Should a pet supplies store in the GCC dropship or hold stock?

Not a decision about the business — a decision about each product. Dropship the long tail you are still testing; hold the few lines that reorder, because those are the ones where margin compounds and where a slow delivery costs you a repeat customer rather than a first one.

How to decide, line by line

A practical rule: once a line sells consistently for two months, price out holding it. If the improvement in margin covers the storage inside one turn of stock, hold it.

Dropshipping trades margin for not holding stock, and the trade only works while traffic is cheap. For a pet supplies store in the GCC, the answer turns on one thing in particular: Pet food is the most reliably repeated purchase in retail: the bag runs out on a known schedule.

What is different about the GCC

The GCC is not one market. Payment habits, delivery norms and language expectations differ enough that a single approach underperforms in at least one country.

Payment preference varies by country more than most planning assumes.

What is different about a pet supplies store

The part nobody plans for is returns: if the supplier will not take one back, the store is the returns department.

Where a mobile app comes into it

This is the clearest case for an app of any category. TicApp built barcode reordering into Pets Lounge for exactly this.