Environmental Allergies in Dogs

The following article concerning environmental allergies in dogs will begin with a basic definition of the term followed by a summary of the possible allergy mechanisms involved. When one begins to appreciate the generalized and loose quality of the term itself, the apparent brevity of the sections shown below concerning symptoms, diagnosis and treatment will become self-explanatory. The intent is to minimize the risk of repeating information supplied elsewhere on this site, however, causes (types of allergens involved) and prevention (with relevant examples) incorporate material not included elsewhere, and are therefore covered in greater depth.

Environmental Allergies in Dogs Definition

As we discovered in Most Common Allergies in Dogs, ‘environmental allergies’ is an umbrella term for allergies/sensitive reactions triggered by allergens/irritants present in the environment i.e. one’s surroundings. By its nature, this category of allergies/allergens is ubiquitous and extremely diverse; collectively, they are believed to account for approximately 80% of allergies affecting canines and represent the most common type of allergic disease in dogs.

Understanding Environmental Allergies in Dogs – Hypersensitivity Reactions Involved

The classic allergic reaction involves Type 1 Hypersensitivity (immediate hypersensitivity), although other responses involving Type 2, Type 3 and Type 4 Hypersensitivity (based on Gell and Coombs 4 Type model) can occur depending on the antigen/allergy in question. For example, an allergy to dander or pollen involves Type 1 Hypersensitivity, whereas a chemical-induced cytotoxic reaction might evoke Type 2, Farmer’s lung triggered by inhaled hay dust or mold represents Type 3, and allergic contact dermatitis to latex a Type 4 reaction. Furthermore, multiple reactions may be involved in certain cases, for example Verlinden et al.2007 noted, “Type I, III, and IV hypersensitivity reactions are the most likely immunologic mechanisms” for food allergies.

Further information about the underlying mechanism and processes involved in allergies, as well an overview of the ongoing debate concerning hereditary and non-hereditary factors in allergies, can be found in the section Understanding Dog Allergies.

Environmental Allergies in Dogs Symptoms

Symptoms associated with environmental allergies will be determined by the type of allergy and the individual themselves. They can be impacted by numerous factors such as the route of exposure e.g. airborne, contact or ingested, the genetic traits of the individual, the dog’s age and gender as well as whether an individual suffers from concurrent allergies or is immune compromised e.g. receiving immunosuppressant drugs. Thus, allergy symptom variability means that whilst one dog might experience very mild allergic conjunctivitis/asthma symptoms, another one might develop notable allergic rhinitis and atopic dermatitis; a minority, unfortunately, may even experience life-threatening anaphylaxis.

The section Allergies in Dogs Symptoms provides a comprehensive review of the possible signs and symptoms of canine allergies.

Causes of Environmental Allergies in Dogs – Types of Allergens Involved

Environmental allergies are thought by most people to simply refer to an allergy to dog or cat hair, dust or pollen with associated symptoms including a runny nose, red eyes, wheezy chest and itchy skin. The reality is, however, that the term encompasses a plethora of allergies (with potentially a spectrum of symptoms) that can affect both people and dogs alike, such as those related to:

• Aromatic and atomized particles e.g. air fresheners or car spray paints
• Chemicals e.g. dyes, household cleaning agents or petroleum products
• Cockroaches
• Cigarette or firewood smoke
• Cosmetics
• Dander (and not hair itself) e.g. cat, dog, guinea pig, horse, human, mouse, rabbit, rat etc.
• Dust and dust mites
• Fabrics e.g. wool
• Feathers
• Indoor plants
• Insect stings or venom e.g. ants, bees, hornets, wasps or spiders
• Latex – natural (10% of all flowering plants) or synthetic; commonly associated with natural latex rubber
• Materials/ irritants e.g. cement powder
• Metals and jewelry e.g. aluminum, gold, nickel or zinc
• Mold and mildew
• Perfumes
• Pesticides and insecticides
• Plastics
• Pollen
• Pollution and traffic
• Resins both natural e.g. pine resin, and synthetic e.g. epoxy resin
• Trees
• Water-related e.g. chlorine, copper, lead, fluoride, styrene
• Weeds
• Wood products and treatments e.g. sawdust or preservatives

In addition, because the term ‘environmental allergies’ is so generalized and encompasses an array of allergen types, the possibility for terminological confusion can arise. Such a vast collective can be sub-categorized in multiple ways and as a result, it becomes inevitable that allergy categories that are normally considered distinct e.g. ‘food allergies’, can according to some authorities, overlap and fall within its remit. For example, this may include aspects to do with:

• Airborne/aero-allergens or inhalant allergies
• Contact or skin allergies
• Ingestion or food-related allergies
• Seasonal and non-seasonal allergies
• Indoor and outdoor allergens
• Allergies based on place e.g. home, school or workplace, or geographical location
• Certain medicinal allergies

In this context, as a group, inhalation allergies associated with environmental allergens account for the most common cause of allergies in dogs.

