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Should I give a Vitamin B12 supplement to my dog?

Sick DogHi Pet Blog Readers! Please welcome Erica, a veterinary clinic technician, with this guest post about the possible uses for vitamin B12 supplementation for your dog. I’d like to preface this by saying that you should always consult with your veterinarian before starting any new supplements, and definitely get your pet to the vet right away if they are showing signs of lethargy (periods of time lacking energy, excitement or extreme weakness).


The vitamin B12 is not only important for the human body- it is also important to the health of a dog or cat’s nervous system and the growth of red and white blood cells. Lethargy, weakness in the legs, or a lack of appetite in a pet may be a result of a vitamin B12 deficiency. This common deficiency may be a result of insufficient levels of the vitamin in the pet’s diet, or of an inherited condition that makes it difficult or impossible for the pet to absorb it through its regular diet. A vitamin B12 deficiency that goes untreated may lead to more serious problems, such as serious gastrointestinal diseases and weight loss. A B12 vitamin supplement is a very effective and simple solution to the problem, whether the problem stems from insufficient dietary levels or from an inherited condition. B12 supplements can also help pets that suffer from gastrointestinal ailments or kidney disease.

How is Vitamin B12 Administered to Pets?

B12B12 vitamin supplements may be administered to pets by a variety of methods, just as it can for humans. The most common method is by oral supplement, which can be administered by crushing a tablet and mixing it into the pet’s food, or by mixing the supplement with water and administering it directly to the mouth by syringe. Increasing meat in the pet’s diet will also provide more of the vitamin. Because many pets have difficulty absorbing the B12 vitamin, injection is a commonly used method of administering the supplement. Some will want these injections to be administered by veterinarians, but the process is simple, and with the veterinarian’s approval, the injections may often be done at home by the pet’s owner. Typically, B12 injections are reserved for serious deficiencies, and they are recommended if the pet has a gastrointestinal illness or an inherited condition that prevents it from absorbing the vitamin through food. Injections are typically administered to a dog’s hind leg. Cats receive the vitamin through subcutaneous injection. B12 injections are typically given once a week for the first five or six weeks, bi-weekly for another period of weeks, and, eventually, on a monthly basis.

How Long Until My Pet Shows Signs of Improvement?

Dog TiredAs the pet is taking the vitamin supplements or injections, the veterinarian will test the pet’s blood regularly, until the B12 level is acceptable. While the pet is taking the supplements, improvements in appetite and energy, weight gain, and improvement of any gastrointestinal problems should be noticeable. For the majority of pets, a few weeks taking the supplement will begin to show improvements in the problems associated with the deficiency, but the breed and medical condition of the pet will ultimately determine whether it will need the supplements in the short or long term.
The potential side effects of a B12 vitamin supplement are minimal. B12 is a safe, non-toxic vitamin. While it is possible for a pet to have too much of certain vitamin supplements, taking too much of a B12 supplement will very rarely harm the pet, because it is not stored in the body. The bloodstream will only absorb as much of the vitamin as it needs at a time, and discard the rest through urination. Vitamin B12 is truly a safe solution for pet lethargy, so talk to your veterinarian today about Vitamin B12 injections or supplements for your pet.

Erica Anderson has spent ten years as a Tucson veterinary clinic technician. She loves writing about pets, parenting, and gardening.


So, have you tried B12 for your dog? How did it work out and what were you treating? I’ve used B12 myself in the past to supplement my diet and increase my energy and I think it worked pretty well for me! Share your stories in the comments!


  1. avatar

    I was unable to take our dog to the vet’s today so my husband took her, the vet gave her a B12 injection & I wondered what it was for, she is currently being treated for a renal problem and a touch of dementia, she is currently taking Fortekor 20mgs & has 1/2 tablet daily also Vitofylin 100mgs taken daily, she has shown improvement but is still sleeping a great deal (she is a 15yr old Collie named Roxy). Your blog sort of answered my query & I will follow it up with her vet on her next visit, thank you for easing a worried owner.

  2. avatar

    I’m glad we were able to help answer your question. Please let us know how things work out!

  3. avatar

    Hi. My 1 year old pet dog suffered from tick infestation but this has been treated. I know that the side effects would be anemia, and currently my dogs gums are pale even his tongue isn’t as pink! I can’t go to the vet till this Friday and I’m desperate for any remedies at all. I gave him some vit b supplements but right now he seems sluggish although he hasn’t lost his appetite.

