A 2-month-old female Pug was presented with a history of the vestibular episodes especially during or after eating. The owners first noticed the episodes when the puppy started to eat dry food. General physical examination was unremarkable. Neurological examination showed very mild vestibular ataxia while the puppy was walking. However, after the postural head testing, playing and eating, the vestibular deficits became transiently pronounced, showing moderate head tilt to the left, moderate vestibular ataxia with drifting to the left and a broad-based stance. After several seconds to a minute, the deficits mostly disappeared. Neuroanatomic localization was consistent with vestbulo-cerebellum. Differential diagnoses included congenital and degenerative causes, nevertheless, inflammatory and infectious conditions were considered as well. The complete blood count (IDEXX Lasercyte) and serum biochemistry results (IDEXX Catalyst, Clip 10) were normal for a puppy.
Brain MRI was performed on the initial presentation day, and multiplanar T2W, T2W-FLAIR, T1W, and T1W post intravenous administration of a gadolinium based contrast agent (Omniscan, GE Healthcare AS, NO, 0.1 mmol/kg) images were acquired. The T1W and T2W sagittal images showed a reduced size of the nodulus and uvula of the caudal cerebellum with hypoplasia of the caudal cranial fossa (Figure 4A), without contrast enhancement. The patient also had a midline fusion defect of the dorsal arch of C1, however, did not demonstrate any associated cervical instability. The cerebrospinal fluid (CSF) analysis [cisternal tap, TNCC and cytology (Statspin Cytofuge 12)] was within normal limits. Both infectious disease PCR assays (Ehrlichia canis, canine herpes virus, canine parvovirus, canine distemper virus, Neospora caninum, Toxoplasma gondii, and Anaplasma phagocytophilum) and tick encephalitis antibody testing from CSF were negative. Caudal cerebellar hypoplasia was suspected and no treatment was administered.
The owners report a stable status after 4 months, and the puppy has learnt to compensate for the deficits. The episodes continue to occur; mostly after playing with sticks and toys and now are rarely noted during eating.