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Castor oil is an outdated remedy for constipation in dogs, but it has been shown to stimulate peristalsis of the colon, leading to defecation.2 Think of peristalsis as a stadium wave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

Dogster’s Weekly Photo Contest Winners: The Cutest Puppy (April 2, 2026)

Every week our team gets the privilege of sorting through our readers photos to choose what dogs will win this weeks contest! See...

The Hidden Risk in Tall Grass That Most Dog Owners Ignore

Finding a tick on your dog can look like a lot of things, depending on when you catch it. Some are engorged and...

America’s Most Popular Dog Breed Is Also One of the Unhealthiest

We’re now 3 for 3 in the category of disappointing canine accolades with the French Bulldog being announced as America’s most popular dog...

Ask Dr. Paola- Help! My Dog Keeps Barking at the TV! (March 30, 2026)

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

More related

8 Different Types of Mastiff (With Info & Pictures)

With their muscular, majestic looks and reputation as a loyal guardian, the legendary Mastiff has been a companion to mankind for more than...

Do Dogs & Ferrets Get Along? Vet-Approved Introduction & Safety Tips

Dogs are one of the most popular pets in the world and ferrets, for their part, are gaining more and more popularity as...

8 Rat Terrier Facts: History, Appearance & Traits

Of all dog breeds, the Rat Terrier is the best-known "unknown" dog around. You'll see what we mean....

4 Corners Cannabis Pet CBD Tincture Review 2026: An Expert’s Breakdown

* Use code PETKEEN15. As a lifelong dog owner, I watch my dogs age and start to suffer from arthritis and other forms...

Keep reading

Merrick Dog Food vs Blue Buffalo 2026 Comparison: Pros & Cons

If there’s one goal you should strive toward as a dog owner, it’s providing your pooch with the best life possible. You can do this by showering him with love, snuggles, and toys, but an even better way to ensure...

Dogster_Dog Food Merrick VS Blue Buffalo

10 Best Dog Foods for Greyhounds in 2026 – Reviews & Top Picks

Greyhounds might not be the most popular breed, but they have a loyal following of enthusiasts who appreciate the dogs’ unique characteristics, particularly their speed. As you may expect, this pup is high energy with equally demanding exercise needs. It’s...

Italian Greyhound dog eating from bowl at home

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

Royal Canin Dog Food vs Hill’s Science Diet: 2026 Comparison, Pros & Cons

There are dozens of dog food brands, and each offers several varieties. This leads to many products to sort through, a great deal of research, and too much misinformation. You want the best food possible for your dog, but you...

Dogster_Dog Food Royal Canin vs Hill’s Science Diet

Can Dogs Eat Yogurt? Vet-Verified Nutrition Facts & FAQ

Yogurt is one of the rare treats that blends a delicious flavor with potential health benefits. If you’re a diehard fan of the tasty dairy delight, you’ve probably wondered whether your pets could enjoy it as much as you do....

Can Dogs Eat Yogurt

Can Dogs Eat Capers? Vet-Reviewed Nutrition Facts & FAQ

You love your dog, so you want to give them treats every now and again, and sometimes those treats are your own food. A lot of the time, depending on the food, this is (mostly) fine for your pet. But...

Can Dogs Eat Capers

Can Dogs Be Vegetarian? Vet-Verified Nutrition & Health Facts

Dogs are considered omnivores, or facultative carnivores, meaning they can digest and utilize both animal and plant-based foods in their diet. However, did you know dogs can be fed a vegetarian diet and thrive? Dogs do not need meat in...

The dog sits near a bowl of food and licks his tongue, dry food and fresh vegetables and fruits

Is Dry Dog Food Bad for Dogs? Vet-Reviewed Pros & Cons

There has been controversy surrounding dry food in the dog food world for years now. Proponents of raw food and fresh food diets argue that dry dog food is unhealthy due to being highly processed, but others have a more...

pouring dog food

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