The disease may be inherited in Pugs and Maltese and has been diagnosed in other breeds as well (Yorkies, Chihuahuas). The prevalence of PDE in pugs is about 1%. It differs in pathology from GME by more tissue breakdown and increased eosinophils (white blood cells). CSF analysis is also unique among inflammatory CNS diseases in dogs in that the cells are predominantly lymphocytes, instead of a mixed population of mononuclear cells. In Maltese and Pugs, there is extensive necrosis and inflammation of the gray matter of the cerebrum and subcortical white matter. The most common early symptoms are related to forebrain disease and include seizures and dementia, and later circling, head tilt, and blindness with normal pupillary light reflexes may be seen. PDE has a poor prognosis. Necrotizing leukoencephalitis
In Yorkshire Terriers there can be severe mononuclear inflammation of the brainstem and periventricular cerebral white matter. Because the condition in this breed frequently affects only the white matter, it has been called necrotizing leukoencephalitis. Symptoms of brainstem and central vestibular disease predominate. Other types of noninfectious meningoencephalitis
Steroid-responsive meningoencephalitis is any noninfectious meningoencephalitis that responds well to corticosteroids and usually has an excellent prognosis. This could represent mild forms of GME or PDE, but there are two separate conditions recognized also. Steroid-responsive meningitis/arteritis, also known as necrotizing vasculitis, is seen most commonly in Beagles, Boxers, Bernese Mountain Dogs, and German Shorthaired Pointers younger than two years of age.
While this theory would fit the fact that molsidomine (which is not reduced) does not exhibit tachyphylaxis, it has meanwhile been refuted. Newer theories include increase of oxidative stress resulting in deactivation of NO to peroxynitrite, and liberation of the vasoconstrictors angiotensin II and endothelin as the blood vessels reaction to NO-mediated vasodilation. Differences in pharmacokinetics
Nitrates mainly differ in speed and duration of their action. Glyceryl trinitrate acts fast and short (10 to 30 minutes), while most other nitrates have a slower onset of action, but are effective for up to six hours. Molsidomine, as has been mentioned, not only acts slowly but also differs from the nitrates in exhibiting no tolerance. Nitroprusside, given intravenously, acts immediately, and after stopping the infusion blood pressure returns to its previous level within ten minutes. See also
History of glyceryl trinitrate
Biological functions of nitric oxide


== References ==