Canine Pituitary Tumors: Endocrine Disease and Neurologic Mass Effect
Overview
Pituitary tumors can be small functional lesions that drive hormone disease or larger masses that compress nearby brain structures. Not every dog with pituitary-dependent hyperadrenocorticism has neurologic signs, and not every pituitary-region mass causes the same hormone pattern.
Common signs
Increased thirst and urination, hunger, panting, abdominal enlargement, skin and coat change, muscle weakness, behavior change, altered sleep, pacing, vision loss, circling, or seizures may occur depending on hormone activity and size.
Common locations
The pituitary sits at the base of the brain near the optic pathways and hypothalamus. Even a modest change in this confined region can affect endocrine control, vision, behavior, or neurologic function.
Diagnosis discussion
Endocrine testing is selected to confirm and characterize hormone disease. MRI or CT may assess pituitary size and brain effects, while bloodwork and urinalysis evaluate complications. A hormone diagnosis and an anatomic mass assessment answer different questions.
Urgency and when to contact a veterinarian
A seizure lasting several minutes, repeated seizures, collapse, severe disorientation, inability to walk, or sudden vision-related distress needs urgent care. Never stop chronic steroid or endocrine medication abruptly without veterinary direction.
Treatment discussion
Medical control of cortisol effects, radiation therapy for selected pituitary masses, surgery at specialized centers, antiseizure treatment, or palliative care may be discussed. Monitoring must account for both endocrine control and neurologic progression.
Home monitoring
Measure water intake only if the team requests it; record urination, appetite, panting, strength, skin, behavior, navigation, seizures, and exact medication times. Report vomiting, diarrhea, profound weakness, or appetite loss promptly when using endocrine medication.
Questions to ask your veterinarian
- Which findings establish pituitary-dependent endocrine disease?
- Is brain imaging needed now, and would it change treatment?
- How will we distinguish medication effects from tumor progression?
- What emergency plan applies to seizures or possible adrenal suppression?