Feline Herpesvirus (FHV) in Cats

What is Feline Herpesvirus (FHV) in Cats?

Feline herpesvirus (FHV) in cats is a highly contagious DNA virus that primarily affectsthe upper respiratory tract , eyes , and certain areas of the nervous system. The disease caused by FHV is often called "feline viral rhinotracheitis" and is one of the most common respiratory infections in the feline population. FHV is a member of the Herpesviridae family and, like other herpesviruses, produces a lifelong infection that cannot be completely eradicated. After initial infection, the virus lies latent in nerve cells and can be reactivated during periods when the cat's immune system is weakened—such as stress, illness, surgery, moving, encountering new animals, or giving birth—causing symptoms to reappear.

Cats infected with FHV may exhibit both acute and chronic clinical symptoms. In the acute phase, the virus multiplies in the upper respiratory tract mucosa and causes tissue damage; symptoms such as sneezing, nasal discharge, eye discharge, conjunctivitis, and fever are prominent. Some cats may develop ulcers on the surface of the eye, which can lead to permanent vision loss. FHV can also be severe in kittens; due to their immature immune systems, severe respiratory distress, dehydration, and rapid deterioration can occur. In the chronic form, cats experience intermittent symptoms, persistent nasal discharge, recurrent eye infections, chronic rhinitis, and sinusitis.

The virus is highly contagious and spreads rapidly to other cats through the eye, nose, and mouth secretions of infected cats. Cats living in the same environment, sharing food and water bowls, shared litter boxes, toys, and carriers increase the likelihood of virus transmission. Human hands and clothing can also mechanically transmit the virus, so hygiene is crucial for controlling FHV. FHV is a cat-specific virus; it is not transmissible to humans or dogs, but it poses a risk of spread to all cats in the area, requiring proper isolation and care.

Types / Clinical Forms of Feline Herpesvirus (FHV) in Cats

While there are no distinct "subtypes" of Feline Herpesvirus, the clinical forms produced by the virus can vary, and the severity of the disease can vary greatly depending on the cat's immune system, age, general health, and viral load. FHV infection typically manifests in three main clinical forms: acute, chronic, and ocular.

Acute FHV infection is the early stage, when the virus rapidly multiplies in the mucosa of the nose, throat, and upper respiratory tract. During this stage, symptoms such as sneezing, profuse serous or mucopurulent nasal discharge, fever, anorexia, eye discharge, third eyelid prominence, and conjunctivitis rapidly appear. The acute form usually lasts 7–14 days; however, in kittens with weakened immune systems, this period may be longer and the disease may be severe. The acute stage is when FHV is most contagious.

Chronic FHV infection is a relapsing form that occurs when the virus remains latent in the nervous system and reactivates periodically. In this form, cats may generally experience milder but frequently recurring nasal congestion, unilateral or bilateral discharge, chronic rhinitis, sinusitis, and eye problems. In some cats, chronicity can lead to anatomical deterioration of the nasal passages, permanent obstruction, and a diminished sense of smell. These cats may experience symptoms intermittently throughout their lives.

The ocular form of FHV is characterized by conjunctivitis, keratitis (inflammation of the cornea), corneal ulcers, and thick periocular discharge. This form is particularly severe in kittens and immunocompromised adults. As corneal ulcers heal, they can leave scar tissue, leading to permanent vision loss or permanent opacification of the eye's surface. In some cats, recurrent ocular infections persist throughout life and require regular eye drop treatment.

In some cases, FHV infection can coexist with other respiratory agents, such as calicivirus or Chlamydia felis, and this combination can exacerbate the clinical manifestations of the disease. In such mixed infections, both respiratory and ocular manifestations are significantly exacerbated, requiring a more prolonged and intensive treatment approach.

Causes of Feline Herpesvirus (FHV) in Cats

The primary cause of Feline Herpesvirus (FHV) infection in cats is the transmission process, which begins when the virus comes into contact with the cat's upper respiratory tract and eye mucosa. FHV is found in high concentrations in the eye, nose, and mouth secretions of infected cats and spreads rapidly, particularly through microscopic droplets expelled during sneezing. The virus has a relatively short survival time in the environment; it typically doesn't survive for more than a few hours on moist surfaces. However, shared food and water bowls, litter boxes, and toys contaminated with cat saliva, eye discharge, or nasal discharge are significant sources of increased transmission.

