Respiratory infections are a frequent health concern for cats, particularly those in environments with many cats like shelters, breeding facilities, and feral colonies. These infections, caused by various viruses, bacteria, fungi, and protozoa, can significantly affect a cat’s well-being. While vaccinations have reduced severe respiratory diseases, highly contagious pathogens still exist.
Infections can affect both the upper and lower respiratory tracts. The upper tract comprises the nasal passages, sinuses, oral cavity, pharynx, and larynx. The lower tract includes the trachea, bronchi, and lungs (Figure 1).
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Symptoms of upper respiratory infections include nasal and eye discharge (clear or colored), coughing, sneezing, conjunctivitis (swelling around the eyes – Figure 2), mouth ulcers, lethargy, and loss of appetite. Difficulty breathing is less common but possible.
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Lower respiratory infections can manifest as coughing, lethargy, anorexia, and rapid or labored breathing (over 35 breaths per minute at rest).
Understanding common causes is crucial for effective Cat Upper Respiratory Infection Treatment. Here are some of the primary culprits:
Common Causes of Cat Upper Respiratory Infections and Their Treatments
Feline Herpesvirus (FVR)
Feline herpesvirus is highly prevalent, with up to 97% of cats exposed in their lives, leading to lifelong infection in up to 80% of those exposed. Stress can trigger viral shedding in up to 45% of infected cats.
Clinical Signs: Feline Viral Rhinotracheitis (FVR), as it’s known, presents with upper respiratory symptoms, corneal ulcers (keratitis), and fever.
Diagnosis: Diagnosis often relies on recognizing upper respiratory signs in young, unvaccinated cats or recurring eye issues in older cats, alongside PCR tests to detect viral DNA and virus isolation tests.
Cat Upper Respiratory Infection Treatment for FVR: Treatment strategies for FVR depend on disease severity. Supportive care, ensuring proper nutrition and hydration, is always vital. Nasal decongestants can offer relief. However, the stress of medication itself can worsen keratitis and conjunctivitis.
For acute cases in young cats, antiviral medications can treat corneal lesions and upper respiratory signs. Antibiotics are crucial to manage secondary bacterial infections, which are common with FVR. Recurrent keratitis or conjunctivitis can be managed with antivirals, corticosteroids, and stress reduction (avoiding overcrowding, new pets, moving, surgeries). Lysine supplementation, once discussed, is now controversial and potentially ineffective or even detrimental.
Prognosis: Cats remain carriers for life and may experience flare-ups, often mild and self-resolving, but severe cases can occur, especially in cats with other health issues.
Prevention: Vaccination against feline herpesvirus is recommended for all cats to reduce disease severity and viral shedding, protecting other cats.
Feline Calicivirus
Feline calicivirus is another highly contagious virus, affecting a significant portion of cat populations, especially in crowded environments.
Clinical Signs: While primarily causing upper respiratory symptoms, calicivirus can extend to the lower respiratory tract, causing pneumonia. Secondary bacterial lung infections can worsen breathing difficulties. Oral ulcers are possible, and rarely, a severe systemic form can develop, often fatal, causing head and limb swelling, skin sores, jaundice, and bleeding. Limping can occur temporarily.
Diagnosis: Suspect calicivirus with oral ulcers and acute upper respiratory signs. RT-PCR tests on blood or oral/eyelid swabs confirm diagnosis. Virus culture is also diagnostic.
Cat Upper Respiratory Infection Treatment for Calicivirus: Supportive care is paramount: hydration and nutrition are key. Oral pain from ulcers and nasal congestion can hinder eating. Non-steroidal anti-inflammatory drugs (NSAIDs) can alleviate oral pain. Clear nasal passages with mucolytics, saline nebulization, and saline wipes. A feeding tube may be needed for severe oral lesions.
Antibiotics treat secondary bacterial infections. Antiviral drugs are generally ineffective or have severe side effects. Corticosteroids and interferon have shown some promise in severe systemic cases, but more research is needed. Chronic oral ulcers may require dental cleaning, immune-modulating drugs, antibiotics, and pain relief, but optimal treatment is still under investigation.
Prognosis: Prognosis varies with severity. Uncomplicated cases recover in days to weeks, while severe systemic cases have a poorer outlook.
