https://www.zoetispetcare.com/giveaway/dental-chew-toy? -the first 5,000 will get a Free Dog Rope Toy from Zoetis.

Download the Buddies app for iOS or Android and  register. You can also get an extra 200 point with referral code: CDAVIEBFFB at registration.
They give you 700 points when you register, which is enough for a Free bag of Blue Buffalo Dog Treats. To get those go to rewards, then redeem. It might take a minute or two for the 700 points to show up.
–Update– It was working slow before, but seems to be loading better now.

https://www.fidoalert.com/ -register and add your pet to get Free Fido Alert Pet Tags. –Update – Still available.

https://www.surveymonkey.com/r/FreeCollar -fill out the form to get a Free YOOS Dog Collar.

https://zignature.com/request/ -fill out the form to get a Free Zignature Dog Food Sample.

https://zignature.com/free-sample/ -fill out the form to get a Free Zignature Dog Food Sample. –Update – still available

https://r71aavfvqnd.pro.typeform.com/petalumasamples -fill out the form to get a Free Petaluma Sustainable Dog Food Sample.

https://karmapetfoods.com/kollective -fill out the form to get a Free Karma Kollective Kit. It includes a t-shirt, leash, and free bag coupon. First 1,000.

https://www.confidenceeq.com/terms/item/13-free-sample-offer-fill out the form to get a Free Confidence EQ Horse Product Sample .