One of the most critical aspects of FHV transmission is that infected cats can shed the virus even if they don't show obvious clinical symptoms. Cats that have previously contracted the virus and become latent carriers can reactivate the virus and spread it into the environment during periods of stress or weakened immunity. Therefore, high-stress and crowded living spaces such as shelters, hatcheries, and multi-cat households are the most likely locations for FHV transmission.

The most common routes of transmission among cats include direct contact (eye-to-eye, nose-to-nose contact), sharing shared objects, and sneezing at close range. Transmission from a mother cat to her kittens is also a common route of transmission. Kittens can become infected very early if a pregnant cat is actively carrying the infection or transmits the virus while grooming her kittens after birth. Because kittens' immune systems are not fully developed, the virus is much more severe and can lead to rapid complications.

Another reason why FHV infection spreads so easily is that the virus can remain latent (hidden) in nerve tissue for life . After the initial infection, the virus doesn't completely disappear; it lies dormant in areas like the trigeminal nerve and reactivates under the right triggering conditions. These triggers include moving, adding a new pet, fear, noise, surgery, childbirth, serious illness, or general stress. This makes the likelihood of FHV recurring very high.

Cats with weakened immune systems—kittens, older cats, FeLV/FIV-positive cats, and cats with chronic illnesses—are more susceptible to FHV infection, and the effects of the virus are more severe in this population. Unvaccinated or inconsistently vaccinated cats also have a higher risk of spreading the infection. FHV is a virus specific to cats; it cannot be transmitted to humans or dogs, but it poses a threat to the entire cat population if there are multiple cats in a household.

Breeds Prone to Feline Herpesvirus (FHV) in Cats

The table below shows cat breeds known to be susceptible to FHV. The table follows the Breed | Description | Susceptibility Level order.

Race	Explanation	Level of Predisposition
Persian (Persian Cat)	Due to the flat facial structure, the respiratory tract is anatomically more sensitive; nasal congestion and chronic rhinitis are more severe in FHV infections.	A lot
Exotic Shorthair	It has similar anatomical risks to the Persian; FHV symptoms become more pronounced because the nasal passages are narrow.	A lot
British Shorthair	Moderate susceptibility to upper respiratory tract infections; FHV exacerbations occur more easily in the presence of stress factors.	Middle
Sphynx	Because of its hairless structure, it is sensitive to environmental changes; the immune system's stress response can increase FHV symptoms.	Middle
Scottish Fold	It has been shown that it is susceptible to viral infections due to immune sensitivity due to genetic factors.	Middle
Maine Coon	Despite being a large breed, susceptibility to FHV may be increased in puppies; it is generally milder in adults.	Little
Domestic Short Hair (Street Cat)	Because they live in unprotected environments, they are likely to be exposed to FHV; the disease can be severe.	A lot

Feline Herpesvirus (FHV) Symptoms in Cats

The symptoms of Feline Herpesvirus (FHV) infection in cats can vary significantly between the acute and chronic stages of the disease. In the acute phase, symptoms usually begin quite suddenly and reflect the direct effects of viral replication in the upper respiratory tract mucosa. One of the earliest symptoms is a bout of intense sneezing . Sneezing is a natural reflex aimed at expelling accumulated secretions and irritation in the nasal passages and is one of the most characteristic signs of FHV infection. Sneezing often begins with a thin, clear nasal discharge that can develop into a yellow-green, thick, purulent discharge within a few days, indicating the development of a secondary bacterial infection.

Eye discharge and conjunctivitis are the most prominent and common clinical signs of FHV. These symptoms include redness, watering, sensitivity to light, and adhesion of the lids. In some cats, the eyelids become extremely swollen, the eye surface becomes matted, and the discharge can form thick crusts. Cases of conjunctivitis, which causes the eyelids to close completely, can be seen, especially in kittens. The damage caused by FHV on the ocular surface can progress to corneal ulcers , which are painful and can lead to permanent vision loss if left untreated.

