top of page

The Bullmastiff coat

The Bullmastiff comes in red, brindle and fawn as well as any shade in-between, all traditionally displaying a black mask.

This article is to show how varied our beautiful breed is, from various tones/ shading to different coat anomalies. All the dogs featured in this article are pedigree bullmastiffs.

​

At its very basic level the breed technically comes in 3 primary colours fawn, red and brindle. Depending on the breed club and country sometimes the classification changes slightly to red/ fawn or red brindle and fawn brindle but ultimately they are the same.

coats 2.jpg

Fawn and red

Below are some examples of a pale fawn, a mid range coloured dog and a dark red. 

102795800_10216837976728282_807273856796

Photo courtesy of- Colin Williams

​

160570848_3998238310254380_6008741468050

Photo courtesy of- Elena Kesareva

​

148020295_10158870935798150_254785818845

Photo courtesy of- Kerry  Young

​

Brindle

​

The brindle was prized by the gamekeeper for his colouring as it enabled the dog to melt away into the dappled light of a forest or the darkness of the night.

 

The base colour of the brindle will be any shade of light fawn all the way through to a dark red with black stripes on top. The stripes themselves also vary greatly in thickness and spacing, they can be spaced far apart giving a striking contrast between and the base the stripe, or the stripes can be very close together making the dog look incredibly dark almost black. 

​

I have seen in more recent years some brindles be described as reverse brindle, this is just a descriptive term borrowed from another breed, the coat regardless of its outward appearance (see below) is always base colour then stripe ontop it is never the other way around.  

​

160219521_2906176646372158_8308028497833

Photo courtesy of- Carole Moloney

(Fawn brindle)

160392148_1869612206538751_4518719262559

Photo courtesy of- Maja LH

(Fawn brindle)

160554784_236284591400020_61953524167602

Photo courtesy of- Steven Hearn

(Fawn brindle)

160957890_3715120015252918_4012583495538

Photo courtesy of- Andrea Malatestinic

(Red/ Fawn brindle)

84441460_10215831282681560_7853350419450

Photo courtesy of- Triona Rogers

(Red brindle)

160763325_4427045767323715_7527330142709

Photo courtesy of- Matt Wildner

(Red brindle)

In Bullmastiffs one parent must be a brindle to have brindle puppies in a litter, this is because the brindle gene is dominant. If a dog carries the gene it will express the brindle pattern, if the dog doesn't have brindle patterning it doesn't carry the gene. With that in mind it is therefore genetically impossible for 2 fawn or red parents to have a brindle puppy.

 

Below are some examples of the inheritance of the brindle pattern in various litter combinations.

​

kbr- Brindle

ky- Fawn or Red

1.jpg
2.jpg
3.jpg
4.jpg

Counter shading/ two toned

​

This term just refers to the lighter/ counter shading present on the inner legs/ thighs, face and chest, it can be seen in all 3 colours of the bullmastiff though tends to be more obvious in red examples. This pattern occurs in many breeds of dogs and even other species of animals such as deers, fox's and coyotes.

160375560_486354162738651_16626842247660

Photo courtesy of- RaBull Ilona

92445031_620103661873225_768920411808622
164526661_770451636945123_28867523743663

Photo courtesy of- Valerie Bosseaux

Photo courtesy of- Ielze Oph

White flash

White exists in the breed, it can range from from single white hair on the chest to a large flash. On rare occasions it can also pop up on the toes and sometimes as a thin line on the head. The white on the head and toes pretty much always grow out but the flash on the chest doesnt.

161064428_10159114839619324_621839471221

Photo courtesy of- Dereze Sandra

161000082_10224265401331076_460604786626

Photo courtesy of- Valerie Bosseaux

Unusual genetic anomalies within the breed

​

Dudley 

​

The dudley is where the black part of the coat is diluted to brown anywhere from a chocolate colour through to a warm cinnamon, the eyes are typically light and sometimes green and the nose brown through to pink. The examples below are from matings of standard colour parents who carried the variation recessively through the B locus (Dilution).

​

B= None dilution 

b= Dilution

​

This means that both parents carried one copy each of the dilution gene and so were Dd, the affected puppies who express this lighter colour inherited 2 copies of the dilution and are dd. 

160612174_793332458264548_91166613294057

Photo courtesy of- Andrei Tenu

160405775_289658119216369_32546510999797

Photo courtesy of- Andrei Tenu

161116817_259686725776766_65707425663852

Photo courtesy of- Ielze Opheij

160525044_10226415457433314_527943528135

Photo courtesy of- Steph Neesam

dudley 2.jpg

Dilute

The dilute happens in the black areas of the coat turning them into a slate grey blue like silver, people sometimes confuse them with the dudley but they are in-fact not the same this is because the mutation has occurred on the D locus not the B. The puppy below is the result of mating 2 standard coloured dogs though they would have carried the dilute d gene recessively as Dd.

163139337_257992595986895_44400825109034
162817223_1160452434429302_5376798503370

Standard colour litter siblings.

163230685_2206981686102803_8055547340044

Photos courtesy of- Brandi Allan Jason Angle

dilute copy.jpg

Somatic mutation 

​

This mutation happens during the development of the embryo and presents itself as black patches of fur usually on a fawn or red base, this is not linked in any way to the brindle gene and is not inherited unlike the dilute or dudley. 

159889915_10160123812091789_349125117482

Photo courtesy of- Tina Russell

119996648_246829783358041_68458573576428

Photo courtesy of- Giuseppe Mazzamuto

somatic mutation.jpg

Long hair

​

The long haired bullmastiff is also affectionately called the 'wooly bully', these guys are pure bred bullmastiffs that have inherited the long hair gene. This gene has been identified now and can be tested at labs such as Labroklin, there is no associated health risk with the long hair as there are many long haired breeds already in existence. 

160515030_3822252831201502_2835941396815

Photo courtesy of- Deb Swain

160826466_224951599326564_39422816055227

Photo courtesy of- Deb Swain

The dog above was the result of breeding 2 standard coated parents that each carried one copy of the long hair gene, it is inherited like this-

​

Clear- A dog that is visually a short coat and carries 2 copies of the short coat gene 

Carrier- A dog that is visually a short coat but carries 1 copy of the short and 1 copy of the long hair gene 

Affected- A dog that is visually long haired and carries 2 copies of the long hair gene 

​

Clear X Clear= 100% clear

Clear X Carrier= 50% clear, 50% carrier

Clear X Affected= 100% carriers

Carrier X Carrier= 25% clear, 25% carrier,  25% affected 

Carrier X Affected= 50% carriers, 50% affected

Affected X Affected= 100% affected 

Pied

​

As far as im aware this is the only photographic example of a pure bred pied bullmastiff. Pied did used to exist in mastiff types long ago and these would have been the foundation stock to the modern mastiffs and and thus the bullmastiff. My assumption is that it was probably more common way way far back when the breed was still in it infancy before the close registry system and it has over time been bred out. There are lots of paintings of old mastiff types that can be found depicting the pied coat.

160392144_430909181507105_75070824449025

I would like to say a big thank you to all the people that have allowed me to use their photographs. If you would like to learn more about coat colour genetics please go to 'this website'. There are also various groups on facebook dedicated to this that you can join.

© 2025  Saturnsrings Bullmastiffs                                                                                                                   

  • Instagram
  • facebook-square
bottom of page