Prevention: Vaccination is recommended to lessen disease severity, though it doesn’t fully prevent infection or shedding.
Feline Chlamydiosis (Chlamydia felis)
Chlamydia felis is a bacterium transmitted through eye secretions, requiring close cat contact. Young cats and those in crowded housing are most susceptible.
Clinical Signs: Conjunctivitis is typical, with initially clear eye discharge becoming mucous-like and yellowish/pus-like. Appetite loss and lethargy are rare.
Diagnosis: PCR testing on eye swabs is the preferred diagnostic method. Lab culture is less sensitive. Antibody tests can be used for unvaccinated cats.
Cat Upper Respiratory Infection Treatment for Chlamydiosis: Antibiotics like doxycycline or amoxicillin/clavulanic acid are usually effective. Systemic treatment is preferred over topical eye application.
Prognosis: Prognosis is generally good with proper diagnosis and treatment.
Prevention: Vaccines minimize symptoms but don’t prevent infection. Vaccination is advised for multi-cat environments or where C. felis has been diagnosed.
Fungal Infections
Various fungi can cause respiratory issues in cats, with Cryptococcus neoformans being most common. Inhalation of spores leads to infection, which can stay nasal or spread.
Clinical Signs: Nasal cryptococcosis is most frequent, causing nasal/facial swelling, sneezing, chronic nasal discharge (possibly bloody), non-healing wounds, and nasal/throat growths. Vocal changes, noisy breathing, anorexia, and weight loss can occur. Lung spread leads to labored/rapid breathing. Central nervous system and skin involvement are also possible.
Diagnosis: Detecting C. neoformans proteins in body fluids, ideally blood, is preferred. Microscopic examination of nasal discharge is helpful. X-rays, CT scans, or MRIs assess fungal invasion and treatment response.
Cat Upper Respiratory Infection Treatment for Fungal Infections: Antifungal drugs are used, but definitive guidelines are lacking. Brain involvement may alter treatment and outcome.
Prognosis: Early diagnosis and no central nervous system involvement lead to a better prognosis. Treatment compliance is crucial and can be lengthy.
Prevention: Keeping cats indoors reduces exposure risk.
Bordetella bronchiseptica
B. bronchiseptica is a bacterium common in high-density cat populations, spread through oral/nasal secretions.
Clinical Signs: Symptoms range from mild coughing, sneezing, and eye discharge to severe breathing difficulty, cyanosis, and death. Severe signs are more common in young cats with lower respiratory infections.
Diagnosis: Respiratory samples can be cultured or tested by PCR, but both can be negative in infected cats.
Cat Upper Respiratory Infection Treatment for Bordetella bronchiseptica: Antibiotics, usually doxycycline, are the main treatment. Supportive care is essential. Antibiotics may be recommended even for mild cases to prevent worsening.
Prognosis: Most cats recover within 10 days of antibiotic treatment. Without treatment, the disease can worsen to pneumonia.
Prevention: A nasal vaccine is available for high-risk cats (shelters, catteries) but not for kittens under four weeks or cats on antibiotics. It can cause mild respiratory signs.
General Supportive Care for Cat Upper Respiratory Infections
Regardless of the specific cause, supportive care is crucial for cat upper respiratory infection treatment. This includes:
- Ensuring adequate hydration: Encourage water intake. Subcutaneous fluids may be necessary in severe cases.
- Providing nutritional support: Offer palatable food. Appetite stimulants or feeding tubes might be needed if anorexia is severe.
- Clearing nasal passages: Use saline nasal drops or wipes to remove discharge. A humidifier or steam from a hot shower can help loosen congestion.
- Creating a stress-free environment: Minimize stress factors as stress can exacerbate symptoms and hinder recovery.
- Veterinary Consultation: Crucially, any signs of respiratory distress or illness warrant a prompt visit to the veterinarian for accurate diagnosis and tailored treatment.
Conclusion
Cat upper respiratory infections are common and caused by various pathogens. Prompt veterinary care is essential for accurate diagnosis and effective cat upper respiratory infection treatment. While some infections are mild and self-limiting with supportive care, others require specific medications like antivirals, antibiotics, or antifungals. Vaccination and minimizing stress play important roles in prevention. With appropriate care, most cats recover well from upper respiratory infections and can return to their healthy, playful selves.
