“FANCY THAT” FOR THE LOVE OF GABBY
By Susan Ritenour, Happi Daze Chihuahuas
I t happened so fast. It started as lameness in both front and rear left legs, leaning to the right when walking which progressed to falling over onto her side, head tilt, and blindness. Eight days after the onset of symptoms, she passed in my arms. She was only 11 months old. Granulomatous Meningoencephalitis (GME) is a disease that sud- denly strikes without warning. While the disease itself does not hap- pen often, it has been seen often enough in Chihuahuas to add them to the list of breeds most susceptible. WHAT IS GME? Encephalitis is an inflammation and swelling of the CNS (central ner- vous system), while meningitis is an inflammation of the membrane surrounding the brain and the spinal cord. Both diseases are often seen simultaneously. Because of protective barriers to the central ner- vous system, both meningitis and encephalitis are seen less often than diseases to other organs of the body. There are three types of GME: Focal is limited to one location in the nervous system; Disseminated or Multifocal involves many locations in the nervous system and is the most common; and Ocular involves the optic nerves. It is not uncom- mon to see more than one type present in the same dog. What causes encephalitis? Encephalitis is considered to be non- infectious and is thought to have an immune-mediated cause. It is sometimes caused by an abnormal response to an infectious agent such as bacteria, parasites, fungi, and tick-transmitted disease. The most common cause is thought to be an overactive immune system. When this happens, the immune system attacks the brain and/or the brain coverings (meninges). This is called idiopathic encephalitis. Most cases of GME occur in Toy and small breed dogs, usually in bitches. The average age for onset is in young to middle-aged dogs, ranging from 6 months to 10 years. SYMPTOMS At the onset, symptoms shown will depend on which part of the brain is affected. Disseminated is the most common type of encephalitis and its symptoms include seizures, walking in circles, lack of balance, stumbling, head tilt, tremors, pain, changes in behavior, and blind- ness. Symptoms usually start with one or two and quickly worsen or expand to include more symptoms. Focal symptoms will depend on the area of the brain where the lesions appear, while Ocular symp- toms will include sight problems and blindness. The Focal type gen- erally has a slower onset, while Disseminated has a more rapid onset. Ocular usually shows up as sudden, and generally permanent, blind- ness in one or both eyes.
DIAGNOSIS Often when a dog is presented, first thoughts can be a bad disc or pinched nerve as well as a pos- sible brain tumor (depending on the symptoms presented at the time), especially to vets who may not have experience with GME. If the neu- rologic abnormalities are focal, other causes such as stroke and brain tumor must be ruled out. The only TRUE way to diagnose is with an MRI or spinal tap. The MRI will not only diagnose GME but will rule out other possibilities as well as let the vet know if a spinal tap is even possible for the individual. Spinal taps are only performed when all other options have been exhausted. Patients with brain swelling or a tumor have a higher risk of compli- cations from spinal taps. If intracranial pressure is elevated, the removal of any spinal fluid could cause a suction effect and cause a brain hernia- tion. A significant increase in white blood cells in the spinal fluid usually indicates encephalitis. Unfortunately for most owners, an MRI and/or spinal tap is not possible due to cost and/or loca- tion. Routine blood work, urinalysis, and a physi- cal exam are usually performed along with an ultrasound to rule out other possible infections and to help determine which medications can be used. Encephalitis is a very serious condition.
T op N otch T oys , S eptember /O ctober 2022 • 27
Powered by FlippingBook