  4. avatar

    We don’t recommend giving your dog any supplements without first seeing your vet. If you explain to your vet that your dog is showing signs of severe anemia (the pale gums), they might get you in as an emergency appointment, or look for an emergency vet clinic in your area. Pale gums and lethargy aren’t something that I’d wait around to see the vet for – I’d be knocking on their doors! They are very serious symptoms that may be related to the ticks, but can also be signs of organ failure or the dreaded Bloat.

  5. avatar

    Hey Hcrostley, you have shared useful information with us and hope every pets lover will like and leave comments for you. But you are missing most important supplements Nuvet Plus. You can get comprehensive detail about this product from http://www.chachadoodles.com/nuvet.htm

  6. avatar

    I have a 15 year old golden/terrier mix that has become unable to eat over the past couple days. I am a Licensed Acupuncturist & Herbalist, and am licensed to give B12 injections to humans. I would like to give my old guy a B12 injection, but am unsure of where on his body to do this. I have been administering transdermal saline for the past 2 days, as well.

    Can you advise me where is most helpful to inject the B12? Thank you!

  7. avatar

    We recommend speaking with your veterinarian. We can’t give specific advice about your pets’ health for safety reasons. Thanks!

  8. avatar

    my son take a vitamin B supplement so that fleas don’t like to bite him. I wondered if this would be good for my dog as well?

  9. avatar
    NuVet Plus Reviews

    Hcrotsley, interesting blog tha providing very useful informaion abuot Vitamin B12 supplement, hope all dogs lovers will like and shar thoughts with you. I have attain good knowledge about this supplement.

  10. avatar

    Proteins are very important for our life as well as for our pets to and it can be gain through taking a proper diet. Thanks for the post and now i understand the importance of vitamin C.

  11. avatar

    What would be the B12 dosage for a 35 lb dog?

  12. avatar

    I suggest you contact your veterinarian for the proper dosage for your pets. Each pet reacts differently to medications.

  13. avatar

    Hello. My seven-year-old miniature pincher has had several blood transfusions due to autoimmune disease. As red cell blood level always seems to be at 25% if not a little lower would giving him vitamin B 12 be okay with him on all his other medications? Thanks.

  14. avatar

    Hi Michele, I would suggest contacting your veterinarian before making that decision, especially since your fur baby is already taking medications. Good luck!

  15. avatar

    thank you for your quick response. My vet said it was fine as long as I follow proper dosage. My last question is ….. Is it possible for some dogs to normally run low on his red blood cells count and live a normal life? Thank you again.

  16. avatar

    We have found that dogs seem to always find a way to make their lives as ‘normal’ as possible – they’re amazing :). I don’t have any specific experience with animals with low red blood cell counts though unfortunately, so I can’t provide any personal recommendations. I would probably again recommend speaking with your vet. Maybe they can put you in touch with others who have pets and families going through similar conditions and health experiences? Sorry we can’t be more helpful in this instance. Good luck!

  17. avatar

    My 6lb Yorkie suddenly started to lose weight. After dropping almost half her body weight and six months of numerous tests in two provinces we finally decided to try B12 shots. Within a month of weekly shots she was pretty much back to her normal weight. Now I notice she is losing again so will start her on the process again, although I would love to do oral supplements.

  18. avatar

    Nice article… Thanks for sharing those wonderful thoughts! The main article and the comments are very useful guidelines specially for first time pet owners. Thanks. 🙂

  19. avatar

    Trying to get the dog to stop eating his poo. Will B vitamin added to his food help? Will adding sweet potatoe purée help? I tried Yucky Poo. It worked but too expensive . $10 a bottle, bought 2 bottles, 2 dogs, lasted 2 weeks..

  20. avatar

    Hi Connie, thanks for commenting. We do sell Coprophagia Stool Eating Deterrent. Depending on the size of your dogs, you should get 15-30 days treatment out of one bottle. You could try that and see if it corrects the behavior long term after the treatment ends. We would also recommend trying a better quality ingredient diet and if possible picking up the waste right away so they don’t have a chance at it. Please let us know if you have any other questions. Thanks!

  21. avatar

    My 13 year old cocker has been losing weight and even though she has a good appetite she can’t put on any weight. I have had blood work done on her and it all came back good-I was wondering if vitamin b12
    would help her to gain?

