Be good to your cats, and just say "No" to dry food for the following reasons:
Dry food is very dehydrating because it contains a lot less moisture (10% typically) than cats need (around 75-80%). Cats derive moisture from their diet and have a poor thirst mechanism. They simply cannot, and in most cases will not, drink enough water of their own accord to make up for this dietary deficit in moisture.
Even the best dry food brands have woefully inadequate amounts of meat protein compared to a mouse's protein content (which is in the mid-50% range).
Further compounding the problem is the high grain content of kibble. Although the so-called low-carb dry foods do not contain corn, wheat, rice, etc. they still have totally inappropriate items such as potatoes, and fruits like apples. Unfortunately, between the grains, fruits, and high-glycemic vegetables, most dry foods contain anywhere from 15-50% of their calories in the form of carbohydrates. This when a mouse is less than 5% carb.
The grains and plant matter in dry foods can cause cats' urine to be too alkaline. Based on research in vet journals, (results summarized here), the ideal urinary pH is between 6.0 and 6.5 The more alkalizing cats' diets are, the higher the risk of struvite crystal (and Bast forbid, stone/urolith) formation.