My dog just went to the bathroom, and his stool was VERY unusual looking. Half of it looked normal- the other half of it was much larger (about twice the size around) and rather than being the usual brown looked like it had a mucus-like casing around it... almost like a sausage (gross comparison, I know, but that's the best analogy I can think of!).
I was concerned, so I split it open with a stick, and inside was very loose stool with what looked like little bits of rice in it. I was concerned it was worms, but it wasn't moving or anything... and the past two days we've given him canned dog food because we ran out of his usual hard dog food... and I know there's rice in that, so I don't want to just assume it's worms... but it just looked really odd.
But why would it look so different from how it usually does? And why would half of the same piece of poop look normal and the other half look so strange? Could it just be the change of food over the past two days? Or should I be worried that it's something worse?

Thanks for your input!

The little bits of "rice" are worms. The stool will get mucusy looking when worms are present. Probably hook worms. Treat dog and within a day or so worms go away. Take to vet for medicine. I order my meds online and keep a good supply on hand for the summer as my Jack is prone to hook worms.

I don't have the money to do it till this coming Thursday... will he be okay till then?
He's acting like his regular self aside from the weird looking poop the other day.
Thanks!