By Dr. Ali, DVM
If your dog has been diagnosed with a dry eye condition known as CSK (Chronic Superficial Keratitis) you may have been prescribed cyclosporine or tacrolimus eye drops.
In some cases, the veterinarian may have suggested purchasing one of these drops and you may be wondering which one is the best option.
This post will help you compare cyclosporine vs tacrolimus eye drops to make the best choice for your dog.
In order to better understand the advantages and disadvantages of both of these medications, it’s important to have a better understanding of why they are used for CSK in dogs.
THE RISKS OF VISION LOSS DUE TO CHRONIC SUPERFICIAL KERATITIS IN DOGS.
CSK is a disorder that occurs on both eyes with symptoms of corneal pigmentation, redness in the eyes, and (in about 70% of the cases according to the Animal Eye Clinic) the third eyelid is also affected.
German Shepherds appear to be most affected by this condition which is thought to be hereditary and can sometimes develop due to increased exposure to UV lights. Dogs tend to develop this condition between the ages of 4 and 7 years of age.

Other breeds predisposed to the disease include:
Australian Shepherd
Belgian Tervuren
Border Collie
Greyhound
Siberian Husky
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CYCLOSPORINE USES
Cyclosporine (brand names Atopica and Optimmune) is an immune-suppressing medication
commonly used to treat atopic dermatitis. It is also used for a variety of other conditions that act on the immune system, like CKD.
It acts by suppressing the immune system of dogs and is used for the:
Treatment of inflammatory diseases of the eyes
Treatment of chronic superficial redness
Treatment of swollen eyelid and cornea
TACROLIMUS USES
Tacrolimus eye drops are also used as immune-suppressing medication. It interferes, or helps to block, a series of biochemical reactions that are caused by t-cell activity.
Cyclosporine vs Tacrolimus – Which is better?
Cyclosporine and Tacrolimus are used to stimulate tear production within the eyes of dogs.
Cyclosporine has been used as a drug of choice for many years and is usually the first-line of defence against conditions like CSK in dogs. Unfortunately, not all dogs respond well to the medication. In that case, the alternative would be Tacrolimus.
Tacrolimus, however, has some limitations and is not recommended in dogs with underlying conditions like:
allergies
fungal infections
viral infections of the eye
ions and electrolyte disturbance
not to be used in pregnant or nursing dogs.
For these reasons, Cyclosporine is considered a better choice.
DOES ONE HAVE MORE SIDE EFFECTS THAN OTHER?
Both Cyclosporine and Tacrolimus are used for long time intervals so that you may observe some unwanted side effects of the drug.
The most notable side effect of Cyclosporine includes gastrointestinal problems such as diarrhea, vomiting, nausea, anorexia and weight loss. It is usually observed after administration of Cyclosporine.
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Less common conditions could include:
Respiratory issues
Gingivitis and papillomatosis
Hyperkeratosis of footpads and nose
Bruising and joint pain
Change in blood glucose level
Liver toxicity
Side effects of Tacrolimus are usually uncommon. But in some dogs, you may observe mild irritation, eyelid twitches, and hair loss around the eyes. Overdose or misuse may give rise to some severe complications such as facial swelling and difficulty in breathing.
Some other side effects could include:
Signs of aversions
Blurred vision
Loss of fur
Discoloration of the fur
Stinging
Burning
ARE THEY SAFE?
Cyclosporine is safe for treating severe dry eye diseases. However, the safety and efficacy of Cyclosporine have not been established in dogs weighing less than 4 pounds or less than six months of age.
It should be avoided or only used cautiously in these patients.
It is prescribed for patients with moderate to severe eyelids eczema, but it is not safe to use for dogs suffering from allergies or any other infection.
WHAT ARE THE INSTRUCTIONS FOR USE
Before administering Cyclosporine, inform your veterinarian if any other medication is being administered because these drugs can interfere with other drugs’ concentration in the blood.
In the case of Tacrolimus, administer your drug to the dog’s eye in the precise amount that veterinarians have prescribed.
Following are the instructions that should be kept in mind while administering the drug:
Do not touch the tip of instrumentation or tube on your pet’s eyes
Do not touch the tube at the side of your finger
Do not miss the dose
If another medication is needed, wait for at least 5 minutes.
Do not administer a double dose
Use a disposable wet cloth to wipe out extra medicine from the face.
Keep it out of reach of kids
If skin exposure happens, wash it using water and soap
Wear gloves to avoid direct skin contact
Do not store in icebox or fridge
If you notice that the color of the medicine has changed, contact the caregiver or do not use it
To discard the medication, remove it from its bottle and mix it with undesirable coffee grounds or litter.
Put the medication sealed plastic bag
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HOW LONG CAN A DOG TAKE CYCLOSPORINE AND TACROLIMUS?
Cyclosporine takes about two weeks to show some improvement in the condition. It may take as long as four to six weeks to see the maximum effects at controlling symptoms.
Tacrolimus is intended to be used for a short period. This medication can take a few weeks before full effects are noted. Gradual improvements are usually noticeable within a few days.
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CONCLUSION
Cyclosporine and Tacrolimus are the two best medicines that are used to treat dry eye or KCS. Both have their benefits and limitations. But Cyclosporine is preferred keeping all aspects in mind.
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Always follow the veterinarian’s advice when choosing the best medication for your dog. It’s not good practice to use outdated medication or to borrow from someone else before having your dog first seen by a veterinarian.
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