Cat with feline herpes virus, infecting one eye

Why pet owners are switching to online vet care with Dutch

  • Prescriptions delivered free to you

  • Fast access to Licensed Vets over video

  • Unlimited video visits and follow-ups

As cherished members of our families, our cats' health and happiness are important to us. Like humans, our felines can face health challenges, from pesky viruses to bothersome skin conditions. Luckily, veterinary medicine offers solutions to keep our furry friends purring with contentment. 

Famciclovir for cats can help manage certain viral infections that can afflict cats, like feline herpesvirus (FHV). This medication offers hope in alleviating the symptoms and discomfort associated with this condition. Keep reading or learn more about famciclovir for cats. 

What is Famciclovir?

Famciclovir is a medication commonly used in veterinary medicine to treat viral infections in cats. It belongs to a class of drugs called antivirals, which work by inhibiting the replication of viruses within the body. Famciclovir is particularly effective against certain types of viruses that commonly affect cats, such as feline herpesvirus.1 

This medication comes in tablet form and is typically administered orally to cats. Once ingested, famciclovir is absorbed into the bloodstream and distributed throughout the body, where it targets the replication process of the virus.1 

By interfering with viral replication, famciclovir for cats helps to reduce the severity and duration of symptoms associated with the viral infection, allowing affected cats to recover quickly and comfortably.1 

What does famciclovir treat?

Famciclovir for Cats: Uses

Famciclovir is commonly prescribed for cats to treat feline herpes virus, also known as feline viral rhinotracheitis or FVR.1 Feline herpesvirus is a highly contagious infection that affects cats' respiratory systems. This virus can cause respiratory symptoms like sneezing, congestion, conjunctivitis (pink eye) and other eye infections, excessive blinking, squinting, runny nose, and eye discharge. Without fast treatment, kittens can pass away due to feline herpesvirus, making it crucial to address symptoms quickly. 

These symptoms can be distressing for cats and impact their overall well-being. Famciclovir helps alleviate these symptoms by targeting the herpes virus, reducing its ability to replicate and spread in the body. Doing so helps manage the symptoms associated with the infection, providing relief while fighting the infection. 

A study used famciclovir to treat symptoms caused by FHV in 10 cats. These symptoms included eye problems, sinus issues, and skin conditions related to the virus. Cats in Australia, Europe, and the USA were given different doses of famciclovir, but all tolerated the medication well and showed improvement in their condition.

The cats with eye problems became more comfortable, with reduced signs of infection and better-looking eyes. Using famciclovir orally was found to be easier than applying medication directly to the eyes. Cats with skin problems also improved, although some experienced a return of symptoms later on. Overall, famciclovir shows promise in treating FHV-1-related diseases in cats, but more research is needed to determine the best famciclovir dosage for cats for safe and effective treatment.2

If you believe your cat has FHV, consult a veterinarian as soon as possible for an accurate diagnosis and appropriate treatment. Early intervention can help alleviate symptoms and prevent complications associated with the virus. Famciclovir, along with veterinary guidance, can play an important role in managing your cat’s condition and promoting their well-being. 

Cat being given medicine in a pill

Dosage & Administration

When it comes to administering famciclovir dosages for cats to treat feline herpesvirus, there are specific guidelines to follow. This medication is typically offered as 125 or 250 mg tablets. You can use this famciclovir for cats dosage chart to help you determine how much your cat should take: 

  • Chronic and severe FHV symptoms: For chronic and severe herpes viral infection, the dosage can range between kittens and adult cats. For adult cats, half of a 250 mg tablet administered orally once daily for three weeks is suggested. For kittens, your vet might recommend a dose of one-eighth of a 125 mg tablet administered orally once daily. 
  • Potential other option: Another dosing option is to administer one-quarter of a 125 mg tablet orally twice daily for 10 to 14 days, with the possibility of continuing once daily for up to 30 days.1 

To ensure the best possible outcome for your cat's health, it's crucial to follow these dosage instructions carefully and consult with a veterinarian for proper guidance on the administration of famciclovir.

Keep in mind that you should always follow your vet's instructions, even if they prescribe a dosage that differs from this chart. When determining the appropriate dosage, your veterinarian will consider your cat's specific condition, age, weight, and other factors. Never adjust the dosage or frequency of administration on your own without consulting your vet first. 

Additionally, ensure that you complete the full course of treatment as prescribed, even if your cat's symptoms improve before the treatment period ends. If you have any questions or concerns about administering famciclovir to your cat, don't hesitate to contact your veterinarian for clarification and guidance. Your vet is your best resource for ensuring this medication's safe and effective use to help your cat recover from feline herpes virus infection.

Side Effects

Side Effects

While famciclovir is generally considered safe for cats, there is not much information about its side effects. Cats seem to tolerate it well when taking it for a short time, usually up to three weeks.1 However, pet parents need to be aware of the potential side effects of famciclovir for cats so they can monitor their pets during treatment. 

