Plant allergies

Many of us are familiar with flea bite or food allergies as potential causes of skin irritation in our pets. But did you know that like us, some pets can be allergic to certain plants?

What causes plant allergies?

There are two ways that plant allergies can occur:

• Atopy – similar to eczema in people, this involves a weakness in your pet’s protective skin barrier, which allows microscopic amounts of airborne plant pollens or moulds to enter their skin. Your pet’s body then develops an allergic inflammatory response to these substances
• Allergic contact dermatitis – this is when direct contact between your pet’s skin surface and a certain plant causes localised allergic skin inflammation

Certain breeds can be more prone to developing atopy, including west highland white terriers, staffordshire bull terriers, golden retrievers, and bulldogs.

What are the symptoms of plant allergies?

Plant allergies commonly cause red, bumpy skin rashes, which are often very itchy. Contact dermatitis tends to affect lightly-furred areas where plants can directly brush against your pet’s skin (such as the paws, belly and armpits), whereas atopy is more likely to affect their face, eyes, ears, paws, belly, armpits and around the bottom.

Affected pets usually scratch these irritated skin areas, and often develop secondary skin or ear infections.

What are some common allergy-triggering plants?

Whilst atopic pets can potentially develop allergies to multiple plant pollens or moulds in their environment, contact dermatitis is more common with certain plants, including:

• Grasses such as Buffalo grass or Kikuyu
• Ground-cover plants such as Wandering Jew, Zebrina, Turtle Vine, Moses-in-a-cradle, Purple Heart, or Inch Plant

How do we diagnose plant allergies?

Unless your pet is very obviously developing symptoms when they walk through a particular type of shrub, or you are able to identify a common “allergy-inducing” plant (as per the list above) in your garden, diagnosis of plant allergies often requires a process of elimination to rule out other allergies or skin disease.

This can involve a thorough flea control program to rule out fleas, a hypoallergenic food trial to rule out potential food protein triggers, and skin tests to rule out parasitic causes such as mites.

Your vet may be able to confirm suspected contact dermatitis allergies by the temporary use of protective boots or clothing for your pet.

Some pets may require referral to a specialist dermatologist veterinarian for intradermal skin testing to check for atopy. This involves injecting tiny amounts of specially prepared plant materials just beneath the surface of your pet’s skin, to check for a reaction.

How can my pet’s plant allergies be managed?

Once your pet’s allergy has been diagnosed, your vet will discuss various options for treatment, which, depending on the severity of your pet’s particular problem, can include:

• Removal of any triggering plants from your garden, and use of protective boots/clothing for walks
• Medications for symptomatic relief of itching – some can be applied topically, whilst others are given as tablets or injections
• Referral to a specialist dermatologist for a course of desensitising vaccines

By working closely with your veterinarian, you should be able to help relieve your pet’s very irritating problem!