Your Dexterity Score Improves by 2 and your Wisdom Score Improves by 1.

Dogs normally reach adulthood after a year. Dogs usually live from 12 to 15 years of age. (Similar to orcs.)

Dogs are typically pure neutral. Seeing to their own needs and having others help them meet them.

You gain Proficiency in the Perception skill.

Additionally you gain advantage on Perception skill checks that rely on Smell or Hearing.

Fully grown Dogs (depending on breed) can stand from 1/2ft tall, to 4ft tall.

You have a base walking speed of 40 feet.

Dogs cannot wield weapons or use tools (unless your DM is incredibly lenient in which case fear him/her for she/he has plans and you may die). They instead must make bite attacks.

The attack is as such.

Melee Weapon Attack: (Strength Modifier + Proficiency Bonus) to hit, reach 5ft., one target. Hit: (1d6 + strmod) piercing damage

Additionally the Bite attack counts as a finesse weapon for the case of sneak attack, and is effected by Martial Arts.

Your AC has a natural +2 bonus. However you need help from a humanoid, access to the Mage Hand cantrip, or access to unseen servant or telekinesis spells to don or doff armor.

As a dog you are unable to provide most material components for spells, however you do naturally work as an Arcane/Druidic Focus or Holy Symbol.

As an action you can growl and gnash your teeth. Causing all nonfriendly (including neutral) creatures within 10 feet of you to make a (DC 10 + your Proficiency bonus) Wisdom Saving throw. On a failed save they are frightened of you for a minute. They may repeat this saving throw every round to attempt break it early.

As a dog you are naturally furry and therefore (because someone ran out of ideas) have a natural toughness when it comes to being hit.

You gain a +1 to your hit points per level.

You understand Common and one language of your choice but do not write or speak them.