Step 1: Recall what foot and mouth disease is.
Foot and mouth disease (FMD) is a highly contagious viral disease. It produces fever along with blisters inside the mouth and on the feet of the affected animal, which is how it gets its name.
Step 2: Identify the animals it affects.
FMD mainly affects cloven hoofed animals, meaning animals whose hoof is split into two parts. Cattle, along with buffaloes, sheep, goats, and pigs, belong to this group and are the animals commonly struck by outbreaks of this disease. It spreads fast in cattle herds and causes major economic loss through reduced milk yield and weight loss.
Step 3: Rule out the other options.
(A) Cats and dogs: These are not cloven hoofed animals and are not the animals associated with FMD outbreaks. Incorrect.
(C) Poultry: Birds are affected by diseases like bird flu and Ranikhet disease, not by foot and mouth disease, since they are not cloven hoofed mammals. Incorrect.
(D) Humans: Human infection with the FMD virus is extremely rare and is not how this disease is classified; it is recognized as a disease of livestock. Incorrect.
Step 4: Final answer.
Foot and mouth disease is a well known viral disease of cattle and other cloven hoofed livestock.
\[ \boxed{\text{Cattle}} \]