  22. avatar

    Hi Vonda, thanks for commenting. Deficiencies in vitamin B12 can affect a dog’s ability to gain or keep on weight. Supplementing could possibly help, as studies and research have shown. As always, check with your vet before making any changes to your pet’s diet. Thanks!

  23. avatar



  24. avatar

    My 4,5 year lab has yeast infection all the time , i know what that emun sistem problem , can i give him B12 shot to increase vitamins level in blood

  25. avatar

    Hi Boris, thanks for messaging. We would not lean towards using a B12 supplement to treat or prevent a yeast infection. Those infections are typically due to water or moisture getting into your dog’s ears, which unfortunately is a really good environment for yeast to grow. It is especially easy for it to grow with dogs that have floppy ears. Your best bet would be to make sure water does not get into your dog’s ears while swimming or during baths. Make sure they stay dry and clean and that should be your best bet to prevent them from happening in the future. Please let us know if you have any other questions. Thanks!

  26. avatar

    Hi Anita, thanks for commenting. We would not recommend a B12 supplement for food allergies and scratching. B12 supplements are typically administered to treat dogs with that vitamin deficiency, and the associated lethargic behavior. If your dog has food allergies, we would recommend switching to a Limited Ingredient or grain free diet. Those types of foods are usually free of the ingredients that cause allergy issues with dogs. There are many many varieties from each manufacturer, so you might try various types until you find one that fits your dog best. As always, if the issue continues, speak with your vet. Please let us know if you have any other questions. Thanks!

  27. avatar

    Thanks for your response, but my dog problem what he has infections all over the body , all his food its grain , corn , potatoes free but looks like he need some kinda buster to help him fight the yeast bacteria, i don’t want to use steroid i want something like vitamins

  28. avatar

    My little Chihuahua is on b12 methylocobalamin and he ate a whole pill 1000mcg….he only ways 6 pounds. He started throwing up after he took the pill and was wondering if this is the cause. I have called the vet but they can’t get him in right now. So frustrated and worried.

  29. avatar

    He is only to take a 1/4 of the amount daily.

  30. avatar
    lakmal amarasiri

    How much of vitamin b12 should give to a puppy .one month old

  31. avatar

    Hi, thanks for commenting. Due to a variety of factors, we would recommend consulting with your vet.

  32. avatar

    Good day my 3 yrs. Old chihuahua is 38 days pregnant,about 2 weeks ago she hardly cant walk now she just lying down cant walk no more, she has vitamins for her pregnacy and my vet gave her another vitamins iron +b complex for her nerves, shes taking it for 3 days, is it ok enough, or do i need to give her vitamin b12 tablets, am so worried for her shes such a veery active dog before my heart breaks when i saw her peeing and poo where she is lying down.. please help us thank you so much. God bless

  33. avatar

    I have a 38kg German Shepherd who is in full work for a show. He is just lacking the pizzazz he usually has so as I have them from my doctor I was told by another person to give him an B12 jab. The strength given to me was 1000ug/ml. He is otherwise healthy and has been vet checked (but no bloods done). He is 23 months old and fed on Royal Canin 4800 endurance, and gibe 20ml Coconut Oil (organic Daily). The canine Chiro suggested the B12.

  34. avatar

    Hi Bambi, We wouldn’t recommend increasing or adding to what you are giving to your dog before checking with a vet. There are little to no side effects from ingesting too much B12, but the vet might want to recommend something else due to the pregnancy.

  35. avatar

    Hi, I’ve a 7 month rottie who is very sluggish and lethargic. Do you think this could give him a boost of energy. He is a raw fed dog, has coconut oil, alfalfa, spirulina, apple cider vinegar added to his feed. Very interested in your answer

  36. avatar

    My pug is 24 pounds and has extreme anemia will B12 help him and how much

  37. avatar

    Hi Kay, You might want to check with your vet first, but it might.

  38. avatar

    Can you shoot up a human with animal b-12?

  39. avatar

    Hi Susan, B-12 is a vitamin that is used in the same form regardless of species. I wouldn’t shoot up b-12, but you can get supplements over the counter. Hope that helps!

