Glendale Animal Hospital - The Family Veterinarian


The world is, to say the least, filled with bacteria. They are everywhere, both inside and outside of all living and non-living surfaces on our planet. Most are at best harmless, and many provide important functions such as helping with digestion, improving soil quality, and with manipulation by man, produce life-giving medicines. Given whatever food sources particular bacteria needs to survive they can reproduce in astronomical numbers.

Certain bacteria, however, are not the friend or man or cat. Others may live in or on the pet, causing no harm until some other circumstance opens the way for invasion. These are called opportunistic organisms. There are literally thousands of bacterial species in our world. The ones that cause specific illness or the most common opportunists are listed herein.



Staph bacteria, located on most skin and hair surfaces, are extremely common. Normal levels of these bacteria help maintain the health of the skin and coat. This bacterium is very opportunistic and can become involved in many types of skin infections including pyoderma or folliculitis among others. Many different strains of staph exist and many of these can be quite resistant to antibiotics. Because of the prevalence of Pasteurella in the cat, staph may be a less important opportunist than in other species. 



Lyme disease has been a growing problem for dogs and man in the last decade. The bacteria Borrelia burgdorferi is responsible for causing this disease. Although there is evidence to suggest that cats do become exposed to the bacteria, there is no evidence that cats actually get any form of "Lyme disease" as do dogs.



Leptospirosis is a bacterial infection of many species that can also be transmitted to man. The bacteria Leptospira interrogans, of which there are over 100 subtypes, may infect and be carried by cats but little evidence exists regarding significant, actual disease conditions caused by the organism.



Most people should, in today's world, be aware of the potential dangers of salmonellosis, a prominent type of food poisoning. There are many different subspecies of Salmonella bacteria and many can easily cause infection. Cats, however, do seem more resistant to these bacteria than other species. Most infections occur due to exposure to (ingestion of) contaminated food or water, especially birds, uncooked chicken and turkey meats and rodents.

Once an exposed cat swallows the bacteria, they invade and reproduce in the small intestine and can travel to lymph nodes, the spleen or the liver. These bacteria are also generally passed out of the cat in the feces for weeks following infection. Clinical signs most often include fever, lethargy, poor appetite, salivation, vomiting, diarrhea and abdominal pain. Mucus and blood is often noted in the feces. Cases of spontaneous abortion and conjunctivitis have also been reported due to Salmonella. Some cats may develop trouble breathing or signs of shock. Diagnosis is based on history of possible exposure, clinical signs, fecal analysis including fecal culture and possibly an intestinal biopsy. ((Bloody Diarrhea))


Although most veterinarians would use antibiotics to treat salmonella, they may not be the best choice in many of the cases. Good supportive care including IV fluids, anti-vomiting drugs, and intestinal protectants are all commonly employed. Some cats can become carriers of the bacteria if antibiotics are used improperly.



Caused by the organism Camphylobacter jejuni, this gastrointestinal disease is uncommon in household cats, but may be seen more so in cats kept in pet stores or shelters. Commonly, infection will occur after exposure to contaminated water or foods. Healthy cats may harbor the bacterium in the intestine without any symptoms occurring. It is not completely certain whether this organism is a primary or secondary pathogen. Viral infections, coccidia or giardia infections and stress can all allow camphylobacter to cause disease. It is felt that infected cats can pass the bacteria in their feces for months, thus acting as a source of exposure for other animals.

Clinical signs include vomiting, fever and a very watery and possibly bloody diarrhea that can last for a couple of weeks, especially in young kittens. Some cats have been known to have a very chronic, continual diarrhea. Most cats, however, do not progress to this extreme. Diagnosis is based on the history, clinical symptoms, fecal analysis and culturing the organism from the fecal material.


In general, cats with fever and bloody stools should receive careful and specific antibiotic therapy with some type of fluid and electrolyte treatment being instituted to combat dehydration and emaciation caused by long-term diarrhea. Disinfection of areas the cat lives in is also quite important. Good supportive care will save most cats.



Tetanus is a bacterial infection that leads to some degree of muscle spasms in the cat. It occurs when the bacteria Clostridium tetani enters a wound, causes an infection and then releases a toxin that attacks the nervous system. This is a relatively rare condition, as cats seem resistant to the infection/toxin. The disease will be most likely in cats kept near or around horses, which shed the bacteria in their (normal) feces.

