Cyclosporine is a treatment that many people won’t have heard of. It was first used in humans to prevent rejection after an organ transplant. In veterinary medicine, it is used for two main purposes – to reduce inflammation and to suppress the immune system. The main forms of cyclosporine used in cats and dogs are oral (capsules or liquid) and a topical eye treatment.

Table of contents

What is it used for?

The oral form is licensed for use in the UK for specific types of canine and feline allergic skin conditions. These conditions can cause signs such as severe itching, sores, hair loss, and redness of the skin. Cyclosporine works by reducing the inflammation that contributes to these symptoms. It is often used as a second line medication – this means that it is used in patients where the more commonly used treatments aren’t effective or cause too many side effects. In most patients it takes around 2-4 weeks to work. Subsequently, if no improvement is seen after this time, then your veterinary surgeon may suggest further tests. These might include a blood test to check if the dose of medication your pet is on is high enough. If the treatment is effective it will often be used long term.

Cyclosporine is also used to treat certain autoimmune diseases. Autoimmune diseases occur when the immune system malfunctions and attacks a part of the animal’s own body. The signs an animal might show vary depending on which organs are affected. Immune conditions affecting the gut, skin and blood cells will sometimes be treated with cyclosporine. For these types of disorders, the drug is often used at higher doses than for allergic skin disease. 

How safe is it?

Cyclosporine is considered to be a relatively safe drug. The most common side effects are vomiting and inappetance. These are most commonly seen at the start of treatment, especially with higher doses. Any vomiting usually settles quickly. In patients where it continues, a dose reduction or giving the medicine with a small amount of food may help. Freezing the capsules and giving them frozen has also been reported to be effective. Occasionally cyclosporine has been shown to cause swelling of the gums. Rarely, and often at the higher doses, the immune system may be suppressed too much. This can leave the patient vulnerable to infections, which they will find harder to fight. In addition, this suppression of the immune response also means that if a treated pet was to develop a cancerous growth, the immune system might be less able to fight it off.

What dogs or cats shouldn’t receive it?

There are some patients that cyclosporine treatment is not suitable for. The manufacturers advise that it is not used in animals less than 6 months of age or 2kg in weight. Secondly, animals that are suffering from or have a history of cancer should not generally be treated with cyclosporine. It should not be used in breeding, pregnant or lactating animals. Your vet will want to rule out and treat any current infections before starting treatment with cyclosporine. Cats should be tested for exposure to a disease called toxoplasmosis and for infection with FIV or FELV before treatment is started. Cyclosporine can also affect blood sugar levels and its use is not usually recommended in diabetic animals. 

What about the eye drops?

The second UK licensed form of cyclosporine for veterinary patients is an eye medication. This is licensed for treatment of Dry Eye (Keratoconjunctivitis sicca or KCS) and Pannus (Chronic superficial keratitis). In the most common form of KCS the immune system is triggered to attack the tear glands, damaging them and reducing tear production. Treatment with cyclosporine suppresses this immune attack and also seems to have a direct action that increases tear generation. Cyclosporine medication should generally not be used if there is an infection present in the eye. Again, if effective, it will usually be prescribed for long term use.

Cyclosporine is a very powerful and useful medicine

In the UK it is licensed for the treatment of specific skin and eye conditions but can also be used for other diseases under certain circumstances. It can only be obtained with a prescription from your veterinary surgeon, and they are the best people to advise on whether it might be a suitable treatment for your pet.

You might also be interested in: