You don't have hands or thumbs. You have disadvantage on any skill checks that would be difficult without those, and some tasks may be impossible. You don't have any difficulty casting spells with somatic components as long as you have one paw free, and you can use a spell focus as long as it is tied around your neck. Any armor you use must be barding armor.

You have a bite attack, and you are proficient with it. This is treated as a two-handed martial melee finesse weapon dealing 2d4 piercing damage.

When you use the Dash action your speed increases to 40 feet.

You have proficiency in Perception and Investigation ability checks.

Your Constitution score increases by 2, and your Intelligence score increases by 1.

Dogs mature around the age of 2 years old, reach middle age around 6 and live between 10 and 20 years, depending on type.

Awakened dogs can range from 30-80 pounds, and count as Medium creatures.

Your base walking speed is 35 feet.

You can speak, read, and write Common and Dwarvish. Dwarvish is full of hard consonants and guttural sounds, and those characteristics spill over into whatever other language a dwarf might speak.