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IMHA – Immune Mediated Hemolytic Anemia

What is an immune-mediated disease? It is any disease where the clinical signs (fever, pain, etc) are caused by the immune system. The immune system normally acts to protect an animal from viruses, parasites, bacteria, and all sorts of other harmful germs. The immune system acts as a ‘search, attack, and destroy’ army, eliminating the countless germs that we get exposed to every day. Immune cells use some pretty strong ‘weapons’ in order to attack the germs. Sometimes these weapons can harm innocent bystanders- the animal’s own cells. So in an immune-mediated disease, the immune system thinks that it is protecting the animal, but is actually damaging body cells.

Immune-mediated hemolytic anemia (IMHA) is a condition where the immune system kills red blood cells. As explained before, the red blood cells are innocent bystanders. There are three types of IMHA: primary, secondary, and idiopathic. Primary IMHA is when the immune system becomes dysfunctional and begins to recognize red blood cells as ‘foreign’. Therefore, your body begins to think that it is being invaded by a germ (the red blood cells) and it works to attack and destroy these invaders.

Secondary IMHA is when the immune system recognizes something foreign that is in or on the red blood cell. In order to get rid of this germ, the immune system kills the red blood cell. Certain types of cancers, infections, and drugs can all potentially cause IMHA. Idiopathic IMHA simply means that the cause of the disease is unknown. Unfortunately, most cases of IMHA are idiopathic.

IMHA tends to be much more common in dogs than in cats. Some breeds are more predisposed to this condition. An animal with IMHA will show most of the same signs as a dog with any type of anemia (decreased number of red blood cells). Anemic pets will be lethargic and will have trouble exercising. This is because they do not have enough red blood cells to supply oxygen to their tissues. IMHA is not the only cause of anemia. Anemia can be caused by other problems, such as loss of red blood cells with excessive bleeding or decreased production of red blood cells in bone marrow disorders (like leukemia).

IMHA is a very bad condition. About half of IMHA dogs do not survive once they are hospitalized. It is a terminal prognosis- the animal will die if it is not treated and unfortunately treatment is very expensive. The pet will need to be hospitalized for at least a week. It is very common for these cases to be referred to a specialty clinic for blood transfusions. The animal will be on steroids for a few months after, in order to keep the immune system from continuing to attack the red blood cells. Treating your pet for IMHA can possibly cost you a few thousand dollars. However, most dogs that recover from IMHA never get it again. These animals tend to have great long-term survival rates. Cost is very often an issue for owners; treating IMHA is a very tough decision to make. This decision should always be made with your veterinarian.

There are other immune-mediated diseases, for example, immune-mediated thrombocytopenia. Thrombocytopenia means a decreased number of platelets. Platelets are blood components that are needed for clotting, so in this condition the animal can quickly bleed to death if not treated. Immune-mediated thrombocytopenia is also expensive to treat but has a better prognosis than IMHA.

Pets can also get immune-mediated arthritis, where the immune system causes inflammation of the joints. This is similar to rheumatoid arthritis in humans. Inflammatory bowel disease, also found in humans, is a fairly common immune-mediated disease. Another common one is flea allergy dermatitis, where the body over-reacts to the presence of fleas and can cause severe skin problems. There are many other immune-mediated diseases that can affect our pets.

Immune-mediated diseases appear to be getting more common. It could be simply because veterinarians are learning to better recognize these conditions. There are also thoughts that pets are being exposed to more harmful substances in their environment. Or maybe the immune-system is being over-stimulated with vaccinations. Perhaps there is too much inbreeding of purebred dogs. There are many guesses, but no answers.

An animal’s immune system is built to protect it from harm. But sometimes, that system is a little bit too efficient and harms body cells in the process. This is what is known as an immune-mediated disease. IMHA is an example of a life-threatening disease. The cause is often unknown and the treatment is expensive. It is one of many immune-mediated diseases that could potentially affect our pets.
By Ashley O’Driscoll – writer

23 Responses to this Article, So Far

  1. Avatar Jim says:

    I have a 2 year old lab/border collie mix. He was diagnoised with IHMA 3 weeks ago, I had him treated at the local vet. for a week. He is now on high doses of steroids. My dog just isn’t the same…the vet. says he will return to his old self but it is very hard to see a once very active dog go to one that just doesn’t want to get excited. I know it is early still and that he will be on steroids for a few months but I am looking for some hope from someone else who went through this and came out with the dog being OK. Any positive comments?

