Dogs that detect diseases like covid-19 and malaria are bred in expensive training centers instead of being kept as pets.

Bruno Rodrigues Baptista da Silva / Alamy

Pet dogs of various breeds can be trained to detect associated scents. Parkinson’s disease with about 90 percent accuracy. With further research, this could be a relatively definitive and inexpensive method of diagnosing the condition enabling earlier access to treatment.

People with Parkinson’s disease have hundreds of unique chemicals in their sebum, the oily substance that hydrates water. The skin. Provided that…