Interview with an Expert: Herpes Eye Infections in Cats

Recognizing, treating and preventing herpes eye infections in your cat.

cat with eye infection

Fiona, a Scottish Fold and one of our five cats, has had eye problems since she was a kitten. She was diagnosed with the herpes virus two years ago, and after some treatment was fine for over a year. Recently I noticed that she was blinking and squinting on a regular basis, so I took her back to the vet. We talked through a range of possibilities before the doctor decided that she was again suffering from symptoms caused by the virus.

Thankfully, Fiona is doing very well after a number of weeks on special eye drops. To learn more about this feline condition, I contacted Dr. Daniel J. Biros DVM, DACVO, a board-certified ophthalmologist at Angell Animal Medical Center in Boston. Below is some information he shared about herpes eye infections in cats. What exactly is a herpes virus eye infection, and how prevalent is it in kittens and cats?

Dr. Biros: Feline ocular herpesvirus, or FHV-1, is a very common virus in cats. While it is thought that most cats (over 90 percent) harbor the virus, only a small percentage of cats actually show clinical disease. These cats are usually immunosuppressed from stress or disease, or they may harbor a more virulent strain of the virus. Is it true that pure-bred cats born in catteries are more likely to have these infections?

Dr. Biros: To my knowledge there is no breed predisposition to cats with FHV-1. Catteries often have problems with FHV-1 due to a high level of cat-to-cat contact, thereby creating the greater likelihood of pathogen transmission. What are the symptoms?

Dr. Biros: Clinical signs are variable and may be mild to severe. Mild squinting, runny eyes, and conjunctivitis are mild generalized ocular signs consistent with FHV-1. More severe signs may involve changes in the cornea such as cloudiness or redness. In severe cases there may be vision impairment, a marked increase in tearing, and squinting. Ocular herpes can be very painful and if untreated could lead to vision loss or loss of the eye in the most severe infections. There may also be upper respiratory signs, such as a runny nose, sneezing, or nasal surface ulceration. How is it determined that a cat has the virus?

Dr. Biros: Diagnostic tests are difficult at best to determine if a cat has FHV-1. A fresh and properly prepared sample of the cat's conjunctival or corneal cells may yield evidence of virus based on a molecular screening test called a PCR (polymerase chain reaction). Viral cultures are rarely done and not necessarily practical in a clinical setting. Most cats are treated based on the history and clinical signs. Often if a superficial linear, or dendritic (branching or lightning bolt shaped), corneal ulcer is noted on the clinical examination, there is a high likelihood of FHV-1 being present. Ulcers on the cornea if present are not exclusively linear and may be geographic, covering a variable area of the corneal surface. Once a cat is infected, is the condition ever cured?

Dr. Biros: There is no cure for herpes virus. It can be driven into remission but never cured. We had a cat that was diagnosed with this condition, but at one point the veterinarian was having trouble distinguishing between symptoms of the herpes virus and a possible allergy or bacterial infection. Is there a difference between the symptoms?

Dr. Biros:: Not always. The symptoms are often similar. Chronic ocular surface inflammation from one cause or another can appear very similar. In severe cases, herpes infections may also acquire a bacterial or dry eye component complicating the situation and causing more damage to the ocular surface. What are the treatment options for a herpes virus eye infection, and does treatment have to be long-term?

Dr. Biros: Treatment is usually a combination of medicine to address the virus specifically, medicine to provide lubrication and antibacterial protection, and in some cases, medicine to manage the pain of the outbreak. Usually there is a combination of oral and topical medication. Surgery to repair a damaged eye is indicated only in the most severe cases. Treatment is often long-term, and for most cats is recommended up to two weeks beyond resolution of clinical signs. When to stop or change treatment should be left up to the veterinarian managing the disease. When giving a cat eye drops, is there anything important to know about how to give the drops or keeping the drop bottle clean?

Dr. Biros: Most eye medication is sterile when opened, but once opened the tip of the bottle is likely to get contaminated at some point. Avoiding contact with fingers, the ocular surface or eyelids when applying the medication will reduce the risk of dirtying the tip of the bottle or tube. Often if you can point the cat's nose to the ceiling and then spread the eyelids open it is easier to apply drops. Ointments can be best applied between the inside of the lower eyelid and the ocular surface or on the top of the eye after manually raising the upper eyelid. There is no specific proper way to deliver the medication, often it is whatever works best for a given cat and client. Is the condition contagious between cats, or between cats and humans or other species?

