Introduction
Cat respiratory infections are a common health problem for cats. According to this source, over 50% of cat respiratory infections are caused by feline calicivirus. Respiratory infections can range from mild to severe and, if left untreated, can be fatal. This article provides an overview of the common causes, symptoms, transmission, diagnosis, and treatment of feline respiratory infections. Understanding cat respiratory diseases is important for any cat owner so they can recognize signs of illness early and get timely veterinary care.
Common Causes
The most common causes of upper respiratory infections in cats are viral infections from pathogens like:
Feline herpesvirus (FHV-1) – This virus accounts for about 80% of feline upper respiratory infections, according to the Cornell Feline Health Center. The virus infects and damages epithelial cells lining a cat’s nose, throat, and conjunctiva. Cats usually contract FHV-1 at a young age from the queen or from contact with other infected cats. The infection then remains latent for life. Stress and other illnesses can reactivate the virus, leading to flare-ups of respiratory symptoms.
Calicivirus – This virus makes up another major cause of upper respiratory infections in cats, second only to FHV-1. According to VCA Animal Hospitals, the calicivirus attacks the oral cavity and upper airways, causing ulcers and respiratory illness. Cats typically contract calicivirus through direct contact with infected saliva or nasal discharge.
Chlamydophila felis – This bacterium can cause conjunctivitis, rhinitis, and bronchopneumonia in cats. Transmission often occurs between cats in multi-cat households or shelters. Stress and crowding may activate the infection.
Bordetella bronchiseptica – This highly contagious bacterium more commonly causes kennel cough in dogs but can also lead to respiratory infections in cats. It spreads through direct contact with discharge from infected animals.
Symptoms
Common symptoms of feline upper respiratory infections include sneezing, nasal discharge, eye discharge, fever, and lethargy, among others. According to Cornell University’s College of Veterinary Medicine, “Symptoms of upper respiratory tract infections include clear or colored discharge from the eyes or nose, coughing, sneezing, swelling of the mucous membranes in the nose, and conjunctivitis (inflammation of the moist tissues around the eyes).”
The VCA Hospitals website also notes that sneezing, congestion, runny nose, coughing, and discharge from the nose and eyes are common symptoms. They add that “Less specific symptoms of an upper respiratory infection include not eating, lethargy, fever, enlarged lymph nodes, and blepharospasm (squinting).”
Cats with an upper respiratory infection may have watery, mucus-filled or thick and purulent discharge coming from their nose and eyes. Excessive sneezing and coughing are also common. A fever over 103F indicates an infection may be present. Lethargy, loss of appetite and enlarged lymph nodes can also occur.
Transmission
Feline respiratory infections are highly contagious and easily transmitted through direct contact, airborne spread, and fomites. Direct contact includes nose-to-nose touching, grooming, and sharing food bowls or litter boxes with an infected cat. The viruses and bacteria that cause respiratory infections are shed in saliva, nasal discharge, tears, urine, and feces. Just brief exposure to these secretions can transmit the infection to another cat (Feline Upper Respiratory Infection – VCA Animal Hospitals).
Respiratory pathogens can also spread through the air via sneezing and coughing. The tiny droplets released can travel several feet and be inhaled by nearby cats. Airborne transmission is most likely to occur where large groups of cats are housed together, like shelters and catteries (Respiratory Infections – Cornell Feline Health Center).
Contaminated objects called fomites can spread infection between cats as well. Shared food bowls, water bowls, litter boxes, toys, bedding, and grooming tools can all harbor pathogens. A healthy cat can pick up respiratory germs by touching surfaces recently contaminated by an infected cat (Upper Respiratory Infection in Cats – PetMD).
Role of Humans
While humans can play a minor role in spreading respiratory infections between cats, they are not considered a major transmission vector. Humans can carry infectious agents like bacteria or viruses on their hands, skin, or clothing after handling an infected cat. However, respiratory infections mainly spread through direct contact and airborne droplets between cats (https://www.dvm360.com/view/some-feline-respiratory-infections-can-cross-species-lines). The role of humans in transmitting infections is small compared to cat-to-cat spread through sneezing, coughing, or shared litter boxes and food bowls.
Simple precautions like washing hands after handling sick cats, separating infected cats from healthy ones, and disinfecting surfaces can reduce any minor transmission risk from humans. While zoonotic spread to humans is possible with some feline respiratory pathogens, transmission from humans specifically back to cats is less common. With good hygiene and proper treatment, humans do not pose a major threat for spreading these infections between cats.
