Idiopathic Epilepsy
Pug Dog Encephalitis
- A non-infectious central nervous inflammatory disease
- Affects pugs.
- Similar conditions are seen in yorkshire and maltese terriers.
- Officially known as necrotising meningoencephalitis of small dogs.
- Characterised by histological forebrain inflammation and necrosis.
- The disease is uniformly fatal.
- Corticosterid treatment has no effect.
Granulomatous Meningoencephalitis
- A non-infectious central nervous inflammatory disease
- May occur as:
- A disseminated disease
- A focal mass lesion
- A primary occular disease
- Brainstem signs are common, although the forebrain is primarily affected.
- May be incorrectly diagnosed as lymphoma.
- Changes are apparent in the CSF.
- There is usually a mononucloear pleocytosis.
- Sometimes only protein is elveated.
- Diffuse inflammatory changes or a mass lesion will be seen by advanced imaging.
- However, biopsy is required for a definative diagnosis.
- Life span is between 6 months and 1 year from diagnosis.
Polyneuritis equi
- A non-infectious central nervous inflammatory disease
- Polyneuritis equi (PNE) is an uncommon disease which affects mature horses
- Formerly known as 'cauda equina syndrome' or 'cauda equina neuritis'
- May occur as:
- A disease effecting the spinal nerve roots and ganglia of the cauda equina.
- A disease effecting the cranial nerves.
- Cauda equina disease is characterised by progressive loss of anal tone, tail paralysis, urinary and/or faecal incontinence, urine scalding of the hindlimbs, hyperaesthesia and muscle fasciculations over hindquarters.
- If the pelvic nerve roots are also involved, there may be changes in hindlimb gait.
- Cranial nerve signs may be apparent, including signs associated with facial nerve paralysis.
- Changes in the CSF are often non-specific.
- There is usually a moderate mononucloear pleocytosis.
- Protein is usually elveated.
- Histologically, the disease presents as a severe, chronic, destructive lymphocytic and histiocytic polyradiculoneuritis.
- Pathogenesis is not completely understood, but considered to be a T-lymphocyte mediated response to myelin, followed by destruction of myelin and axons by macrophages
- Disease appears similar to:
- Guillain-Barré Syndrome (GBS), an autoimmune demyelinating diease in humans
- Experimental allergic neuritis (EAN) in laboratory animals
- Important differential diagnoses for progressive neurologic signs effecting the bladder, rectum, perineum, tail, penis and hindlimbs in horses include:
- Equine herpesvirus-1 myeloencephalopathy
- Sacral/coccygeal trauma
- Equine motor neuron disease
- Abberant parasite migration (e.g. Strongylus spp.)
- In endemic areas, Sarcocystis neurona myelitis (equine protozoal myelitis), rabies and rhodococcus equi myeloencepahlitis should also be considered.