How to use a discriminating union type for an initial value in a useReducer?

Question

Is there a way to properly type an initial value in a useReducer hook using a discriminating union?

I am passing an initial value into my context that can either be an object of Dog or Turtle. I am getting an No overload matches this call error because there are properties that exist in Dog and not Turtle and vice versa.

type Dog = {
  name: string;
  breed: string;
  tail: number;
}

type Turtle = {
  name: string;
  breed: string;
  spots: number
}

type AnimalItem = Turtle | Dog;

export type Props = Readonly<{
  initialValue: AnimalItem;
  type: AnimalType;
}>;


export const CardConfigEditContextProvider: React.FC<
  PropsWithChildren<Props>
> = ({ children, initialValue, type }: PropsWithChildren<Props>) => {

  const reducer = getAnimalReducer(type);

  // getting an error overload matches this call error
  const [state, dispatch] = useReducer(reducer, initialValue);

  return (
    <CardConfigEditContext.Provider value={{ state, dispatch }}>
      {children}
    </CardConfigEditContext.Provider>
  );
};