Because taurine is highly concentrated in the retina and the brain, the first symptoms will arise due to complications with these parts of your dog's body. Your vet may also suspect a taurine deficiency involving heart disease, retinal disease, or cystinuria. A specific type of DCM can arise secondary to a taurine deficiency in dogs. Luckily, this form of DCM has a good prognosis with taurine supplementation.