Occurrences of group G Streptococcus in animals are mostly associated with S. canis, which normally infects domesticated dogs and cats. However, the pathogen can be horizontally transferred to other domesticated animals from either of these two animals. A documented instance of this transfer occurred on a central New York farm between a cat which was exhibiting chronic sinusitis and a dairy cow. This transfer resulted in S. canis mastitis on the udder of the cow, which appeared to be normal, leading to a prolonged diagnosis. Additional horizontal disease transfer to other cows in the herd was facilitated due to poor udder health management procedures, which included the use of a common cloth to wipe the udders of the cows following milking and the failure to use disinfection techniques. An outbreak of S. canis mastitis occurred from these transfers, but was controlled using antibiotic treatments and prevention techniques.