Fever , loss of appetite , weakness , and general depression are common systemic symptoms of acute FHV infection. The cat's energy level decreases, the desire to play disappears, hiding behavior increases, and movement slows. Fever is particularly high in the early stages of infection and can lead to decreased water consumption, dehydration, and rapid weight loss.

Hoarseness or loss of voice is a prominent symptom of FHV in some cats. Inflammation in the throat can weaken or even completely stop a cat's meowing. This is often described by cat owners as one of the first signs of infection.

FHV generally does not cause oral sores unless there is a mixed infection with calicivirus; however, in some severe cases, a sore throat and difficulty swallowing can occur. However, loss of smell due to FHV is one of the most common reasons why cats refuse to eat. A cat unable to smell may show no interest in even its favorite food, worsening appetite and deteriorating the cat's general condition.

In chronic cases of FHV, symptoms may be milder but more prolonged. Chronic rhinitis , sinusitis , persistent nasal congestion, intermittent sneezing, one-sided discharge, recurrent conjunctivitis attacks, and chronic ocular surface problems are typical symptoms of the chronic form. In these cats, the nasal anatomy may change over time, and the airways may become narrowed, leading to lifelong respiratory problems.

In cats with weakened immunity, the infection can be much more severe, and serious symptoms such as respiratory distress, rapid breathing, wheezing, and open-mouthed breathing may occur. The effects of FHV are particularly devastating in FIV/FeLV-positive cats and require more intensive treatment.

Diagnosis of Feline Herpesvirus (FHV) in Cats

Diagnosis of FHV in cats is made by carefully evaluating clinical symptoms, combining history, laboratory tests, and advanced imaging techniques when necessary. One of the most distinctive features of FHV is the profuse sneezing and conjunctivitis accompanied by eye and nose discharge; therefore, the clinical presentation often raises a strong suspicion. The veterinarian obtains initial information about the severity of the infection by evaluating the cat's eye contour, nasal structure, consistency and color of the discharge, fever, lymph nodes, and respiratory function.

The PCR test provides the highest accuracy in diagnosing FHV. PCR (Polymerase Chain Reaction) directly detects the genetic material of the virus and is the most reliable laboratory method for distinguishing FHV from other respiratory pathogens. Testing typically uses eye discharge, a nasal swab, or an oropharyngeal swab. PCR is particularly critical for identifying chronic rhinitis, eye infections that do not respond to treatment, or outbreaks in multi-cat households.

Blood tests are also helpful in diagnosis. A complete blood count indicates the body's response to infection; white blood cell counts provide clues to distinguishing viral from bacterial infections. Biochemistry tests help plan treatment by assessing the cat's general health, dehydration level, and organ function. In some severe cases, electrolyte disturbances or changes in kidney and liver parameters may be observed.

Ophthalmologic examination is important in cats with severe ocular findings. Fluorescein staining is used to assess the presence of corneal ulcers. Intraocular pressure measurement also plays a critical role in assessing the risk of secondary glaucoma. Viral-induced damage to the ocular surface is highly characteristic, and ophthalmologic findings are an important component of diagnosis.

In cases where respiratory findings are severe, an x-ray may be necessary. Lung infiltration, bronchial thickening, or suspicion of pneumonia can be assessed on an x-ray. In cats with chronic rhinitis and sinusitis , CT (computed tomography) imaging or endoscopy may be preferred for more detailed examination of the nasal passages; these methods are highly valuable in detecting permanent changes in nasal anatomy.

In some cases, particularly in chronic cases resistant to treatment , culture and antibiogram testing may be performed. This test is performed to identify concomitant bacterial infections, not FHV itself, and to determine which antibiotics are most effective.

In the diagnosis of FHV, the presence of immunosuppressive diseases such as FeLV/FIV must also be evaluated, as these diseases significantly affect the severity of the infection and the speed of recovery.

Feline Herpesvirus (FHV) Treatment in Cats

Treatment of FHV infection in cats is primarily based on supportive care , symptom management , control of secondary infections , and immune strengthening , as there is no method that ensures complete eradication of the virus. The scope of treatment depends on factors such as the severity of the cat's clinical presentation, age, and immune status. Aggressive supportive care in the acute phase shortens recovery time and reduces the risk of complications.