  2. Avatar lynn says:

    i have a 7 year old chihuahua that just didn’t act like her self as i went off to work… i couldn’t put my finger on how she seemed different i thought it was from the strom we had as she is affraid of thunder. but when i came home she did not come with tail wagging. i picked her up do not know why i did but i looked at her gums they were white. off to the vet i went. i was told about imha off to the airport clinic for a transfusion that took 4 hours. then we got to see my baby. she had some improvement and was sent home with us on the 2nd day. she is eating and playing some it has now been 3 days into this awful terrible diease.i just am looking as we all seem to be here for what to do as iam so new to this and scared to little chi is on prednisone 2 times a day and azathioprine 1 time a day. as of just a few hours ago my chi gums are showing color and her red cells are going up.i am taking her to her vet tomorrow to get her blood checked little girl chi is eating and drinking but plays and gets tired sleeps more but is is just 3 days of treatment. i try to keep her still but she is playing .what i have read is very scarry stuff.the vet thinks it was caused from her last shots had a very bad reaction to them.she has a wavior fro any shots ever.

  3. Avatar Jim says:

    Lynn this is Jim I posted on 11-28-11 regarding IHMA. Since that posting I had to put MoeJo to rest. It was the best thing for him, IHMA is very bad and mortality rate is 50/50 if treated. I am not here to be the person with bad news but please allow your dogs eye’s to talk to you…the eye’s are image of the soul. I knew 2 days prior to putting MoeJo to rest but I wanted just some more time with him.

  4. Avatar lynn says:

    to up date you on my little chihuahua hayley. the whole nightmare started on march the 9th upon returning from work. off to the vet to learn my hayley had IMHA i had never heard of it before this day. a transfusion was done it took 4 hours.hayleys blood count was at 8.5 after the transfusion it went to 25 and it held there on the 17th it was 27 and on 24th it went to 38 my little one is onprednison,azathioprine,famotidine ,and taken off her pet tonic. she eats and drinks but did this from the start.plays for a while but rests alot. the vet said to let her rest not to over do. this is a very scarry thing and so serious.hayley blood pack cell test stayed at 25 until 17th.that is when it started going up.i also learned after she gets stronger i will be ordering her a wheel chair the meds have taken there toll on her back legs and help hayley walk when she is stronger to pull the load and keep the pressure of her weak hips and legs. but we will get through this wheel chair thing. i have friends who’s dogs have used them one for 5 years and one after surgery.i am so sorry for others who are going through this awful ordeal as i know it’s one of the most helpless feelings as a pet parent to watch their baby no matter the size each are our babies that we dearly love.i have prayed so much for my hayley and i keep all pets even though i do not know where they maybe that they each get well and wish this awful diease would never hit another little dog or cat anywhere.and i have been cooking for hayley as that has seemed to help her.i cook a whole chicken with lots of green beans, yellow and green squash, garden peas, sweet potato and carrots a little just a little celery no salt nothing but food drain and puree. it makes it easier to digest for her.oh, i get the chicken at earthfare as it has all the organs in side even heart and the kidneys i cook along with the other organ meat. too many just livers are toxic but the whole chicken evens it all out.we think it is the shots but i was reading on line that late spring and early summer there are more cases of IMHA and they did not know why .and with flea season up on us i do not use flea anything but i do use vets +best it is peppermint and clove and it is safe to use. as my vet said hayley can never ever have any shots or flea meds of any kind but gave the a-ok on the vets best.we have to watch everything that these babies who have IMHA get inside and out side their bodies.i hope any info i have given will takes a good 6 weeks or longer to see your baby back from what my vet has told me about IMHA. serious meds for a very serious diease.i will keep you up dated and will read yor up dates . we all need support and hope.i know i sure do. i will only look up i will not look at anything but belief that we all will lick this diease.

  5. Avatar lynn says:

    jim i am so sorry about your moejo. it has taken me so long to respond as i know what it is like to lose a pet i had my last dog for 21 1/2 years. yes… 21 1/2 years. it broke my heart. my hayley is doing better but not all the way back. she still gets very tired and she rests alot. her eyes have had from the get go that spark. but i do know what you mean the eyes say it… my macey had that at the end and i saw it in my moms dog.this is a very awful diease. i wish with all my heart that not one dog or cat ever had to go through this and it takes part of your heart as a pet parent. but you were there for moejo that is the important thing and did the very best for you baby.that is what we all who face this will do.and i am so very sorry that this has happend to your family.lynn

  6. Avatar tom says:

    I recently just got home around 3 pm to my mom crying she told me my Harley <3 was dead. I can't explain the pain its just so depressing. I was running around with Harley in my kitchen Sunday night.
    The doctors told my mom she had IMHA. I read a lot about this terrible disease and it just breaks my heart. We seen her act different yesterday but my parents thought it was because of the different dog food. I even fell asleep on my coach with her lastnight and she was just starring into my eyes with that look. I knew something was wrong.the on the way to the hospital she wasn't breathing. By the time she got there they gave her CPR because her heart stopped. They brang her back twice and then they came out to my mom with the option of a blood transfusion that would cost 5000 on the spot which she didn't have. By the third time the nurse came out she was unable to have the option to make the transfusion because she died. I miss my little puggle so much..I love you Harley RIP. My heart and prayers also go out to the other poor dogs that were effected by this terrible disease.

