What can i do to prevent this massive gash from turning into a scar?

Massage: The act of massaging the scar will help tremendously...Different creams including vit e works well.

Good wound care.: A scar is made by new skin cells that are arranged differently. You cannot heal a wound without a scar. You can minimize the bulkiness of the scar by keeping the wound clean, moist and avoiding infection. Do not clean with hydrogen peroxide or iodine antiseptics such as betadine as these will impede the healing process. Scrub lightly w/ soap & water, and cover with antibiotic ointment.

Massive gash?: If you have a massive gash, it may need stitches to help it heal. If you haven't done so already, please let a physician see your wound & help you. Be safe.

See a physician: Closure may be appropriate. If underlying structures are disrupted or there is a wide gap debridement znd closure maybe your best option. All wounds heal with some scarring, some are just nicer than others.

Keloid: Some patients have a tendency to develop hypertrophic scars or keloids.

Scar management: Have the gash closed properly. Massage the scar. Use a silicone based scar product. Use sunscreen / avoid sun.

Gash = Scar: If you have a massive gash, you will have a scar.