Because FHV tends to cause extensive damage to eye tissues , eye treatment is crucial. In cats with conjunctivitis or corneal ulcers, antiviral eye drops or gels (e.g., idoxuridine, trifluridine, cidofovir) are administered regularly. These medications suppress the virus's proliferation on the ocular surface and prevent ulcers from deepening. In some cases, antibiotic eye drops may be prescribed in addition to antiviral therapy because of the high risk of bacterial secondary infection.

Nasal cleansing and humidification are essential components of treatment to alleviate upper respiratory symptoms. Nasal congestion can make it difficult for a cat to breathe and smell, leading to food refusal. Therefore, the area around the nose should be cleaned several times a day with warm saline solution, and dried crusts should be softened and removed. Additionally, humidification can be increased by using a steam generator or hot shower; this helps loosen blocked mucus.

Although FHV is a viral infection in itself, many cats develop secondary bacterial infections during the acute phase. Therefore, broad-spectrum antibiotics are frequently used. While antibiotics do not treat the viral cause, they significantly reduce signs of bacterial infection, such as purulent nasal discharge, thick eye discharge, fever, and loss of appetite. The choice of antibiotic is determined by the cat's condition, comorbidities, and examination findings.

Pain management is crucial in severe cases of FHV with oral ulcers. Cats with oral inflammation, ulcers, or difficulty swallowing may experience rapid weight loss due to difficulty eating. Therefore, the cat's comfort is enhanced with analgesics and anti-inflammatory medications as deemed appropriate by the veterinarian. Soft food, recovery products, or energy-dense supplements are used when necessary.

In the chronic form of FHV, treatment focuses on symptom control. Cats with chronic rhinitis may experience permanent nasal damage and persistent discharge; in such cases, long-term antibiotic courses, nasal decongestants, and immune boosters are used more intensively. Cats with chronic eye infections may require regular antiviral eye treatments.

L-lysine supplementation is an important supplement in the treatment of FHV. L-lysine may help suppress herpesvirus replication and reduce the frequency of relapses in certain cats; however, it may not be effective in every cat and should only be used with veterinary advice.

In severe cases , IV fluid therapy may be administered due to dehydration, malnutrition, and high fever. Dehydration exacerbates the course of FHV and weakens the immune response; therefore, intravenous or subcutaneous fluid therapy may be critical in the clinical setting. Temporary feeding tube placement may also be necessary in severely debilitated cats.

The success of treatment is directly related to the quality of home care. Stress reduction, providing a warm and quiet environment, monitoring food intake, regular eye and nose cleaning, and taking medications regularly are the cornerstones of recovery.

Feline Herpesvirus (FHV) Complications and Prognosis in Cats

Complications of FHV infection in cats vary depending on the level of viral load, the cat's immune system, its age, and the presence of other comorbidities. The risk of complications is particularly high in immunocompromised cats and kittens. One of the most common complications is the development of chronic rhinitis and sinusitis . Viral damage to the nasal mucosa in the acute phase can progress to permanent tissue damage, causing lifelong chronic nasal discharge, frequent sneezing, a decreased sense of smell, and periodic congestion in cats.

Corneal ulcers are one of the most serious complications of FHV. Ulcers on the eye's surface can deepen, leave scars as they heal, or, if treatment is delayed, can progress to corneal perforation. This can lead to irreversible vision loss in cats. In some cats, permanent corneal clouding, vascularization, or pigmentation develops, impairing vision.

Another serious ocular complication of FHV is chronic conjunctivitis and ocular recurrences . Herpes-related eye infections tend to recur, with redness, discharge, and pain recurring during periods of stress or immunosuppression. These cats may require regular eye drop therapy for life.

In some severe cases, the viral infection can progress from the upper respiratory tract to the lower respiratory tract, causing bronchitis or viral pneumonia . This leads to serious clinical signs such as rapid breathing, open-mouth breathing, wheezing, and increased oxygen demand. In kittens, this process can rapidly deteriorate and become life-threatening.

Complications affecting the mouth and throat include oral inflammation , stomatitis , and sore throat . These conditions make it difficult for the cat to eat and can lead to significant weight loss. Some FHV-positive cats may develop chronic stomatitis, a condition resulting from the complex interaction between the immune system and the virus and requiring long-term treatment.

