Nickel Allergies in Dogs

Nickel is a trace mineral that helps the body absorb iron both in humans and their canines. It is found naturally in many foods, such as peas, grains, soy, and shellfish. Nickel is also incorporated in many day-to-day products which can cause an allergic dermatitis rash in animals with allergies to nickel. Nickel is found in may stainless steel products, including dog dishes and collars. Surgical stainless steel usually has a negligible amount of nickel, but if your animal has an allergy to nickel and requires surgery, it is important that the surgeon is made aware of the allergy.

Nickel can cause either contact allergies from touching something with the metal in it, or food allergies from the inclusion of this mineral in foods.

Dogs with contact allergies will have outbreaks at the site of contact and sometimes around the face and groin area and the pads of the paws as well. Symptoms of allergies tend to get more dramatic with each subsequent exposure. Food related allergies may include nausea, vomiting, and diarrhea along with the other symptoms of an allergic response, which can include: 

• Bumps
• Chewing on affected areas
• Coughing 
• Ear infections 
• Hair loss 
• Itching 
• Nasal congestion
• Obsessive licking
• Oozing sores
• Redness
• Scratching
• Thickened skin
• Ulceration of the skin

Types

Food allergy - A food allergy is a response by the portion of the body’s immune system that is located in the gastrointestinal system to defend itself against a threat. An allergic reaction doesn’t happen the first time an individual is exposed to the allergen but rather after repeated exposures. Any ingredient is capable of causing an allergic reaction, but some foods, such as beef, chicken, dairy, and eggs tend to cause allergies in canines more often than others.

Contact allergy - Allergies in canines are the defensive mechanism of the immune system which employs specialized immune cells in the dog’s body to defend it against an amino acid that it has labeled as an invader. The specialized cells the body employs to protect the body are known as mast cells, and when the immune system is stimulated by the amino acids, known as allergens, the mast cells release histamine into the animal’s system. Histamine has an inflammatory effect on any tissues that it comes into contact with. The inflammation is what causes the itchy and swollen skin conditions characteristic of most allergic reactions in canines.

Nickel can be introduced to your pet’s environment or diet in several ways. Typical vectors for metal related contact allergies in dogs can include dog collars, food and water bowls, metal walkways and metal fences. Less common causes for nickel allergy reactions can include veterinary or identifying tattoos and some fabric dyes. There are many different foods that are naturally high in nickel and  could trigger dietary allergies in your pet, such as shellfish, chickpeas, and oatmeal. Nickel can also be introduced into your dog’s diet if it leaches into their food from metal containers, particularly with wet canned foods.

The skin’s condition during the physical examination will most likely prompt your veterinarian to collect a skin sample.  This skin sample will be used for a procedure known as cutaneous cytology which is the microscopic examination of the harvested skin cells from the affected areas. This procedure can be used to identify organisms that can cause similar symptoms to allergies. These could include issues such as mites, fungi, or even bacterial infections. Conventional blood testing, including complete blood count tests and biochemical profiles, are often completed at this time as well. This will help to rule out disorders like chronic bacterial illness, hypothyroidism, or even chemical imbalances in the blood. 

The results of these tests combined with the timing of the symptoms may give an initial indication of either a contact or food allergy. If a contact allergy is suspected a patch test, also known as an intradermal skin test, will often be done to pinpoint which allergen or family of allergens is causing the distress. If the allergy to nickel is related to dietary intake, an elimination diet will be implemented to reach a definitive diagnosis.

Once a definitive diagnosis of nickel allergy has been made, the most efficient treatment is avoidance. Nickel is a commonly used component to many metal alloys and is also a common dietary component as well, which can make avoidance more difficult than it might at first sound. If your allergic canine comes into contact with nickel, there are some ways that you can minimize the discomfort your pet experiences. 

Adding omega-3 rich supplements or foods to your canine’s daily regimen, as well as healthy probiotic, may help prevent the skin reactions from getting debilitating by improving the overall skin health of your pet and supporting the immune system. Corticosteroids may be recommended by your dog’s doctor to reduce the swelling if a reaction occurs, as well as antihistamines to calm the itching. Secondary skin infections quite common with canine allergies and antibiotics may be prescribed to combat this dangerous development.

Dogs that develop an allergy to nickel are somewhat predisposed to developing additional allergies, particularly to other metals or minerals. Although contact and food allergies to nickel often occur in conjunction with each other, it is not always the case. Unfortunately, if your canine has developed an allergy to one type of food, they are more likely to develop an allergic reaction to other ingredients as well. The approach to combatting this situation varies within the veterinary profession, with some doctors recommending that your pet remain on a single source of food, while others maintain that a rotation of three or four novel protein foods is optimal.