Lagotto Romagnolo
- BREED GROUP:Non-Sporting
- WEIGHT:24 to 35 lbs
- HEIGHT:14 to 19 inches
- COLOR(S):Brown and white, orange and white, cream, orange, brown, and brown roan.
Lakeland Terrier
- BREED GROUP:Terrier
- WEIGHT:17 lbs
- HEIGHT:14 to 15 inches
- COLOR(S):Blue, black, liver, red, or wheaten. Wheaten or golden tan with a saddle of blue, black, liver or grizzle.
Lancashire Heeler
- BREED GROUP:Herding
- WEIGHT:18 to 20 lbs
- HEIGHT:10 to 12 inches
- COLOR(S):Black and tan.
Landseer
- BREED GROUP:Working
- WEIGHT:100 to 150 lbs
- HEIGHT:26 to 32 inches
- COLOR(S):Black and white.
Leonberger
- BREED GROUP:Non-Sporting
- WEIGHT:100 to 170 lbs
- HEIGHT:27 to 31 inches
- COLOR(S):Red, yellow, sandy, reddish brown with a black mask.
Lhasa Apso
- BREED GROUP:Non-Sporting
- WEIGHT:13 to 15 lbs
- HEIGHT:10 to 11 inches
- COLOR(S):White, black, brown, gray, or cream.
Lowchen
- BREED GROUP:Non-Sporting
- WEIGHT:8 to 18 lbs
- HEIGHT:12 to 14 inches
- COLOR(S):Any colors or combinations accepted.
Mal-Shi
- BREED GROUP:Toy
- WEIGHT:6 to 15 lbs
- HEIGHT:8 to 14 inches
- COLOR(S):Many colors and patterns.
Maltese
- BREED GROUP:Toy
- WEIGHT:4 to 7 lbs
- HEIGHT:9 to 10 inches
- COLOR(S):White
Malti-Pom
- BREED GROUP:Toy
- WEIGHT:3 to 9 lbs
- HEIGHT:8 to 12 inches
- COLOR(S):White, black, orange, red, and cream; may be solid or patterned.
Malti-Poo
- BREED GROUP:Toy
- WEIGHT:5 to 15 lbs
- HEIGHT:14 inches
- COLOR(S):Black, gray, white, or yellow-orange.
Manchester Terrier
- BREED GROUP:Terrier
- WEIGHT:7 to 12 lbs
- HEIGHT:8 to 13 inches
- COLOR(S):Black and tan.
Maremma Sheepdog
- BREED GROUP:Herding
- WEIGHT:66 to 99 lbs
- HEIGHT:25 to 29 inches
- COLOR(S):White
Mastiff
- BREED GROUP:Working
- WEIGHT:175 to 190 lbs
- HEIGHT:28 to 30 inches
- COLOR(S):Reddish brown, apricot, or brindle, all with dark muzzle, ears and nose.
Mcnab
- BREED GROUP:Working
- WEIGHT:25 to 50 lbs
- HEIGHT:15 to 25 inches
- COLOR(S):Black with white markings, red with white markings; may be tri-colored.
Mexican Hairless Dog - Xoloitzcuintli
- BREED GROUP:Miscellaneous Class
- WEIGHT:5 to 40 lbs
- HEIGHT:9 to 30 inches
- COLOR(S):Black, slate, gray, brindle, reddish brown, red, bronze; spotted or solid.
Miniature Pinscher
- BREED GROUP:Toy
- WEIGHT:8 to 10 lbs
- HEIGHT:10 to 13 inches
- COLOR(S):Red, or black and tan.
Morkie
- BREED GROUP:Toy
- WEIGHT:4 to 9 lbs
- HEIGHT:6 to 10 inches
- COLOR(S):Black, tan, white, black and tan; may be solid, sable, or distinctively marked.