We show that the Painleve test is useful not only for probing (non-)integrability but also for finding the values of spins of conserved currents (W currents) in Toda field theories (TFTs). In the case of the TFTs based on simple Lie algebras the locations of resonances are shown to give precisely the spins of conserved W currents. We apply this test to TFTs based on strictly hyperbolic Kac-Moody algebras and show that there exist no resonances other than that at n=2, which corresponds to the energy-momentum tensor, indicating their non-integrability. We also check by direct calculation that there are no spin-3 nor -4 conserved currents for all the hyperbolic TFTs in agreement with the result of our Painleve analysis. (orig.)44 refs.Available from TIB Hannover: RA 2999(95-076) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman