Forebrain dysfunction

The forebrain (prosencephalon) includes all structures rostral to the midbrain, including the cerebral hemispheres and diencephalon (thalamus, hypothalmus, epithalamus, subthalamus). The thalamus is anatomically the rostral end of the brainstem, but is functionally similar to the cerebrum.

Common clinical signs of forebrain dysfunction

  • Seizures
  • Behavior change and/or loss of trained habits (e.g., urinating/defecating in house)
  • Circling toward side of lesion
  • Compulsive pacing or wandering aimlessly
  • Head pressing, staring off into space, or getting stuck behind furniture or in tight spaces
  • Head turn toward side of lesion
  • Contralateral postural reaction deficits
  • Contralateral vision deficits
  • Mental status changes (dull, stupor, coma) – most often with diffuse forebrain disease due to limbic system dysfunction
  • Endocrine signs are possible if hypothalmus or pituitary gland dysfunction


Case example of a dog with left forebrain dysfunction as a result of a left cerebral infarction.