We studied experimentally the low-frequency uniform longitudinal susceptibility of a nearly isotropic cubic ferromagnet CdCr₂Se₄ (T_c ≈ 128 K) in weak magnetic fields. The measurements have been performed mostly at T = 82 K, i.e. outside the critical region near T_c. At frequencies higher than the two-magnon threshold the longitudinal susceptibility behaves as χ∝(i/ω)^ρ, with the exponent ρ (T = 82 K) ≈ 0.28. This exponent is found to be slowly increasing with temperature. Both the low-frequency crossover scale to the above dependence and the characteristic frequency scale are determined by the internal magnetic field H_i. We propose the description of χ(ω, H_i) in terms of a phenomenological scaling and attribute the observed anomalous behavior to the influence of dipolar forces.