Spoilers alert I remember in the novel how Chase almost killed Josh number of times: 1...

a dog??? .......

josh, no!! he's such a nice person too, he doesn't deserve an std infested alpha like miller I thought he knew the father of his kid in kiss me, liar, or at least that he was with an alpha that treated him well LIKE HE DESERVES, nooo my heart breaks for him

I can't blame him too much as among the Millers he is literally the most normal and the one who presented late so he has emotions unlike his siblings who are literally faking emotions. Not to mention he doesn't have sex to alleviate his pheromones in sex parties(Something all Extreme alphas have to do- disperse their pheromones or they get crazy). Not to mention his older brother told him in his desperation he had sex with a dog further traumatizing him (which is fake).
I guess he became insane to cope with all the other insane people LOL

nevermind, i was thinking about grayson lol but still, a dog...

Yeah, Chase was the "normal" amongst the siblings. The rest grew up without emotions just like their dad.

There was a scene where Chase's pet died and young Chase was so sad, told Grayson and his dad that his pet died. However, they just told him to throw it away and find a new pet. They don't understand why Chase was so affected with his pet demise. Poor child.

Josh knew who is the father of his baby. Chase doesn't remember sleeping with Josh or any omega. Chase thought he slept with a dog during his rut... I'm blaming Grayson on this, he likes teasing Chase coz he thinks Chase is not normal to them. He is different from the what a Miller family should be.