JSDoc actually has the @extends tag

  /**
   * @typedef {object} Dog @extends Animal
   * @property {string} childProp
   */

But I don't really use that feature in TypeScript. Instead I rely on `&`. This works in exactly the same way in JSDoc.

Also if you're curious about the equivalent of `extends` in generic slots, here's an example I have from a different project

  /**
   * @template {Record<string, unknown>} [T=Record<string, unknown>]
   * @typedef {{
   *   children?: NewickNode<T>[];
   *   name?: string;
   *   length?: number;
   *   data?: T;
   * }} NewickNode
   */

The generic slot here, T, is "extended" by Record<string, unknown>. The equivalent in TypeScript would look like

  type NewickNode<T extends Record<string, unknown> = Record<string, unknown>> = {
    children?: NewickNode<T>[];
    name?: string;
    length?: number;
    data?: T;
  };