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Finding the Perfect Size: Measuring Your Large Dog for a Harness

By Canada Pooch on Oct 3, 2023

Properly fitting a harness is essential for the comfort and safety of large breed dogs. An ill-fitting harness can rub, chafe, and restrict movement. Taking accurate measurements and selecting the right style of harness suited for your dog's needs will ensure everyday walks are pleasant and pain-free. This guide covers everything you need to know about sizing, fitting, styles, and proper usage of harnesses optimized for bigger dogs. 

Measuring Your Large Dog for a Perfect Fit 

The first step in finding the ideal harness is accurately measuring your large dog. Like collars, harnesses are adjustable but not as much, pet parents need to ensure they take into account their pups size and weight to ensure proper fit. Follow these steps for measuring your big pup: 

Neck Circumference  

With your dog standing or sitting, use a soft measuring tape and measure around their neck. This gives you the neck size needed. 

Chest Girth 

With your dog standing wrap a soft measuring tape around the broadest part of your dog's chest, behind the front legs. Make sure the tape is snug but not tight. Where the ends meet is the girth size.


A very important step to ensure a proper size to keep your pup comfortable is weight. Take note of your dog’s weight and if they are still growing.

Refer to the manufacturers size charts to find a neck circumference and chest girth range suitable for your large dog. Make sure you look at the weight rating of the harness as well to ensure a safe harness. Once you have the measurements, you can better gauge what size options will best fit your pup. 

Importance of Fit for Large Dogs 

A properly fitted harness should not rub, chafe or restrict your dog's movement. Large dogs with deep chests need wide, well-spaced chest straps to avoid irritation. 

Signs your dog's harness may not be fitting properly: 

  • Rubbing or hair loss on legs, chest or armpits 
  • Difficulty getting free movement and normal gait 
  • Easy slipping out of the harness 
  • Strap irritation at the neck or waist 
  • Whining or signs of discomfort 

Ongoing issues with an improperly fitted harness can cause pain, and changes in behavior, and make walks unpleasant for your large pup. Taking the time to find the right size and style provides optimal comfort. 

Harness Styles for Large Dogs 

For big dogs that pull hard during walks, certain styles disperse force better for control and steering without discomfort: 

Front Clip Harness 

The leash attachment is on the chest at the sternum level on these harnesses. This steers dogs back around when they pull, correcting the unwanted behavior. They provide excellent control but ensure no strain is put on the delicate neck area. The front design also allows freedom of shoulder movement. Check out our Complete Control Harness at Canada Pooch for a great no-pull harness. 

Back Clip Harness 

For trained dogs that walk nicely on leash and do not pull, a standard back clip harness provides a comfortable no-pull experience. The leash attaches on the upper back, allowing natural forward movement without torsion. All of our dog harnesses at Canada Pooch feature a front and black clip.

Step-in Design 

Harnesses with a step-in design and wide neck opening allow you to easily get the harness on without having to maneuver the straps over the head. This is convenient for big dogs that don't like to duck down or get straps caught on their ears. 

Thick Padding 

Many large breed harnesses feature plush padding on the chest plate, belly, and at pressure points. This prevents the harness from digging in or irritating the skin during walks. Padding also provides a more customized fit.

Proper Harness Use and Adjustments 

Once you have a properly fitted harness, there are still some usage tips that ensure it continues keeping your large pup comfy and secure: 

  • Check the tightness of the straps before each walk, especially if your dog is between sizes. As weight fluctuates the fit may need adjusting. 
  • Pay attention to where the harness lays after being on for a while. If it starts riding up or shifting, adjustments may be needed. 
  • Consult sizing up guidelines for puppies or young dogs. Growing pups need harnesses adjusted progressively. 
  • Clip the leash to the front ring for training loose leash walking skills. Once mastered, switch to the back ring for normal walks. 
  • Use the fit indicators like chafing, rubbing, or inhibition of movement to gauge if sizing needs adjustment. Refit as needed. 
  • Routinely inspect for signs of wear like damaged straps, torn stitching, or cracked plastic clips. Replace if an issue is found. 

Proper harness sizing, style, and use will keep your large dog comfortable on walks. But it takes consistently monitoring fit, being aware of any issues, and refitting as needed. 

Training A Large Dog to Walk Nicely In A Harness 

In addition to proper fit, taking time to train your big dog to walk politely on leash while in a harness is key to an enjoyable stroll: 

Acclimate Slowly 

When first introducing a harness, let your dog sniff it and give treats for calm behavior. Gently put it on in stages, praising and rewarding each step. Build up durations wearing the harness slowly. 

Correct Pulling Right Away 

Use harnesses made for training, like front clip styles. At first sign of lunging or pulling, stop and redirect your dog back to your side. Reward when attention is focused back on you, then continue the walk. Stay consistent. 

Practice Loose Leash Skills 

Work on skills like automatic check-ins, saving heel for rewards, and changing direction. Keep sessions short and upbeat. Use high-value treats only for harness sessions to associate positively. 

Fit Properly Each Time 

A comfortable, properly fitted harness is less likely to cause resistance. Check snugness, strap placement, and size before each session. Refit if any signs of rubbing or inhibition of movement occur. 

Watch For Body Language 

Note if your large dog seems distressed, shuts down, or avoids the harness. Slow down training. Make sure the harness style suits your dog's needs. Seek professional help if problems persist. 

With patience and consistency using force-free methods, you can train your strong large breed dog to walk nicely on leash in a harness. Proper fitting maximizes comfort during the training process. 

Finding a properly fitted harness optimized for your large dog will make walks more pleasant for both of you. Avoid injuries and escape risks by taking careful measurements and selecting styles best suited for your dog's size, body type, and training needs. Introducing a harness gradually while monitoring fit will set you both up for safe, comfortable adventures 

Frequently Asked Questions 

How can I tell if a harness is too small for my large dog? 

Signs a harness is too small include rubbing or hair loss, straps digging into shoulders or chest, whining/retching when put on, and difficulty moving naturally. If straps are tight with no room for adjustment, size up for better fit. 

Should large dogs wear a collar or harness for walks? 

For safety and comfort, most trainers recommend a well-fitted harness designed for large breeds. Properly fitted wide harnesses disperse pressure away from the neck for control without pain. 

When is the right time to start harness training a large breed puppy? 

Work on introductory harness training in a positive way starting as young as 8 weeks old. Have them wear a properly fitted puppy harness for brief periods at first. Slowly increase wearing time as they grow, ensuring you size up for optimal fit. 

How can I make my large dog like his new harness? 

To promote positive association, introduce the harness gradually using treats and praise. Have your dog sniff and paw at it first. Give treats as you fit it on your dog. Allow short harness wear sessions to start. Use your favorite treats and make it fun. 

What's the best way to measure my extra-large breed dog for a harness? 

Use a soft flexible tape measure. For length, measure from neck base to tail base adding 2-3 inches. For girth, measure behind front legs around the widest chest area. For width, measure across chest between armpits. Refer to brand size charts to pick the right fit. 

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