Grass Allergies in Dogs

Your dog gets allergies just like you do, from different foods (corn, grain, fish, chicken, beef) to pollen, dander, and fleas. A grass allergy is caused by the pollen that floats through the air even though we cannot see it. These microscopic spores can be absorbed by your dog’s skin and nasal passages and cause an allergic reaction. In addition, your dog’s fur can pick up pollen, not just from grass but from other surfaces that have grass pollen on them, such as the ground. As a matter of fact, even if you keep your dog inside during the spring and early summer, you can be bringing in the pollen on your clothes, shoes, and body. Some of the signs are scratching, licking excessively, rash, red and oozing skin, and redness and watering of the eyes and nose. If your dog has a severe reaction, it may produce inflammation of the airway (anaphylaxis) and cause a constriction that makes it hard to breathe. Anaphylaxis due to grass pollen inhalation is not well recorded in dogs,  but researchers feel it can be a possible occurrence. Because of this, if you notice your dog sneezing, coughing, and wheezing you need to pay attention and make sure that they are okay.  

Dogs with a grass allergy will have many different signs that can be difficult to diagnose. The scratching and inflammation may be mistaken for fleas, dry skin, or chronic dermatitis when it is actually the grass that your dog is allergic to. These problems can all appear very similarly.  In fact, it is not the grass causing the skin irritation, but the grass pollen. That is why your dog may seem fine during the fall and winter, and is only affected when the pollen is being released from the grass. Even if you get rid of the grass and have a rock garden instead of a lawn, your dog may have signs anyway due to the airborne grass pollen.

Signs of grass allergy may vary, but the most often reported are:

• Bald spots from scratching
• Diarrhea
  
• Excessive licking
  
• Hives
  
• Moist or crusty skin
• Red and watery eyes
  
• Runny nose
  
• Scratching (paws, muzzle, underarms, eyes, ears, anus, groin)
• Sneezing
  
• Snoring caused by an inflamed throat

 Types

All dogs of any species, gender, and age can develop an allergy to grass, but it is more frequently seen in:

• Dogs over three months of age
• Bulldogs
  
• German Shepherds
  
• Miniature Schnauzers
  
• Pugs
  
• Retrievers
• Setters
• Terriers

Grass allergies in dogs are caused by pollen, which is the powdery yellow material that you see all over everything in the spring and summer. This powder is the substance that flowers and grasses put out to be transported from plant to plant by the birds, bees, or wind. There are several ways your dog can be exposed to grass pollen:

• Absorbed through the skin
• Breathed into lungs
• Brought into the house by owners or guests who then pet your dog
• Licking fur with pollen on it

Diagnosing your dog may be hard to do because it seems to be just a general, all-over itchiness and the veterinarian may think it is just dry skin or chronic dermatitis. You should mention to the veterinary team the seasonal differences (if your dog is fine during the winter and fall) so they can consider a grass allergy. The veterinarian will do a complete and thorough physical exam including vital signs, general health, skin and coat condition, and may order laboratory tests. Some of the tests your veterinarian may suggest are a complete blood count, blood chemistry profile, electrolyte level, bacterial and fungal swab, urinalysis, and fecal examination.

Even with a physical examination, the veterinarian may not suspect an allergy to grass because skin afflictions are so common. However, if your dog is fine during the winter and fall, but itchy in the spring and summer, grass could be the culprit. It can also be accompanied by sneezing, coughing, watery eyes, and runny nose, which are not related to chronic dermatitis so be sure to mention these to your veterinarian.

Serum Allergy Test

If you think grass pollen is the cause of your dog’s itchiness, be sure to mention this to your veterinarian and ask for a serum allergy test. This test is done by using a blood sample that is tested  for signs of allergic response. The test results can give you an idea as to what allergens may be causing problems for your dog.  

Intradermal Allergy Testing

This test is done by the dermatologist and costs a little more than other tests, but it is considered to be the most accurate test for topical allergens. In this procedure, your dog will be sedated and they will shave an area to be tested (usually on the side). The dermatologist will use a small needle to inject your dog with different allergens (usually about 50-75 of them) and wait to see if they show signs of inflammation or redness. 

There are many treatments and medications available to help with allergies in dogs, and it will depend on your dog's particular signs as to which medications might be recommended.  Additionally, a special shampoo may be prescribed to decrease the itching and an antibiotic to prevent infection.

Immunotherapy Injections

These injections work like allergy shots for humans, and they are effective but can take some time to work. The veterinarian will show you how to give your dog an injection with a small amount of allergen (grass) daily, adding a bit more each day to desensitize your dog to grass gradually. The problem with this method is that it can sometimes take several months of injections before your dog is fully desensitized. In some cases, it may not completely resolve the signs. Also, these injections can rarely trigger a serious reaction called anaphylaxis, which is a life-threatening emergency. Your veterinarian can provide you with an epinephrine pen (epi-pen) to inject your dog with epinephrine in case this complication happens.

Treating the Skin

Your dog’s skin is the best way to determine allergies, so it is important to get the skin back to normal as soon as possible. A medicated shampoo will help relieve the itching within a few days.

Usually, your dog will show improvement within the first several months, but it can take up to 12 months in some dogs. Immunotherapy does not cure the allergies, but it can make your dog more comfortable and can prevent a secondary infection from scratching. No matter which treatment works for your dog, you have to stick to the regimen for the rest of your dog’s life in order for it to work. If you stop the treatment, the signs will likely come back and they may be worse than before. If you have questions or concerns, give your veterinarian a call right away.