Meningitis in Dogs

Steroid responsive meningitis not distemper in Mini Schnauzer

Q: My question is regarding my nine-month-old minature schnauzer. We got Heidi about five months ago. She has had all of her puppy shots and has always been very hyper and very active, just as a puppy should be.

About a month and a half ago, we noticed that Heidi was having trouble keeping her eyes open. We took her to vet and were told that she had allergies and to put some antibiotic ointment in them twice a day. he also had a slight runny nose at that time and we were told that this too was from allergies and we were told how much Benadry to give her when she flared up.

Time went on and her eyes cleared up. However, her nose continued to be cracked and dry and would become crusted over with drainage. On Sunday June 24, I noticed Heidi becoming unsteady on her feet (especially on our ceramic tile). I trimmed her toe nails and the fur around her paws but her clumsiness continued to worsen throughout the day. I returned to our vet on Monday July 25th and was told that she most likely has distemper. She did have a low-grade fever that day. The vet told me (in front of my kids) that if she started developing seizures, she would need to be put to sleep. I was so frustrated and angry. The vet would hardly answer any of my questions at all. He gave her a shot of cortisone, a prescription antibiotic pill, and some prednisone pills. He said she would either get much better or much worse in the next ten days and to let him know if we needed him. My daughters and I were so distraught at this news. We are so attached to this dog - she is truly a member of our family.

I went home that night and found this website. In the meantime, I decided to get a second opinion. I was able to see a different vet on Wednesday June 27th. He was so sweet with Heidi. He checked her from head to tail. He watched her walk and agreed that there was definitely something wrong with her neurologic system. He said he could not promise me that it was not distemper but said that it would be very rare for her to have it after being vaccinated. She did not have a fever on this day. He wants to continue the prednisone and switched her to a stronger antibiotic which will cover other diseases such as rocky mountain spotted fever, etc. which could also interfere with the neurologic system. The vet also told me that her teeth were in perfect condition which was a good sign because dogs with distemper sometimes have rough and pitty teeth. He checked her ears and told me that they were full of mites. He said that this too could be part of her clumsiness.

Today is Friday June 29th. Heidi is walking, even sometimes running, so much better now. Her nose has not ran at all today or yesterday. The vet did warn me that sometimes prednisone can "mask" the symptoms and they may seem like they are doing better when maybe they really are not. She has always acted like she feels pretty good, even when the first vet gave her the death sentence. She wags her tail, she eats, drinks, goes outside to play, her only problem seems to be her coordination.

I just wanted your insight as to what you thought. She seems to be getting so much better. We are going to do blood work later after she finishes the prednsione (two weeks) to rule out other diseases. How common do you think it is for a young vaccinated puppy (who is never around any other dogs) to catch distemper and would a dog with distemper act just the same as usual only with a lack of coordination? If it is distemper, how progressive is the disease and how can I know for sure that there is no hope for her?

Thanks for your time.

P.S. I figured out a great way to give dogs medicine. Take a little bit of extra crunchy peanut butter and hide the pill in that and let them lick it off your finger. They can't tell the difference between the pill and the peanuts! She gobbles it right up. Thanks again. Jennifer

Steroid responsive meningitis in puppies

A: Jennifer-

It is unusual for puppies who have been vaccinated against distemper after they are twelve weeks of age to develop distemper. Some puppies do develop vaccine induced encephalitis but this normally happens in very young puppies or in puppies who are immune compromised for some reason. This problem usually develops 1 to 2 weeks after vaccination when it occurs, so I suspect that it is not likely in Heidi's case, because she was most likely vaccinated several months ago. The only time we give up on patients who we believe have distemper is when they can not get over the initial clinicals signs (gastrointestinal problems or pneumonia) and reach a point that it seems hopeless to keep going or when they develop severe seizures after the initial signs that won't respond to anti-seizure medications.

The most likely problem with the symptoms that you describe is steroid responsive meningitis. Puppies with steroid responsive meningitis usually have a fever, they have a stiff or uncoordinated gait, they often resist having their head and neck touched or manipulated and may show signs of severe pain. Paralysis, severe weakness or seizures may also occur. Unfortunately, these are also the signs of most other forms of meningitis, so bacterial meningitis, distemper induced meningitis, vasculitis and fungal infections can cause similar signs.

Examination of a cerebrospinal fluid (CSF) sample is helpful in confirming that this condition is probably the cause of the symptoms seen. The number and type of cells seen in the sample and the composition of the fluid varies from one disorder to the next. It may not be possible to absolutely confirm the presence of steroid responsive meningitis from the CSF sample but it can be helpful in guiding how long to use corticosteroids and whether other therapy, such as antibiotics, is necessary.