Dr. Biros: None of the common infectious ocular surface diseases in cats can be passed to other species including humans and vice-versa. On the other hand, cats can easily spread FHV-1 to other cats through nasal and ocular secretions, especially during an outbreak. Are there preventive measures that can be taken to either avoid infection in the first place, or recurrence of symptoms after treatment?

Dr. Biros: A low-stress environment, good nutrition and health, and in some cases, some degree of ongoing medication can all contribute to reducing or altogether eliminating outbreaks. Where can cat lovers learn more about this condition?

Dr. Biros: Your primary care veterinarian can provide you with more detailed information on FHV-1. The internet can also be a good resource for additional help on the topic. Specifically, Web sites that are linked to veterinary ophthalmology practices will provide the most helpful tips and information.

It's good to know our little Fiona has a condition that, although life long, can be managed. Hopefully we can avoid any future outbreaks -- but we'll be "keeping an eye on her" for any future symptoms!

Faye Rapoport DesPres writes about pet care issues for and other publications. She has five cats and a website at

Like this? Get more. Sign up for the latest articles, news and tips of your choice. All delivered weekly to your inbox.
Enter your email address:
Comments (21)
My Siamese shelter kitty had red around the eyes but no other signs. She is very active and eats like a horse. I believe she was born with the herpes virus. She liked to get on the bed and kiss me on the mouth and though most every source tells me I can not get the herpes from a cat, my pharmacist said I could and I have a fever blister and flu like symptoms for 3 weeks or more. And My 13 year old daughter has gotten bouts of ring worm since we adopted the Siamese. I use Tinactin cream ( drugstore)for ring worm and it goes away in a week or so. My other cat who is 13 spit up yesterday and began to sneeze and looked a little like he was not himself. I think that the Siamese infected him, too. I am not sure what to do I love my cats and the children adore them but like to kiss them and I don't want to put my children at risk with the cats--I am not sure what to do. I heard that human lysine can have heavy metals and is not good for cats better to use cat lysine or maybe get human lysine from the health food store,( no heavy metals??)
Posted: March 27, 2014 at 9:22 AM
i have had my rescue tortie for 10 years. she was in a terrible state when i got her, obviously had had much stress as was missing a leg and lost most of fur. her fur grew back after lots of TLC but had lots of itchy skin problems so i had a food tolerance check done on her and found i was harming her by feeding her chicken now and again... the results of the test showed she was allegic to just about everything. so for 6 years now she has been on Hills ZD low allergen and loves them! skin all healed... i give her a treat now and again(no chicken!) but mainly its those biscuits.
my vet thinks she has the herpes virus, as her eye has an outbreak every couple of years...just clearing up for the 2nd time... he rubbed the cornea (ouch) to disperse the ulcer and she has had a month of drops Fucithalmic... touch wood all looking much better. but i do think you need a vet that knows what they are doing re cats. and dont just diagnose and treat by yourself!!
Posted: December 29, 2013 at 11:21 AM
My 10 yr. old cat Morandi and my 2 yr. old cat Sky were just diagonosed with feline herpes since they both seem to have eye infections. The vet. prescribed eye drops and eye cream and lysine treats. I am giving the medicines 4X per day and hoping and praying they will both get better soon, however I am most concerned with my 10 year old cat as he seems to be "limping" today? I hope this is not a reaction to the medicines and just a result of him resting and sleeping more often from being sick? Thank-you for any insights.
Posted: August 17, 2013 at 10:22 PM
jean, cats do not die from herpes (calicivirus). They will have the virus their whole life and it will become active in times of stress. The lysine (500mg/day adult cat), will keep their immune system healthy and prevent the virus from becoming active. If the virus is active and the cat has an ulcer in the eye the vet will usually put the cat on either Cidofovir or Idoxuridine ophthalmic solution (both anti-viral eye medication) and possibly and oral anti-viral (Famciclovir). If your vet if NOT using an anti-viral medication your cat will not get any better. It will not repond to antibiotic eye meds only. Natalie R.V.T.
Posted: August 13, 2013 at 7:03 PM
My little Buster has herpes, 12 trips to the vet, $1500, and he has started sneezing AGAIN this morning. I love this little guy, but I am on a fixed income and am out of money. will he die from this? Drops salves, shots, I have another appointment in the morning with my vet. He said if he was no better I need to see an opthamologist.. HELP. I don'y know what to do! I give him 4 lysine treats a day as the vet said.. is that enough?
Posted: July 14, 2013 at 7:31 PM
