GME in dogs is an inflammatory neurologic condition that can cause a range of problems from seizures to blindness. Integrative veterinarian Dr. Julie Buzby explains the symptoms, diagnosis, treatment, and prognosis for GME in an effort to help support and empower dog parents whose dogs may be facing this difficult diagnosis.
Most dog parents have a general understanding of the common illnesses that can affect their beloved furry friends. If dogs have been part of your family for a while, you’re probably no stranger to gastrointestinal upset, urinary tract infections in dogs, and skin issues like wounds or pyoderma in dogs. Neurologic problems, however, can seem like a whole different—and much scarier— beast.
Watching your dog suddenly start stumbling around or having seizures is hard enough. It is even harder if you discover your dog’s tentative diagnosis is something you have never heard of—granulomatous meningoencephalomyelitis (GME).
After a diagnosis like that, it can be easy to fall down the research rabbit hole and wind up feeling overwhelmed and confused. That isn’t a fun place to be, so I hope that this article can offer you a bit of clarity and hope.
What is GME in dogs?
Granulomatous meningoencephalomyelitis (i.e. granulomatous meningoencephalitis) is an inflammatory disease of the central nervous system (CNS). If we break down the name, it gives us an overview of what is going on.
“Meningoencephalomyelitis” refers to an inflammation (“itis”) that affects the brain (“encephal”), spinal cord (“myel”), and the covering of these structures, which is called the meninges (“meningo”). The term “granulomatous” indicates that the predominate types of inflammatory cells in these patients are white blood cells like monocytes and lymphocytes.
Which dogs tend to get GME?
Granulomatous meningoencephalomyelitis primarily affects middle-aged small breed dogs, and there is no sex predisposition. On average, a dog might develop GME around four to eight years old. GME can technically affect any breed. However, it is possible there is a hereditary component as it is most common in the following breeds:
- Chihuahua
- Dachshund
- Maltese
- Miniature Poodle
- Rat Terrier
- Toy Poodle
- West Highland White Terrier
- Yorkshire Terrier
What causes GME in dogs?
Unfortunately, GME is still a condition that is not entirely understood and the true underlying cause is unknown. Thus, in the early stages of diagnosis, the veterinarian or veterinary neurologist may refer to it as meningoencephalitis of unknown origin (MUO) or meningoencephalitis of unknown etiology (MUE).
Most researchers who study GME have suggested that it is an autoimmune disorder. In other words, the immune system starts attacking nervous system cells which are normally hidden from it. Many agree that GME can be multifactorial. There may be congenital and environmental influences combined with delayed reactions to things like vaccinations or infections. At this point, researchers do not believe GME is contagious.
Whatever the true trigger may be for GME, the result is an activation of T-cells. These are special cells the immune system normally uses to fight off infections and attack cancerous cells. However, in the case of GME, T-cell activation leads to the uncontrolled release of inflammatory mediators. The end result is oxidative damage, neurologic cell toxicity, and disruption of the blood-brain barrier (BBB). The BBB is a kind of filter that prevents infectious and harmful agents from entering the brain through blood vessels.
What are the types of GME?
GME cases are typically classified based on the location of the lesion within the CNS. In most cases, the type of GME will influence the kind of clinical signs the dog shows. The three types of GME are as follows:
- Focal—The inflammatory lesion is located in one place instead of being more diffuse (i.e. widespread). It usually affects the deeper tissues of the brain (i.e. the white matter) and can sometimes look like a tumor on imaging.
- Disseminated—In this type of GME, the inflammatory lesions are more diffuse or multifocal (i.e. occurring in multiple separate locations). For example, dogs may have disease in their brain and spinal cord.
- Ocular—The least common type of GME, the ocular form, tends to affect the back of the eye where the retina meets the optic nerve.
What are the symptoms of GME?
As you can imagine based on the description of GME, it generally causes neurologic signs. These symptoms can start very rapidly or can gradually intensify over time. And they will vary based on the location of the inflammatory lesion.
In the ocular form of GME, blindness is usually the only clinical sign. In some ocular cases, a dog may have asymmetrical pupils (i.e. anisocoria) or the pupils may respond abnormally to bright light. This happens because ocular GME affects the nerves that send the signal for the muscles to dilate and constrict the pupils.
Sometimes the inflammatory lesion appears at the center of the brain or affects the brainstem. This can lead to an altered mental state or a tired or lethargic dog. It can also affect a dog’s ability to walk normally, resulting in a dog who is wobbly and off balance (i.e. ataxic).
