Your dog may have been prescribed tacrolimus or cyclosporine to treat an eye condition.
Any medication comes with the risk of side-effects. When a veterinarian makes the decision to prescribe something for your pet, they take into account the risks vs benefits.
Veterinarians tend to prescribe cyclosporine first because of the inherent benefits.
Rather than just producing artificial tears, cyclosporine triggers the secretion of physiologic tears or “real tears”. These tears contain things like growth factors for healing and antibodies for infection control.
If cyclosporine doesn’t produce the wanted effect in dogs with dry eye, the veterinarian may switch to tacrolimus, which is more potent.
In this post, we’ll cover the risks vs benefits of Cyclosporine vs Tacrolimus. We’ll talk about what these eye drops are used for, including any potential side-effects to be aware of.
In addition, will discuss whether there is a substitute for tacrolimus for dogs.
What is the Difference Between Cyclosporine and Tacrolimus?
Cyclosporine and tacrolimus are both used to stimulate tear production in your pet’s eyes. The effectiveness of the drug depends on a number of factors including the individual dog’s condition and medical history.
Cyclosporine – How it Works
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. Oral cyclosporine has been used to treat things like atopic dermatitis in dogs.
This medication works by increased tear production while decreasing inflammation of the eye and tear gland. It has natural anti-inflammatory properties to help sooth inflammation of the cornea. Dogs who respond well to this treatment will likely need to remain on it for the rest of their lives.
Unfortunately, not all dogs respond well to the medication. In that case, the alternative would be Tacrolimus.
Tacrolimus – How it Works
Tacrolimus works by stimulating natural tear production in dogs. It’s a newer lacrimal stimulant that can be compounded in an oil or water solution. The topical use of tacrolimus may be an option if cyclosporine isn’t producing the best results.
Tacrolimus, however, has some limitations and is not recommended in dogs with underlying conditions like:
- Allergic reactions
- Active infections (viral, bacterial, or fungal) of the eye
- Liver disease
- Kidney disease
- Pregnancy or lactating dogs
Understanding Keratoconjunctivitis Sicca (KCS) in Dogs
Dry eye syndrome, otherwise known as keratoconjunctivitis sicca (KCS) is a condition where the dog’s eyes are not able to produce enough tears.
Tears play a crucial role in maintaining the health and function of the eyes.
Without natural lubrication the eyes become dry and uncomfortable. Over time, the eye irritation can lead to pain, corneal scarring, and vision loss.
Eye drops like Tacrolimus or Cyclosporine are vital to reduce inflammation, increase tear production, and reduce the long-term risk of eye damage.
Causes of Dry Eye in Dogs
There are a variety of conditions that can lead to dry eye in dogs. Some of these include:
- Addison’s disease
- Canine distemper
- Certain medications
- Hyperthyroidism (immune-mediated diseases)
- Allergies
- Injury to the eye
- Neurological conditions
- Congenital cause
Breeds Most Susceptible to KCS
Although dry eye is common in dogs, there are some breeds that have a higher prevalence of eye problems in general.
These include:
- English Spaniels
- Yorkshire Terriers
- Pekingese
- Cocker spaniel
- Pugs
- Cavalier King Charles Spaniel
- Lhasa Apsos
- Shih Tzus
- West Highland White Terriers
Clinical Signs of KCS in Dogs
Dry eye is an uncomfortable condition that can leave your dog squinting and pawing at the eyes. The most common signs of dry eye include:
- Sticky eye discharge that clings to the eyelids (yellow or green in color)
- Red eyes
- Conjunctiva appears red and possibly swollen
- Excessive squinting
- Holding the eyes shut
- Corneal ulcers
Diagnosis of Keratoconjunctivitis Sicca in Dogs
To diagnose dry eye in dogs, the veterinarian will conduct a thorough eye exam. A Schirmer Tear Test-1 is used to measure tear production.
To perform this procedure, a small piece of filter paper is placed inside the lower lid of the eye.
After a few minutes, the paper is removed and tested for moisture content.
Treating Keratoconjunctivitis Sicca in Dogs
The most commonly prescribed treatment of KCS in dogs is ophthalmic cyclosporine or tacrolimus. These eye drops help to stimulate tear production. The treatment of choice is usually cyclosporine because is keeps the immune system from harming the eyes.