  7. Avatar kat says:

    I just wanted to note on this article that there are only two types of IMHA: primary and secondary. Idiopathic IMHA is primary. If people are turning to this for useful information, then it should be correct.

  8. Avatar barb says:

    I know how you feel. My dog “Bailey” was put to rest on Monday of this week from IMHA. She was an 8 year old but had the energy of a puppy. We brought her to the vet Saturday and she was gone by Monday morning. I still can’t believe she is gone … We love her so very much.

  9. Avatar lynn says:

    barb i am so sorry to hear about bailey it is such a terrible disease. my baby is fighting this and will be fighting as it never goes away just into remission. my little chihuahua is 7 years old and she is fighting her pcv went from 8 % before the transfusion to 24 then 27 then 35 to 38 to 40 now it is at 33 % it is up and down getting the meds just right.she has to use a wheel chair but after it is safe to cut the dose of predisone it will be better but she can move in the wheel chair with her back legs down. it is very heart breaking to watch your baby go through all of this but i will help my baby as long as her will is strong as jim said the eyes have it and her eyes is she is fighting with her tail wags and kisses she loves to play .i had never heard of this disease until i was told my baby had it. books should inform pet parents about this disease and what to look for.very terrible disease. some day maybe there will be a cure or something to know a pet has it before they get so sick. to all i and my baby wish you the best from our heart to yours and remember my baby too. bless you all

  10. Avatar lynn says:

    my little hayley pcv is at 43 now…. i got her wheel chair but had to wait until stable…. but still am affraid to use as if it stress to her can put her into a relasp. i hate this disease!!!the predisone has done such bad things to her little body… but helpped her in other many ups and downs

  11. Avatar lynn says:

    i haven’t written about hayley in a while we did not have to use the wheel chair after the predisone was cut back she is walking and playing. hayley is on 1/4 predisone will be cut back more on next visit and on azathioprine 1 time per week.still takes famotidine for anacid not taking the pet tinic. her pcv has been stable for a few months in the high 40′s. this is a awful disease . we hope to be in remision with hayley n the next few months. but can reslaspe w/ each dose is a long haul to get over the first part of IMHA and hayley is due to the yearly shots… hayley can never have shots period. she is playful… but even though very sick hayleys eyes never looked weak just her hind legs from high dose of predisone but as it is cut back the wasting goes away and your fur baby will get strenght back. just remember that predisone dose bad things but as it is cut your fur baby will be able to walk and is a roller coaster ride of many ups and downs and this disease has its own mind.any stress can trigger a reaspe very nasty disease. and i check hayleys gums many times a day now… don’t think i will ever stop this as fear of reaspe.wishing the best for anyone fighting this w/ their fur baby. it is july now and this nightmare started in march for us.

  12. Avatar Jami says:

    My husband and I just took our Molly to the vet Sunday night and we knew it wasn’t good. The vet told us it was IMHA and I have been online since trying to find some hope. I hear not to ever give up, but also hear that sometimes you need to think of your pet. It has only been a couple of days, but our 4 year old Cocker Spaniel Molly is not at all the same girl. She just has such a sad look in her eyes. This sounds like a horrible disease. I won’t give up, but it sure is hard to watch her go through this.

  13. Avatar Jami says:

    Well….just got done visiting Molly. She is now on an IV-bilirubin levels are very high. Her RBC has stabalized, but not increasing like we had hoped. She is now on azathioprine as well as the prednisone. Any ideas out there on what stage she is at?? Probably hard to tell right now….still early.

