Pastoralism supports livestock production, household livelihoods and the use of variable rangeland resources in the dryland counties of Kenya. However, its contribution to productivity, income, food security and resilience is constrained by interacting environmental, institutional and economic pressures. This paper examines these constraints through a critical narrative review of 24 sources published between 2020 and 2025, combining dryland counties-specific research with Kenyan, regional and international evidence. Sources were identified through targeted searches of publisher platforms, institutional repositories and official agency websites and assessed for geographical relevance, methodological transparency and the distinction between observed outcomes and policy intentions. The synthesis identifies recurrent drought and heat stress, inadequate access to forage and water, restricted mobility, land-use change, insecurity, livestock disease, weak market coordination, financial exclusion, uneven service provision and socially differentiated adaptive capacity as factors of concern. These factors impact pastoralism through three connected processes: deterioration of livestock condition and reproduction; restriction of access to resources, services and markets; and erosion of household assets and recovery capacity. The review argues that poor outcomes cannot be explained by climatic exposure alone or treated as evidence that pastoralism is inherently unproductive. Performance depends on whether the institutions and services surrounding livestock production support flexible resource use and timely risk management. A proposed intervention framework combines negotiated grazing access, animal-health services, anticipatory finance, transparent markets and inclusive governance. Longitudinal research is required to test the relative importance of these pathways and distinguish viable diversification from involuntary withdrawal from pastoral production.