Check this for an in depth guide: https://www.reddit.com/r/Warframe/comments/txntgk/comprehensive_guide_to_hound_companions/

TLDR:
Hec Model
Raiju Core
Urga Bracket
Hinta [Stabilizer]

These mods are in order. And order matters, as the priorities of your hound change based on Precept location in the build. With the new [Vicious Bond], since Hounds all use Melee Attacks, as do the Mini Hounds from [Diversified Denial], you can armor strip much faster!
Short Guide Below:

The basics of this Pet is that it will run around, turning Eximus into regular enemies, and then splitting into immortal Mini-Dogs when in danger. This build is viable in the steel path, and is especially good in situations where you'll find yourself fighting against lots of Eximus units that can be dangerous to your team, like the new Energy Leech Eximus, or Arson Eximus. Because of the buffed Eximus abilities, this pet can easily kill even an entire room of enemies, with the right effect.