Faecal Furphy

When do you worry about a C. perfringens positive on faecal PCR? Well… Never. PCR tests for the genetic material to produce the toxin, not the toxin itself. There is no correlation between amount of genetic material and toxin levels, so this test is a bit of a furphy. Then why do so many patients respond to diet modification and metronidazole, you say? Most infectious or inflammatory GIT processes, even transient gastroenteritis will cause some degree of dysbiosis (aka altered GIT micro biome). So feeding a quality diet, full of “prebiotics” (foods that feed “good bacteria”), and metronidazole will help to rebalance things and decrease the effects of the original injury. There is currently minimal evidence to say that probiotics benefit these dogs, though the evidence is very strong in humans – and it doesn’t do any harm!