According to the table, the total number of people who preferred dogs is 2,241. To find out how many of those are 40 years old or younger, we can subtract the number of people older than 40 who preferred dogs from the total number of dog preferences.
The number of people older than 40 who preferred dogs is 1,258.
So, the number of people 40 years old or younger who preferred dogs is: 2,241 - 1,258 = 983
Therefore, the answer is 983.