What is a major factor in a dog’s ability to detect odors effectively?

A dog's ability to detect odors effectively is influenced by several interrelated factors, making the choice that includes all of them the most comprehensive answer.

The breed of the dog plays a significant role because certain breeds have been developed specifically for their keen sense of smell. Breeds like Bloodhounds and German Shepherds possess more olfactory receptors and have historically been used in tracking and detection work, enhancing their natural abilities.

Age can also impact odor detection, as younger dogs often have sharper senses compared to older dogs, who may experience a decline in olfactory function over time.

Training is crucial because even the best natural sniffers need to be taught how to interpret and act on the scents they detect. Proper training helps dogs learn to focus on specific odors, ignore distractions, and perform their tasks efficiently.

Thus, all three factors—breed, age, and training—combine to influence a dog’s effectiveness in detecting odors, making the choice that includes all of these elements the best answer.