Cat Bordetella

Introduction

Bordetellosis is a highly contagious bacterial disease of cats that causes mild to severe respiratory symptoms, especially in kittens and other cats with underdeveloped or weakened immune systems. The causative organism, Bordetella bronchiseptica, is a small, aerobic gram-negative coccobacillus microorganism that targets the upper respiratory tract of cats, dogs and even people.

How Bordetellosis Affects Cats

Cats exposed to Bordetella bronchiseptica are much less commonly affected clinically than are dogs. Some cats are chronic carriers of the bacteria and periodically shed it without ever showing any clinical signs. Other cats show only periodic mild symptoms, while some - especially very young kittens – will develop severely progressive and life-threatening bronchopneumonia. When affected cats do show clinical signs of Bordetella bronchiseptica infection, they typically include fever, sneezing and nasal and ocular discharge which last less than 2 weeks. Cats also can have enlarged lymph nodes and lose their appetite. Coughing is an inconsistent sign in cats. Kittens can die in as little as 12 hours after their initial signs appear. The most threatening aspect of Bordetella infection is that it can weaken the cat's immune system to the point where dangerous secondary bacterial and viral infections can occur.

Causes & Prevention

Causes of Bordetellosis in Cats

The bacterium that causes bordetellosis in cats is the same one that is responsible for causing "kennel cough" in dogs. Infected dogs can transmit this infection to cats, and vice versa. Bordetella bronchiseptica can be transmitted through aerosolized microdroplets from infected animals and also by direct physical contact. It is highly contagious. Barking, hissing, spitting and meowing are all common animal behaviors that can release infectious secretions into the air. This disease tends to plague areas that house multiple cats, especially if the cat population continually changes. Catteries, pet shops and animal shelters are primary sites for bordetellosis. Kittens and unvaccinated cats that live outdoors are also at increased risk of developing clinical disease.

Preventing Feline Bordetellosis

Given the extreme contagiousness of this disease, the best prevention is to avoid contact between infected and non-infected animals. New animals should be separated from household members for several weeks to reduce the chance of cross-infection. Good hygiene and responsible feeding and environmental care are of course important to the welfare of any companion animal. Vaccinations are available for feline bordetellosis, although their effectiveness is somewhat questionable. They are not routinely used, but can be considered in high-risk, multi-cat environments.

Special Notes

Bardetellosis is a zoonotic disease. It is especially dangerous for people with compromised immune systems, who should not be around infected animals.

Symptoms & Signs

Bordetellosis is a highly contagious bacterial disease of cats that causes respiratory symptoms, especially in kittens and other cats with underdeveloped or weakened immune systems. Cats exposed to Bordetella bronchiseptica are much less commonly affected clinically than are dogs. Some cats are carriers of the bacteria and periodically shed it without showing any clinical signs. Other cats may show only mild symptoms, while some - especially very young kittens – will develop severe and life-threatening bronchopneumonial disease.

Symptoms of Feline Bordetellosis

When affected cats develop clinical signs of infection with Bordetella bronchiseptica, they typically are characterized by fever, sneezing and nasal and ocular discharge that last less than 2 weeks. Cats also tend to develop swollen submandibular lymph nodes and may become lethargic, intolerant to exercise and stop eating. Coughing is an inconsistent sign in cats but is the most common sign in dogs. When cats do develop a cough from this disease, it typically is moist and productive and is accompanied by breathing difficulty. These signs can appear together or separately and frequently are progressive, especially in immunocompromised animals.

Bordetellosis symptoms often progress rapidly in cats that are fighting other underlying medical conditions such as feline leukemia, feline immunodeficiency virus or other upper respiratory infections such as viral feline herpes. Kittens can die in as little as 12 hours after their initial symptoms appear. Death is usually the result of secondary bacterial infections that thrive on the kitten's weakened immune system. While the clinical manifestations of so-called "kennel cough" in cats may not seem particularly serious, the infection is very contagious and should be treated immediately.

Diagnosis & Tests

Bordetellosis in cats is somewhat difficult to diagnose because the causative bacteria, Bordetella bronchiseptica, causes clinical signs that mimic those caused by other infectious agents. Definitive diagnosis requires identification of the particular bacterial culprit.

Diagnosing Bordetellosis in Cats

When a cat comes into a clinic with signs that suggest possible Bordetella infection, the veterinarian will take a swab sample of secretions from the cat's nasal passage and/or from its throat. The sample will be placed into a sterile glass tube and sent to an outside laboratory for culture and microorganism identification. Isolation of the bacteria in cases of active clinical disease is fairly easy. It is more difficult to isolate Bordetella from samples taken from cats who are chronic carriers but show no signs of clinical illness. PCR tests are available to identify the bacteria's specific DNA rather than identifying the bacteria itself.
Outside laboratories often take 48-72 hours to produce results. As a result, many veterinarians will make an initial diagnosis of feline bordetellosis based upon the animal's history and clinical presentation. If the cat lives, or recently lived, in an area housing multiple cats or in a household with a dog that was recently diagnosed with Bordetella infection, then the cat is at a high risk for developing bordetellosis. Many cats that are infected with the Bordetella organism are also suffering from other causes of upper respiratory tract disease. Thorough blood and urine evaluation, including feline leukemia and feline immunodeficiency virus tests, are normally performed to round out the assessment of the causes of the affected cat's condition.

Treatment Options

Feline bordetellosis typically can be treated successfully with antibiotics. Treatment of affected cats coming from multi-cat households should include treating all cats for the disease and using proper disinfecting measures.

Treating Bordetellosis in Cats

Uncomplicated cases of feline bordetellosis are best treated on an outpatient basis, both for the welfare of the affected animal and equally importantly to prevent cross-infection of other hospitalized cats. A number of oral antibiotics are available to treat this disease in cats and kittens, normally over a 10-to-14 day course of therapy but possibly longer. Cats with complicated disease, including pneumonia, should be treated as inpatients in a veterinary hospital, as they likely will require intravenous fluid and antibiotic therapy. Cough suppressants can also be helpful, although they can reduce clearance of infectious organisms and are not recommended for cats with pneumonia.
Because bordetellosis is very contagious and rapidly progressive in kittens and immunocompromised cats, many veterinarians will begin antibiotic treatment for suspected Bordetella bronchiseptica infection even before laboratory results are completed. All cats that have come into contact with an infected cat (or with environmental areas frequented by the infected cat) should be placed on antibiotic treatment as well. Owners should not wait until their cats begin to show signs before starting antibiotic therapy. Feeding dishes, water dishes and living spaces should also be thoroughly disinfected. Cats and kittens that are diagnosed with Bordetella bronchiseptica infection should be quarantined from all other cats until their treatment is finished. Enforced rest for the duration of treatment, and often for up to 21 days, is highly recommended. Adequate hydration is essential as well.