Can Dogs Use Human Eye Drops for Allergies?

Can Dogs Use Human Eye Drops for Allergies?

 If you've ever had one of those days where your dog is fine one minute, and the next minute, you're on Google trying to diagnose the crustiness around its eyes, then you've probably had to resist the temptation to reach into your medicine cabinet for your eye drops to administer to your dog. 

You should never use human eye drops on your dogs without consulting a vet. Although the active ingredient in human eye drops might be the same active ingredient found in dog eye drops, some compounds found in the solution for humans may be toxic to dogs. 

Remember, you shouldn’t take any chances when it comes to your pets. Even if your friends have done it to their dogs and turned out fine, the risks are not worth taking, and you should always seek the expertise of a veterinarian before making those calls. This article will take a deep dive into the science behind dog allergies and why dog owners should abstain from trying treatments on their dogs that are not formulated or approved for pets.

The Pathophysiology of Allergies in Dogs

Allergies happen when the dog's immune system develops hypersensitivity to a substance it usually tolerates. Allergic responses never occur upon first exposure to an allergen. The immune system creates antibodies against the allergen over a period of days, months, or even years. 

By the time this sensitization process is mounted, subsequent exposures to the allergen will trigger an overreaction by the immune system. The severity of allergic reactions may vary and worsen with each exposure. 

Causes of Allergies in Dogs

The usual culprits in allergic reactions in dogs can be found in everyday things that the dog may have had frequent exposures to in the past. Identifying the cause of the allergies may be challenging. You will need the guidance of your vet to diagnose the allergies.

Common causes of allergies in dogs are:

  • Proteins of insects, plants, or animals
  • Chemicals found in household or pet care products
  • Pollens, mold spores, dust mites, shed skin cells
  • Flea saliva and some insect bites
  • Some medications

Eye Allergies in Dogs

This article will look more closely at eye allergies in dogs and what you can do about them. The first clue that your dog might be having an eye allergy is redness in either one or both eyes. If the redness is acute and happens after playing with other dogs, or being out in the yard, it might simply be an irritation. But if the redness doesn’t go away, It’s time to consider another underlying cause. 

Inflammation of the eye that is caused by allergens such as pollen and mold is known by its medical term “allergic conjunctivitis.” Dogs with dermal allergies are more predisposed to developing allergic conjunctivitis than the general population. Here are other signs of allergic conjunctivitis to look out for in your dog:

  • Pawing at the face
  • Squinting of one or both affected eyes
  • Discharge from one or both eyes
  • Crustiness around the affected eyes
  • General discomfort

Allergic Conjunctivitis

If you suspect your dog might have allergic conjunctivitis, take it to the vet for medical evaluation. The vet will either confirm the diagnosis or rule out allergic conjunctivitis. If your dog has had a history of itchy skin, it’s worth mentioning it to your vet as this can guide them in their assessment of your pet. 

Predisposing Factors

As mentioned above, dogs with a history of skin allergies are more predisposed to developing allergic conjunctivitis. Other than their history of existing dermal allergies, other predisposing factors include age and breed. 

  • Age - Allergic conjunctivitis commonly arises in dogs under three years of age, although it can occur in any dog of any age. 
  • Breed - Although any breed could develop the condition, it has been found that certain breeds are predisposed to developing allergic conjunctivitis:
  • Boxer
  • Cocker Spaniel
  • French Bulldog
  • German Shepherd
  • Golden Retriever
  • Labrador Retriever
  • Poodle
  • West Highland White Terrier


A vet will employ several diagnostic tests to confirm or rule out a diagnosis of allergic conjunctivitis on your dog. In instances where the tests are inconclusive, the vet will resort to a process of elimination to arrive at a diagnosis. Some of the tests the vet might perform are discussed below.

  • Conjunctival Cytology - This test will reveal the presence of inflammatory cells in the conjunctiva, confirming a diagnosis of allergic conjunctivitis. Although this test is reliable, there are times when the cells are not present or are undetectable to the test. 
  • Process of Elimination - If conjunctival cytology is inconclusive, your vet might proceed to run other tests to check for other underlying causes of the inflammation. Eye infections, dry eye, or corneal ulcers can also cause inflammation of the eye.
  • Biopsy - When all other tests fail, the vet might opt for a biopsy of your dog’s conjunctival tissue. The specimen will have to be obtained while your dog is under sedation with general anesthesia. However, these are rare cases. 
  • Conjunctival Provocation Test - A new test called the conjunctival provocation test shows the potential of being a definitive tool in diagnosing eye conditions. However, further research is needed to establish it in veterinary practice. 

Treating Eye Allergies in Dogs

The treatment of allergies is vital to restoring your dog's overall well-being. Allergic responses can trigger inflammatory processes. When this state of inflammation is chronic, other health problems may arise and lead to complications. 

Identify the Allergen

The first step in treating allergies is to identify the allergen. Identifying the allergen enables you to avoid or minimize your dog's exposure to it. Stopping exposure to the allergen will cause the allergic reaction to subside. This will bring relief to your dog. Identifying allergens is not easy. You will need the expertise of your vet.

Start Anti-Itch Therapy as Prescribed