Does anyone know what kind of plant this is in the photos?
My dog keeps eating the leaves, and it makes him sick.
That is lantana. ASPCA Website says:
Additional Common Names: Shrub Verbena, Yellow Sage, Red Sage
Scientific Name: Lantana camara
Toxicity: Toxic to Dogs, Toxic to Cats, Toxic to Horses
Toxic Principles: Pentacyclic triterpenoids
Clinical Signs: Vomiting, diarrhea, labored breathing, weakness. Liver failure - more common in livestock."
As above, this is Lantana, which is a decorative shrub originally from tropical Africa and America. In Australia, at least, it's classified as a Weed of National Significance (one of 32), so it's illegal to sell and it generally should be eliminated where possible. I have spent many weeks removing Lantana from my aunt's outback property; it's a real nuisance.
Poisoning from Lantana can be quite serious, particularly if the berries are eaten, and I'd recommend taking your dog to a vet. There's extensive information here.