Antibiotics may resolve feline diarrhoea but the veterinarian has to do extensive tests in order to diagnose antibiotic-responsive diarrhoea. The veterinarian has to rule out all other possible causes of the diarrhoea first.
Apparently, it is not uncommon for cat owners to ask if antibiotics can cure their cat’s diarrhoea but antibiotics are only useful if a specific bacterial cause is found in faecal cultures. In fact, in most cases of diarrhoea, we are told that antibiotics are not helpful and they can even make matters worse.
When antibiotics are effective to treat diarrhoea it is believed that cause of the diarrhoea is a “small intestine bacterial overgrowth” (pet MD website).
The source of this information is Dr Bruce Fogle.
P.S. The most common cause of diarrhoea is a sudden change in diet. Some cats develop lactose intolerance causing diarrhoea. Lactose-free milk should be used. If diarrhoea has been caused by scavenging it will normally clear up quite quickly. Adding an appropriate probiotic supplement to a cat’s diet will help diarrhoea clear up faster. Other causes of diarrhoea include: medicines, poisons, intestine problems including inflammatory bowel disease, worms and tumours, intestinal infections caused by viruses, single celled parasites and bacteria, metabolic diseases such as diabetes and hyperthyroidism and gastrointestinal infections.
Click on this link to see a list of articles on this website about feline diarrhoea.