Brain tumours in dogs cause progressive neurological deterioration and are among the most emotionally and ethically challenging conditions in small animal medicine, requiring careful welfare assessment throughout.
Brain tumours impose a unique welfare burden because of their neurological effects on personality, cognition and consciousness. Dogs with frontal lobe involvement may show personality changes — aggression, reduced recognition of owners, disorientation — that are distressing for both animal and family. Seizures cause acute suffering: the post-ictal period (recovery phase) involves confusion, temporary blindness and extreme distress that can last hours. Cluster seizures (multiple seizures within 24 hours) represent medical emergencies requiring immediate intervention. As tumours grow, neurological signs progress — circling, head pressing, ataxia, visual loss — representing increasing impairment of normal experience. The ethical tension between extending life with treatment and maintaining quality of life is particularly acute: treatment side effects (radiation-induced brain inflammation, surgical recovery) must be weighed against the quality of additional time gained. Euthanasia timing decisions are among the hardest in veterinary medicine — owners and vets must assess whether the dog's subjective experience remains positive.