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

Share

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Castor oil is an outdated remedy for constipation in dogs, but it has been shown to stimulate peristalsis of the colon, leading to defecation.2 Think of peristalsis as a stadium wave of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 single dog paw 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

Can a Relationship Work When One Person Doesn’t Like Dogs? Tips & When to Walk Away

For dog owners, a partner who doesn’t like dogs isn’t a minor quirk to overlook. Dogs aren’t a hobby you can scale back...

Good Luck or Bad Luck? The 13th Floor Rescue of a Dog Trapped on a Balcony for Two Days

In many cultures, the number 13 is considered bad luck, and while most people don’t put much stock in superstitions these days, there...

Ask Dr. Paola- Help! My Dog is Really Thin! (May 4, 2026)

Welcome to our “Ask Dr. Paola” series, where every Monday we bring expert advice straight from Dr. Paola Cuevas (MVZ) to help our...

Saying Yes When It Matters Most: Coco’s Heart Dog Rescue

In the world of animal rescue, some organizations focus on one species, one type of care, or one specific mission. Coco’s Heart Dog...

More related

Frengle (French Bulldog & Beagle Mix): Info, Pictures, Care & More

The Frengle, also known as the French Bulldog Beagle, is a cross between a French Bulldog and a Beagle. They make excellent family...

ororo Koldpwoof Heated Dog Vest Review 2026: How To Keep Warm On Every Dogventure

Are you up for adventuring, even when the skies are threatening to unleash a downpour or fresh dusting of snow? Ororo is happy...

Wufers Homemade Gourmet Dog Cookies Review 2026: An Expert’s Breakdown

Review Summary Wufers bakes and delivers homemade gourmet cookies straight to your house. This small business is based in London, Ontario and sources...

Are Pitbulls Good Family Dogs? Breed Facts & FAQ

If you ask someone what a Pitbull is, you’ll likely get several responses. That is because many breeds fit the description of a...

Keep reading

Acana Dog Food Review 2026: Pros, Cons, Recalls & FAQ

Acana is a unique company that produces dog food in Alberta, Canada, and Auburn, Kentucky. It manufactures dog food for the American market in Auburn and formulas for Canada and Europe in Alberta. Champion Pet Foods, Acana’s parent company, has...

Dogster_Acana Dog Food Review

Can Dogs Eat Goat Meat? Vet-Approved Facts & FAQ

Dogs are facultative carnivores, meaning they can be quite adaptable when it comes to food. Although their ancestors evolved to eat a primarily carnivorous diet, dogs can do well on diets that have a lot of, a little of, or...

Can Dogs Eat Goat Meat

Can Dogs Eat Tamarind? Vet-Verified Nutrition Facts & Info

Tamarind is a pod-like fruit with a tangy and sweet flavor. It’s native to tropical Africa, though it can grow in some places in the United States (namely Southern Florida). Though it is not as easy to find in most...

Dogster-Can-Dogs-Eat-Tamarind

Ziwi Peak Dog Food Review 2026: Recalls, Pros & Cons

Review Summary Introduction When it comes to commercial dog food, you’re going to be hard-pressed to find something better than Ziwi Peak. It offers high-quality, environmentally friendly ingredients that combine the nutrition of a raw diet in a convenient dry...

Dogster_Ziwi Peak Dog Food

11 Best Dog Foods for Golden Retrievers in 2026 – Reviews & Top Picks

Golden Retrievers are one of the most beloved dogs in the United States. These friendly and lovable dogs can be prone to specific health conditions and diseases, so it’s important to make sure that they’re eating the right kinds of...

golden retriever dog eating healthy dry food from bowl at home

Scheduled vs Free Feeding Dogs: Vet-Verified Comparison, Pros, Cons & Facts

You may just scoop up a cup of dry kibble and toss it into your dog’s bowl every day, without giving it a second thought. But if you want more information about the two main types of feeding—scheduled and free...

Golden Retriever dog eating

8 Best Dog Foods for Weight Loss Made in the USA in 2026 – Reviews & Top Picks

Just like humans, dogs may struggle with excess weight. However, it’s more than just an aesthetic problem. Weight gain in dogs can contribute to a variety of health conditions that can shorten their lifespan and diminish their quality of life....

boston terrier dog eating from white bowl

Can Dogs Eat French Fries? Vet-Approved Nutrition Facts & FAQ

French fries are an incredibly popular human treat. The fried slivers of potatoes, typically covered in salt, are commonly served at fast food chains and takeaways, and it is also possible to buy packaged fries that have already been fried...

Can Dogs Eat French Fries

Love Dogs? So Do We! Join the Dogster Community

Stay informed with expert pet care insights delivered straight to your inbox! Discover professional guidance on animal behavior, feeding tips, trusted product picks, and much more.




Sign up for the Dogster Email Newsletter