FHV infection can also lead to complications such as middle ear infection (otitis media) . When middle ear infection develops, cats may experience loss of balance, head tilt, incoordination, and pain. These conditions require long-term antibiotic and supportive care.

Prognosis varies depending on the cat's overall health. In healthy adult cats, most FHV infections can be controlled with supportive care. However, in immunocompromised, FIV/FeLV-positive cats and kittens, the disease can be very severe, and the risk of complications is significantly higher. Frequent relapses are common in FHV carrier cats, with mild to moderate symptoms recurring throughout life.

Feline Herpesvirus (FHV) Home Care and Prevention in Cats

Home care for cats infected with Feline Herpesvirus (FHV) is one of the most critical stages, directly affecting the course of the disease. Because FHV causes symptoms such as intense nasal discharge, congestion, conjunctivitis, and loss of appetite in the acute phase, supportive care at home both increases the cat's comfort and reduces the risk of complications. The key steps in home care are improving the cat's breathing and maintaining mucosal cleansing . Because nasal congestion is one of the most distressing symptoms of the disease, nasal irrigation should be performed several times a day with warm saline solution, gently softening and removing dried and hardened mucus. Keeping the nostrils clean allows the cat to smell more easily and increase food intake.

Regular eye care is also essential in managing FHV. Any discharge from the corners of the eyes should be gently cleaned with sterile eye cleansing solutions, and a separate cotton pad should be used for each eye. When conjunctivitis and discharge are excessive, the eyelids may stick together; in this case, the area should be wetted first, then the discharge should be softened and cleaned. If the eyes are painful, red, or opaque, veterinarian-prescribed eye drops should be applied without delay.

Humidity levels in the home also significantly impact the symptoms of FHV. Dry air causes nasal mucosa to dry out more rapidly, exacerbating congestion. Therefore, maintaining humidity levels at 40–60%, using a steamer, or briefly leaving the cat in a steamy room after a hot shower can alleviate symptoms. However, during these practices, the cat should not be stressed, and the ambient temperature should not be changed suddenly.

Nutritional support is vital in the care of FHV. Because the virus weakens the sense of smell, cats may avoid food. Therefore, strongly flavored wet food should be preferred, and the food should be slightly warmed to increase its appeal. The cat's water consumption should be monitored regularly; if necessary, a water fountain should be used or wet food options should be offered. For cats with very poor appetite, high-calorie supplements or syringe feeding may be recommended with a veterinarian's recommendation. Prolonged anorexia can pose serious risks, so this should be carefully monitored.

Isolation and hygiene are important components of home care. Because FHV is highly contagious, contact between an infected cat and other cats should be limited. Food and water bowls should be kept separate, the litter box should be cleaned regularly, and hands should be washed after contact. Toys, bedding, and carriers should be disinfected regularly. Even if it's important to remember that the virus only survives briefly on surfaces, precautions should be taken.

A cornerstone of any prevention strategy is the vaccination program . While the FHV vaccine doesn't completely prevent infection, it significantly reduces the severity of symptoms and reduces viral shedding. Unvaccinated or irregularly vaccinated cats are much more susceptible to FHV. When a new cat is brought home, quarantine should be implemented for at least 10–14 days, and contact with other cats should be avoided without a veterinary check. Similarly, cats adopted from shelters or strays should be isolated until their initial evaluation and vaccinations are complete.

Another key aspect of home care is stress management . Stress is one of the most potent triggers for herpesvirus reactivation. Keeping the home quiet, avoiding sudden changes, not disturbing the cat's preferred areas, not forcing it into the carrier, avoiding loud activities, and maintaining routines are crucial. Environmental enrichment elements—scratching posts, hiding places, and window lookouts—help maintain a cat's psychological stability.

The success of home care directly determines the course of the disease. Regular nose and eye cleaning, monitoring nutrition, fluid intake, stress reduction, and implementing hygiene protocols are the most important supports in a cat's recovery.

Owner Responsibilities for Feline Herpesvirus (FHV) in Cats

Owning a cat with FHV infection requires additional responsibilities beyond ordinary care routines. These responsibilities are crucial both for improving the cat's comfort during the acute phase of the disease and for reducing the frequency of relapses during chronic stages. Owners' first priority is to carefully monitor their cat's clinical signs and act quickly upon any signs of deterioration. Signs such as increased sneezing, thickening of the discharge, swollen eyes, complete loss of appetite, or difficulty breathing require immediate veterinary evaluation.

