犬の熱射病の病態と病理学的所見

Pathophysiology and pathological findings of heatstroke in dogs.

• Mariarita Romanucci
• Leonardo Della Salda

抄録

犬の熱射病は、熱の放散と生産のバランスが崩れた結果として生じる生命を脅かす疾患であり、体温が41℃以上に上昇することを特徴としています。いくつかの外因性および内因性因子が犬に熱射病の発症を引き起こす可能性があり、一方では、細胞の熱ショック反応と熱順化によって代表される熱ストレスの有害な影響に生物が対抗することを可能にする適応機構も存在します。熱射病の病態生理と結果は、敗血症で観察されるものと多くの類似点があり、熱による直接的な細胞毒性、代謝需要の増加、低酸素症、循環不全などの高熱症に伴う急性の生理学的変化、広範囲に及ぶ内皮および組織の損傷に対する宿主の炎症性および凝固反応との相互作用に関連している。

Canine heatstroke is a life-threatening condition resulting from an imbalance between heat dissipation and production, and characterized by a nonpyrogenic elevation in core body temperature above 41°C (105.8°F). Several exogenous and endogenous factors may predispose dogs to the development of heatstroke; on the other hand, adaptive mechanisms also exists which allow organisms to combat the deleterious effects of heat stress, which are represented by the cellular heat-shock response and heat acclimatization. The pathophysiology and consequences of heatstroke share many similarities to those observable in sepsis and are related to the interaction between the direct cytotoxicity of heat, the acute physiological alterations associated with hyperthermia, such as increased metabolic demand, hypoxia, and circulatory failure, and the inflammatory and coagulation responses of the host to the widespread endothelial and tissue injuries, which may culminate in disseminated intravascular coagulation, systemic inflammatory response syndrome, and multiple organ dysfunction.

© 2013 Romanucci and Della Salda.