Dog sweater question

my grandmas knitting a dog sweater that has 3 diff colors, shes wondering what u do with the loose ends , thanks

You have to weave them in. I prefer not to tie knots, but with a dog sweater a knot and then weave in the ends will work fine.

she said something about 90 loose ends, isnt there a better/easier way ? thanks

Sounds like she knit stripes. If they’re only 2 or 4 rows apart you don’t have to cut them when you change colors, just carry them up one side.