In humans, famciclovir can cause nausea, vomiting, diarrhea, and headaches. More severe side effects like a decrease in white blood cells and renal failure have been reported, particularly when doses aren't properly adjusted in patients with kidney dysfunction.1

While data on the side effects of famciclovir for cats is scarce, common observations suggest that decreased appetite, vomiting, diarrhea, and increased thirst can lead to increased urination.1 These symptoms are typically mild and go away on their own but should be monitored during treatment. 

You should remain vigilant for any signs of adverse reactions whenever your cat is on any medication. If any concerning symptoms arise, it's essential to contact your vet immediately for further guidance. Your vet can provide personalized advice and recommend adjustments to the treatment regimen if necessary to ensure your cat's well-being. 


While considered safe for healthy cats, famciclovir or penciclovir should not be used in cats with known allergies to it.1 If your cat has underlying health issues, the dosage might need to be adjusted, so it's essential to be cautious and follow your vet's advice. 

In animal studies, high doses of famciclovir didn't seem to harm developing babies. In pregnant women, it's generally considered safe to use during pregnancy. However, there haven't been enough studies to be positive on its effects in humans or cats.1

When it comes to nursing animals, famciclovir can pass into the milk of rats, but more research is needed to determine how it affects nursing kittens.1

Unfortunately, there's not a lot of information about what happens if an overdose occurs. If your cat consumes too much famciclovir, contact your vet as soon as possible for the next steps. 

This medication may also interact with other drugs, such as probenecid. Probenecid can reduce the amount of famciclovir that gets removed by the kidneys, which can cause drug levels in the blood to increase. Always let your vet know if your cat is taking any other supplements or medications, as these can interact with famciclovir for cats and affect its safety and efficacy.1 

As a general rule, famciclovir tablets should be stored at room temperature to ensure their effectiveness.1

A cat being examined by a veterinarian

Final Notes

Famciclovir for cats offers a promising solution for managing feline herpesvirus. Its ability to inhibit viral replication and alleviate symptoms associated with the infection relieves cats suffering from respiratory issues, eye problems, and skin conditions caused by the virus. While more research is needed to optimize dosing regimens and fully understand its safety profile, famciclovir holds great potential. 

Try Dutch if you're looking for convenient access to veterinary care. With our telemedicine for pets, you can receive timely guidance on your pet's health concerns. Through virtual consultations with experienced veterinarians, you can address your cat's health needs from the comfort of your home. 

We also offer an online pet pharmacy, providing easy access to medications like famciclovir and other essential treatments. With prescriptions delivered directly to your door at no extra cost, Dutch simplifies the process of getting medications for your cat. We also offer a price match guarantee to ensure you get the best value. Sign up for a Dutch membership today. 



  1. Plumb, Donald C. "Pentoxifylline." Plumb's Veterinary Drug Handbook, Six ed., Blackwell Publishing, pp. 371–372,

  2. Malik, Richard, et al. "Treatment of Feline Herpesvirus-1 Associated Disease in Cats with Famciclovir and Related Drugs." Journal of Feline Medicine and Surgery, U.S. National Library of Medicine,

Memberships to keep your pet healthier

billed $132 yearly
20% off of all memberships
billed monthly

All memberships include:

  • Fast access to licensed vets
  • Virtual care for up to 5 pets
  • Customized Rx treatment plans
  • Unlimited video calls & follow-ups
  • Guaranteed low prices on medication
  • Free shipping on every order

Frequently Asked Questions

Who is Dutch?

Dutch is an online veterinary pet telehealth service, created by pet parents and board-certified veterinary specialists. We use a science-backed approach to provide pets relief for their everyday physical and behavioral health issues. Dutch connects you with licensed veterinarians over video chat and messaging to help you get care for your dog or cat quickly wherever you are — without the stress or expense of a vet visit. We also partner with pharmacies who can deliver prescription medication (in applicable states only) and over-the-counter treatments directly to your door. Dutch isn’t a veterinary practice or pharmacy, but a company that helps facilitate these services for pet parents to make veterinary care more accessible to all.

What is a visit with Dutch like?

When booking a video call with a vet, you'll be asked a few questions about your pet’s health issue. Depending on the issue, you may also be asked to fill out a longer questionnaire about their symptoms and share photographs of them so our veterinarians can better understand what’s going on. You’ll then pick an appointment time that works best for you.

During your video call, one of our licensed veterinarians will talk to you about the symptoms your pet is experiencing, ask you questions, review your pet’s medical history if you’ve provided it, and answer any questions you have. The vet will ask to see your pet and their environment. And they may ask you to perform some simple checks on them if needed.

After your video call, the vet will send you a message with a custom treatment plan to help your pet feel better, including a link to buy any recommended prescription or over-the-counter medications. Place your order and we’ll ship it free.

How much will it cost for Dutch to treat my pet?

The Dutch membership starts at $11/mo for unlimited access to the vet. No more long waits for appointments or surprise bills.

In addition to the base membership plan, our veterinarians may also recommend additional medication (Rx and/or OTC) that you will have the option of adding to your plan at an additional cost.