When GME impacts the cranial nerves, the dog might have an impaired sense of balance, resulting in a head tilt and difficulty standing. This can look a lot like vestibular disease in dogs (i.e. doggie vertigo). Additionally, sometimes GME may cause seizures in dogs.
Is GME in dogs painful?
Symptoms like ataxia and head tilt might not affect a dog’s overall quality of life, but GME in dogs can be painful in some cases. It is possible for dogs to experience neck pain. Also, if a dog cannot correctly sense the position and movement of his or her lower extremities—a neurologic sign known as a deficit in conscious proprioception in dogs—he or she may experience knuckling in dogs. As a result, the dog may drag his or her feet, causing painful sores to develop.
Seizures may not be painful, but they can be harmful if a dog suddenly falls near steps or off of furniture. Also, dogs with prolonged seizures can experience a dangerous increase in body temperature.
As you can see, GME can cause a variety of concerning symptoms. If you suspect your dog could have a neurological issue, please contact your vet immediately.
How is GME diagnosed?
Unfortunately, GME can be tricky for your veterinarian to diagnose. There are many different disorders that result in neurological symptoms, and no easy test for GME.
Your veterinarian will probably start by gathering a bit of information about your dog and the symptoms you are seeing. Then he or she will perform a complete physical exam, neurological exam, and additional diagnostics.
Baseline lab work such as blood and urine testing can be useful for ruling out infectious causes that can also lead to neurologic symptoms. Some of those conditions include:
- Tick borne disease in dogs
- Fungal infections
- Canine distemper virus (Distemper in dogs)
- Leptospirosis
- Toxoplasmosis
Based on your dog’s medical history, clinical signs, and the absence of an infectious cause, the vet may presumptively diagnose your dog with GME.
Unfortunately, reaching a definitive diagnosis of GME requires a biopsy of the brain tissue. This is very difficult to achieve in a living and breathing small animal. As a result, confirmation of the diagnosis via brain histopathology is typically only performed postmortem.
However, there are a few tests that can help solidify the presumptive diagnosis of GME. Your vet may refer your dog to a veterinary neurologist for magnetic resonance imaging (MRI). MRI testing can look for other problems like brain tumors and can help distinguish GME from other meningoencephalopathies like necrotizing meningoencephalitis.
Another helpful test is cerebrospinal fluid (CSF) analysis. CSF is the fluid around your dog’s spinal cord. In dogs with GME, the CSF may have increased mononuclear cell types like monocytes and lymphocytes or increased levels in special types of proteins like beta- and gamma-globulins.
What is the treatment for GME in dogs?
After reaching a presumptive diagnosis of GME, your vet will discuss the treatment options with you. Vets often treat GME with immunosuppressive therapy. This is primarily achieved with steroids in the initial phase, but most studies suggest that multi-agent therapy (usually a steroid plus one or more immunosuppressive drugs) is the best course of action.
Prednisone for dogs with GME
Steroid medications like prednisone for dogs and dexamethasone are useful for GME because they help maintain the blood-brain barrier, suppress T-cell activity, and reduce inflammation. Veterinarians use high doses of steroids to achieve these effects. Unfortunately, the downside is that this also increases the risk of side effects such as gastrointestinal upset, increased thirst in dogs, and increased urination.
Dogs with GME should stay on steroids for at least three months. Stopping steroids abruptly increases the risk of a relapse.
Immunosuppressives for dogs with GME
There are several different immunosuppressive medications your veterinary neurologist may consider when treating your dog’s GME. Cyclosporine is one of the most common immunosuppressives used for GME because it is well absorbed when ingested. It also works fairly quickly. This is advantageous because other immunosuppressive agents like azathioprine can take eight to twelve weeks to take full effect.
It is important to know that the resolution of clinical signs doesn’t mean that your dog’s GME has been cured. Ideally, the vet would repeat the MRI and CSF testing before discontinuing immunosuppressive medications. Otherwise, if the lesion hasn’t completely resolved, stopping the medications often results in a relapse.
Additional therapies for dogs with GME
Dogs with seizures may need to start taking anti-seizure medications like zonisamide and levetiracetam. Veterinary neurologists prefer both of these over other anti-seizure medications because they cause less sedation.
Additionally, dogs with the focal form of GME may benefit from radiation therapy. Radiation works much better for focal GME than disseminated since for focal GME the radiation only needs to be directed at one area.
What is the prognosis for dogs with GME?