Environmental Allergies in Dogs Diagnosis

Depending on the nature of the allergy involved, diagnosing environmental allergies may involve various skin and blood tests, an elimination diet or even a challenge test. Blood tests for allergens such as dust mites, grasses, molds and weeds are increasingly replacing the need for skin test involving shaving the skin.

The section Allergies in Dogs Diagnosis looks at the various tests and approaches used to help determine the underlying reason for a dog’s symptoms i.e. likely source/allergen involved.

Environmental Allergies in Dogs Prevention

When implemented successfully, preventative strategies aimed at minimizing exposure to environmental allergens have the potential to impact allergy frequency/severity and the amount/strength of any medication required. As shown later, taking control of one’s surroundings involves not only avoiding the allergen itself but also applying other factors, such as aiming to reduce/eliminate items that can harbor, trap or spread them.

Realistically though, some allergens can be more easily avoided than others. For example, it is much easier to avoid a discrete allergen, such as an allergy triggered by a particular indoor plant or household air freshener, than when attempting to tackle widespread allergens exemplified by an allergy to environmental dust or traffic fumes.

Providing a definitive all-in-one checklist of preventative measures that encompasses each and every allergy falling under the guise of environmental allergies is, in practice, virtually unworkable because:

• Even though the majority of common allergies are caused by a relatively small cohort e.g. to dander, dust, pollen etc. there exists literally tens of thousands of possible allergens. The potential for almost any substance to trigger a response (so long as an individual is hypersensitive to it) is illustrated by less well-known allergies/sensitivities, such as those to water (aquagenic urticaria), semen (seminal plasma hypersensitivity), skin pressure (dermatographic urticaria), cold (cold urticaria) or even exercise (exercise-induced anaphylaxis and urticarial).
• For an optimal outcome to be achieved, preventative strategies should be tailored based on both the allergy and individual in question.

Therefore, taking the above into account, we will initially list some general principles underlying allergy prevention and then show possible strategies to tackle a selection of environmental allergies. Supplementary information can be found throughout the various articles located in the section Allergies in Dogs Prevention.

General Allergy Prevention Principles

• Allergy avoidance e.g. if dog has pollen allergy keep it inside when pollen counts are high; if allergic to wool avoid contact with sheep and related products such as clothing/household fabrics ; set physical boundaries – you can control the dogs environment easier and minimize inadvertent allergen exposure etc.
• Reduce allergen load e.g. lower surface allergen levels by frequent wiping; regular foot baths and weekly dog baths reduce dander and other allergens trapped/transported in coat. Using a medicated shampoo can help maintain a healthy skin moisture barrier thereby minimizing the risk of dry skin whilst providing itch relief; use HEPA air filters to reduce airborne allergens etc.
• Reduce/eliminate items that harbor/trap/spread allergens e.g. allergy to cockroaches will require exterminating insects in/around property; remove unnecessary soft furnishing or carpets that trap allergens etc.
• Minimize irritants/aggravators e.g. dogs can be very sensitive to air fresheners, harsh cleaning products, antibacterial/microbial sprays, cigarette/firewood/incense smoke, water contaminants etc.
• Holistic approach e.g. avoid the use of unnecessary antibiotics (gut flora balance issue as well as antibiotic resistance), vaccines (stimulate immune system) and steroids (possible serious side-effects); maintain sensible hygiene for dog; healthy immune system requires both physical and emotional well-being; fatty acid supplements may help reduce inflammation; consider not buying an allergy-prone dog breed etc.
• Communication – Family and friends need to be aware of the dog allergy problem and act appropriately etc.

How to Prevent Environmental Allergies in Dogs – Various Examples

Environmental Allergies in Dogs Treatment

The most appropriate treatment for a given environmental allergy will be determined by both the type of allergy and the allergy response experienced by an individual; it should therefore be highly individualized. This may take the form of conventional allergy treatment e.g. symptomatic (e.g. antihistamines), antimicrobial (e.g. antibiotics) or immunotherapy (e.g. allergy shots), and/or natural allergy treatment e.g. natural symptomatic/antimicrobial/immunotherapy approaches or nutritional and dietary supplements e.g. omega-3.