  14. Avatar lynn says:

    jami, you are right this is a very nasty awful disease… it is best to find a vet who has treated this disease before as it is a long battle there is no cure only our fur baby can go into remission and anything that stress our pets can cause relaspe after remission. the predisone in the high dose is very needed but it does cause our fur baby to have wasting in the back legs they fall and have a hard time getting up while on predisone but as the dose is lowered the muscels do regain strenght and that stops but takes time also some get to remission much quicker than others that too is normal. but most not all have a transfusion even the ones who got to remission and relasped. if your fur baby is on predisone and azathioprine your molly will also need famotidine to protect her tummy from these hard meds and a blood builder called pet tinic that is great stuff pet tinic. and you did not say what her pcv wasthat is the red blood pack cell count. my girl when she had the tansfusion was at 8 % very low but after the transfusion it came up to 24-25 % and stayed for ever. we are in battle aganist this disease since march 9TH hayley is now she is on azathioprine 1 time a week no predisone now but does take the famotidine to protect her tummy her pcv is up to the mid 40′s now… it can take a very long time in treatment… some have to take low doses of meds for the rest of lfe to ward off relaspe. wishing you and molly the very best .. prayers coming your way for molly lynn and hayley

  15. Avatar lynn says:

    jami…. it is best to let molly rest just go out to pottie and right back in… remember some meds to can trigger a IMHA attack like yearly shots and fles meds oral or the spot oneven having flea’s best to treat natural before they start. i use what is called vets best found at earthfare and her is what i use.diatomaceous earth also found at earthfare by lumino i put outside and in crackes i do not have carpet but n one room i have hardwood floors i mass it into the carpet after i vac i also use mule team washing powder every month on the room with carpet i spread it all over let it stay 24 hours vac it up then mass in the d.e. that is fossil shell flour great stuff haven’t had a flea in the yard or house over 20 years but they are bad this year our imha babies can’t handle fleas. home made meals are good way to go w/ the imha fur children i have some great recipes if you would like. and one by jean dodds a wonderful vet on line for the liver… predisone is hard on our babies liver.i forgot to write this in the top post. did you find out what triggered molly’s imha? for my baby it was her yearly shots a very bad reaction then .. imha. hayley can never have any shots for life. wishing molly to get to remissiom fast. lynn & hayley

  16. Avatar Jami says:

    I am sorry to report that we lost Molly on the 27th of July. DIC came into play from the meds and got into lungs. She was starting to show signs of suffering, so we had her put down.

    We are not exactly sure what brought it on. She was healthy as could be one week ago, then this all happened. We thought we saw signs of improvement, but then she would regress again. So sad to see her go through that. Her eyes just had the saddest look. It was definitely time to put her out of her misery.

  17. Avatar lynn says:

    i am so very sorry to hear this about molly…she is whole and playing w/ other fur babies at the rainbow bridge and waiting for her family you .this is a disease that is just so awful and it takes a toll on the fur baby and your heart. this makes me so very sad and i am so sorry. but you were there for molly and did everything you could molly knew this too. lynn

  18. Avatar CM says:

    For nearly three years, our cat battled with IMHA. At the onset of the disease, we had no clue what was happening, and the experience was very frightening. Have was given a bad prognosis from the start, and we were unable to pay for expensive treatments, but we cared for him the best we could, and he survived against the odds. (hemocrit was 7% when we started Pred & tlc).

    Over the next two years, we learned what we could, experimenting with different foods, treatments, etc. In the end, after surviving two more relapses, at 8yrs old, with a slipping joint, a few weeks after experiencing three unavoidable environmental-stressors, he relapsed again, and quickly! Despite our familiarity and conventional treatments, his hemocrit was dropping by 1% a day, and we choose to say good-bye.

    What I want you to know, is that I would never give up the three years we were able to buy, and that in our experience, each relapse became more sudden and dramatic. That no matter how careful we were, since he never achieved full remission, at some point this disease would take our cat. Love carried us through, but we reached a point, when it was no longer fair to ask him to keep fighting for us, and had to let him go.

  19. Avatar lynn says:

    i am very sorry for your loss. but you did everything in your power and did the most loving thing a pet parent has to face… what is best for the fur child. lynn

