It depends on the size of your bottle of wild Alaskan salmon oil.

Here is how long 1 bottle will last depending on your pet's weight and daily dosage.

 Pet weight
 8oz Bottle
 16oz Bottle
 32oz Bottle
 0 to 12.5 pounds
 ~6 months
~1 year
~2 years
 12.5 to 25 pounds
 ~3 months
~6 months
~1 year
 25 to 50 pounds
 ~6 weeks
~3 months
~6 months
 50 to 75 pounds
 ~4 weeks
~2 months
~4 months
 75 to 100 pounds~
 ~3 weeks
~6 weeks 
~3 months
 More than 100 pounds
 ~2 weeks
~4 weeks
~2 months