One of the most important responsibilities in an owner's daily routine is ensuring regular and accurate medication administration . Antiviral eye drops, antibiotic treatments, nasal solutions, or immune boosters should be administered regularly and as frequently as recommended by your veterinarian. Incorrect timing or irregularity, particularly with eye and nasal treatments, can prolong the illness and lead to complications.

Feeding monitoring is also an important responsibility for owners. Daily food intake should be carefully monitored in cats that refuse food due to FHV symptoms. On days when the cat skips meals, alternative foods, high-calorie supplements, or flavorful wet foods should be tried. Regular monitoring of the cat's food intake, water intake, and weight should be monitored.

Hygiene in the home environment is another critical point under the direct control of owners. Areas that the infected cat has come into contact with, including food and water bowls, toys, and bedding, should be cleaned and disinfected regularly. The litter box should be cleaned daily, and, especially in multi-cat households, the equipment used to meet the infected cat's needs should be separated from other cats.

Another responsibility for owners is to manage stress . Because FHV cannot be completely eliminated, stress triggers the virus to reactivate. Therefore, caution is necessary when planning major changes, such as adding a new pet to the cat's home, avoiding loud noises, maintaining routines, and moving. Furthermore, creating a safe environment for the cat—quiet resting areas, elevated platforms, hiding spots—reduces the risk of relapse.

Adhering to the vaccination schedule and regularly attending veterinary checkups are also among the responsibilities of owners. While the FHV vaccine does not provide complete protection, it reduces the severity of symptoms, slows the rate of spread, and moderates the viral load. It is vital, especially for kittens, that the primary vaccination series be completed completely.

Finally, owners should develop a long-term care plan , recognizing that FHV-positive cats may experience periodic relapses throughout their lives. This plan should include dietary changes, stress management, hygiene protocols, regular follow-up visits, and rapid response strategies for potential flare-ups. This approach is the most effective way to maintain the cat's quality of life.

Differences Between Feline Herpesvirus (FHV) in Cats and Dogs

Feline Herpesvirus (FHV) is a virus entirely specific to cats and does not infect dogs. While the term "herpesvirus" appears to be similar at first glance, feline FHV and canine herpesvirus (CHV) have completely different genetic structures, host specificity, and pathogenesis mechanisms. Therefore, FHV cannot be transmitted from cats to dogs or from dogs to cats; each virus only infects its own species.

FHV in cats primarily affects upper respiratory tract tissues , the conjunctiva, and corneal surfaces , and in some cases, nervous tissue . The most prominent clinical findings are upper respiratory-related symptoms such as sneezing, nasal discharge, conjunctivitis, eye discharge, corneal ulcers, and chronic rhinitis. Furthermore, FHV is characterized by a lifelong latency in nervous tissue and reactivation by stress. This can lead to lifelong recurring symptoms, chronic nasal problems, and periodic eye infections in cats.

Canine Herpesvirus (CHV), which occurs in dogs, has a very different clinical picture. CHV is known for its severe and rapidly progressing infections, especially in newborn puppies . Due to the unstable body temperature in puppies, the virus replicates rapidly and can cause systemic infections that can be fatal within a few days. The effects of CHV in adult dogs are often subtle; some adult dogs can be carriers without showing any symptoms. However, in adult female dogs, CHV can cause reproductive problems such as miscarriage, infertility, premature birth , and postpartum puppy loss.

Another important difference between FHV in cats and CHV in dogs is the type of tissue damage the viruses inflict . While FHV causes extensive damage to eye tissue, CHV rarely causes eye complications. In dogs, CHV primarily targets reproductive tissue, while in puppies, it targets organs such as the liver, spleen, and kidneys. Corneal ulcers are a characteristic finding in feline FHV infection, while systemic organ damage is prominent in canine CHV.

There are also differences in the immune response between the two species. Cats experience FHV infection in a chronic, lifelong form with frequent relapses; in contrast, in dogs, CHV is often latent in adults. Vaccines are available for both FHV and CHV, but they only protect against their respective strains; a cat's FHV vaccine will not protect a dog, and a dog's CHV vaccine will not work in a cat.

