Leaves Allergies in Dogs

Although spring is usually the season most commonly blamed for seasonal allergies, many allergies occur in the fall as well. One of the most common sources of fall allergens are the piles of dead leaves that gather on the ground during the autumn months. The piles of leaves that gather together in the fall also collect pollen from other plants and provide a hiding place for nuts, molds, and insects that can trigger an allergic reaction in sensitive individuals.

Piles of leaves in the fall months can lead to allergic reactions from several possible sources. Animals with allergies should avoid contact with the fallen leaves.

Dogs with allergies may have many of the same respiratory symptoms that you see in humans, but the skin reactions are generally more noticeable. Dogs who develop symptoms of seasonal or environmental allergies typically start showing symptoms when they are between one and three years old, and symptoms generally intensify with each exposure. 

• Asthma symptoms
• Bumps
• Chewing on affected areas
• Coughing 
• Ear infections 
• Hair loss 
• Itching 
• Nasal congestion
• Obsessive licking
• Red and itchy eyes 
• Redness
• Scratching
• Shortness of breath
• Sneezing
• Thickened skin
• Ulceration of the skin

Types 

Allergens that may be found in piles of leaves can include:

Insects - The leaf piles of autumn are also a host to a large number of insects. Bugs like fleas and ticks can cause a skin rash if they bite or sting the host. Anaphylactic shock is sometimes caused by insect bites or stings.

Molds and mildews - Molds and mildews can be highly allergenic to sensitive canines, and leaf piles are the perfect place for them propagate.

Nuts - Nuts and acorns are often found in leaf piles that are raked together in the fall. If your dog is sensitive to the proteins in the nuts they will have an allergic reaction if they ingest the fallen nuts.

Pollen - Pollen from the trees themselves are often still stuck to the leaves, and plants like Ragweed also tend to release their pollens in the autumn. The pollen can then get into the pile of leaves, triggering a reaction when encountered.

Many animals, human and otherwise, develop allergies during the spring and fall. Allergies are the aggressive response of specialized immune cells in the body to a protein that it views as a threatening invader. The specialized cells the body uses to protect the body from intrusion are called mast cells, and they release histamine when the immune system is stimulated by specific allergens. The itchy and inflamed skin conditions characteristic of most allergic reactions in canines is caused by the histamine, which has an inflammatory effect on any of the tissues that it comes into contact with. When the cells in the sinuses and eyes are affected by the irritant, the symptoms of a runny nose and sneezing are activated.

A complete health history and timeline of the symptoms can be particularly useful in diagnosing seasonal allergies. The description of the disorder and the condition of the skin during the physical examination will usually prompt your veterinarian to get a skin scraping for cutaneous cytology.  Cutaneous cytology, the examination by microscope of the harvested skin cells, is a  technique that can be used to identify biological organisms that may cause similar symptoms such as mites, fungi, or bacterial infections. General tests are often done at this time as well, to rule out disorders like chronic bacterial illness, hypothyroidism, or even imbalances in blood chemistry.

The timing of the symptoms combined with the results of these tests may give an initial indication of either seasonal allergies and an intradermal skin test, also known as a patch test, will often be done at this time to pinpoint the individual allergen or family of allergens. In this test, tiny amounts of the suspected antigens are injected under the skin to induce a localized reaction for identification. Blood may be drawn to check the reaction of the allergens directly to the blood, but with environmental or seasonal allergies this technique is usually only employed if the patch test is unable to be administered, due to skin damage or other unusual circumstances.

Hydrocortisone shampoos and salves are often applied to relieve swelling and irritation on the skin, but the ingestion of hydrocortisone can cause gastric distress, so your pet needs to be monitored to ensure they don’t lick the hydrocortisone off. Antihistamines are only effective for approximately twenty to thirty percent of our canine companions to start, and their effectiveness often fades as canines develop a tolerance to them. Medications such as corticosteroid oral tablets or injections are usually very effective in reducing the allergic signs, but they do have some serious side effects so are only recommended when milder treatments fail. In short-term therapy with corticosteroids the symptoms generally stay fairly mild, ranging from increased thirst to diarrhea. The long-term side-effects can contribute to much more critical disorders such as diabetes and liver dysfunction. As these developments are often dose dependent, the lowest effective dose should be used, and ongoing monitoring of blood chemistry levels may be required in situations necessitating the long-term use of corticosteroids.

When allergens are unavoidable, injected immunotherapy may be another option. This is especially effective with reactions that are present for at least four to six months of the year and are resistant to antihistamines. An intradermal test will first need to verify the active allergens so that an injection can be prepared with altered antigens specifically designed for your pet’s condition. This personalized formula is injected into the patient on a weekly or monthly basis, desensitizing them to the allergen. This method of treatment is time consuming and expensive, however, it has a very high success rate, especially in younger dogs.

Seasonal allergies can be hard to avoid, and the temptation to play in piles of leaves is very inviting for most pets. If you or your pet are prone to allergies, it would be best to remove any piles of leaves promptly, before any molds or mildews can infest it. If your pet has been playing in piles of leaves, it is a good idea to give them a bath to remove any allergens from their skin. Your canine companion should be watched carefully for signs of allergic distress as signs and symptoms can sometimes be delayed by several hours.