Online Pet Clothing Retailers

• There are a multitude of pet clothing retailers online with the gear you're looking for, most with similar prices. Shop around, as prices change and shipping is often different. Most sites are official merchandise retailers, and you can assume their products are all the same. Ebay and Amazon are also good resources.
  
  

Visit Local Pet stores

• Pet stores often carry pet clothing. Big chain stores such as PetSmart carry a small assortment of clothes and, if you are in the Boston area, will likely carry what you are looking for. Outside the Boston area, call ahead to see whether Red Sox pet clothing is in stock.
  
  

Go the Custom route

• A few companies offer customization for pet clothing, and Zazzle.com is one of them. You can custom-design pet clothing such as T-shirts on Zazzle.
  
  

Alter a jersey for your dog

• If your dog is extremely large you may want to consider altering a jersey made for a human for your dog.