Introduction
Feral cats are cats that live outdoors in colonies and do not have an owner. They are un-socialized to humans and avoid human contact. According to research, upper respiratory infections (URI) are very common in feral cat colonies, with some studies showing infection rates as high as 80% (https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3552587/). URI can spread quickly and easily in groups of feral cats due to their close contact and lack of medical care.
URI in feral cats can cause significant illness and even death. The most common pathogens are feline herpesvirus and feline calicivirus. Symptoms include sneezing, runny nose and eyes, lethargy, reduced appetite, and fever (https://www.vet.cornell.edu/departments-centers-and-institutes/cornell-feline-health-center/health-information/feline-health-topics/respiratory-infections). URI also leaves cats more vulnerable to secondary infections. Treating sick feral cats can improve their health, reduce suffering, and prevent spreading infection to other cats in the colony.
Causes
There are several potential causes of upper respiratory infections in feral cats:
Viruses: The most common viruses that cause URI in cats are feline herpesvirus (FHV-1) and feline calicivirus (FCV). These highly contagious viruses can spread rapidly through a feral cat colony. FHV-1 targets the eyes and nasal passages, while FCV affects the mouth, nose, and upper airways.
Bacteria: Secondary bacterial infections often occur as a result of the viral infection. Common bacteria include Bordetella bronchiseptica, Streptococcus spp., and Chlamydophila felis.
Environmental factors: Feral cats living outdoors are exposed to various irritants like cigarette smoke, dust, and pollution that can exacerbate respiratory infections. Stress, malnutrition, and overcrowding are also risk factors in feral colonies.
Symptoms
The most common symptoms of upper respiratory infections in feral cats include:
Sneezing – Feral cats with an URI will often have frequent sneezing episodes. The sneezing is the body’s attempt to expel mucus and irritants from the nasal passages.
Nasal discharge – Cats with an URI usually develop a thick nasal discharge that can vary in color from clear to yellow or green. This is caused by inflammation in the nasal passages.
Eye discharge – Infected cats frequently have discharge coming from one or both eyes. This is usually a clear, watery discharge but can sometimes be thicker and discolored.
Lethargy – Upper respiratory infections make cats feel unwell. A feral cat with an URI may seem more tired and inactive than usual.
Loss of appetite – Since cats with a respiratory infection have a decreased sense of smell, they often have a decreased appetite. Feeding a highly palatable canned food may help entice the cat to eat (1).
Diagnosis
Diagnosis of an upper respiratory infection in feral cats is typically based on the characteristic clinical signs observed during a physical examination by a veterinarian. Common symptoms that may indicate an upper respiratory infection include sneezing, nasal discharge, watery eyes, squinting, lethargy, reduced appetite, and ulcers on the tongue, mouth, and nose. The veterinarian will listen to the cat’s breathing with a stethoscope to check for crackling sounds indicating pneumonia. They will also feel for lymph nodes under the jaw to see if they are enlarged, which often happens with respiratory infections.
Laboratory tests may be performed if the veterinarian suspects a bacterial infection, needs to identify the specific pathogen involved, or determine antibiotic sensitivity. These can include cultures from the throat or eyes, blood tests, and PCR tests. X-rays of the chest may also be taken if pneumonia is suspected. However, diagnosing the exact causative agent is often not critical for treatment in feral cats since the approach usually involves broad-spectrum antibiotics for likely bacteria along with supportive care.(Source)
Treatment
URI in feral cats requires aggressive treatment to prevent complications and alleviate symptoms. Some treatment options include:
- Antibiotics like doxycycline or amoxicillin help treat secondary bacterial infections that often arise and reduce damage from the infection.
- Anti-inflammatories like prednisolone help reduce inflammation in the upper respiratory tract.
- Nebulization therapy delivers medication via mist to open congested airways.
- Fluids help feral cats stay hydrated since URI often leads to reduced eating and drinking.
- Nutritional support through soft foods, nutritional gels, and appetite stimulants can aid cats who aren’t eating.
Veterinarians will tailor the treatment plan based on the cat’s symptoms and response. Quickly starting cats on appropriate antibiotics and supportive care is key to effectively treating URI in ferals.
Trap-Neuter-Return
Trap-Neuter-Return (TNR) programs are crucial for managing feral cat colonies and stopping the spread of disease. During the TNR process, feral cats are humanely trapped, spayed/neutered, vaccinated, and eartipped to mark them as part of the TNR program. Any sick cats can also be treated for issues like upper respiratory infections before being returned to their colony site.