In summary, despite their similar names, FHV and CHV are distinct viruses that occur in different species, in different tissues, and with different clinical courses. Each replicates only in its own host and is managed only by the health protocols for that species.

Frequently Asked Questions (FAQ)

What exactly is Feline Herpesvirus (FHV) infection in cats?

Feline Herpesvirus (FHV) infection in cats is a highly contagious viral disease that primarily affects the upper respiratory tract, ocular surface, and certain areas of the nervous system. In the acute phase, symptoms such as severe sneezing, nasal discharge, conjunctivitis, eye discharge, and fever are observed. In the chronic phase, because the virus remains latent in the nerve tissue, it can cause recurring problems such as nasal congestion, eye infections, and chronic rhinitis with periodic exacerbations.

How is Feline Herpesvirus (FHV) transmitted in cats?

Feline Herpesvirus (FHV) infection is transmitted through contact of virus particles in the eye, nose and mouth secretions of infected cats with the mucous membranes of another cat; while sneezing droplets, shared food and water bowls, toys, litter boxes and living in the same environment accelerate transmission, the virus does not spread to humans, but humans can mechanically transmit the virus between cats as surface carriers.

When do symptoms of Feline Herpesvirus (FHV) appear in cats?

In a cat infected with Feline Herpesvirus (FHV), symptoms usually appear within 2–6 days; during this time, the virus rapidly multiplies in the upper respiratory tract mucosa and early signs such as sneezing, watery eyes, nasal discharge, loss of appetite and weakness become apparent.

Are Feline Herpesvirus (FHV) and cat fever the same thing?

Yes, Feline Herpesvirus (FHV) is one of the most common and primary causes of upper respiratory tract infections known as cat fever; however, it is not the only cause of the disease, as Calicivirus and some bacterial agents may also accompany the condition.

How does Feline Herpesvirus (FHV) affect the eyes in cats?

Feline Herpesvirus (FHV) can cause severe inflammation on the surface of the eye, causing intense conjunctivitis, discharge, sensitivity to light, eyelids sticking together, and corneal ulcers; especially if treatment is delayed, ulcers can lead to permanent scarring, clouding, or loss of vision.

Does Feline Herpesvirus (FHV) cause mouth sores?

Pure Feline Herpesvirus (FHV) infections rarely cause oral sores; however, in mixed infections, especially when found with Calicivirus, it can cause painful ulcers in the oral mucosa, increased salivation, bad breath and severe anorexia.

Why does Feline Herpesvirus (FHV) recur in cats?

Feline Herpesvirus (FHV) remains latent in nerve tissues such as the trigeminal nerve after the initial infection has passed and can reactivate and cause symptoms again in situations where immunity is reduced, such as stress, illness, moving, surgery, birth or adding a new animal.

What is the most reliable diagnostic test for Feline Herpesvirus (FHV) in cats?

The most reliable method for diagnosing Feline Herpesvirus (FHV) is the PCR test; the genetic material of the virus is directly detected in samples taken from the eye discharge, nasal swab or oropharyngeal region, allowing a definitive diagnosis and differentiating FHV from other respiratory agents.

Are antibiotics required for Feline Herpesvirus (FHV) treatment?

Because Feline Herpesvirus (FHV) is a viral disease, antibiotics do not kill the virus; however, since secondary bacterial infections are very common, antibiotic treatment is necessary when there is a purulent discharge, fever or signs of severe breathing.

Can cats be cured completely from Feline Herpesvirus (FHV)?

Feline Herpesvirus (FHV) is not completely cleared from the body; the virus remains latent in the nerve tissue for life and can be reactivated under suitable conditions, so although the disease is not completely cured, the symptoms can be successfully controlled with the right care and treatment.

Can Feline Herpesvirus (FHV) in cats be fatal?

Feline Herpesvirus (FHV) can be fatal, especially in kittens, immunocompromised cats, and FIV/FeLV positive cats, causing serious complications such as severe respiratory distress, dehydration, and progression of eye ulcers.

How long is the Feline Herpesvirus (FHV) contagious period?

Feline Herpesvirus (FHV) is contagious for 2–3 weeks in the acute phase; however, cats that are latent carriers may be periodically contagious throughout their lives because they can re-shed the virus during periods of stress or illness.

