If your dog ate one, then why are you spending precious time on a site like this in order to find out what the pills are. Please take your dog to the vet as soon as possible! Based upon the speed at which you have received an answer here, I would hope that what you should do should be obvious.
I would like to help you. But, ethically, I don't think that would be a wise choice on my part.
I would suggest checking out the information that you might find on the following site or take them to a pharmacist for identification and disposal. The site below is good, but not foolproof. But, to be sure, I would take them to a pharmacist. Anyone answering you here runs the risk of the ramifications if they answer and are incorrect no matter what you say the reason or reasons are as to why you are asking.
Below, is the site to which I am referring:
Pill Identifier - Drugs.com
I don't know what the pills are. I don't know you and you don't know me. I could say the pills were something that they are not. What might happen next? What if the information you have been given here is incorrect? Maybe the pills are something harmless? I don't know. What if you decided to believe what I said is true and then you take the pills and something bad happens to you because you have taken it when I have said that they are something harmless? What if I was really wrong and the pills could turn out to be something deadly to you if you took them, or you said that you asked an "expert" on this online site who said that they were really sure of what the pills were and that you should not worry about going any further with trying to identify the pills? There are people who answer that way on this site. Please see information about that on the following link if you have any doubt as to people actually acting like theirs is the last word on the identification of a pill or pills.
https://www.askmehelpdesk.com/medicat...ll-144678.html
Reliable pharmacists are usually very easy to find around where you live, and can visit with you and see the pills first hand.
I'm not a pharmacist and I'm not going to pretend that I'm some sort of expert at identifying pills. So, unless someone is a pharmacist here and has actually seen the pills that you have found and is truly sure of the reason or reasons as to why you are asking, even though they are trying to be kind and think that they are answering in your best interests, it is not in your best interests or in the best interests of any person here who thinks that they have the correct answer for you because of the possible ramifications when being incorrect when giving out such information.