Antibiotic Use in Cats

By now you have heard of the MRSA (methicillin resistant Staph. aureus) problems in people.  Just as in humans, animals have problems with drug resistance.  To compound the problem further, many bacterial species can found in both animals and people.  This creates an exposure risk to people if the animal has a resistant bacteria and the owner is handling bacteria-containing material. 

In the past, resistant bacteria were primarily picked up in hospitals or institutions where the potential for exposure was high and/or there was a high level of antibiotic use.  As with MRSA, it is now more common for infections to be picked up in general public locations.  Most of the time, common sense and reducing potential contamination will prevent illness.  It is important not to panic but to be aware of what creates the resistance in order to prevent the development of the resistant bacteria.

The most common cause of drug resistance is the inappropriate use of antibiotics and the second most common cause is not following directions for use.  All too frequently, antibiotics are used at an improper dose (too high or too little), an inappropriate frequency (once per day versus a prescribed twice daily) or an inappropriate length of time (two days versus a prescribed 10 days).  Use of antibiotics creates a "death" or lack or reproduction of bacteria.  If directions are not followed correctly, many bacteria are able to mutate to "protect" themselves against the killing action of future antibiotics.  Naturally, the bacteria reproduce and the new generation carries this resistant gene and the cycle continues until the bacteria are completely resistant to an antibiotic. 

A couple of prime examples of inappropriate antibiotic use specific to the cat include upper respiratory infections and urinary tract inflammation.  Too often, antibiotics are given when an actual bacterial infection is not even present.   In the case of upper respiratory infections, those are most commonly caused by viruses (feline herpes or calici viruses) and antibiotics should only be used if a secondary bacterial infection is present.  As with people, antibiotics do nothing for a viral infection; giving them just increases the risk of resistance.  As to urinary tract inflammation, in the cat, bacterial infection accounts for <3% of causes for blood in urine.  More commonly stress in the environment, cystitis, and bladder stones are the cause of the straining, with blood and/or inappropriate urination.  Correcting the underlying cause will result in resolution or control of the problem.  Treating inappropriately will increase the risk of development of resistant bacteria with concurrent environmental contamination. 

The best way to prevent the development of resistant bacteria is to properly diagnose and incorporate a few procedures into the treatment plan.  One should seek to use an antibiotic with a narrow spectrum of use rather than one that might get everything.  Culture and sensitivity should be utilized to identify the bacteria and the best antibiotic to use.  This is very important in the case of urinary tract issues where a culture diagnosis is superior to seeing "bacteria" on a slide and where so few urinary tract problems are caused by bacteria.

Recognizing risk factors for infections and correcting or preventing the problem where possible will assist in choosing which cases may need antibiotics.  Dental disease, diabetes, and cat fights are common risk factors of infection for cats.  Likewise, cats with feline leukemia, feline immunodeficiency virus or those on immunosuppressive medications (glucocorticoids, cancer therapy) are at an increased risk of bacterial infections.  Additionally, kitties with dilute urine commonly have a concurrent bacterial infection which is not picked up on routine urinalysis.

Utilizing proper health care protocols which include knowing viral status of all cats, proper dental care and routine health screening of blood and urine  (including culture) will go a long way to decrease the risk of resistant bacterial infection in both cats and the people who are around them.  Combining this along with following the proper dosing and treatment recommendations prescribed for the particular patient will protect all of us.