Our size guide helps you to choose the right style and size of Optivizor for your dog. Sizes are colour coded and grouped into three styles according to your breed’s nose length - normal, long and short.

Dogs come in all shapes and sizes. Breed, gender and age affect the style and size that is the best fit for your dog, so we recommend checking measurements and comparing below for specific breed recommendations.

For example if you have a pug and look under Short Nose Length you will see they are typically one of three sizes.

Where to Measure

Normal Nose Length / Long Nose Length - measure from the the tip of the dog’s nose to the mid-point of the back of the ears. Measure in a straight line and do not follow the contours of the dog’s face.

Short Nose Length - measure the head circumference around the dog’s head from the middle of the ears, down under the chin and back up to the ears.

Size and weight charts are based on measurements. Breed recommendations are based on customer feedback. Please contact us after purchase if you can help to update any listing.

Where possible we have included links to our Photo Gallery to help you make a visual comparison by breed. Sizes are colour coded.

Normal Nose Length

Head Length - measure from the the tip of the dog’s nose to the mid-point of the back of the ears. Measure in a straight line and do not follow the contours of the dog’s face.

Weight - check the current weight of your dog. Your vet will usually have a record of this. To weigh small dogs using bathroom scales you can carry them for a first measurement, put them down and measure your own weight, and then deduct one reading from the other.

Dog breeds with a normal nose length:

• Affenpinscher
• Airedale Terrier / Medium / see Sam
• American Akita / Large / see Zada
• Alaskan Malamute / Large
• American Collie
• Appenzell Mountain Dog
• Australian Shepherd
• Basset Hound
• Bearded Collie
• Beaglier
• Belgian Shepherd
• Berger de Brie
• Bernese Mountain Dog
• Bloodhound
• Border Collie / Small / Small-Medium / sometimes Medium / see Jessie
• Bichon Frise / Toy / Small / see Chipper and FAQs about fluffy heads
• Bull Terrier
• Cairn Terrier / Small
• Chihuahua
• Chow Chow
• Cocker Spaniel / Small-Medium / sometimes Small
• Cumberland Sheepdog
• Dachshund
• Dalmatian
• Dandie Dinmont Terrier / see FAQs about fluffy heads
• English Setter
• Eskimo Dog
• Foxhound
• Fox Terrier
• German Shepherd / Large / sometimes Medium
• German Longhaired Pointer
• German Shorthaired Pointer / Medium / see Oscar
• Great Dane / Large / Extra Large / see Domino
• Golden Retriever
• Gordon Setter
• Groenendael / Tervueren
• German Hovawart
• Hungarian Vizsla / Small-Medium / sometimes Medium / see Piri
• Husky
• Irish Setter
• Irish Jack Russell Terrier / Toy / see Lucy
• Jack Russell Terrier / Toy / see Spud and Bertie
• Lakeland Terrier / Small / see Jack
• Lancashire Heeler (Ormskirk Terrier) / Toy
• Lhasa Apso / Toy
• Karabash
• Komondor
• Kuvasz
• Labrador / Medium / Large / see Rufus , Zola and Max
• Leonberger
• Maltese
• Mastiff
• Mastino Napoletano
• Miniature Pinscher
• Miniature Poodle / Toy / Small / see Hugo
• Miniature Schnauzer / Toy / Small / see Tasha and Storm
• Munsterlander
• Newfoundland (Newfie) / Large / Extra Large / (sometimes larger)
• Old English Sheepdog
• Parson Russell Terrier / Toy / Small / see Oscar
• Pembroke Welsh Corgi / Small / see Loaf
• Pointer - see German Shorthaired/Longhaired Pointer
• Poodle / Small-Medium / Medium / see Willis
• Portuguese Water Dog
• Rehpinscher
• Rhodesian Ridgeback
• Rottweiler
• Samoyed / Medium / Large
• Schnauzer
• Shetland Sheepdog
• Springer Spaniel / Small-Medium / Medium / see Jester and Bailey
• Spitz
• Sprocker / Small-Medium / Medium
• St Bernard / Large / Extra Large / (sometimes larger) / see Yogi and Spencer
• Staffordshire Bull Terrier / Small / Small-Medium / sometimes Medium / see Millie
• Tibetan Terrier
• Vizsla - see Hungarian Vizsla
• Weimaraner
• Welsh Corgie
• Welsh Springer Spaniel
• West Highland White Terrier (Westie) / Toy / Small / see George

Long Nose Length

Head Length - measure from the the tip of the dog’s nose to the mid-point of the back of the ears. Measure in a straight line and do not follow the contours of the dog’s face.

Dog breeds with a long or narrow nose:

• Afghan Hound
• Bedlington Terrier / Small / see Gracie
• Borzoi
• Doberman Pinscher
• Greyhound / Small-Medium / see Dreamy and Lucy
• Irish Wolfhound / Medium
• Lurcher / Small-Medium / see Bob
• Rough Collie
• Saluki x Greyhound / Small-Medium
• Scottish Deerhound / Small-Medium / Medium
• Sloughi
• Spanish Galgo
• Spanish Podenco / Small-Medium
• Whippet / Small / see Bry and Kiera

Short Nose Length

Circumference - measure the head circumference around the dog’s head from the middle of the ears, down under the chin and back up to the ears.

Following extensive testing we have found the Optivizor is unlikely to provide a comfortable fit for French Bulldogs, Cavalier and King Charles Spaniels due to their characteristic head shape, and it may not fit some Boston Terriers.

Dog breeds with a short nose or flat face:

• Bolognese
• Boston Terrier / Toy / Small / Small-Medium - May not fit (see above)
• Boerboel / Extra Large
• Boxer
• Brussels Griffon / Mini Mini / see Peggy
• Bulldog / Small-Medium / Medium / see Marge and Barney
• Bullmastiff
• Cavalier King Charles Spaniel - Not recommended (see above)
• Cavapoo (Mini Doodle)
• Cairnoodle / Mini
• Dogue de Bordeaux / Large / see Diesel and Zinfandel
• English Bulldog - see Bulldog
• French Bulldog (Frenchie) - Not recommended (see above)
• Havanese
• Japanese Chin
• Japanese Akita (Akita Inu) / Medium / see Nunook
• King Charles Spaniel - Not recommended (see above)
• Papillon (Continental Toy Spaniel) / Tiny / Mini-Mini / Mini / see Quipp
• Pug / Mini / Toy / Small / see Pugly, Bertie , Toby, Huxley, Vinny, George and Annie
• Pekingese
• Shar-Pei
• Shih Tzu / Mini / Toy / see Dolly and Bailey
• Tibet Spaniel
• Yorkshire Terrier