DNA Tests for French Bulldogs-Understanding Genetics & the Health Panel

DNA Tests for French Bulldogs-Understanding Genetics & the Health Panel

When beginning your breeding program you will want to have DNA tests for your French Bulldogs. These fall into two categories: 1. Color. 2. Health panels. Today we will discuss understand basics genetics and health panel testing. You will want to order swabs from the company to perform the testing at home. There is more information on this in the Frenchie breeding membership site. 

The first thing is to understand genetics. As a dog breeder, you are officially a scientist and will need to understand genetics. I have a cell and molecular biology degree for my undergrad and taught genetics labs at Missouri State University to second year students. What you need to know is fairly simple and straight forward. 

Genetics Terminology:

Dogs have 38 pairs of autosomal (non-sex) chromosomes and one set of sex chromosomes, one from each parent. Total of 39 pairs of chromosomes. Females have two X chromosomes. Males have one X and one Y chromosome. 

Chromosomes are strands of DNA wrapped up really tight. 

DNA is a molecule in cells that carries the genetic information. It is made up of building blocks. ·

Genes  live on chromosomes and are portions of the DNA strand. A section of DNA that encodes for a certain trait. Genes=Genotype. 

An allele is the name geneticists give to each version of the gene on each of the different chromosomes. Looking at alleles allows us to understand probabilities regarding potential genotypes. Alleles=phenotype

An allele is the name geneticists give to each version of the gene on each of the different chromosomes. Looking at alleles allows us to understand probabilities regarding potential genotypes. Alleles=phenotype

One Gene. Two alleles. 

Examples of gene vs allele

Gene: eye color, fur color.      Allele: blue eyes, lilac fur

Gametes are the eggs from the female and the sperm from the male. 

Genotype: What is at the DNA level. 

Phenotype: What we see.

Ex. Genotype vs Phenotype

  • Genotype: Brindle Frenchie but carries one copy of blue. Phenotype:  Brindle French Bulldog 

Recessive gene: two copies to express the gene. 

  • The disease we test on for the health panel. 
  • Blue gene
  • Chocolate genes

Dominant gene: one copy to express the gene. Ex. Merle gene

Affected: If it’s a recessive gene the pup will be affected as it carries two copies of the gene.  

Carrier: The pup will be a carrier but will not be affected by that gene. 

Clear: The pup carriers no copes of the negative gene mutation and will not pass on the gene to future generations. 

The 4 genes tested for French Bulldogs–Taken directly from Animal Genetics website. 

Canine Multifocal Retinopathy Type 1 (CMR1)

The mutation causes raised lesions to form on the retina. The lesions alter the appearance of the eye but usually do not affect sight. The lesions may disappear, or may result in minor retinal folding. Symptoms of the mutation usually appear when a puppy is only a few months old, and generally do not worsen over time.

Degenerative Myelopathy (DM)

Degenerative Myelopathy (DM) is a progressive neurological disorder that affects the spinal cord of dogs. Dogs that have inherited two defective copies can experience a breakdown of the cells responsible for sending and receiving signals from the brain, resulting in neurological symptoms.

The disease often begins with an unsteady gait, and the dog may wobble when they attempt to walk. As the disease progresses, the dog’s hind legs will weaken and eventually the dog will be unable to walk at all. Degenerative Myelopathy moves up the body, so if the disease is allowed to progress, the dog will eventually be unable to hold his bladder and will lose normal function in its front legs. Fortunately, there is no direct pain associated with Degenerative Myelopathy.

The onset of Degenerative Myelopathy generally occurs later in life starting at an average age of about 10-12 years. However, some dogs may begin experiencing symptoms much earlier. A percentage of dogs that have inherited two copies of the mutation will not experience symptoms at all. Thus, this disease is NOT completely penetrant, meaning that while a dog with the mutation can develop Degenerative Myelopathy, the disease does not affect every dog that has the genotype.

Hyperuricosuria (HUU)

Dogs with this genetic mutation metabolize waste products as uric acid in their urine. The uric acid forms into hard stones in the bladder, causing pain and inflammation as the stone moves through the urinary tract.

A dog that has difficulty urinating or appears to have an inflamed bladder may have HUU. Other signs can include blood in the urine and frequent urination. If the dog is unable to pass the urate stones without medical intervention, surgery may be required to remove them. And if the urinary tract is blocked, the condition can be life threatening. Even in the best case scenario, HUU is uncomfortable and painful for the dog.

Juvenile Hereditary Cataracts (HSF4)

Juvenile Hereditary Cataracts (JHC) cause a clouding of the lens of the eye due to a breakdown of tissue in the eye. This condition generally results in an inability to see clearly and can cause total blindness. In canines, cataracts are often familial; this is known as Hereditary Cataracts. A mutation in the HSF4 gene causes this type of cataracts in several breeds of dogs. In this case, the dog is typically affected bilaterally. This means that both eyes are affected by the cataracts. The cataracts associated with HSF4 also occur in the posterior region of the lens. They usually start by being small and grow progressively, though the speed of growth is highly variable. Some cataracts will grow so slowly that the dog’s vision remains relatively clear, while others will grow such a way that the dog will quickly go blind. Corrective surgery is possible, though it is costly and is not always effective. 

This mutation is only responsible for early-onset hereditary cataracts.

It should also be noted that not all cataracts are hereditary. Cataracts can also be caused by old age or injury. Also, cataracts that occur in different regions of the lens can also be familial, however, are not attributed to this gene mutation.

Overall, have your French Bulldog health panel completed. Once you receive the results back, you will have the information you need to properly match your male and females to the appropriate partner. Remember, if your Frenchie carries a gene it doesn’t mean he/she isn’t breeding quality. You will need to appropriately match the pair in order to prevent their offspring from carrying two copies of the gene. If you have a male that is four panel clear (carries no negative gene mutations), it makes matching your males and females based on health much easier. 

Find out

Make sure to get the Ultimate Guide to Know if French Bulldog Breeding is Right for You!

If you’re ready to start breeding, get the course and let’s get your French Bulldog breeding program in place. 

Follow us on Instagram.