Medical management of KCS usually involves supporting treatments (eye wash and removal of excess mucus) to improve ocular health while waiting for the cyclosporine or tacrolimus to work. Multiple topical medications may be required in the beginning.
In some cases, dogs require topical antibiotics to treat underlying bacterial infection. Dogs who don’t respond to medical treatment may require surgery known as parotid duct transposition. This procedure redirects the salivary gland from the dog’s mouth to the eyes. This way, the saliva can be used as tears.
Chronic Superficial Keratitis (CSK)
Another serious eye disorder is known as chronic superficial keratitis (CSK). It’s also known as pannus or Uberreiter’s disease.
This chronic inflammatory condition affects the cornea in dogs. Although the exact cause of the condition isn’t known, it’s thought to be an immune-mediated condition.
Breeds Most Susceptible to CSK
This condition is seen in the following breeds:
- German shepherds
- Greyhounds
- Border collies
- Belgian Malinois
CSK, or pannus, can also occur in other do breeds, including mixed breeds, at any age.
Clinical Signs of CSK in Dogs
The signs of CSK in dogs may include:
- Change in eye pigmentation beginning from the outer portions of the eye.
- Reddening of the third eyelid
- Pigment change in the third eye membrane
- Excessive mucus discharge from the eye
Read Next: Why Are My Dog’s Eyes Red? 11 Common Causes
Diagnosing CSK in Dogs
Chronic superficial keratitis is often diagnosed during a routine eye examination. It is usually diagnosed by a veterinary ophthalmologist with eye pressure screening and tear production measurement.
Treating CSK in Dogs
Treatment can involve an aggressive response to help reduce or clear corneal inflammation. Over time, dogs may not require as many treatments once the disease is under control.
Although CSK, or pannus, cannot be cured, some dogs may go into remission. That said, the treatment of pannus is generally for life.
Medications used include topical eye drops or ointments. Either cyclosporine or tacrolimus may be prescribed along with a steroid like dexamethasone. In some cases a steroid injection may be given under the conjunctiva.
Antibiotics may be required if there is a secondary infection.
In severe cases, surgery may be required to remove scar tissue to improve the dog’s vision.
Side Effects of Cyclosporine Eye Drops in Dogs
Ophthalmic cyclosporine drops work by decreasing inflammation to allow for natural tear production.
Side Effects May Include
- Mild burning
- Stinging
- Irritation
- Redness of the eyes
- Eyelid spasm
- Loss of hair around the eye
Side Effects of Tacrolimus in Dogs
Side effects are uncommon but could include:
- Mild irritation when applied to the eye
- Eyelid twitches
- Hair loss around the eye
In rare cases, serious side effects include difficulty breathing, facial swelling, hives, fatigue.
Is Cyclosporine Safe?
Cyclosporine is safe for treating severe dry eye diseases in both humans and animals. It is considered safe and effective when prescribed by a veterinarian.
There are some known drug interactions with cyclosporine which is why it’s important to let the veterinarian know if your dog is on any other medications, supplements, vitamins, etc.
How to Administer Cyclosporine to Dogs
Cyclosporine may be in the form of an ointment or could be compounded into higher concentrations if your dog isn’t responding to the ointment. Typically, the medication would be applied every 12 hours.
Following are the instructions that should be kept in mind while administering the drug:
- Wash your hand before and after administration.
- Avoid contaminating the container tip.
- You may need one person to gently hold the dog’s face while you apply the drops.
- Keep out of reach of other pets or children.
This medication should be stored at room temperature and kept away from moisture, heat, and direct sunlight.
Watch the following YouTube Video on how to apply cyclosporine ointment
How Long Can My Dog Take Cyclosporine or 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.
To Read Next: 11 Reasons for Dog Coughing and Gagging
Is There a Substitute for Tacrolimus for Dogs?
The only substitute for tacrolimus eye drops in dogs would be cyclosporine. If the veterinarian has already tried cyclosporine, and it hasn’t worked as well as it should, tacrolimus would be the only other option.
Over-the-counter products are available to help ease the adverse effects of dry eye. Ask your veterinarian about using artificial tear solutions in conjunction with the prescribed drops.
CONCLUSION
Cyclosporine and Tacrolimus are the two best options for the treatment of dry eye and corneal inflammation.
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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