GoodRx Holdings Inc.
09/24/2024 | Press release | Distributed by Public on 09/24/2024 11:12
Lysine for Cats: A Supplement for Some Eye and Upper Respiratory Infections
Lysine (Enisyl-F, Felisyl, Incremin, Optixcare, Viralys) is a natural supplement that manages symptoms of feline herpesvirus (FHV). FHV is a highly contagious, common viral infection in cats. Its symptoms include eye and upper respiratory infections.
Lysine has few negative side effects and is relatively inexpensive. This makes it worthwhile for pet parents to see if it manages their cat's symptoms.
In this article, we will discuss what lysine is, how it works in cats, and common side effects.
Popular stories this week
Gabapentin for Cats: Uses and Side Effects
Metronidazole for Cats: How Flagyl Works, Side Effects, and More
Prednisone and Prednisolone for Cats: A Complete Guide
If Your Cat Won't Eat, Consider These 10 Common Reasons
Lysine for cats at a glance
Common names
Lysine (Enisyl-F, Felisyl, Optixcare, Viralys)
What it treats
Eye and upper respiratory infections caused by herpesvirus
How it comes (forms)
Powder, paste, tablet, chewable tablet, chews, flavored gel
Common side effects
Loss of appetite, soft stools
What is lysine for cats, and how does it work?
Lysine is an amino acid and a nutritional supplement that helps reduce FHV symptoms, such as eye infections in cats.
We don't know exactly how lysine works to reduce symptoms. But it seems to interfere with arginine, another amino acid. Without lysine to counteract it, arginine reproduces the virus in cats. Keep in mind, your cat needs the right amount of arginine to stay healthy.
Lysine is sold over the counter and does not require a prescription. It's considered off-label because it's not approved by the FDA for use in cats.
Advertisement
Advertisement
What is lysine used for in cats?
Lysine is a dietary supplement that may help manage FHV symptoms. Herpesvirus is a highly contagious, incurable virus that is common in cats. The virus' symptoms include:
Painful conjunctivitis that causes squinting
Eye discharge
Redness in the eyes
Loss of vision (in severe cases)
FHV can also cause upper respiratory infections with sneezing, nasal discharge, and in rare cases, skin ulcers.
Studies on the effectiveness of lysine to manage FHV symptoms showed mixed results. Some studies concluded that lysine is effective, but many other studies suggested it's not. Most of the evidence to support the use of lysine in cats is based on pet owners who say it helps.
How is lysine dosed and given to cats?
The standard dosage of lysine for cats is 400 mg by mouth once daily mixed in with a small amount of food. But a vet may recommend higher dosages given more often.
Lysine is available over the counter, though many veterinarians keep it in stock at their clinics. It comes in several oral forms, including:
A powder that can be mixed with food
Crushable tablets
Chewable tablets
Paste
Gel
Lysine typically takes a few weeks to reach its full effects. But you may notice gradual improvements in your cat's symptoms after a few days.
What are the common side effects of lysine in cats?
Research is mixed on potential side effects. Some research suggests cats may experience gastrointestinal side effects, including reduced appetite and soft stool. If side effects occur, give lysine with food. Some cats may throw up if they swallow a large amount of lysine.
You should give your cat lysine only if they tolerate it. If giving your cat lysine causes stress or loss of appetite, stop the medication and consult your veterinarian.
What are the most serious risks of lysine for cats?
There isn't enough research to fully understand the serious risks of lysine for cats. But researchers point out that lowering a cat's arginine levels too much can cause problems.
Arginine is an important amino acid for your cat's well-being. Because lysine may lower arginine, it could cause a condition called hyperammonemia, which is when there's too much ammonia in your cat's blood.
Symptoms of this life-threatening condition can include:
Lethargy
Circling
Head pressing
Blindness
Seizures
Coma
Does lysine interact with other cat medications?
Lysine has very few drug interactions. Use caution when the following medications are given at the same time as lysine:
Arginine (may interfere with lysine absorption)
Calcium supplements
Be sure to tell your veterinarian about all medications, vitamins, and supplements that your cat takes before giving them lysine.
What should you do if your cat misses a dose of lysine?
If you miss giving your cat a dose of lysine, give the next dose as soon as you remember. Then resume the regular dosing schedule the next day. If it is close to the time of the next dose, skip the missed dose and give the next dose at the regular time. Never give 2 doses at the same time to catch up.