactation, so it’s not recommended during breastfeeding. For safety, it’s best to follow these human recommendations in canines.

Using castor oil in dogs can lead to them licking it off their skin and potentially have side effects similar to those when used orally. The more they’ve eaten, the greater their risk of side effects. There is also some evidence of castor oil causing an allergic reaction when used on sensitive people and dogs.4

sick dog in vet clinic
Image Credit: AnnaStills, Shutterstock

divider dog paws 3 oct 2024

Frequently Asked Questions (FAQ)

How Can I Treat My Dog for Constipation?

Dogs can be constipated due to their diet, underlying illnesses, dehydration, obesity, and lack of exercise. Your veterinarian should be the first point of call to diagnose and treat your dog.

In severe cases, constipation can cause abdominal pain, vomiting, and dehydration, which can make them very sick and necessitate veterinary treatment. However, if your dog hasn’t defecated for 24 hours, is not straining, and is otherwise well, sometimes natural fiber can help them.

Boiled pumpkin and psyllium husk are good sources of fiber for dogs. You can also purchase over-the-counter laxatives which are safe to use as directed on the label.

Does Castor Oil Shrink Tumors?

Castor oil has not been shown to shrink tumors. Castor oil is a possible anti-inflammatory, which means the inflammation around a tumor might settle with castor oil application. However, this effect does not correspond to the suppression of cancer cells, which can spread and harm your dog.

We recommend all possible tumors be examined and treated by a veterinarian. Timely removal of cancers can save your dog’s life.

sick dog with veterinary assistant doing examination of his head tumor.
Image Credit: sarocha wangdee, Shutterstock

What Oils Are Best for Dog’s Skin?

Omega-3 fatty acids have an anti-inflammatory effect on the skin. They are present in high quantities in fish oils. For dogs with dandruff, supplementing an omega-6 fatty acid, like those found in corn and evening primrose oil, can sometimes be helpful.

divider dog paws oct 2024

Final Thoughts

Castor oil is mainly used as a laxative, as its main component, ricinoleic acid, acts on the intestines to promote peristaltic movement. However, when used inappropriately, castor oil can have severe side effects, including vomiting, diarrhea, aspiration pneumonia, worsening disease, and abortion.

Topically, it can also lead to allergic reactions. Since there are safer laxatives available, and the use of castor oil for anything other than specific constipation cases is unproven, we recommend only using castor oil under veterinary supervision.


Featured Image Credit: Alexander Ruiz Acevedo, Shutterstock

Want content like this delivered to you?

Sign Up For Our Newsletter

News, insights, expert advice, and everything dog

* By submitting, you agree to our Terms & Conditions and Privacy & Cookies Policy.

How useful was this post?

Click on a star to rate (you can leave written feedback after clicking submit)

Help us improve Dogster for pet parents!

Your feedback really matters.

What did you like about this post? Also how can we improve it?

Join the conversation

Leave a Reply

You’re very welcome to leave a comment or question. Please know that all comments must meet our community guidelines, and your email address will NOT be published. Let’s have a positive and constructive conversation.

Talk With A Vet Online

Peace of mind,
anywhere, anytime

Affordable vet advice

Sesame Shiba Inu: Info, Pictures, History & Origin

Sesame is a rare color in the Shiba Inu. They’re a beautiful variant that originated in Japan (just like the breed as a...

National Walk Your Dog Day 2025: Here’s How It’s Celebrated

National Walk Your Dog Day is on February 22 every year. This day combines two things people love: exercise and walking their dogs....

Can Dogs Eat Almond Flour? Vet-Verified Nutrition Facts & Portion Awareness

Almond flour is an alternative to wheat flour that, in humans, is considered healthier because it has fewer carbs, contains plenty of nutrients,...

How to Clean Maltipoo Eyes: 6 Vet-Approved Tips

Eye care is a regular part of your dog’s grooming routine, but some breeds, including the Maltese, Poodle (the two breeds that make...

More related

How Big Do Newfoundland Dogs Get? Average Weight & Growth Chart

Newfoundland dogs, affectionately known as Newfies by their adoring fan club, epitomize the gentle giant. These massive dogs are renowned for their power,...

How Much Do Basset Hounds Smell? What You Should Know

Every dog comes with its pros and cons. While the Basset Hound is known for its charming, patient demeanor, it is also known...

Cane Corso Beagle Mix: Info, Pictures, Care & More

If you’re looking for an energetic companion, consider the Cane Corso Beagle mix. This fascinating mix is a cross of the powerful and...

Whipador (Whippet & Lab Mix): Info, Pictures, Care Guide & More

A cross between the Whippet and a Labrador Retriever, few mixes present such a unique appearance and mixture of two completely different breeds....

Keep reading

10 Best Raw Dog Food Delivery Services in 2025 – Reviews & Top Picks

It can be overwhelming to choose food for your dog, especially a raw diet. Raw diets have been becoming popular, so many companies are offering raw foods. However, that doesn’t mean all companies produce balanced, high-quality raw diets. We’ve compiled...

raw dog food

Merrick Dog Food Review 2025: Recalls, Pros & Cons

Review Summary Garth Merrick founded Merrick Pet Care in 1988 out of a desire to create homemade food for his dog, Gracie. He crafted his recipes in Hereford, Texas, where the company still has offices. Merrick prides itself on producing...

Dogster_Merrick Dog Food Review

Can Dogs Have Pumpkin Spice? Vet-Verified Health & Nutrition Guide

Fall brings with it the advent of pumpkin spice everything—pumpkin spice lattes, pumpkin spice cookies and bread, pumpkin spice scented candles, and more! There’s really no better way to get into the fall season than with some pumpkin spice. But...

pumpkin spice

Can Dogs Eat Oatmeal? Vet-Approved Facts & FAQ

Many dog owners often wonder, “Can dogs eat oatmeal?” And the answer is yes! Most dogs can absolutely eat oatmeal in moderation. However, like any other human food, certain rules apply. So, let’s go on an informative journey to understand...

Can Dogs Eat Oatmeal

Can Dogs Eat Pudding? Vet-Reviewed Facts & FAQ

Imagine this: You’re feeling nostalgic for the school lunches you ate as a kid. You’re halfway through your peanut butter and jelly sandwich when you spot a fresh cup of pudding. As you pull back the lid, your hands slip,...

Can Dogs Eat_pudding

Goat’s Milk for Dogs: Vet Reviewed Benefits, Uses & More

Many people add milk to cereal or use it in a favorite cake recipe. For dog owners, a splash of cow’s milk is a common treat for their canine companions. However, cow’s milk has its downsides, as it can cause...

farmer pours goat's milk into can

Can Dogs Eat Brown Rice? Vet-Approved Facts & FAQ

Brown rice is an excellent carbohydrate to include in your dog’s diet. It’s seen as one of the more nutritious types of rice that is safe for your canine companion while being easy to digest. Many households have white or...

Can Dogs Eat_Brown Rice

11 Best Dog Foods Made in the USA in 2025 – Reviews & Top Picks

With so many quality dog foods on the market today, dog owners rely on several criteria to help them decide between them. For some, the first question to answer is where the food is manufactured. With several high-profile incidents of...

brown dog sniffing a dog food