A Shih Tzu can be allergic to a wide range of allergens. However, these can be placed into 3 main categories:
1. Food Allergies
- It is often additives in dog food that cause a problem. And far too many brands are guilty of adding these. This includes chemical preservatives and artificial coloring dyes. Other triggers include wheat, corn, or soy.
While it is rare, dogs can be allergic to such things as eggs or even a certain protein such as chicken (normally very well tolerated).
2. Environmental Allergies- This includes airborne allergens such as seasonal pollen, weeds, and grasses. This is not just a summertime issue; seasonal allergies can start in the springtime, and ragweed is a top trigger in autumn.
There can be year-round allergies due to indoor triggers, most notably dust mites and their droppings. A half of a teaspoon of dust contains up to 1,000 mites and over 25,000 droppings, which dogs can also be allergic to.
Finally, such things as cleaners or air freshener sprays that are used in the house can contribute to a Shih Tzu's allergies.
3. Contact Allergies
- This is the least common type of allergy with dogs, but should not be ruled out. This refers to something that a dog is coming into physical contact with. High on the list are plastic bowls. But, this could also include carpeting, and fabrics such as bed linens. In some cases, even rubber toys can cause an allergic reaction.
In most cases, there will be a localized skin reaction on the area that touches the allergen element. For example, with bowls this will often be on the nose, and may be around the mouth. If a Shih Tzu is allergic to carpeting or even laundry detergent that used to wash throw rugs, a dog bed cover, etc. there can be a full body rash.