Our beautiful 11 year old Maine Coon has herpes eye infection since birth. He was taken to the vet, and our vet suggested oral powder L-Lysine HCI in the hard food, and in the morning we give him Forti Flora Feline Nutritional oral powder in soft food, and apparently this one tastes really good. The eye medications are as follows: Cyclosporin oil 15ml 3 drops/day, Tacrolimus 0.02% oil 10ml 2 drops/day, Optixcare 2 times a day, and Tears Naturale 2 times a day. He has dry eye caused by this, and his number when tested is 0, meaning no tears? The numbers go back and fourth to 0, then 5 or 8, but it is suppose to be higher. His nose filter is damaged and that is why cats always seem to have a cold, but the nose filter is damaged. We also did a MRI. We have two Maine Coons and the other one did not get this disease and they are very close together, licking, sleeping together and on and on. Thank God! as this is painful. Unfortunately as indicated in this article, Feline ocular herpesvirus, or FHV-1, is a very common virus in cats, at least 90%. We have done everything to make his cat life comfortable. Just give your buddies their medications, hugs and kisses, they know you love them.
Posted: May 13, 2013 at 6:11 PM
Lillie's Mom
My Lillie is a rescue kitty who has always had one eye that leaves a trail down her face. The eye never seems to bother her but the vet says she has FIV. She has been getting Lysine daily and had Tobra drops for a couple of months. The condition never seems to change, no worse but no better. What should I try? I am tired of spending $ for meds that don't do anything! The eye has never been cleared up. It's more a cosmetic issue at this point - her white face is always stained below that eye. As I said she has no ulcers or anything else and she doesn't seem to notice it other than grooming that side more.
Posted: April 30, 2013 at 9:48 PM
Cindy G
Pleae take your kitty to a feline vet. My Ragdoll (Max) got very sick right after I purchased him. I spend tons of money at a regular vet and my Max was still suffering. I finally found a great feline vet that took one look at him and knew exactly what was wrong. She gave me a RX for Famciclovir (10 day treatment) and it worked like a charm. He takes Lysine treats (purchased at the vet) everyday.
Posted: April 19, 2013 at 1:51 PM
Victoria S.
Lysine really helps my Mom cat and her 2 daughters who've had FHV-1 since birth.
500 ml a day; open capsule and put in their Science Diet Light canned food.
They never mind the taste at all. They have been in remission pretty much for
over a year just with this alone. However just had a flair up yesterday, went to animal eye care doc who prescribed famciclovir tablets ($$) and ofloxacin drops
Posted: March 23, 2013 at 12:37 PM
Our little Meowsers, definitely has something going on with her, I've taken her to 2 vets, and each wants a fortune just to test her, thinking it could be herpes, ringworm, or mange. She is 14 weeks old, we got her free to a good home one week before Christmas, and she had a patch on her right ear that had no fur. Because how young she was I thought it was a birth mark. Two weeks ago she kept squinting her right eye, that's when I first took her in. They gave me Erythromycin ophthalmic using it 3x's a day, the eye then got cloudy and now she has two ulsers, and more spots have shown up on her, mostly on her paws and other ear. Is there any hope for her. Any advice ASAP would be a blessing. We are afraid we're going to have to give her up, and she is part of the family now. The good think is her spirits are high, she is very active, and loving.
Posted: February 08, 2013 at 11:34 PM
My 6 month old Devon has been constantly afflicted with herpes which settles in his eyes and immediately goes bacterial. The little darling has now infected his brother, from another mother. LOL Anyway lyseine has been very helpful and more recently famvir (famciclovir) has worked very well. The plan is to give my boy famvir at first squint for 5 days in a row (1/4 tab) and hoping this kicks the snot out of the virus before it goes bacterial. The lysine is 500 mg a day maintenance and 1,000 for an outbreak. I am hoping that as he matures, so will his immune system. He get grain free food and likes yogurt with his lysine. I realize it is all about controling the number of outbreaks. Honestly, I look at that little face and just love him to bits.
Posted: January 31, 2013 at 3:26 PM
I have a 2 year old cat and noticed just yesterday that his eye was runny and crusty, I brought him to the vet today and the vet said that the cat had Herpes in his eye. No tests were done and the vet prescribed Ofloxacin Ophthalmic Solution, since using it he's been rubbing his eye and it seems to have gotten a lot worse, my husband thinks its just that the virus is in the beginning stage and is showing more serious signs... and that the solution will help over the next few days. Should I be concerned that his eye has increasingly worsened since the first application? Please help! Thanks!
Posted: January 03, 2013 at 2:02 AM