Prevention
To prevent the spread of cat respiratory infections, vaccination is critical. Vaccines for major viruses like rhinotracheitis, calicivirus, and panleukopenia help reduce the severity of symptoms if a cat contracts a respiratory infection. Annual booster vaccines are recommended by veterinarians to ensure continued immunity. Source: VCA Animal Hospitals
Limiting exposure to infected cats is also important. Keep cats indoors to reduce contact with stray or infected cats. Properly isolate any new cats before introducing them to other household cats. Follow sanitation protocols like washing hands before and after contact with cats and regularly disinfecting food bowls, litter boxes, and toys. Good hygiene helps prevent spread between cats. Source:PetMD
Diagnosis
Diagnosing a feline respiratory infection begins with a thorough physical exam by a veterinarian. The vet will check for symptoms such as discharge from the eyes or nose, sneezing, coughing, fever, and enlarged lymph nodes. They will use an otoscope to look inside the cat’s ears for inflammation or discharge. The mouth will also be examined for ulcers on the tongue, palate, and gums.
To identify the specific cause of the respiratory infection, the vet may take samples for laboratory testing. Common tests include:
- Nasal swabs or nasal flushes to collect discharge and look for bacteria, fungi, or viruses under the microscope.
- Conjunctival swabs of the eye to check for chlamydia or herpesvirus.
- Oral or pharyngeal swabs to identify calicivirus.
- Serology testing of blood samples to detect antibodies to infectious agents.
Imaging such as X-rays or ultrasound may also be used to evaluate the severity of the infection and look for complications like pneumonia. These diagnostic tests allow the vet to pinpoint the cause and determine the most effective treatment.
Source: https://vcahospitals.com/know-your-pet/feline-upper-respiratory-infection
Treatment
Treatment for a feline upper respiratory infection depends on the underlying cause. If a bacterial infection is present, antibiotics may be prescribed. Commonly used antibiotics include doxycycline, azithromycin, clindamycin, and amoxicillin (https://vcahospitals.com/know-your-pet/feline-upper-respiratory-infection). Antibiotics are ineffective against viral infections.
Antiviral medications may be used in some cases, especially if the cat is immunosuppressed. These can include drugs like famciclovir or interferon. However, antivirals are not routinely used in healthy cats (https://www.petmd.com/cat/conditions/respiratory/upper-respiratory-infection-cats).
Supportive care is important for all cats with an upper respiratory infection. This includes ensuring the cat stays hydrated by encouraging drinking or administering subcutaneous fluids. Appetite stimulants like mirtazapine may be prescribed if the cat is not eating. Nebulization and coupage can help loosen and clear mucus from the airways. Reduce environmental stress and keep the cat isolated from other pets until symptoms resolve (https://www.webmd.com/pets/cats/upper-respiratory-infection-cats). With appropriate care, most cats fully recover within 2-4 weeks.
Prognosis
The prognosis for feline upper respiratory infections depends on a few factors. The infection is often self-limiting if the cat’s immune system is healthy. Mild cases may resolve within 2-4 weeks without treatment as the cat’s immune system fights it off. However, the infection can become chronic or fatal if left untreated, especially in high-risk cats.
Kittens, senior cats, immunocompromised cats, and cats with concurrent illnesses are at higher risk of severe disease. Bacterial infections, pneumonia, or infections that spread to other organs also have a guarded prognosis. With aggressive antibiotic therapy, supportive care, and good nursing care, many cats fully recover. However, relapses are common and some cats become chronic carriers. Overall mortality rates are estimated between 10-20% but may be higher in high-risk groups.
Early veterinary intervention, identifying and addressing predisposing factors, patient monitoring, and owner compliance help ensure the best outcome. But upper respiratory infections can still persist or have lasting effects like corneal scarring despite treatment. Prognosis is generally good with appropriate care but potentially serious without it.
Conclusion
Feline upper respiratory infections are common in cats but can sometimes spread to humans or other cats. While the infections often resolve on their own, some can lead to more severe illness if left untreated. The key points to remember are:
- Most upper respiratory infections in cats are caused by viral or bacterial pathogens like feline herpesvirus, calicivirus, Chlamydophila, and Mycoplasma species.
- Symptoms include sneezing, discharge from the nose/eyes, fever, lethargy and loss of appetite.
- Humans play a minor role in transmission between cats through contact with respiratory secretions on hands or clothing.
- Preventing infections requires keeping cats up-to-date on vaccines, minimizing exposure to infected cats, reducing stress, and maintaining good sanitation.
- While many cases resolve on their own, antibiotics may be prescribed for bacterial infections. Severe cases may require hospitalization and supportive care.
- With prompt treatment, the prognosis for upper respiratory infections in cats is generally good.
In conclusion, feline upper respiratory disease is common but manageable with prevention and care. Limiting human transmission between cats along with vaccination, sanitation and stress reduction are the keys to safeguarding cat health.