Many general practitioners are not comfortable obtaining a CSF sample or in interpreting the sample once it is drawn, so there is some resistance to this diagnositc procedure among veterinarians. However, response to therapy with corticosteroids is a pretty good sign that this condition is present and in ruling out other causes. Its biggest drawback is the need to use high doses of corticosteroids for some time if a patient doesn't actually have this problem and the small risk of suppressing the immune system in the face of a fungal or bacterial meningitis that might get worse with this therapy.

I am going to go on the assumption that steroid responsive meningitis is present for the rest of this note, even though I hope that you understand that is something that your vet should determine, based on eliminating the other possibilities.

Steroid responsive meningitis is named that because it is unclear why it occurs, so naming it for the underlying cause isn't possible. It responds well to the use of corticosteroids, so for now, that name seems best. It is usually necessary to use corticosteroids daily for a couple of weeks to a month or more to resolve the initial signs. Once the patient seems to be back to normal, the dosage of corticosteroids can be tapered off, slowly, to try to keep the illness from recurring. It is not unusual to have to go back to the starting dosage of corticosteroids if a relapse occurs when the corticosteroid is being reduced, at least for a short period of time. Most dogs with this condition can be weaned completely off of steroids after a few months but a few seem to need long term corticosteroid therapy. It is possible that these patients may have a vasculitis disorder affecting the central nervous system or something other than the typical steroid responsive meningitis. The overall prognosis for this condition is usually good, with most dogs either recovering completely or at least having manageable disease.

The most common corticosteroid used in treating this condition is prednisone, usually used at a dosage of about 1 to 2mg/kg daily for the first weeks of treatment and then going to an every other day dosing scheme and finally tapering the dosage down slowly to stop the medication after several months. If a relapse occurs while the prednisone is being tapered, going back to the original dosage for a few days and then going back to the last alternate day dosage that was working seems to control the problem again in most cases.

I am hoping that Heidi has continued to do well.

Mike Richards, DVM 8/2/2001

Meningitis

Q: Dr. Mike,

I wrote you last week about our dog which we were told had distemper. Now it turns out that the autopsy shows that many things wrong with the dog but not necessarily distemper. Our dog had menigitis, congenital liver problems, pneumonia etc... I did not know that dogs got menigitis? What can you tell us about this? Also, we are now about to get a new puppy. We have throughly cleaned like you said, with bleach. Is there anything else we need to worry about? Is menigitis also carried through the air?

We really appreciate your answers. We are getting our money's worth, for sure!

Shirleen

A: Shirleen-

The definition of meningitis is inflammation of the meninges, the layer of tissue that covers the brain and spinal cord. It can happen for a number of reasons. Encephalitis is inflammation of the brain itself.

In dogs, the most common form of meningitis is known as "steroid responsive" meningitis. The name is derived from the fact that the inflammation can be treated by using corticosteroids and because the reason it occurs is not known. This form of meningitis may seem more common than it is due to the infrequency of complete necropsy (autopsy) examinations in veterinary medicine, but even when pretty intensive effort is made to determine an underlying cause for meningitis it is impossible to find one in many cases. In one study published in 1995 (the Journal of Veterinary Internal Medicine, Tipold), the author could not find a specific cause for meningitis in about 33% of the cases. This problem normally occurs in young dogs but they are usually older than four months of age.

There are a bunch of other causes of meningitis, including viral infections, bacterial infections, fungal infections and parasites. There are several meningitis syndromes that are not clearly understood, other than steroid responsive meningitis. Granulometous meningoenephalitis of older dogs is an example of one of these conditions.

The two viral diseases in dogs that are known to cause meningitis are distemper and parvovirus, with distemper being much more likely to be the culprit in viral meningitis. The findings on the necropsy exam that you have mentioned do not rule out distemper, which can sometimes be hard to definitively identify. Most of the pathologists we have dealt with will at least mention it as a strong possibility unless they think something else is going on.

Bacterial infections that can lead to meningitis include staphylococcal infections, pasteurellosis and sometimes other bacteria. The biggest problem with bacterial meningitis is that it is hard for antibiotics to penetrate the blood/brain barrier so it is sometimes necessary to use antibiotics for a really long time in order to control these infections.

Most (possibly all) of the systemic fungal infections such as histoplasmosis and blastomycosis can cause meningitis.

Congenital liver diseases often lead to encephalitis. This is different than meningitis but close enough that it seems reasonable to include the congenital liver diseases in the differential diagnosis for your puppy, since there is evidence of liver disease.

Fortunately, in dogs, there does not seem to be a highly contagious meningitis (other than distemper virus, which doesn't survive well in the environment). It still seems very likely that there is very little risk to a new puppy you might adopt after even this much time.

Mike Richards, DVM 4/27/99