Give some stream of consciousness and then the answer. In dogs and cats, chips are usually inserted below the skin at the back of the neck between the shoulder blades on the dorsal midline. According to one reference, continental European pets get the implant in the left side of the neck. The chip can often be felt under the skin. Thin layers of connective tissue form around the implant and hold it in place.

Based on this passage, where do they put the chip in dogs?
To answer the question, consider the following: In dogs and cats, chips are usually inserted below the skin at the back of the neck between the shoulder blades on the dorsal midline.
Therefore, the answer is below the skin at the back of the neck between the shoulder blades on the dorsal midline.