Dogs who undergo treatment for GME can have a fair to good prognosis. However, left untreated, GME can be fatal. It is estimated that 44% to 75% of dogs show a positive response to therapy. Many dogs require lifelong therapy, but it is possible for some dogs to go into remission once treatment is complete. However, those dogs may not be truly “cured” of GME as relapses are common.
Overall, studies indicate that the survival times vary from 14 to 1,063 days post diagnosis. The odds of a good prognosis and longer life expectancy are better when patients have a clean MRI within three months of diagnosis. On the other hand, patients with a poorer prognosis tended to have dull mentation, seizures, and multifocal signs. And prognosis was better for all dogs who were taking at least two different immunosuppressive drugs.
Finding hope in the midst of GME
I know it can be scary when your dog suddenly starts showing neurological signs and your vet mentions granulomatous meningoencephalomyelitis as a potential cause. No one wants to hear their dog has a difficult to diagnose condition that often requires multiple potentially lifelong medications. However, the good news is that GME is treatable. And some dogs may even go into remission.
If your dog has GME, work closely with your veterinarian and a veterinary neurologist. This partnership is a great way to give your dog the best possible chances of continuing to live a good life despite GME.
What advice do you have for dog parents who are facing a GME diagnosis with their dog?
Please share your insights below.
Mike says
My best friend Rocky (Chihuahua) passed away in 2017 from gme.I would like to know if there are still studies going on that there is a link to vaccinations triggering gme. I know most vets will say no but back then I did a great deal of research (as much as I could find at the time) and talked to several different vets, both “regular” and holistic. Most of the holistic vets were a yes while the rest were no. I also think there should be more study about gme being contagious, the reason I say that is because I had two dogs at the time and my mixed breed Buddy came down with it first, (didn’t know what is was then) but he had all the classic signs of disseminated gme. He went fast, but the point is they ate together and played together. I was more aware with Rocky and got him to the vet as soon as he started showing signs of walking funny and I did everything the vet could think of including having a custom drug made. I never got to try it, Rocky passed away the afternoon I picked up the drug. This a nasty, nasty disease and I am hoping there will be a cure one soon.
Julie Buzby DVM says
Dear Mike,
I am so sorry you have lost two beloved pups to this horrible disease. Scientists are still researching GME and trying to determine if it is contagious after all. Also, as the article mentioned, GME is thought to be an autoimmune disorder. This means anything that stimulates the immune system could be a potential trigger (such as vaccines). So, we have learned a lot about GME over the last few years but there is still much to be explored. Thank you for sharing your experience. Buddy and Rocky will never be forgotten and may their memories be a blessing in your life.
Maxine says
thanks for your write up it’s really good. our 3 year old pup was diagnosed with GME I don’t know what kind but we saw dark matter in a few spots on her CT scan and CF tap. she got treated with a one of dose of chemo and then was put on very high 15mg dose of prednisone… the good news is we have over the period of a year tapered her down to 1.25mg a day.. none of our vets will agree to do another CT scan or tap to confirm if the GME is gone.
now we are in a stage of confusion if we should take her off of steroids or not. she has zero lingering effects but we are seeing side effects from the steroids such as weight gain which we are dealing with and a luxating patella, our pups get brain foods and a weight maintaining diet and probably eat better then we do.
I just wanted people who read this to know there is hope and our pup was one of the worst cases of GME seen she was basically uncontrollably seizuring in the form of a crocodile roll before chemo was suggested.
they can come back you just need to treat them and make sure you get great advice like the wrote up here. thank you!
Julie Buzby DVM says
Hi Maxine,
What a blessing your pup was able to beat this awful disease! I understand your concerns with the prednisone side effects. I am hopeful that you will be able to discontinue the steroids at some point in the future. Thank you for being willing to share your story with our readers. I have no doubt this will offer hope to others when facing an unknown path after a GME diagnosis. Wishing you and your sweet girl the best. Bless you both!
Lynn says
Are the medications to treat this expensive?
Julie Buzby DVM says
Hi Lynn,
I am sorry I can’t give specific information. It really depends on what medications your vet recommends and what your dog requires based on their case details.
Matthew says
My dogs had problems the recent weeks he’s had a CT Scan and a CStap they originally thought it was this disease and had told be to be prepared for the worst within 2 to 6 weeks but from that point onwards he’s gone from strength to strength so now they’re unsure and think it’s possibly meningitis.