  40. avatar

    We have a 12 year old pitt-mastiff mix with an inherited form of arthritis. He hasn’t done well for the past year. The inflamation has had an effect on the nerves in his back and legs. He has progressively lost muscle in his right hip and even in the muscles on the right side of his head. He is almost completely deaf. He had lost the ability to control bowel movements and would sometimes defecate in his sleep. He was having to be helped to stand. We built a ramp for him to get in and out of the house because he could no longer navigate the steps. The vet that cares for him at the last visit gave him about 2 months before we will need to address euthanizing him. That was approximately 3 weeks ago. We changed his dog food to a holistic one and cut the people food. I began inserting a sublingual b12 in his joint supplement in the mornings. He has felt so much better. He’s able to get up and move on his own and even play without falling. He seems to be in less pain and his hearing has improved tremendously. I don’t know what the outcome will be but so far I am pleased with the quality of life we have been able to regain.

  41. avatar

    How about pets besides that of the dogs and cats, like pet ratties for example? I have 3 female rats. I’m taking all precautions necessary to make their lives better n longer. They’re spayed to reduce any tumors. Would B 12 work as far as speeding up the metabolism allowing for a longer life span?

  42. avatar

    Hi i have 7 month old long hair german shepard dog n she has not improve her growth as other gsd..her hair is also not good as other gsd..so i mate a vet n he has given me a suggestion to give a vitamin b comples to her..i dont know any thing about it so can u help me what can i do..

  43. avatar

    You can also text me on my fb..hot_god10@yahoo.com

  44. avatar

    We are so happy to hear about your pups recovery!

  45. avatar

    Thanks for the article–my onece-78-lb lab was sooo lethargic it was awful. He has been receiving B-12 injections for a year now, and the lethargy is usually not present. But, he is now 88 lbs! Please write something about B12 and weight gain.

    Thank you,

  46. avatar

    Thank you for the suggestion Barb! We will definitely keep that in mind for a future blog.

  47. avatar

    Vitamin B12 as we know serve several important functions such as keeping the brain functions in good shape. Aside from this, it also has a part in metabolic functions as well as energy and appetite booster. Vitamin B12 is abundant in meat and meat products and so dogs usually receive them in steady amounts.

  48. avatar

    Hi. Thank you very much for your post.
    I started my Golden retriever on oral supplements and there is a noticeable improvement within few days.

  49. avatar

    You can most definietly use B12 at any age as a supplement. B12 much like Vitamin C is water-soluble, so any excess intake will get urinated out. You cannot overdose on B12. Many pet lovers will use B12 supplements for healthy skin & coat. I hope that helps to answer your question 🙂 If you are ever unsure about something, just double check with your local vet.

  50. avatar

    My long haired German shepherd rescue, around 80lb, we think now around 7/8 years old. We actually think he might be older though as legs starting to go. Anyway, he’s had chronic diarrhoea for a while and we’ve been to and from vets. Fine in himself, wants to play, excitable etc. Still eating lots. Antibiotics didn’t work. Blood test showed bit low in b12 so had his first jab last Thursday, I have 3 more to give him over coming weeks, once a week, 2ml in each syringe, on his body above his front leg. At same time we also stopped using tap water and moved to bottled water. Water has been only common thing as no treats etc. He’s also on Royal Canin sensitive control dry food (which he loves!).
    Friday night he had his first solid poo and has been solid since. I don’t think vitamins work that quickly (?), or within 24 hrs, so has to be water! I’m sharing this in case anyone else has similar. He’s always had same tap water but his stomach just changed(?!).

  51. avatar

    Nice post. I be taught one thing tougher on totally different blogs everyday. It’s going to at all times be stimulating to read content material from different writers and practice a little bit something from their store. I’d want to make use of some with the content on my weblog whether you don’t mind.

  52. avatar

    Hi my name is Gina I hove dog 2 years old he was diagnosed with EPI he take pancreplus tylosin and still has loose poop I ask the vet if I could give him supplement and he said he das not need I want to give him Pet Factor B12 folic Acid intrinsic Factor but I don’t know if is safe ?

  53. avatar

    Just ran across this product and need a second opinion. I’m trying to add weight to my rescue pit. Here’s the product: https://miraclevetlabs.com/ — What are your thoughts on this? Is this something you would feed your dog?

  54. avatar

    Hi folks. My mini schnauzer is 12 and a half ad has always had a delicate tummy! He’s had periods of chronic diarrhoea and scratching ad the think that works for him is raw food. Bought frozen, it includes meat and bone (low fat- 4%) and it’s like a miracle! His poos are now nicely formed and the urgency has gone. More active and bright eyed I’d recommend it!

