Coat Color: Genetics

I've always wondered where Bruno's stripes came from. Many pit bulls can have brindle coats - and so can other breeds like Plott Hounds, Great Danes, French Bulldogs, Mastiffs, Boxers, Corgis and lots more.

(Bruno at the dog park)

However, some people have a bias against brindle-colored dogs, and that may lay in the genetics. For example, it is difficult for Mastiffs with brindle coloring to compete against Apricot and Fawn colored Mastiffs. My boyfriend's grandmother automatically disliked Bruno when she met him because of his "ugly Brindle coat." 

I decided to learn a bit about the genetics behind the bias:

First of all, many animals have stripes. It is generally agreed that stripes occurred over millions of years of evolution for camouflage purposes, however, dog coats can evolve must faster due to special extra genes that can mutate faster with human breeding.

 (see how well I can blend into my surroundings?)


Dog coat color, shape, and length genetics are based in 16 specific locations of the geneome.

The basic color loci are:
Agouti Locus (A), Brown locus (B), Dilute locus (D), Extention locus (E), Harlequin locus (H), dominant black locus (K), Merle locus (M), and Spotting locus (S).

Brindle is mostly determined on the Dominant Black (K) locus. In many brindle breeds, fawn is a recessive trait - so dogs need two recessive genes to be completely Fawn colored. Dark is the dominant trait and Brindle occurs when the pup recieves a dominant and a recessive gene.

If a pup recieves "K" and "k^br"- he will be black or  dark, and if he recives "k^br" and "k^br" he will be brindle. Also, if he recieves "k^br" and "k"  he will be brindle, but he will be light or fawn if he has "k" and "k."

In other words, if one parent is Black, chances are no dogs will be brindle because the "K" will be dominant, much like brown eyes in humans. Brindle is dominant over non-brindle- so if one parent parent is brindle and is bred with a dog that has no brindle ancestry- the resulting pups will be between 50% and 100% brindle. (100% if the brindle parent is not brindle recessive.)

Some brindle dogs will have a black face mark in the "eumalanin" color (sometimes also on the ears). This is caused by the presence of an "E^m" gene on the Extension-locus.

The differences in color are controlled by pigmentation genes, but most brindle dogs' have "eumalanin (black)" stripes on a "phaeomelanin (red)" base. The wide diversity of brindle colors in the pit bull population is due to interactions between the B (brown) and D (dilute) loci which can result in black brindle, blue brindle, brown brindle, and fawn brindle.

Of course, Pit bulls and pit bull mixes can have extreme varieties in coloring from pure white, to piebald, to blue, to red to any mixture of colors.

In the past, "blue" pit bulls were seen to be very rare. Currently, back yard breeders use this precieved "rareness" to attract buyers, but there are actually a large number of blue-nosed pit bulls. This is so because the homozygous recessive alleles that cause blue-ness are (dd), so any dog with a (D) would not be blue. To increase the number of blue pit bulls, breeders had to breed blue pit bulls with other blue pit bulls which results in 100% blue or fawn/blue offspring.

See examples of each color pit bull here.

Read more about discovering the genetics of your dog here.

Sources:

http://www.chromadane.com/standardcoat.htm

http://abnormality.purpleflowers.net/genetics/brindle.htm

http://bowlingsite.mcf.com/genetics/Brindle.html

http://en.wikipedia.org/wiki/Coat_(dog)

http://www.adbadog.com/uploads/pdf%20forms/colorgenetics.pdf



Designer Pit Bulls

As you may know- many different types of dogs masquerade as "American Pit Bull Terriers" or "pit mixes" or "pitbull type dogs." Winnie sometimes looks more like a lab than the 1/4 Staffie terrier that she is, but I think of her as a pittie-mix. Bruno is mostly mutt (maybe some Dalmatian and boxer) but he is certainly a pit-mix (my mother says "its the shape of his head!" and apparently that's all that matters.)

Last weekend was Easter weekend: we were home with Bruno and my Mom asked- What is a pit bull after all? Can you have a pure-bred pit bull?

I answered no- there is no such thing. I decided to write a post about the different types of dogs that are considered pit-bulls and the ones that really shouldn't be.

To me- a "pit bull" is a type of mixed-breed dog that looks a certain way and has a particular affection for people, they tend to have smooth coats, have short folded- or up straight ears, be 35-55 pounds and somewhat muscular with a short snout and a square-shaped head. A lot of shelter dogs fall into this category. (As I showed in a previous post, all of these dogs are considered Pit mixes at Animal Care and Control of NYC:)

PBRC.org reminds readers: "A "Pit bull” is NOT a breed. It's a generic term often used to describe all dogs with similar traits and characteristics known to the public as "pit bulls." When we use the term “pit bull” here, it should be understood to encompass American Pit Bull Terriers, American Staffordshire Terriers, and Staffordshire Bull Terriers." Here is some more info on pit bulls at Pit Bull Rescue Central.

