Low Dose Naltrexone For Dogs

I had to figure out a Low Dose Naltrexone dose for a dog not too long ago.

A quick look at the doses people said their Vets were prescribing was a bit confusing, as the doses being prescribed were equal to – or bigger than – what is recommended for people. But… people were reporting succcesses with those doses.

After checking out the data that I could find in the literature for the blood levels and metabolism of naltrexone in dogs and people, I think I understand why those doses work.

Dogs’ livers break down naltrexone MUCH faster than peoples’ livers. So, it takes a bigger dose than you would think necessary to get blood levels that are equivalent to what you have when people take the doses that are recommended for them.

In fact, dogs’ livers chew up naltrexone so fast that it probably becomes impossible to maintain adequate blood level profiles in dogs much bigger than a cocker spaniel with a single dose.

The theoretically based graph pasted below illustrates this effect.

The Series 1 line is the blood concentration for a ‘normal’ sized person plotted against hours on the x-axis…

The lines for Series 2, 3, and 4 are blood concentration levels for increasing doses of naltrexone in a cocker spaniel sized dog.

Notice that the blood concentration level curves fall below the human profile curve for all doses somewhere between 3 and 4 hours after administration.

Basically, what this graph shows is that dogs’ livers deactivate naltrexone so quickly that you just can’t get a reasonable Low Dose Naltrexone dose that will give a human-like plasma level curve in dogs larger than a cocker spaniel.

So, what can we do?

If I had a large dog I would dose them with a normal ‘human’ dose two times every evening, with the second dose being given around two and a half hours after the first. If possible, dose titration to effect would be desirable. (in other words, you might have to increase your doses in some predictable manner if the original doses don’t work)

But, you often don’t have time to do this kind of work. In those cases you’ll just have to dose as described and hope the dose is ok.

Too big a dose and it won’t work. Too small and it won’t work either. Keep this concept in mind. If you increase your doses and don’t see an effect think about your doses for a second. They might be too big.

Print this posting out and take it to your Vet. He will understand what I am talking about.


NTX Single doses

Hope this helps.

Again, remember… I am not a physician. Just a pharmacist telling you what the literature shows. Always seek professional advice from your physician, care giver, or veteranarian… as applicable…




31 thoughts on “Low Dose Naltrexone For Dogs

  1. Hi, great info on naltextrone para canines, my dog is dying…. I have a question:
    As a pharmacist, would you consider taking ldn
    simply as a quality of life nutrient (supplement) for yourself -(well aged in my case)
    while doing research on yr (dawg??
    I AM!
    WHY NOT?
    wes the mad (cientist..

  2. Excellent site you’ve got here.. It’s hard to find high-quality writing like yours
    these days. I really appreciate individuals like you!
    Take care!!

  3. It is hard for me to understand all of this chemistry stuff, but I do have a cocker spaniel and she is 21.6 lbs. and is on .05 mils LDN every am for her non contagious mange. I will keep her on it for life for her since D…. mange is auto immune. Even though the mites are gone. My last Cocker had live cancer and disease and a bum leg she lived a yr and half long then expected and gained full use of her back leg. My vets was stunned. I was Grateful!

  4. Thank you for posting this; your effort is very much appreciated. Our dog has IBD, and we will be looking into using this medication to help treat it; it seems very promising.

  5. My 10 year old Samoyed is very ill at the vets at the moment…2nd day on drips to rehydrate him, his kidneys not functioning says vet.
    Would you know if LDN would be beneficial…that’s if my dog will take it and the vet administer it?

  6. Our dog weighs 52lbs. She is an Aussie with non-contagious mange as well. What dose would you recommend for her? Does this control your dog’s itching and self harm? Our dog has regained her hair and is improving but she still digs and bites herself and causes bleeding on a daily basis, she has been suffering with this for nearly 6 years and we have spent thousands on vet visits and treatments, natural and conventional. I am thinking of starting her on ldn. Please advise?

  7. I have a 3.5lb Chihuahua who was diagnosed with Sards 2 weeks ago…would LDN help her…and what Vet in Philadelphia area would prescribe it.

  8. I have one BT rescue who has suffered with skin and yeast disorders since we got her. Nzymes and Dermagic have made a HUGE Difference for her!