  55. avatar

    I have a 1 1/2 year pit mix rescue. She became really lethargic and stopped eating and drinking. From the time we got her she was extremely skinny but had started gaining some weight took to vet who said she was very dehydrated and b12 defence. This will be the third week of her getting injections how long does it usually take to get their energy back she perks up on her walks. We also have to give her IV fluids on the days we can’t get her to drink.

  56. avatar

    Generally vitamin B12 deficiency is found in vegetarian’s. Almost all dogs are non-vegetarians. If doctors suggests to take Vitamin B12 then you should definitely move forward.

  57. avatar

    my dog is 9year old..now he is very low energy his not eating food till 6day and his potty colour vry blackish and too much weak and lost weight suddenly.. i am feeding him with injection.

  58. avatar

    You should take your dog to the vet as soon as possible. Lethargy and loss of appetite could be very damaging, especially if the dog is also not drinking.

  59. avatar

    I have an 8 year old pitbull diagnosed with vestibular ear disease with no ear infection with partial Paralysis on the left side of his face jaw ear and eye that won’t blink said he had vertigo still eats and drinks any recommendations on any treatments

  60. avatar

    Hello,my name is kam, I have a 3yr old chihuahua. She is overweight,she lays around slot,she sleeps slot,she quit playing with my yorkie,she acts like she’s depressed. I don’t know what to do. She needs to loose weight but she don’t want to be active,and I have cut down her food intake. Do you have any idea what I should do? Please email me,thank you.
    Very worried.

  61. avatar

    Mike 123s@hotmail.com.
    Hi. My dog was diagnosed with enzyme inefficiently. Which means she can’t keep the nutrition from the food in her. We do mix powder with her food so she can keep the nutrition in her system. Her b12 levels were low. She got 3 injections to get her b12 up. The bet said to give her b12 vitamins. My question is. Can she take human b12 vitamins? And how many mg is needed at day? She is 42 lbs.

  62. avatar

    My chichuahua and her three puppies have parvo and i found some oil B-12 from 2011 and gave them all a shot after one die and with in minutes the rest was drinking on there own and wagging tails. not saying the same would do the same for others but sure help me after 5 days of feeding every 30 minutes. it been 2 hours and all is doing good thanks to the good Lord love..God Bless..

  63. avatar

    I lost my rottwelier last nyt after giving b12 and b complex along with ceftrazoine(antibiotic)i,e is prescribe by a doctor.mr.monoronjion sarkar.is it the ryt way of treatment.plzzz suggest me.my leo condition was not dat much bad.he was suffering frm anerixioua and till bit indigestion.i guess this has happened due to lack of ryt tretment.he was almost cured frm indigestion and acidity bt he was unable to stand up.after dis condition dr.pushed b12 with b complex.plzzz suggest me.

  64. avatar

    Hello ~ I just got home from the vets office where my 14 year old yorkie received a B12 shot to help with her appetite. She had/has IBS and pancreatitis over the holidays. She is on prednisone for that – working towards tapering that as we can. I also came home with a change in diet – Z/D.

    My question is – how long after the injection, should I see some possible improvements? I know it depends on the pet and the ailment, but is there a general idea out there of how long it might take?


  65. avatar

    I have my son’s miniature Shetland Buttercup who is now 19 yrs old and have had her for the past year. She has vestibular disease about 3 years ago. She could not walk and had no balance, her eyes were going from one side to the other and vomiting. Took her to the vet and he gave her a corozone shot and double B12 shot and said she would either get better in a week to two weeks or worst. It is possible she would have another seizure and could get worst. Just watch and see how she does. She kept getting better and better as the days went on. I have her as his yard is connected to a couple of yards that have big dogs and she was scared to go out. Since I have had her I give her cosaquin chewable and 1 vial of B12 liquid on a little piece of bread or in her food and she is doing really well. She walks slow when she first gets up but then can trot when coming in from outside. It is amazing how well she is doing, she is pretty much deaf but site is not bad. It has been an amazing experience for me just watching her. She is a beautiful and very loving part of our family. Hope this helps.

  66. avatar

    My dog had a B12 shot for the first time today. He urinated an orange color is that normal. Peed the second time it was yellow

About hcrotsley

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Currently an owner of 3 dogs and 2 cats, I’ve gained a plethora of pet-related experience over the years. I strive to provide the best home I can for my little terrors, and you’ll read all about our trials and tribulations as I continue down the rewarding yet rocky road of pet parenthood.
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