Trembling can also be a sign of serious issues like injury, poisoning or kidney disease. Dr. Jo Gale, BVetMed CertLAS MRCVS, Senior Manager, Global Science Advocacy at Waltham Petcare Science Institute urges pet owners to be vigilant: “If a pet is unwell in another way, they could be trembling.” If their shaking is accompanied by symptoms like diarrhea, limping or vomiting, you should consult your vet straight away.