Egg Yolk Allergies in Dogs

Allergies are not exclusive to humans, and our canine companions can be troubled by them as well. An allergy occurs when the immune system of the body responds aggressively to a perceived threat, in this case, egg yolk. Canines who develop food allergies, such as allergies to egg yolk, can experience itchy and inflamed skin as well as chronic conditions such as ear infections, gas, and wheezing. Although rare, anaphylactic shock may also strike. Dogs who have demonstrated allergies to other foods are more likely to develop allergies to new food sources, such as egg yolk.

Egg are high on the list of likely food allergens for dogs. An egg yolk allergy is an over-reaction of your dog's immune system to the proteins present in the egg yolk.

The symptoms of an allergy to egg yolk could include: 

• Bald patches
• Chronic ear infections
• Chronic gas
• Chronically inflamed feet
• Coughing 
• Face rubbing
• Hives
• Obsessive licking
• Paw biting
• Poor growth 
• Skin infections
• Skin rashes
• Vomiting
• Wheezing

Food allergies can also cause anaphylactic shock in dogs. Symptoms of anaphylactic shock should be considered an emergency and your pet should be rushed to the nearest veterinary hospital. In addition to common signs of an allergic reaction, your pet may also exhibit:

• Cold limbs
• Coma
• Difficulty breathing
• Elevated heart rate
• Excessive drooling
• Low blood pressure
• Pale gums
• Seizures
• Sudden diarrhea
• Sudden vomiting

Types

Often animals that are allergic to egg yolk are allergic to the whites and shells as well. Allergies to eggs are often inclusive of all kinds of bird eggs, including chicken eggs. Egg proteins may be listed several ways on an ingredient list for prepared human or canine foods, such as: 

• Simplesse
• Surimi Trailblazer
• Vitellin
• Whole egg
• Fat substitutes
• Mayonnaise
• Meringue
• Meringue powder
• Albumin
• Lipovitellin
• Cholesterol-free egg substitute
• Dried egg
• Dried egg solids
• Egg wash
• Egg white
• Egg yolk
• Ovalbumin
• Ovoglobulin
• Ovovitelia
• Ovovitellin
• Powdered eggs  

The following products may also have egg in them, and may trigger symptoms to flare up by ingestion or by simple contact. 

• Artificial flavoring
• Antihistamine
• Baked goods
• Immunizations
• Fur garments
• Lecithin
• Natural flavoring
• Nougat
• Pasta
• Photographic film
• Shampoos
• Unwashed printed natural fabrics

Allergies are due to an unwarranted defensive response to a protein that your dog’s immune system considers an invasive substance. It is estimated that around 60-70% of the immune system cells reside within the digestive system. The process of digestion breaks down the food we eat into their smallest parts, which are known as amino acids. These amino acids are then absorbed by white blood cells called enterocytes. When these proteins are not properly broken down during digestion, the enterocytes see them as intruders and launch an attack. Over time the response of these cells to the allergen, in this case, egg yolk, becomes more aggressive, and symptoms intensify.

The symptoms caused by the allergic reaction will prompt your veterinarian to collect skin scrapings from affected areas for cutaneous cytology. Cutaneous cytology is the microscopic evaluation of dermal cells to search for nuisances like mites, yeast infections, or signs of disease. If no underlying cause is apparent, then a food allergy may be suspected. In order to confirm the allergy, an elimination diet is usually implemented to confirm the diagnosis. An elimination diet involves replacing the diet your dog is currently eating with either a reduced ingredient or hypoallergenic commercial food or a diet of bland human food.

When choosing an appropriate replacement diet, all of the ingredients in the dog’s current food should be avoided. In many cases it may be the entire food family that your pet is reacting to, so switching from a chicken diet to a mammalian source such as rabbit may have better results than switching to another avian species like duck. A properly implemented elimination diet will cause the signs of allergy to cease.

It can take several weeks for the elimination diet to reveal that egg yolk is the allergen and during this time your pet may experience lingering symptoms. Use of corticosteroids may ease the swelling and itching of the skin, but they also make it harder to determine the source of the allergic reaction by masking the signs and symptoms.  For this reason, many veterinarians prefer to complete the elimination diet before applying any medications to address the symptoms.

Antibiotics may be prescribed to ward off any secondary skin infections as are commonly seen with food allergies. Once the allergen has been identified as egg or egg yolk, you will want to avoid feeding that ingredient to your dog. If anaphylactic shock symptoms are showing, your pet will be admitted to the veterinary hospital as soon as possible for an injection of epinephrine, as well as for support treatments, such as IV fluids and oxygen therapy.

Allergies to foods like egg yolk are not curable, but the symptoms will dissipate if the allergen is cut from your dog’s diet. Any exposure to egg yolk or egg protein can incite a relapse, so care must be taken with which treats are offered to the canine as well as flavorings agents that may include egg. Unfortunately, if your canine has had an allergic response to one type of food they are more likely to develop an allergy to the ingredients in the replacement diet over time as well. The approach to combat this situation varies within the veterinary profession, with some doctors advocating that your pet remains on a single source of food, while others maintain that a steady rotation of three of four novel protein foods is optimal.