Approximately how many olfactory sensor cells are inside a German Shepherd's nose?

• A. 50 million
• B. 120 million
• C. 220 million
• D. 600 million

Answer: (C)

Dogs rely on a much larger olfactory system than humans, and the number of olfactory receptor cells is a key factor in how well they can smell. A German Shepherd has about 220 million of these odor-detecting cells, which places the breed in the high end of dogs’ scent capabilities. This large count, along with a vast surface area of smelling tissue and brain processing devoted to odors, lets dogs detect scents at incredibly low concentrations and distinguish between many different smells. Humans, by comparison, have around 5–6 million olfactory receptor cells, so the dog’s sense of smell is dramatically more powerful.

So, 220 million is the best approximate figure for a German Shepherd, aligning with common estimates used in veterinary and training contexts. The other numbers are either too low to reflect a dog’s scent-detecting power or exceed typical dog-range estimates.