Here is your picture

{{gwi:299597}}

Looks like something used to chop roots.

Not likely cast iron, but forged steel or iron, made by a blacksmith.

Hey there, Svanoy!
It looks like "trade goods," inexpensive tools/trinkets traded to the Noble Salvages (Native Americans, First Peoples) probably in the 18th or 19th centuries. I worked for the Anthropolical Collections of the University Of Connecticut (USA) where we had a number of these, or similar. They were associated with the Norris Bull Collection of Indian antiquities assembled from the wilds of Connecticut. HOWEVER, I personally own one which was in a building purchased from a blacksmith, very similar. It looks to be commercially manufactured, has a curved handle, and is useful for hacking at things like roots.
Personally, I believe what your doggies have excavated is an archaeological artifact from Native American/First Peoples days. No, it probably is not worth much commercially. Don't you wonder what it was traded for?
Do not share your conjecture with your wife/signifcant other.

Great to know Polkapete, thanks for the response. I live in central Kentucky. A little bit of a trip from Connecticut.

Yes my dogs seem to have a nose for old artifacts. They will dig at the same spot in the yard for days, eventually something like this will pop up and they will move on to dig somewhere else.

I agree with polkapete, looks like a trade "tomahawk" from the 18th century. Primarily a weapon with other uses. Both the Cherokee and Shawnee had them as well as multiple other tribes, but those were the tribes that tangled most often with Kentucky settlers.

I think that's a maddox (spelling?)

Used for planting seedlings. Swing it like a pick ax, pull the soil/gravel back. Put the seedling in the hole. Continue down the row.

I have one that much larger, maybe two feet end to end. Definitely for tree seedlings.

Not a mattock (grubbing hoe for old timers) Those have a hoe on one side and a narrow axe blade on the other, Whereas the tomahawk has as an axe blade on one side and and a spike on the other side.