Japanese research has found evidence of treponemes in equine canker by looking for specific portions of RNA characteristic for the organisms.
Canker is a chronic proliferative condition of the horse's foot - affecting the frog and bars and sole. In severe cases it may extend to involve the hoof wall. Similar conditions in cattle and sheep have been shown to be associated with spirochete bacteria - in particular treponemes.
Dr Kyaw Kyaw Moe and colleagues examined samples from lesions in two horses and compared them with samples from an unaffected horse.
They found spirochetes in microscopic sections of the canker lesions. They also found 114 clones in the affected horse samples and none in samples from normal horses.
The clones could be classified into 19 separate groups - corresponding to many different treponemes, including those implicated in bovine papillomatous digital dermatitis.
Despite this the researchers were unable to culture the organisms. This is not surprising as treponemes are slow growing and are often overgrown by more rapidly growing bacteria.
The research confirmed the presence of treponemes in canker lesions in two horses and their absence in a normal horse. However, as the study was based on only a couple of cases, the researchers could not confirm that treponemes are the cause of canker - further work is required involving more cases.
Read more at equinescienceupdate.com