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

A complication of many pet allergies is secondary infection. This is especially concerning with eye allergies, as your dog’s scratching and pawing could injure the eye. Dogs will scratch and bite themselves to relieve the itchiness. Your vet will order either oral or injectable anti-itch therapy to block itch pathways in your dog.

Give Antihistamine Medications

Antihistamines are not usually prescribed for itching. They are prescribed for sneezing and runny eyes. Many regrettable instances of wrongful application of human medications to dogs occur under these circumstances. Some pet owners assume that their antihistamine eye drops will have the same effect on their dog to the detriment of their pet. 

Dangers of Using Human Treatments on Dogs

Some substances or compounds that are harmless to humans can be toxic to dogs and found in everyday products. The rule of thumb should be to always consult the vet before giving anything to your dog as a treatment. Examples of some substances that are harmless to humans but potentially deadly for dogs can be found in human eye drops.

Human Eye Drops

Naphazoline is a decongestant that relieves puffiness, watery eyes, and allergies. It is found in human allergy medications, including eye drops. However, when ingested or absorbed through the ophthalmic route, it can cause a dangerous reduction in heart rate, even in small amounts. Brimonidine, found in glaucoma medications for humans, also has the same effect.

Even though the pathophysiology of allergies or glaucoma and many other diseases are quite similar in humans and dogs, the treatments are very different. Active ingredients may be the same, but there are some compounds in the solution that can cause harm to your pet. This is why seeking a vet's expertise is always the best action to take.

What You Can Do for Dogs With Eye Allergies

I get it. The impulse to reach for a quick fix to your dog's problems arises from a natural need to protect it, comfort it, and relieve it from whatever is causing it distress. However, many well-intended home treatments for dogs have ended in tragedy. Here are ways to avoid the pitfalls that many pet-owners have fallen into.

Always Seek the Expertise of the Vet

When it comes to our dogs, anecdotal evidence isn't always valid. Your friends may assure you that giving your dogs human eye drops worked out fine for their dogs, but this does not mean the same will be the case for yours. It isn't like trying out a cure-for-all chicken soup recipe. Human medications can have additives that are harmful to dogs. 

Pharmaceutical companies update their formulas. So when a friend tried the eye drops on their dog, it might not have contained any compounds that could be harmful to dogs. But the same medication from the same brand with the same label and packaging may have differences in solution if you buy a more recent batch. 

The expert advice of a vet cannot be substituted by anecdotal evidence when it comes to your dog's health. Verify the information you find online. Be skeptical when the information is not science-based. If there is any information online that you find compelling, run it by your vet first. If you wouldn't try adult medication on a child, the same logic should apply to your pets. Always.

Always Be Prepared

If you have a dog living with allergies, especially multi-seasonal allergies, always stock up on medications so that the temptation to give it human eye drops will never have to occur to you. Saline washes, antihistamine eye drops, and other vet-approved medications should always be on hand. 

Be Compliant With Treatments

If your dog is following a treatment regimen, strict compliance is vital for the medications to take effect. Having a dog undergoing aggressive treatment can be very stressful for both you and your dog, but compliance will significantly increase the chances of resolving the health problem. This will save you many vet appointments and spare you from the heartache of watching your dog suffer from a chronic condition. 

Invest in Quality Pet Care Products

If your dog has a chronic allergy, chances are you'll be making a lot of trips to the vet, which means your dog will be spending a ton of time in the car. Dogs with allergies tend to shed more than healthy dogs. 

Spare yourself the backache of scrubbing fur out of your car upholstery and invest in a quality car seat cover or cargo liner for your dog. Their waterproof, non-porous material will prevent fur from sticking to it. And just like that, your life can be a lot easier.

Choose Quality Over Affordability

There are many over-the-counter medications on the market that are substandard and poorly regulated. They may be a little lighter on the pocket, but they could lead to more expenses because they lack efficacy. Their lack of efficacy will lead you to hop from one brand to another.

To stay out of this cycle, opt for quality over affordability. It is more cost-effective in the long run. Determine the quality of a product with thorough research. If you're buying online, consider these quick tips to avoid buyer's regret:

  • If you're buying from an online store, look up the brand. They should have a legitimate website. Be skeptical of brands with nothing more than a Facebook or Instagram page.
  • Read the reviews. They are telling. When trying to determine the quality of the product, do not only look at reviews of the product you intend to buy. Look at the reviews of their other products. 

Using the same example, read the reviews for our car seat covers. Even if you aren't looking to buy a car seat cover or cargo liner from their brand, the reviews are illuminating as it gives you a broader picture of the brand's overall quality. The reviews of the other products will bolster your confidence in their therapeutic eye drop. 

Some brands can have one good product, with the rest of the catalog lacking. When you encounter brands with only one highly rated product and the rest poorly reviewed, move along to another brand with more consistency. 

Final Thoughts

Having a dog living with allergies can be a challenge. With the help of your vet and the right treatments, the condition can be overcome or managed so that your dog can still live its best life. Acquaint yourself with brands and products that have your dog's best interests at heart.

Visit our site and check out their premium car seat covers and pet health line to start you down the right path. Keep an eye out for their up-and-coming products that will give you value for your money and satisfy both you and your dog. 

Plush Paws: Premium Pet Products
Rau Animal Hospital: Allergies In Dogs: What You Need To Know
Pet MD: Dog Eye Allergies: Symptoms & Treatments
Cuteness: Use of Allergy Eye Drops in Dogs
All About Vision: What Eye Drops Are Used for Dogs?
APCA: Pet Poisons That Can Be Lurking In Your Purse or Bag
Wag Walking: Are Visine & OTC Eye Drops Safe for My Dog?
MSD Manual: Allergies in Dogs
VCA Hospitals: Allergies in Dogs

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