The Animal Farm Foundation writes, "Over time, we realized that the dogs we were helping were not necessarily pure bred American Pit Bull Terriers, but dogs that people called "pit bulls." "Pit bull" is not a breed or breed mix, but an ever expanding group that includes w...hatever an animal control officer, shelter worker, dog trainer, politician, dog owner, police officer or newspaper says it is."

However, Backyard-breeders and people who have developed the breed for its tough-look, large head, muscles and sometimes fighting ability do advertise their dogs as "American Pit Bull Terriers." I do not consider these dogs to be "pit bulls," they are often double the weight of an average pit-bull type dog and have very specific characteristics that would be better categorized in their own new breed. Backyard breeders are breeding their dogs based on what is trendy- like this new "tri-color trend."

This dog's puppies are being sold for $1000 each online as "ABPT"s:

It would take genetic analysis, but I would venture to say that a dog like this is as different from a typical "pit bull type dog" as a pit-bull is from a bulldog.
These dogs' (probably actually mixed with bulldogs) puppies are going for $2000 each:

 

This one is advertised as being "XXL" and "Extra Wide" with "thick bones, wide chests" and somehow "pure bred, top of the line, blue ribbon"

This 92 lb monster with his "26.75 inch head" is somehow considered a pit bull terrier even though he is 2-3 times heavier than the standard pit-mix.

These dogs are bred to look as beefy as possible-- like this when they are only 2 weeks old (this one goes for $3000 by the way.)

It only takes a brief online search of "pit bull puppies for sale" to find horrifying pictures like this-poor dogs treated like masculine extensions for their owners' self-esteem.

Breeders of all types of dogs evolve the breeds they work with through generations of selective breeding, and the same thing is happening here- pit bulls selected and inbred over many generations are being bred to be bigger, tougher, and more serve-looking.

This practice has gone on for centuries to produce guard dogs and working dogs, but the problem here is that these dogs are being sold to people who do not know how to handle them- who often refuse to neuter them- and who want to breed them themselves to make money. This ends up putting more genetically aggressive dogs into the stray and unwanted dog populations and floods many city shelters. It also hurts the reputation of "pit bull type dogs"- dogs that may be smaller, better with children, and less dog-aggressive like these:

How exactly are these dogs considered the same breed? I think it might be time to gather the "real" APBT "breeders" out there who seem to be merging their dogs with bulldogs and selecting for large/short characteristics and form a new breed, a breed that can be standardized like all the others. That way, these pittie mixes and be recognized as different and unique from this other "designer" breed of dogs.

What do you think? What do you consider your pitties to be?

Funky Mixes in the USA

Hello bloggies--Strut your Mutts!

I was inspired by some of the beautiful mixed breed dogs in my neighborhood to highlight the mixed-breed dogs in shelters-
Mixed breeds have a lot going for them:
1) They are unique
2) They are less prone to genetic diseases
3) You will get lots of questions about them, which helps you make more friends
4) They are often really beautiful combinations of other breeds
5) You won't have to own a "pure-bred"- sorry if you have one (my parents have a "pure-bred" Wheaton terrier) but people who use the word pure-bred as if it matters or somehow makes their dog better than mine  really bother me.
6) You get to do their DNA tests, which is fun

So I decided to highlight some funky and beautiful mixed dogs available for adoption!


Max- A Rhodesian/Lab Mix in New York

Honey - A Blood hound and lab mix in Liberty Center, OH

Scrappy - a Wheaton Terrier and Border Terrier in Chicago

Strauss- an Afghan Hound/ Smooth Collie mix in Atlanta

Basil - a Basset Hound Pit Mix in Chicago

 

Miniature Pit-bull anyone?
Beacon - a smooth coated Chihuahua and Pit Bull Terrier in Los Angeles

Stop Puppy-Mills!

Tell them to stop breeding!

100,000 Pitbulls die in shelters every year, but puppymills in Missouri and elsewhere continue to breed these animals and sell them to pet stores for a profit. Puppy mill pups often are bred and grow up in cramped cages. Many develop neurological disorders or have genetic diseases or other problems.

Missouri is home to 23% of the Puppy mills in the U.S., many dogs from Missouri are shipped out via the internet to unknowing buyers in other states. Many shelters resue pups from Missouri and bring them to other states for veterinary care and better homes (which is our my own precious Winnie came to find me through Animal Haven in Soho, NYC). However, there is finally a proposed bill to stop the cruel practice in Missouri, called Proposition 8 (the Puppy Mill Cruelty Prevention Act) which sets restrictions on the size of these commerical breeding facilities and provides the animals with more basic care.
See the add for Prop 8 below:

Background Info on Puppy mills

Please see the ASPCA's list of ways to help stop the puppy mills:

ASPCA- 10 ways to help