What are the clear signs of this disease
Julie Buzby DVM says
Hi Matthew,
I understand your concern for your dog and know how hard it is to not have a definitive diagnosis. Unfortunately, there are no “clear” signs of this disease. Like the article states, this condition is not entirely understood, and the underlying cause is still unknown. That is why it can be so hard to diagnose. I am glad your pup has been improving. That is such great news! Hoping you can continue to partner with your vet to ensure your boy makes a full recovery.
Spela says
Hello. Our 5,5 year old chihuahua was diagnosed with multifocal GME after MRI, 2 months ago. We started treating him with prednisolone (2mg/kg/day) immediately and so far the symptoms are under control. There are still some ”worse days” when he is walking in circles for short time and sometimes he can be confused. We also started adding krill oil (to increase omega-3 fatty acids which are good for brain) and B-complex vitamins (for nervous system) to his food, and I hope we will benefit from all that medications. Anyway I would like to know if there is any other way to increase the treatment result? I hope current treatment will be successful, and the symptoms won’t get any worse.
Julie Buzby DVM says
Hi Spela,
I am sorry your little pup has received such a difficult diagnosis. I am glad to hear his symptoms seem to be under control most days and he is doing well with his current treatment regimen. I am not sure I have any specific advice to give. You seem to be doing everything I would normally recommend. The only other options you could try would be treatments/supplements that aim to reduce inflammation. Here is a link to another article with more information: Natural Pain Relief for Dogs: 13 Methods
I know this article is addressing pain, but most of these treatments also reduce inflammation as well. Since GME is inflammation in the Central Nervous System, some of these therapies may be able to help. I hope this info will give you something to discuss with your vet. Wishing you both the best of luck and many happy days ahead.
Jill says
My Puppy (6 month old, labradoodle) has just been diagnosed with this horrible disease (focal). I have been researching GME for the past 3 weeks and this is one of the best descriptions I have read. Thank you!. She is currently just on prednisone. 3 weeks and no ‘wobbly’ episodes. Do you have any other info or experiences you can chat with me about? One Dr. recommends getting her into ketosis and using MCT oils. Thoughts? Thanks, Jill
Julie Buzby DVM says
Hi Jill,
I am sorry your young puppy is facing this difficult disease. I am glad the prednisone seems to be helping and there have been no wobbling episodes recently. I am afraid there isn’t much I can add, and it is hard to make recommendations without examining your dog myself. I don’t have any experience using ketosis or MCT oils to treat this condition. With that being said, it might be a good idea to reach out to a holistic vet or one that practices alternative medicine to see if they have any additional recommendations. Also, you may want to schedule a consult with a specialist. I hope your sweet girl can make a full recovery. Wishing you both the best.
Jill B says
I am following up on my Pup Gidget. She is a survivor. It has now been 9 months since her first episode of her Focal GME. She started with Prednisoe, then Cyclosporine was added. I was making her food (anti-inflammatory diet), Then the seizures/episodes continued. Her Dr. prescribed anti seizure meds: first Keppra, and eventually we had to add Phenobarbital. At this time her Dr. also recommended Purina NeuroCare kibble. I had a hard time embracing the kibble idea, but it seems to be helping and way easier than cooking for her.
Yes this condition is quite expensive to treat. I think her meds are around $180 a month (cyclosporine is the most expensive, but there is a generic pill available), plus any dr visits/blood tests. We have good pet insurance (Embrace)
Unfortunately she is still having these horrible episodes a little more frequently now, So we are going to try Cytosar radiation therapy. Im praying this gets the inflammation down and we might be able to get her off some of the other meds (now this treatment is very expensive! good think we have pet insurance!).
The good news is her episodes, though they last around 4-6 hours and sometimes longer (about every two weeks-2 months) all the other days she is a happy, ball chasing, loving pup. I have noticed that she does get tired easily, so I need to limit the distance of her walks and do one in the morning and one in the eve, instead of one long walk.
Treating a dog with GME, can be very expensive and very time consuming, but the joy of the pup when she is well…which is most days, is well worth the effort! Im not sure how much time with will have with her, but I am now realizing that the meds really do help and it’s just something we will have to deal with for the rest of her life…Many dogs live long full lives with GME., and some go into remission.
I hope this information can help any others with a GME pup.
Julie Buzby DVM says
Hi Jill,
I truly appreciate you being willing to share your experience with our readers. This is such helpful information and may be the hope someone else needs while dealing with a similar situation. It makes me so happy to hear that Gidget is doing well and loving life most days. I hope she continues to tolerate her medications and pray you both have many happy years ahead. Thank you for the update! ♥