  9. Thank you, this is great info. I brought your findings to the attention of our vet as LDN was recently prescribed (at my request) for our 52 lb dog to treat an auto immune condition. Our vet (an internal medicine specialist) said that 3mg daily is all she is comfortable prescribing. (Our case is the first time she has used this drug). So I am hoping you might be able to refer me to one of the veterinarians you mentioned who have prescribed larger doses as maybe s/he has more hands-on experience with LDN and could provide us a 2nd opinion. Perhaps you could email me the info? Thank you!

  10. Thank you for the info. I know LDN has placed my husband’s Crohn’s practically in remission, and so I’m hoping you can advise us about our 120 pound Great Pryenees dog. She has been diagnosed with encephalitis (although blood tests don’t indicate infectious encephalitis). She shows most of the symptoms, and she is a very weak and disoriented girl right now. Breaks my heart! She’s on prednisone to reduce inflammation, but will be titrating down later this week. My experience is to start low and increase the dose. I’m thinking Angel, considering what you wrote about dog livers, should start at 4.5 mg once daily to see if this makes a difference. We could increase the dose if need be, but I’d like your opinion. She could have auto-immune encephalitis, but the vets where we live have never heard of LDN. Thanks for any guidance you can give, Cathy

  11. My 11 yr. Lab..MATILDA..has HEMANGIOSARCOMA. ..we are in shock..diagnosed Oct 2nd. Immediately started her on LDN…ACTIGAL .RED PALM SEED OIL..LACTILOSE SYRUP..RICE..LIVER. CHICKEN..AND LOTS OF LOVE. ..Vet. didnt think she would live thru surg. Praise GOD SHE IS STILL LIVING LOUD! Removed 3 gallons of blood from abdomen and found bleed. Was able to stop with VIT. K..and surgical paste. ..had abdominal tap last Monday 30th.to remove fluid build up..1 gal. NO BLOOD….Thats the only problem is abdomen responding to tumor around intestine. Lab values unremarkable. My question..We have her on LDN 2CC’S at bedtime…her weight is 64.5 lbs. .no new tumors…no bleeding…the abdominal tumor did grow some. .what would be your advise on dosage. She eats, runs, plays, LICKS AND LOVES….i saw too info on Budwig Protocol and Artemisinin-Wormwood? Gradford Stokes

  12. Excellent information for dogs. How about cats? Do you have similar information for cats, by any chance? My cat needs help with his Kidney failure, diabetes, and pacreatitis, and arthritis.

  13. Hi. You said you’d give a normal human dose (seems too low) twice each eve. Have you any lab results to show what happens when given in this manner? I’d be willing to experiment with my dog and author a case study to inform other vets/owners. Can you suggest a lab to analyze the blood? Pls email me.

  14. Hi Debbie. I’ve had good luck using DMSO to treat pancreatic and liver inflammation in a cat. You might see if your vet would help you find a dose that could help your cat. Currently, I’m experimenting with .02ml/lb on a mild CKD case with gastritis (possible pancreatitis). Wth the advanced case of pancreatic and liver disease, the most effective dose was .5ml/lb administered topically. It was diluted to 50% smd divided into 4 doses daily. The cat didn’t like sensation, but improvement was drastic and life-saving. It can be given through the skin although this may be uncomfortable for concentrations higher than 25%. Under tge advice of your vet, it could be diluted in subcutaneous fluids to prevent the tingling/pickling sensation. It can be ministered via IV which is often complicated and might be stressful for the cat, but it’s something I would want to do in a crisis (eg severe inflammation from toxicity or cancer). If you are already giving the cat subcutaneous fluids, considered asking your vet to show you how to infuse DMSO so that the cat receives a low concentration without irritation. I am not a vet Denso the advice I can offer is limited please call your vet and if your gut is unwilling, call aroumd until you find one who is willing. An equine or holisric vet may be more willing to assist than a standard small animal vet.

  15. Sorry so many typos, I can’t see my screen. Pls email me if u need explanation. Lj model call @gmail.com call ( no spaces) subject “DMSO & cats” please note DMSO may suppress thyroid function, so levels of T4, BUN, & creatinine should be checked regularly.

  16. My pug just got home from Veterinary Specialist Center. Recovering from Acute Pancreatitis. I had read about LDN and I am wondering if I should try it on her?? She doesn’t want to eat but I finally figured it out how to make her eat some food! Some of the medications has to be taken with food.. so I went to Walgreens and asked the Pharmacy if they have plastic syringes without any needles. . well in my surprised they do. Of course! ! But I would really like to try LDN on my Pug Dolce for her Pancreatitis.

