How to Measure Your Dog for a Proper-Fitting Service Dog Vest

When it comes to service dog gear, fit matters not just for comfort, but for safety and function. A properly sized vest ensures your dog can move freely while still looking professional and identifiable in public. At Humble Dog, we specialize in custom service dog vests and Y-front harnesses, and here’s how you can take the right measurements before ordering.

📏 What You’ll Need:

• A soft measuring tape (or string + ruler)

• Your dog standing in a natural, square position

• Treats or a helper to keep your dog still

 

🔹 Key Measurements

 

1. Girth (D) – The Most Important One!

Measure around the widest part of your dog’s ribcage, just behind the front legs. This determines the size of the vest and the strap length needed.

📝 Example: A dog with a 29” girth would use a vest panel of 14” wide, with side straps approximately 9–9.5” long on each side to allow for buckling and adjustability.

2. Front Chest Strap (A)

Measure from the center of the chest between the front legs to the widest point of the girth. This is where the Y-front harness attaches to the body of the vest.

3. Shoulder Straps (B & C)

Measure from the top of the shoulder blade down to the center of the chest, forming the “Y” shape. These straps help keep the vest secure and centered on your dog.

 

🖼 Visual Guide to Measurement Points

 

🟢 D – Girth (Largest part of the ribcage)

• Shown in green, looping behind the front legs

• “D – Girth: Measure around the widest part of your dog’s ribcage, just behind the front legs.”

🔵 B & C – Shoulder to Middle of Chest

• Shown in light blue, running diagonally from the shoulder to the center of the chest

• “B & C – Shoulder to Chest: Measure from the top of the shoulder blade to the middle of the chest.”

🟣 A – Front Chest Strap (Girth to Chest through the front legs)

• Shown in purple, running between the front legs from the girth to the chest

• “A – Girth to Chest: Measure from the center of the chest between the front legs to the widest part of the girth.”

 

🧵 Fitting Tips from a Service Dog Gear Maker

 

• Always round up slightly if your dog is still growing or fluctuates in weight.

• Leave enough room for your dog to breathe and move—but not so much that the vest shifts around.

• If you’re layering over sweaters or winter gear, consider that in your sizing.

• Use soft materials like fleece padding under straps to reduce rubbing (all of our Y-fronts include this for comfort).

 

❗ Common Sizing Mistakes to Avoid

• Guessing your dog’s size based on breed alone.

• Not accounting for seasonal coat or gear layers.

• Forgetting to add adjustment space for buckles.

• Choosing a vest that’s too tight, which can restrict breathing and movement.

💬 Not Sure What Size You Need?

No problem—reach out! I’m always happy to walk you through your dog’s sizing and help plan the best fit for your vest or harness. We believe in getting it right the first time, so your dog can do their job with comfort and confidence.