Can a cat carrying Feline Herpesvirus (FHV) appear healthy?

Yes, many cats carrying Feline Herpesvirus (FHV) can live healthy for long periods without showing obvious symptoms; however, factors such as stress, illness, childbirth or seasonal changes can reactivate the virus, causing symptoms to appear.

What should be done if a cat with Feline Herpesvirus (FHV) has a loss of appetite?

Nasal congestion and loss of appetite due to pain are very common during the Feline Herpesvirus (FHV) period; food should be warmed to increase its aroma, strong-smelling wet food should be used, the cat's water consumption should be encouraged, and if loss of appetite approaches 24 hours, veterinary evaluation is essential.

Can Feline Herpesvirus (FHV) be transmitted to other cats in the household?

Yes, Feline Herpesvirus (FHV) is very contagious and can spread quickly to other cats in the household, so isolating the infected cat, separating shared litter boxes, keeping litter boxes separate, and implementing hygiene protocols is essential.

What is the most effective home care for Feline Herpesvirus (FHV)?

The most effective care is regular nose and eye cleaning, humidification, providing a warm and quiet room, using strongly flavored wet food, reducing stress, and the disciplined application of medications prescribed by the veterinarian.

How to tell if Feline Herpesvirus (FHV) is causing eye ulcers?

Findings such as severe redness in the eye, avoidance of light, blinking, a dull spot on the eye surface, complete closure of the eye, or increased discharge suggest a corneal ulcer caused by Feline Herpesvirus (FHV) and require urgent ophthalmologic evaluation.

Why is Feline Herpesvirus (FHV) more dangerous in kittens?

Because kittens' immune systems are not fully developed, Feline Herpesvirus (FHV) progresses rapidly and can cause complications such as severe nasal congestion, dehydration, refusal to eat, eye ulcers and pneumonia, severely reducing their chances of survival.

Why is Feline Herpesvirus (FHV) triggered by stress?

Because stress suppresses the immune system, Feline Herpesvirus (FHV), which lies latent in the nervous tissue, is reactivated; situations such as moving, adding a new animal, being alone, noise and illness are the strongest triggers of relapses.

Does the Feline Herpesvirus (FHV) vaccine prevent disease in cats?

The FHV vaccine does not completely prevent infection; however, it reduces the severity of symptoms, reduces the risk of complications, reduces contagiousness and largely prevents severe illness, especially in kittens.

Why does my cat have Feline Herpesvirus (FHV) and a constantly stuffy nose?

Feline Herpesvirus (FHV) causes intense inflammation and tissue damage in the nasal mucosa, disrupting mucus flow, narrowing the nasal passages, and a continuous cycle of congestion and discharge can develop, leading to chronic rhinitis and sinusitis.

Does a cat with Feline Herpesvirus (FHV) have an increased susceptibility to other diseases?

Yes, because Feline Herpesvirus (FHV) exhausts the immune system, susceptibility to other infections such as FIV, FeLV, Mycoplasma and Chlamydia may increase; also, bacterial secondary infections are more common.

Can cats with Feline Herpesvirus (FHV) live a normal lifespan?

The vast majority of cats carrying Feline Herpesvirus (FHV) can live a completely normal life with proper care, proper nutrition, stress management, and periodic veterinary checkups; however, periodic flare-ups may occur.

Can Feline Herpesvirus (FHV) be transmitted to other animal species?

No, Feline Herpesvirus (FHV) is specific to cats; it does not infect dogs, humans, or other species, but it spreads very quickly among cats in the same household.

When should a cat with Feline Herpesvirus (FHV) be taken to the vet?

Complete loss of appetite, closure of the eye, thick purulent discharge, difficulty breathing, bruising, severe weakness, suspicion of eye ulcers, or rapid worsening of symptoms over a few days are conditions that require urgent veterinary intervention for Feline Herpesvirus (FHV).

Sources

• Cat Fanciers' Association (CFA)

• The International Cat Association (TICA)

• American Veterinary Medical Association (AVMA)

• Mersin Vetlife Veterinary Clinic – Open on Map: https://share.google/XPP6L1V6c1EnGP3Oc