Allergic to Dogs and Allergies in Dogs Resource

Allergic to Dogs Causes

Allergic to dogs causes in its purest form relates specifically to dog allergens. However, there are a number of other aspects that can impact the condition. Therefore, we will consider these as follows:

  • Dog Specific Allergy –
    To allergens produced by the dog itself i.e. dog allergens such as found in dander or saliva etc.
  • Dog Related Allergy –
    Not to allergens produced by the dog itself but to other allergens transported by them  e.g. dietary or environmental allergens.
  • Concurrent Allergies –
    Involving both dog specific and dog related allergy.
  • Allergen Dispersal
    • Dog factors determining dispersal.
    • Human factors associated with dispersal.

Dog Specific Allergy

Dog Allergens – Type and Location

A dog specific allergy refers to those people who are truly allergic to dogs i.e. allergens produced by the dog.

The various dog protein allergens responsible for triggering an allergic reaction in people are present in:

  • Dog dander.
    The material shed by a dog similar to dandruff is composed of cells that originate from the upper layer of skin (desquamated epithelium). It is rich in the allergens Can f1 and Can f2.
  • Skin secretions/Sebaceous oil glands.
  • Dog saliva. This appears to be the primary source of the main dog allergen Can f1 (canis familiaris allergen 1).
  • Dog urine.
  • Dog blood contains the allergen albumin.
  • Dog feces.


Allergic to Dogs Causes Dog Allergens


Dog Related Allergy

A person with a dog related allergy means their symptoms are not due to the allergens produced by the dog itself, but are triggered by other types of allergen transported/carried by the dog e.g. in the dog’s food or from environmental allergens trapped in or on its coat.

Tackling an allergy problem effectively involves determining the precise cause/source through appropriate diagnosis. It is not uncommon for people to assume they have an allergy to dogs, sell the dog, only to find much later that they have in fact a dog related allergy e.g. to dust. Poor dog! To paraphrase a common expression, one does not want to throw out the baby and keep the bathwater!

To illustrate this point, the following examples represent allergies related to dogs but which are NOT dog allergies per se:

Type of Allergy Role Played by Dog
Food allergy Cause: Food allergens from dog food becoming transferred to humans.

Scenario 1
Dog licks its coat after eating thereby depositing food allergens on it.
A person with a food allergy may stroke the dog and subsequently experience an allergy response.
Scenario 2
The dog may eat and transfer food allergens to a person by licking them.

Environmental allergy Cause: Grass, pollen and other environmental allergens trapped in coat/undercoat of dog becoming transferred to humans.

Scenario 1
A person with a pollen allergy may stroke the dog and subsequently experience an allergy response.
Scenario 2
The dog may groom itself and transfer pollen allergens from its coat to a person by licking them.


Concurrent Allergies

Concurrent allergies refer to a person having more than one type of allergy. In this context, it is therefore possible for an individual to have both a dog specific allergy (to the allergens produced by the dog) as well as dog related allergies e.g. pollen carried into the home on the dogs coat may trigger an allergic response in those hypersensitive to it.

Allergen Dispersal

Dog Factors Determining Dispersal

Dander, saliva and urine represent the main means of dispersal for mammalian respiratory allergens (Allergens and Allergen Immunotherapy – 3rd Edition – Lockey et al. 2004). Studies have suggested dander levels/allergenicity appears unrelated to shedding, is determined both by genetics (role in protein expression) and the environment e.g. frequency of bathing, and that there exists a greater difference within breeds than between breeds e.g. Ramadour et al. 2005

Dog hair itself has been shown not to be an allergen. Allergens are present in the dog’s saliva and are produced by the sebaceous oil glands in the animal’s skin, therefore, when the dog grooms itself, the allergen-rich water-soluble protein mixture sticks to its hair. In fact, because cats tend to groom themselves more often and spend longer periods indoors than a dog, the risk of a person experiencing an allergy reaction to a cat is up to two times greater. As noted previously, pet hair can collect dander as well as numerous additional allergy triggers such as environmental allergens, dust and mites.

Aside from direct and indirect contact with dog allergens (See: How do Allergy Suffers Come into Contact With Allergens?), airborne dispersal of microscopic allergen particles is an important means of transmission; even allergens originating from dog urine can become airborne!

Other dog factors commonly associated with allergenicity/allergen dispersal include:

  • Dog size. The surface area of a dog can contribute to the amount of allergens emitted or collected e.g. the dander dispersed or the amount of other allergens that become trapped in their coats such as pollen or dust. In addition, the amount of urine passed by a dog will depend on its size. Therefore, small-sized dogs will generally tend to emit less dander and dog allergens, collect fewer environmental allergens in their coat and produce less urine than large-sized dogs.
  • Dog coat/undercoat and shedding. The type and length of hair and the nature (volume and its density) of its undercoat (if it is a breed that produces one)  may affect the build–up, trapping and dispersal characteristics of allergens. Aside from dog size, the interplay of the coat/undercoat and its shedding characteristics (frequency and volume), can help determine the degree of indoor hair pollution. Typically, the following applies:

Dog Breed and Hair Pollution
Single coat breed = no undercoat/winter coat
Second coat breed = produce undercoat/winter coat

  • Dog breed. The issue of whether hypoallergenic dog breeds exist creates much heated debated between advocates and skeptics and this is covered in greater depth within the section Allergy Friendly Dogs.
    Advocates believe certain breeds exhibit allergy friendly characteristics based upon ‘real world’, albeit circumstantial, evidence from various dog owners, breeders and dog allergy sufferers. Conversely, skeptics raise a number of objections to the idea, for example:
    – It is a biological fact that protein allergens are present in skin secretions, saliva, urine and blood of all dogs.
    – Even though hair (coated with dander/allergens) may be less noticeable on the floor from a low shedding dog, there will still be airborne allergen particles present. These can trigger an allergic reaction through inhalation or by contact when touching surfaces upon which they settle. If fingers are then placed in the mouth, a response can occur through allergen ingestion or alternatively, allergens can be transferred to the eyes or other mucous membranes by touching them.
    – Certain studies have suggested hypoallergenic breeds do not exist e.g. Vredegoor et al. 2012.
    However, there does exist a large group of people who currently take a neutral position i.e. although certain studies have received attention grabbing headlines that appear to be compelling, limitations in those studies and the need for further research mean a consensus of opinion is not possible at present.
  • Dog barking. This aids in the dispersal of airborne allergens.
  • Dog gender. Male dogs tend to disperse allergens more readily than females e.g. possibly by cocking their leg to urinate or through different activity patterns. In addition, they tend to secrete more allergens e.g. Can f1, than either neutered males (castrated i.e. testicles removed) or females. For example, Vredegoor et al. 2012 noted that castration was “clearly associated with lower air levels” of the dog allergen Can f1 and “was associated with reduced Can f levels in hair.”  Interestingly, it went on to say that, shedding, as represented by coat levels, was not different between castrated and noncastrated dogs.”

Human Factors Associated With Dispersal

Although the ‘dog oriented’ points shown above play an important role in determining the outcome of a person’s allergy, issues related to the person themselves are important and represent the other side of the equation. These include:

  • Sensitivity.  The allergy response to dog dander and allergens varies on an individual basis i.e exposure to the same dog will produce different allergy reactions in people allergic to dogs. The role that nature or nature plays in an individuals allergy response is discussed in more depth in the section on Understanding Dog Allergies.
  • Management. How effectively the person manages the condition through prevention and treatment.
  • Possibly their choice of dog (See: Allergy Friendly Dogs).
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