https://www.facebook.com/PurinaOne/posts/2272312322801384 -click the get offer button and fill out the form to get a coupon for a Free Purina One True Instinct Dog or Cat Food. You may have to visit this on a desktop browser browser to request it. -this is still available if you didn’t get it earlier this year.

https://app.sampler.io/milkbone/ -login or register to get Free Milk Bone Dog Chews Samples.

https://pet-fx.com/product/puppy-love-shampoo-sample/ -click add to cart and checkout to get a Free CannaLove Puppy Shampoo Sample with free shipping.

https://www.facebook.com/EssencePetFoods/photos/ -click the send message button and request a free sample of Essence Ranch & Meadow Dog Food.

https://lowsugarhorsetreats.com/free-sample-request -fill out the form to get a Free Buckin’ Good Brownie Bites Low Sugar Horse Treats Sample.

https://docs.google.com/forms/d/e/1FAIpQLScoA94hIiynUTPz6H97wnQs4wgpKPhN5Tc1dI-sM3kGe6t3QA/viewform -fill out the form to get a Free TLC Pet Products Hot Spot Oil Sample.

https://www.facebook.com/flx/warn/? -click follow link and fill out the form to get a Free Canidae Dog or Cat Food Sample. These links are limited use, I’ll try to keep finding new links as they expire.

https://try.pawtree.com/boxermom/mysample -click the get sample button and fill out the form to get Free pawPairings Dog Food Seasoning Samples.

https://www.canidae.com/request-a-sample-epxk4v3/ -copy paste the link and fill out the form to get Free Canidae Dog or Cat Food.-working again. These links are limited use, I’ll try to keep finding new links as they expire.
You can also try to request one at this link if the other one is gone.