As this infection, like many others, starts simply and innocently with a wound that becomes infected, it is important to be reminded that all wounds should be properly tended to early and not just allowed to heal or "see what happens". Ten to twenty-five days after the bacteria invades a wound, symptoms occur including muscle spasms made worse or stimulated by noise; the cat may be unable to stand with all four legs being outstretched and stiff and the head and tail may be curled up and over the back. Death will soon occur due to respiratory failure. Diagnosis is based on the clinical signs and history of having a recent wound.


Once tetanus is suspected, rapid treatment is essential. Any infected wound should be cleaned. Dead, infected tissue should be cut away under sedation. Flushing the wound free of any pus and administration of antibiotics is basic. Administration of a tetanus antitoxin can be given in an IV drip, but many cats are allergic to the serum, which would preclude its use.

Cats that have developed the more severe clinical signs can be saved with intensive care. They should be cared for as above, plus hospitalized on IV fluids with strong muscle relaxants and anti-spasmotics or antiseizure medications. Keeping the cat in a dark and very quiet environment is also important. Feeding through the IV or with a feeding tube can be used to maintain the patient. As long as the cat does not stop breathing and can be sustained for 7-10 days, they can recover completely in about a month.



Although this bacterium is not a primary pathogen, it is a common organism found in chronic and recurrent infections, often of the ear canal and in some cases of bacterial cystitis. This organism has the nasty tendency to be very resistant to treatment, to have few antibiotics that will even work to kill the infection, and even when it has seemingly been eradicated, somehow makes a return appearance. Some cats with chronic pseudomonas infections will require constant treatment with antibiotic mixtures simply to keep the infection in check. All recurrent or chronic infections should have culture and sensitivity analysis done so that the most direct and practical treatment can be quickly begun. ((Pseudomonas Ear Infection))



The bacteria Bordatella bronchiseptica has been noted to be present in cases of Feline Upper Respiratory Disease Complex and Infectious Pneumonia. The bacteria may reside in the respiratory tract of healthy cats and then cause infection secondary to a virus or some other agent. There is now a vaccine available for this disease as there is for dogs. For clinical signs please refer to the above noted diseases associated with this bacteria.



The bacterium Pasteurella multocida commonly lives in the mouth of the domestic cat. Knowing this fact, it is no wonder that this bacteria is so commonly isolated from bite and scratch wounds which have resulted in abscesses and cellulitis. Deeper punctures may result in cases of pyothorax. Besides the obvious problems noted above, the clinical signs of pasteurellosis include draining wounds of the face, legs and tail, hot and swollen legs and feet, fever, enlarged lymph nodes, pain and loss of appetite.  ((Abscess))



Mycoplasma spp. are the smallest and simplest bacterial organisms known. There are many different varieties and many reside in the nose, eyes and genital membranes of normal cats. Mycoplasma can cause conjunctivitis, but most commonly will become involved along with other organisms in cases of rhinitis, conjunctivitis and Feline Upper Respiratory Disease Complex. Most are easily killed with tetracycline-type antibiotics.



Mycobacteria are another special type of bacterial organism that tends to cause chronic granulomatous infections. Granulomas are hard, tumor-like masses composed of inflammatory materials and infectious organisms. Human tuberculosis is caused by mycobacteria, and human infection is a concern with the feline versions of mycobacterial disease. Three unique but uncommon conditions caused by these organisms are seen in the cat.

Feline Tuberculosis is quite rare in the United States as cats previously caught the disease from the unpasteurized milk of infected cows. Bovine tuberculosis is rare in this country. The bacteria would most commonly attack the digestive tract causing diarrhea, weight loss and abdominal distention due to fluid accumulation and the enlargement of the liver and the spleen. Disease of the skin, lungs and lymph nodes is also possible. It is generally recommended that infected cats not be treated although medications are available.

Feline Leprosy is another rare condition caused by an unidentified strain of mycobacteria. The disease manifests as multiple nodules (lumps) on the skin that are firm, ulcerated and draining a pus-like material. These occur most often near the head or on the legs in cats under three years of age. Local lymph nodes may also become enlarged. Surgical removal of the lumps and/or treatment with dapsone, rifampin, clofazimine or streptomycin can be effective.

Atypical Mycobacteriosis is a disease of the skin caused by mycobacteria that do not otherwise cause leprosy or tuberculosis. The disease seems to be transmitted from cat to cat by bite and scratch wounds. Lumps on or just below the skin will be present and these may drain bloody fluid or pus-like material. These masses are often confused with typical cat-bite abscesses or cellulitis. Diagnosis is confusing and treatment may be equally as difficult. Various antibiotics used for long periods of time and surgical removal of larger masses can be useful but are often unsuccessful. ((Mycobacterial Infection))