Necrotizing Meningoencephalitis (NME) in Cats and Dogs: Update on Long-Term Management
World Small Animal Veterinary Association World Congress Proceedings, 2011
Hee-Myung Park, DVM, PhD
College of Veterinary Medicine, Konkuk University, Seoul, South Korea

Necrotizing meningoencephalitis (NME) is an idiopathic, breed specific, unique inflammation disorder of brain in small breed dogs diagnosed more frequently in young adult animals, from six months to seven years of age. The disease primarily affecting the cerebral hemispheres has been described in Pug, Maltese, and Yorkshire terrier. Even though the cause of this disease is unknown, a certain autoantibody against a canine brain tissue was detected in the cerebrospinal fluid (CSF) and serum, indicating an autoimmune pathology in NME.

The most common clinical signs of NME patients include seizure episode, circling, vestibule-cerebellar signs, but variations exist by the multifocal intracranial inflammation including ultimate death. CSF analysis reveals monocytic pleocytosis and total CSF protein elevation. Brain magnetic resonance imaging (MRI) examination finds focal or multifocal intracranial lesions showing hyposignal intensities on T1-weighted images and hypersignal intensities on T2-weighted images. Histologically, NME has characteristics of nonsuppurative inflammation of the brain with extensive necrosis and is similar to granulomatous meningoencephalitis (GME) on the basis of the dense aggregations of inflammatory cells, around blood vessels, especially lymphocytes, reticulohistocytes and macrophages (perivascular cuffing). However, the microcavitations, the necrosis and the extensive sclerosis are different features from GME.

Administration of immunosuppressive doses of glucocorticoids is the traditional primary treatment in NME in dogs. However, response is variable and clinical signs often recur quickly with tapering dosage. Adverse effects such as polyuria-polydipsia, polyphagia, weight gain, hepatotoxicity, iatrogenic hyperadrenocorticism and lethargy are frequently seen during long-term therapy. Glucocorticoids given at immunosuppressive doses, which may help reduce inflammatory and immune reactions during initial stage of the disease but many dogs require sustained therapy to avoid relapse. Prognosis is poor and long-term therapy causes many complications.

Recent reports suggested that the cyclosporine is the effective therapeutic options for NME in dogs. We compared the long-term effects of cyclosporine plus prednisolone therapy with sole prednisolone therapy in management in dogs with NME.

Cyclosporine, cyclic oligopeptides, which is able to block the transcription of cytokine genes in activated T cells is nor nephrotoxic or hepatotoxic in dogs unless extremely high blood concentrations (over 3,000 ng/ml) are maintained. No major adverse effects were associated with long-term cyclosporine administration, except for mild dermatologic changes and transient lymphopenia. Because combination therapy of cyclosporine can reduce prednisolone dosage of treatment, the major side effects of prednisolone were more diminished than those of high dose prednisolone therapy. When combination therapy was used, steroid could improved clinical signs initially, and prolonged effect until cyclosporine exert its effect. Combination treatment of prednisolone with cyclosporine is more effective in survival time than administration of only prednisolone in NME cases.

Another combination therapy consists of azathioprine and prednisolone was reported to be a safe and effective treatment for canine meningoencephalitis.

In addition, several immunomodulatory drugs including cytosine arabinoside (CA), procarbazine, lomustine (CCNU), leflunomide, and mycophenolate mofetil (MMF) have been reported as adjunctive therapy combined with glucocorticoids.


1.  Adamo PF, Adams WM, Steinberg H. Granulomatous meningoencephalomyelitis in dogs. Compend Contin Educ Vet 2007;29:678–690.

2.  Adamo FP, O'Brien RT. Use of cyclosporine to treat granulomatous meningoencephalitis in three dogs. J Am Vet Med Assoc 2004;225:1211–1216, 1196.

3.  Dewey CW. In: A Practical Guide to Canine and Feline Neurology, 1st ed., Iowa State Press. 2003:160–162.

4.  Gnirs K. Ciclosporin treatment of suspected granulomatous meningoencephalomyelitis in three dogs. J Small Anim Pract 2006;47:201–206.

5.  Jull BA, Merryman JI, Thomas WB, et al. Necrotizing encephalitis in a Yorkshire terrier. J Am Vet Med Assoc 1997;211:1005–1007.

6.  Jung DI, Kang BT, Park C, et al. A comparison of combination therapy (cyclosporine plus prednisolone) with sole prednisolone therapy in 7 dogs with necrotizing meningoencephalitis. J Vet Med Sci 2007;69:1303–1306.

7.  Levine JM, Fosgate GT, Porter B, et al. Epidemiology of necrotizing meningoencephalitis in Pug dogs. J Vet Intern Med 2008;22:961–968.

8.  Lotti D, Capucchio MT, Gaidolfi E, et al. Necrotizing encephalitis in a Yorkshire Terrier: clinical, imaging, and pathologic findings. Vet Radiol Ultrasound 1999;40:622–626.

9.  Matsuki N, Fujiwara K, Tamahara S, et al. Prevalence of autoantibody in cerebrospinal fluids from dogs with various CNS diseases. J Vet Med Sci 2004;66:295–297.

10. Talarico LR, Schatzberg SJ. Idiopathic granulomatous and necrotising inflammatory disorders of the canine central nervous system: a review and future perspectives. J Small Anim Pract 2010;51:138–149.

11. Wong MA, Hopkins AL, Meeks JC, et al. Evaluation of treatment with a combination of azathioprine and prednisone in dogs with meningoencephalomyelitis of undetermined etiology: 40 cases (2000–2007). J Am Vet Med Assoc 2010;237:929–935.

12. Young BD, Levine JM, Fosgate GT, et al. Magnetic resonance imaging characteristics of necrotizing meningoencephalitis in Pug dogs. J Vet Intern Med 2009;23:527–535.

13. Zarfoss M, Schatzberg S, Venator K, et al. Combined cytosine arabinoside and prednisone therapy for meningoencephalitis of unknown aetiology in 10 dogs. J Small Anim Pract 2006;47:588–595.


Speaker Information
(click the speaker's name to view other papers and abstracts submitted by this speaker)

Hee-Myung Park, DVM, PhD
College of Veterinary Medicine
Konkuk University
Seoul, South Korea

MAIN : Medicine : Necrotizing Meningoencephalitis
Powered By VIN