Fluid regulators are described. An example regulator includes a regulator body defining a sensing chamber between an inlet and an outlet of a fluid flow passageway of the fluid regulator. A bonnet is coupled to the regulator body and defines a loading chamber disposed adjacent the sensing chamber. The loading chamber is substantially sealed relative to the sensing chamber and an environment surrounding the fluid regulator. A sensor guide is disposed between the sensing chamber and the loading chamber and has at least one seal to fluidly isolate the loading chamber from the sensing chamber. The sensor guide has a vent flow path between the sensing chamber and the loading chamber to vent the sensing chamber during a failure condition of the at least one seal.