  17. The good things that LDN does comes AFTER it has left the system. It makes the body believe there is a shortage of endorphins while it is being metabolized, and after it leaves the system, the body makes more endorphins and endorphin receptors, and upregulates the OGF factors. THIS is when you benefit from LDN. It takes about 4-6 hours for humans to metabolize LDN, so the dog example is not too far off that. You want to maximize the time LDN is OUT of the system and helping the body, therefore, avoiding large doses and giving LDN more than once every 24 hours is NOT a good idea. While it is in the body, it will block endorphins and endorphin receptors and is actually a time where cell proliferation can occur, which is good for wound healing but NOT for cancer or autoimmune diseases. The general rule of thumb for dosing an animal is .03mg LDN times the weight of the animal, given once in 24 hours.

  18. Hello, my son forwarded your website to me, as our dog, an Akita has been diagnosed with VOGT-KOYANAGI-HARADA (VKH) & SYSTEMIC LUPUS ERYTHEMATOSUS …she is being treated with Prednisone to manage her inflammation, and also drops to stabilize her eye sight. Prognosis is not good, and a long haul of meds., and testing in her future. Do you know of any clinical trials for dogs using Naltrexone? Her vet is hesitant to use Naltrexone due to unavailable studies. Thank you so much. Sonja

  19. Actually, the proper diagnosis for Mochi is UVEODERMATOLOGIC SYNDROME IN DOGS. Would you mind sharing your sources if clinical trials on Naltrexone, if you have any.

    Again thank you so much.

  20. How do I find a vet. to prescribe this for my dog, who is 17 1/2 years old? My friend gave me a few pills to try on him and within 2 days he was acting like a puppy! The day I took him to my friend in tears that he was dying in my arms, he gave him a 1.5 mg dose and he ztopped hyperventalating right away. I could not believe that he saved my dogs life with a small dose of Naltrexone. I need help in getting a prescription fir him asap. Please advise. Thank you.

  21. Hi my dog is 2 years old and has immune mediated polyarthritis, we’ve been unsuccessful treating with steroids and are now using immune suppression’s of atopica, chlorambucil and leflunomide plus paid killers

    He’s now got pancreatitis and has lost even more weight – c 1kg in 3 weeks

    He’s not eating well but prior to that had been doing pretty well

    As it’s his immune system causing the issues I’m unsure if this is would be appropriate

    Thanks Jen

  22. I showed my vet the literature on the safety profile for high dose naltrexone in dogs. They actually will use 50 mg. for behavioral issues and the safety profile is good. So if 50 mg. is safe than low dose is definitely safe. If your vet refuses I would try another vet in the area. Just my input in case the pharmacist doesn’t respond. Best of luck!

  23. Why not for cancer? I’ve read some good success stories of people treating their dogs cancer with Naltrexone at bedtime

  24. I am so happy that I found your website! My dog has been feeling crummy from autoimmune thyroiditis for at least 2 years, even though he has been on thyroid med AND ldn. I gave the ldn to him at night, on an empty stomach, according to the directions of .03 x his weight. He never seemed to feel better from it. I just tried the crazy pharmacists theory and my dog is back to his silly, happy self! I just wish I had been doing this a long time ago. Thanks very crazy pharmacist for sharing your theory.

  25. Where did you get this dose from, and what are the units f the animal’s body weight? Can you post a link to the information?

  26. At my request my vet prescribed low dose naltrexone for a cat I adopted in very ill condition. She is a chocolate point siamese named Kali weighed 2.5kg had skin ledions rotten teeth and her bloods were so bad the machine couldn’t give an accurate reading. She came back positive for both feline leukaemia and feline Aids. We dosed her at 0.044mg/kg. Often I dosed her twice a day morning and night. She cleared the leukaemia and aids (negative pcr). She now weighs 4.8kg and is one of the loves of my life. I am now looking for information on dosing my horse. We’ve started him low and went up to 10mg. Plan to titrate to 25mg. Does anyone have any information for horses?

  27. I put my now 8 year old Golden on LDN when he was three. He got Lyme 4.5 years ago and almost died. I had been put on LDN a year prior and had a lot of the smaller doses I titration up on and used them on JJ.
    Jay has had one episode of Lyme yearly where as before he couldn’t walk and stopped eating and drinking. His Lyme episode is meet with doxy and he’s as good as new for another year.. ldn is hard to find a vet who will prescribe. I share my prescription with him. I live eastern WA could use some help.

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