  20. Avatar lynn says:

    it has been a while that i have reported about hayley…. she has had a normal hct for a long time and all test’s have been normal for many months.. waiting to reach the year mark for remission. then i will jump for joy and i am already so thankful that hayley has had the strenght to fight tis horrible disease. some are not able to fight this is a awful disease.march 9th will mark when this all started w/ this nighmare…. there is hope that your pet can beat this awful disease.never give up on your fur baby it take some a long time and others get through it faster. my hayley pcv was at 8% the day of transfusion went upp to 24 % and stayed for some time but the baby red cells kept making them self until she was at normal lots of praying got me through each day… but hayleys will got her through.and it takes 24/7 home nursing and lots of rest for the fur baby until the hct is in the mid 30′s it is best not to let the fur baby run through the house rest is the only way they can recover . taking off meds too soon is a no no will cause a reslaspe. the predisone will cause your fur baby to want to eat more and drink more also pant but get ready for muscel waisting in the back legs normal -normal it will get better after the predisone is cut back but each time a cut in meds watch very close as relaspe can happen. here ar the meds hayley was on predisone,azathioprine,pet tinic and famotidine. she is still on the aza once aweekand the famotidine for the tummy so the harsh meds won’t hurt her tummy. hayley is running and playing again all the time her hct is 49 and holding seems to be her norm since june. but that was what her hct was on yearlys before the imha. and her trigger was the yearly shots. anyone new coming to this post… i hope this will give you hope and faith that your fur baby can have remission no cure ever but only remission and i can handle remission. this disease is a heartbreaker and leaves you helpless feeling… keep up the smile and tell your fur baby you are taking care of them they can tell when your are up set and try your best to be up beat around him or her.stress is the worst thing as iot can trigger this awful disease also.and read-read-read as much as you can to learn and how others get through this and what works.a must is a good diet and alot of tlc. wishing any neebies the best luck lynn

  21. Avatar dean says:

    my mini dachshund, my best friend in the world, Filmore, was put to rest today because of IMHA. he seemed lethargic on wednesday and wouldnt eat or drink or really do anything other than sleep, by thurs he looked like he was dying and we were at the vet. he had very low red cell count. they gave us the steroid pills and told us to try an get fluid into him. i spoon fed him milk to get going, then changed it quickly to pedialyte mixed with water. he would only take very small amounts. we got some baby rice cereal and he started eating it well on sat night. he drank from his bowl a whole bunch of water, and walked outside on his own to pee. momma took him to bed around midnight looking good and we were happy thinking he was getting a little better, but by the time i came in around 3am he was breathing very shallow and fast and it sounded “wet” like he had a bunch of mucus in his throat. by this morning he seemed 2 lbs lighter, was totally white looking on all his skin and gums, and was having very rapid breathing. took him to the emergency vet today and it was decided the best thing was to lay him to rest. this disease took my spunky, full of life, happy dog and withered him to nothing in 4 short days. i pray for anyone who has to experience this dilemma. he was only 8 yrs old and extremely healthy. RIP Filmore, i love you, and i will play my guitar by you under the tree just like we always did……

  22. Avatar lynn says:

    i know it has been months since your loss of filmore but just read your post. i am so very sorry . IMHA is a heartbreaker of disease. when the gums and skin get very white that is because the pcv is very,very low and the breathing is because of lack of oxgen in organs and blood. i am shocked the vet did not keep filmore and do a transfusion. alot of vets have only studied in school about this once rare disease but now seems to be on the rise. my hyleys vet is treating many cats as well as dogs. some causes for imha can be flea meds, flea bites,spider bites, bee stings, snake btes , fur baby eating a penny from zinc,some rat poisin,yearly shots,stress,tick disease from the bites some show up months after the bitethese are some reason but most never know what triggered this disease that many as myself had never heard of until it hit home. this diseae leaves us with a broken heart and no answer to why. we can not blame ourself as this is a very serious diseae and the meds that treat this disease can even kill our fur baby. some fur children are in treatment for many many months and some as my hayley couldn’t walk due to the predisone but that is what saves their life. hayley as her predison was cut was able to walk and run in time. she is now in remission almost a year. it can take a long time for remission but for some it does happen for some nothing works but you and your family gave filmore a chance and he knew your love this disease they do not feel pain just very,very tired and rest and running or playing until the hct gets to mid 30′s. very serious disease with very serious treatments.i hope this explains something about this diseae. it is awful and cruel and a heartbreaker leaving us with our heart broken and empty. i am so sorry that you went through this most of all a sweet little fur baby had to go through this. i hope you are able to smile at all the wonderful times that you did have with filmore. i know someday he will met you at the rainbow bridge and you can walk sisde by side once again.again i am so very sorry for the breaken heart that you and your family have gone through. lynn

  23. Avatar Surbhi says:

    My Zoey has been diagnosed with this horrible illness.
    What’s horrible about this is that I don’t know the cause.
    So far she is battling very hard and doing better, her RBCs were at 18 2 weeks ago and has steadily gone up to 29 this week.
    Hopefully she will pull through. But i am automatically prepared for the worst.
    She eats like its nobody’s business thanks to those steroids. But she is not the same, she does not play and has lost that spark, her legs, already weak, are getting worse. I can’t supplement her with glucosamine or shots because it counteracts with the steroids.
    I am so terrified and at a loss, i don’t know what to do.
    Stay strong everyone, and let’s do whats best for our babies.
    Wishing you all the very best of luck!

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