I have a kitten thats about 6 weeks old. They all came down with a URI and all the kittens started having eye problems, closing up and swollen. Most of the kittens are better now but there is one kitten whose eye looks like it is fusing shut with skin....Ive been using Erythromycin ophtalmic but his eyes are just getting worse. Should I get him checked for the herpes virus or can anyone recommend drops I really hate for him to loose his vision. THANKS
Posted: June 02, 2012 at 8:19 PM
My cat is taking 6 Lycine pellets a day and it seems to be helping.
Posted: May 29, 2012 at 4:56 PM
Go to your local health food store and ask there. If they won't advise you then go to another store that will. Alternative can often do stuff that regular meds cannot do. I once knew a woman who treated her cats rattle snake bite and the cat survived. She couldn't afford the regular. If you cannot afford the meds and you HAVE to, then have the eye removed. Cats acclimate very well, better than humans. But please try the alternative. I once cured incurable fibrosarcoma with alternative care. Good luck!
Posted: April 11, 2012 at 10:34 AM
See my comment. You do not have to spend a fortune. Lysine is trick to prevent outbreaks. Oral famciclovir if it is acute and treat with a topical antibiotic as written. Lysine, I tell you, works wonders. Just read one of my passages
Posted: April 03, 2012 at 6:09 PM
try oral medications like famciclovir of which you would need a prescription from your vet if the condition is severe. I heard that they typically do not respond to topicals..I may be wrong. Also give them oral L-lysine HCL, 250 mg for kittens and 500mg for adults on a routine basis to prevent outbreaks. It is an amino acid which stops the replication of the virus. Best to read the literature on how this works. Just type lysine for cats. I have had to deal with upper respiratory infections quite frequently which in many cases, especially the kittens involves corneal ulcers. Herpes and chalmydia are the main culprits but sometimes I feel that I am dealing with something else. If a corneal opacity starts occurring it could be an infectious ulcer from either herpes, chlamydia, or a secondary infection ie bacterial. If it is bacterial, I treat with vigamox because many of my kittens have been resistant to the topical erythromycin, bacitracin, and gentamycin etc.. which is typically given from veterinarians. When I treated with the vigamox, within 1 -2 days I had a significant improvement. If it is severe, give 1 Q H. I now get my veterinarians to treat with the medication. But the problem is the expense. This ridiculous small bottle cost between 80- 100 plus. If the upper respiratory forms into a sinus infection, the next step is zythromax. Clavamox does nothing for my cats. I usually buy it in the pediatric liquid form (for humans) that you can get a script from any GP. You would have to look up the dosage. But it works great for any longterm sinus infection. Give once a day for 5 to 7 days. I usually buy a large portion of dry powder form of zythromax and formulate it with water when I need to give it to one of my cats. It works like a miracle. And yes, I have now convinced my local veterinarians to use this medication as well. Hope this helps
Posted: April 03, 2012 at 6:06 PM
Hi, Thank you for your helpful comments. I was told that my cat needs thousands of dollars worth of medication for his ocular herpes. I'm so worried that I can't afford all the medication. He said the otheroption is to remove his eye, which would also cost thousands...any advice? My cat is only 3 years old and I dont know what to do...
Posted: March 07, 2012 at 10:05 PM
julie j
I give my little rag doll crushed human lysine in her food 250 for daily prevention and 500 if I see a break out in her eye starting. This is what my vet told me. Not expensive. humans that get cold sores use in also.
Posted: February 17, 2012 at 10:22 PM
My vet prescribed GenTeal (mild to Moderate) eye drops for our cat. It can be purchased over the counter at any drugstore I found it at CVS. It seems to really help with the discomfort. I have been using it on her for about a week now and her eye seems to be clearing up nicely. I wrap her up in a towel so only her face is showing, this helps keep her from squirming and I can get the drops in easily this way. Hope your kitty feels better soon.
Posted: August 19, 2011 at 2:15 PM
My beautiful Simba is a yellow cat I adopted from our local animal shelter & his eye is terrible w/ the Herpes virus. Our vet has prescribed several different drops that have never helped him. He's been given Tobramycin & Idoxuridine and one script for drops that cost $90 & didn't touch it. Can't remember it's name. Does anyone know of a drop that really works to ease his suffering?
Posted: August 15, 2011 at 6:23 PM
Leave a Comment
You can post a comment by logging in to your account or continue as a guest below.
Display Name*
Success! Your comment is waiting to be approved. It will post soon.
Post another comment

Connect with

Join Free Today!
What would you like to do?
Membership Type*
By clicking Join Now, you agree to our Terms of Use and Privacy Policy.
Put Safety first
Read our Safety Guide for tools and tips to keep you and your family safe.
Visit Sheila's Blog
Get advice for your family from our founder (and chief mom officer), Sheila Lirio Marcelo.