It’s important to treat any URI symptoms during the TNR process to stop the infection from spreading. According to the ACRS Guide to Managing Community Cats, antibiotics can be used to treat URIs in feral cats during TNR. The antibiotics help clear up the infection so the cat can be safely returned without transmitting the illness.
Overall, TNR prevents reproduction and disease transmission within feral colonies while allowing the cats to live out their lives. Treating sick cats during TNR is a compassionate way to improve cat health and public health.
Nursing Care
Providing proper nursing care is essential for feral cats recovering from upper respiratory infections. Since ferals are not socialized to humans, the main focus should be on keeping the cat warm, hydrated and eating during recovery (source). Here are some tips for nursing care:
Warmth is important, as cats with URIs can develop fevers. Provide warm, dry shelter and bedding so the cat can rest comfortably. Insulated shelters or heated pads can help maintain body temperature if the cat is struggling with fever.
Encourage eating by providing smelly, appetizing foods like tuna, salmon or chicken. Place food and water near the shelter so the cat doesn’t have to exert itself to reach them. Hydration is critical, so provide canned or meat-based foods with high moisture content.
Monitor the cat’s condition from a distance, allowing it to remain in its shelter as much as possible. Watch for signs of worsening illness, such as open-mouth breathing, severe lethargy, or loss of appetite. If symptoms persist beyond 2 weeks, veterinary intervention may be needed (source).
With supportive nursing care at home, most cats can recover fully from minor URIs within 2-4 weeks. Be patient, allow plenty of rest, and ensure basic needs for food, water and shelter are met during recovery.
Prevention
The most important way to prevent upper respiratory infections in feral cats is through vaccination. Vaccines for feline herpesvirus, calicivirus, and panleukopenia are critical to protecting community cats from illness. Kittens should receive an initial series of vaccines starting at 4-6 weeks of age, with boosters every 2-4 weeks until 16 weeks of age. Adult cats should receive routine booster vaccinations annually according to veterinary recommendations (1).
Reducing stress is another key factor in prevention. Overcrowding, poor nutrition, and competition for resources can stress cats and weaken their immune systems. Providing adequate food, water, and shelter for all cats in a colony helps reduce stress levels. Separating sick cats from healthy ones also limits exposure and spread of illness (2).
Maintaining a clean living environment helps stop transmission of upper respiratory pathogens. All food bowls, litterboxes, bedding, and shelters should be cleaned regularly with diluted bleach to disinfect surfaces. Any toys, bedding, or supplies used by a sick cat should be thrown away or thoroughly disinfected before being used by other cats (3).
(1) http://www.saveacat.org/uploads/4/8/4/1/48413975/acrs_guide_to_managing_community_cats_-_ch._11_-_health_care_for_feral_cats_guidlines_for_colony_caretakers.pdf
(2) https://icatcare.org/advice/cat-flu-upper-respiratory-infection/
Prognosis
The prognosis is often good for feral cats with upper respiratory infections if proper treatment is provided (Cornell Feline Health Center). Most cats will recover fully with appropriate antibiotics, anti-inflammatories, and supportive care. However, upper respiratory infections can recur in feral cats since they usually remain in colonies where viruses persist. Without treatment, respiratory infections can progress to pneumonia or other complications that pose greater risks. Kittens and older cats tend to suffer more severe effects if left untreated. Providing early medical care improves the prognosis and prevents transmission to other cats in the colony.
When to Seek Help
You should seek veterinary help for a feral cat with an upper respiratory infection if the symptoms persist for more than 2 weeks. Upper respiratory infections in cats are usually caused by viral infections and tend to resolve on their own within 1-2 weeks. If symptoms such as nasal discharge, sneezing, coughing, watery eyes, or fever continue past 2 weeks, veterinary care is recommended.
Additional symptoms that warrant a veterinary visit include difficulty breathing, loss of appetite, and lethargy. Difficulty breathing or open-mouth breathing could signal the infection has progressed to pneumonia. Not eating or a lack of energy/engagement are also concerning signs that point to a more serious illness. In any of these situations, the cat likely needs medical intervention with antibiotics, anti-viral medication, fluids, and supportive care.
While adult feral cats often recover from upper respiratory infections on their own, kittens with URI tend to deteriorate rapidly. Any feral kittens exhibiting URI symptoms should be evaluated by a vet as soon as possible for the best chance of survival and recovery.
