Meningitis affects the covering of the spinal cord and/or brain in a dog. This disease may be uncommon, but for dogs that have the disease, serious symptoms will occur. It's helpful for dog owners to be aware of this disease and aware of what breeds of dogs are at risk for developing it.
What Is Meningitis in Dogs?
Meninges are the outer membranes that cover the spinal cord and brain. When these membranes become inflamed, a dog is diagnosed with meningitis. Meningitis can be caused by several different factors, and if it also includes inflammation of the brain, it is called meningoencephalitis.
When the meninges become inflamed, they can cause severe pain in a dog. Just petting the neck of a dog that has meningitis can be painful, so it may not seek as much attention, be lethargic, and not want to move its head much due to this discomfort. Chewing and swallowing can be painful, so a decrease or lack of appetite may also occur.
In addition to the symptoms of meningitis, dogs with meningoencephalitis may also experience blindness, seizures, and other neurological signs of the disease. Losing consciousness, painful spasms of the muscles, losing balance when standing or walking, pacing or circling around the house, and even the loss of the normal function of the limbs is possible. This is because of the inflammation in both the brain and the spinal cord, which affect coordination and sight as well as many other bodily functions.
Causes of Meningitis in Dogs
There are many potential causes of meningitis in dogs, but some reasons are much more common than others.
- Bacterial infection: While not a common cause of meningitis in dogs, bacterial infections can sometimes get into the central nervous system. This usually requires bacterial migration through the sinuses, inner ear, vertebrae, or other routes to get to the spinal cord and/or brain.
- Viral infection: Just like bacterial infections, a viral infection is not a common cause of meningitis in dogs but it can still happen. A virus, such as rabies, distemper, or parvovirus, needs to access the central nervous system in order to cause meningitis.
- Fungal infection: Yet another uncommon cause in dogs, severe fungal infections, such as Valley Fever (coccidioidomycosis), can occasionally migrate into the central nervous system causing meningitis.
- Protozoans: Toxoplasmosis, an uncommon type of protozoan in dogs, can be a cause of meningitis. This protozoan needs to travel to the central nervous system in order to cause this issue, just like bacterial, viral, and fungal infections.
- Tick-borne diseases: Tick bites can transmit diseases like as Rocky Mountain Spotted Fever (Rickettsia rickettsia), Ehrlichiosis (Ehrlichia canis), and Lyme disease/Borreliosis (Borrelia burgdoferi), and these infections can in return cause meningitis in some dogs.
- Parasites: In rare cases, the raccoon roundworm (Baylisascaris procyonis) and heartworms have both been known to cause meningitis in dogs.
- Immune-mediated: This cause of meningitis is non-specific. Immune-mediated diseases occur when the body starts attacking its own immune system, and no one really knows what causes it. Meningitis can occur in dogs due to an immune-mediated reason.
Diagnosing Meningitis in Dogs
Meningitis is diagnosed after your veterinarian performs a full physical examination on your dog and discusses any symptoms you may be seeing at home. Blood work, fecal tests, urine tests, and an X-ray will be performed to look for underlying diseases but to diagnose meningitis your veterinarian will need to collect a sample of your dog's cerebrospinal fluid (CSF). This requires your dog to be under anesthesia to collect. An MRI or CT scan may also be recommended.
Treatment of Meningitis in Dogs
Some types of meningitis are treated using steroids but antibiotics, anti-fungals, anti-parasitics, and other medications may be needed depending on the cause and severity of the meningitis. Hospitalization with IV fluids and pain medication may be needed in severe cases as well. Depending on the underlying reason for the disease, meningitis may be able to be successfully treated but unfortunately not all cases are treatable.
How to Prevent Meningitis in Dogs
Since meningitis can be caused by a number of things, it is difficult to prevent it but there are a few things you can do. Thankfully, meningitis is not common in dogs, but some good ways to help prevent meningitis include following your veterinarian's guidelines for treating infections, thoroughly cleaning any and all wounds, administering regular parasite preventatives, keeping recommended vaccinations up to date, and having regular blood, urine, and fecal screenings performed.
Meningitis in Dogs. VCA Hospitals.
Meningitis and Encephalitis in Dogs. Merck Veterinary Manual.
Coelho, A. M. et al. Serological Prevalence Of Toxoplasmosis And Neosporosis In Dogs Diagnosed With Suspected Meningoencephalitis In The UK. Journal Of Small Animal Practice, vol 60, no. 1, 2018, pp. 44-50. Wiley, doi:10.1111/jsap.12937