I tend to disagree with @bob1 here. From my knowledge ticks are identifiable for the average person by the visible small legs, in all its stages. Also, unless they are not some very specific type, they don't tend to be this shiny. Again, they don't flock together like this. Check the way they move, watch their legs and speed. Also, if you check your dog, it should have ticks stuck in places where the skin is thin, usually around the eyes and ears.

From the shine and the size I first thought of fleas, dogs get them, but they are not so easy to get rid of (dogs tend to have them for a long time -- has your dog scratch itself like crazy recently?). Also, I've never seen them to be so many in such a group. If they jump then they are most probably fleas.

Third guess, like @Mehdi Abbassi said, are bed bugs, but those have a more prolonged shape

It would be helpful to know where you live.

I tend to disagree with @bob1 here. From my knowledge ticks are identifiable for the average person by the visible small legs, in all its stages. Also, unless they are not some very specific type, they don't tend to be this shiny. Again, they don't flock together like this, they can be found in groups only right after hatching (but these look bigger than the smallest tick I've ever seen with the naked eye). Check the way they move, watch their legs and speed. Also (as bob1 pointed it out), if you check your dog, it should have ticks stuck in places where the skin is thin, usually around the eyes and ears.

From the shine and the size I first thought of fleas, but they are not so easy to get rid of (dogs tend to have them for a long time -- has your dog scratch itself like crazy recently?). Also, I've never seen them to be so many in such a group. If they jump then they are most probably fleas.

Third guess, like @Mehdi Abbassi said, are bed bugs, but those have a more prolonged shape