The Skinny on Frenchie Skin Disorders
Lori Hunt, DVM
http://www.centerwestanimalhospital.com/
We have all seen, owned, or known a frenchie with “bad skin”. They are itchy, crusty and otherwise uncomfortable. Unfortunately for our beloved French bulldogs, skin disease is a very real concern in this breed. Several types of underlying diseases can cause skin issues. Some of these are atopic (allergic) dermatitis, bacterial or fungal infections, hypothyroidism and other endocrine problems, such as Cushing’s syndrome. When talking about dermatologic disorders, we must be careful to specify with which one we are dealing. Most of these conditions are heritable, meaning they can be passed from generation to generation by the inheritance of genes that predispose the dog to developing these issues. For this article, I will define these dermatologic conditions in the following sections.
Atopic Dermatitis
Atopic dermatitis is also referred to as allergic dermatitis or atopy. Atopy is an inherited predisposition to develop allergic symptoms to an otherwise harmless substance, or “allergen”. The kinds of things that cause us to have runny noses and eyes (pollen, dust, dander, etc.) most often cause dogs to develop skin problems. Also, foods can become allergens to some dogs. Certain protein sources, grains, vegetables, and many others can also cause a dog to exhibit allergic symptoms. These symptoms develop after repeated exposure to this allergen, rendering the dog “allergic” to it. Symptoms most often arise in animals 1-5 years of age. This helps explain why, all of a sudden, a dog that showed no signs early on, is now allergic after repeated exposure. The incidence of atopy is increasing in both animals and humans, and is most common in purebred dogs due to its inherited nature. Intradermal skin testing and/or blood testing is used to diagnose atopy. Often times, when it is thought that a food may be the cause of the atopy, a food trial or elimination diet is tried for 6-8 weeks to see if symptoms resolve. If so, this can be considered diagnostic for a food allergy.
Bacterial or Fungal Infections
Pyoderma, also known as bacterial folliculitis, is the most common type of bacterial skin infection in the dog. It is characterized by a multitude of symptoms such as skin fold infections in the face, between the toes, around the vulva in the bitch, external ear canal infections, chin acne, pustules, crusts, etc. The most common bacterium isolated from cultures of these dogs is Staphylococcus intermedius. This is actually a normal resident bacterium of canine skin, but under certain circumstances it can take over and cause infection of the skin in some dogs. If a dog is itchy due to atopy, and scratches, it can break the skin which then can allow microorganisms to enter and cause an infection. Usually pyodermas are secondary to underlying abnormalities of the metabolic or immune systems, i.e. allergies, skin parasites (mites, fleas) and endocrine diseases, like hypothyroidism. There is, however, also an idiopathic primary bacterial folliculitis most common in short-haired dogs. Idiopathic means a folliculitis of spontaneous origin without an underlying abnormality. Pyodermas are not limited to bacterial origin, but can also erupt with a fungal component, such as yeast or ringworm. It is important to get to the source of the infection, particularly with recurrent infections.
Endocrine disorders
Endocrine diseases such as hypothyroidism and hyperadrenocorticism (Cushing’s syndrome) can also result in dermatologic issues in the canine. Hypothyroidism is perhaps the most common and notable endocrine issue in the dog, and for the matter of brevity, it will be my focus here. Hypothyroidism has an inherited form as well as a form from an unknown/undetermined origin. According to some researchers, there are dogs that inherit a genetic susceptibility to disease that attacks their own immune systems. The presence of autoantibodies in the thyroid test is considered by some researchers and breeders to be a forecaster of autoimmune lymphocytic thyroiditis, the inherited form of the disease. Breeding dogs should have their thyroid function assessed.
Skin Issues and Our Frenchies
There has always existed a debate amongst French bulldog breeders that light colored dogs more often suffer from skin allergies. I, too, have seen the creams and fawns with chronic moth eaten coats, but I have seen it just as often in brindles, pieds, and even black masked fawns. I have seen it in cream dogs born from 2 cream parents, AND I have seen it in brindle dogs born from 2 brindle parents. As a veterinarian and fellow breeder, I have NOT found evidence to support a higher incidence in “lighter” coated dogs. Instead, I have found it to be inherited in certain lines and/or environments, and completely color blind. This common feeling that lighter coats are more often involved may be because lesions are easier to see on the lighter coat colors. But so this article is not based on my opinion only, I interviewed a renowned veterinary dermatologist to get her feedback on the skin issues that she sees in our breed.
Alice Jeromin, DVM, Dipl. ACVD, is a board certified dermatologist who practices in Cleveland, OH, and is greatly respected in the veterinary world. She is a published author on many dermatologic topics as well as a speaker at multiple veterinary conferences around the country. I questioned her with regard to coat color and French bulldog skin issues, heritability of skin issues, as well as several other factors, such as intact vs. altered, young vs. old, import vs. American bred, etc. I did ask her to broaden her answers to other breeds as well if she felt it was necessary. She sees a moderately sized French bulldog practice, and she states, “the atopics I see are both fawn and black {brindle} and white.” In regard to inheritance of atopy, Dr. Jeromin states, “the only study of atopy as far as inheritance was done in golden retrievers and 50% were found to be genetic and 50% found to be environmental.” She also had a few interesting observations in that “atopic French bulldogs seem to have a lot of bacterial pyoderma as an accompanying secondary problem” and that while most of the French bulldogs she sees are altered, she did witness “flare ups while in heat”. Lastly, Dr. Jeromin mentioned “the latest findings in atopics are that they can become spontaneously food allergic so I always prefer my atopic patients to be on hypoallergenic diet as well.”
It appears that the skin issues we are seeing in French bulldogs are not, in fact, color sensitive, but instead are related to genetics and environment. If we truly look at genetics and study pedigrees of affected dogs, I think many will be surprised at the commonality of lines and/or environmental factors in these dogs, which goes way beyond coat color in this breed.
