This is a term used in veterinary medicine. Canine species have a cerebellumThis word means the “little brain” and refers to a large part of the brain that sits in lowermost part of the skull, at the back of the head, immediately above the top of the spine. This part of the skull is known as the posterior fossa. but do not have cerebellar tonsilsThe lower-most part of the cerebellum is made up of a pair of structures, one on each side of the midline, known as the tonsils. These structures have no relationship with the tissue at the back of the throat, which becomes inflamed and sore with a viral infection. It is simply the case that the same Latin term was applied by (presumably) different anatomists, at different times and working in different places, to name these very different body parts. The word tonsilla literally means a stump; Roman ships were moored to “tonsilla” when in port.. Certain toy breeds, in particular the cavalier King Charles spaniel, may nevertheless develop herniation of part of their cerebellumThis word means the “little brain” and refers to a large part of the brain that sits in lowermost part of the skull, at the back of the head, immediately above the top of the spine. This part of the skull is known as the posterior fossa. through the foramen magnumThe large, ovoid opening at the base of the skull, measuring about 3 x 3.5cm, through which the spinal cord passes, to continue on as the brain stem., causing the animal to develop symptoms and, in a significant proportion of cases, syringomyeliaA cavity, within the spinal cord, which is filled with cerebrospinal fluid. Syringomyelia cavities come in various “shapes and sizes”, from short, spindle-shaped cavities through to long, tense cavities extending throughout the greater part of the spinal cord. Read more.