65. The following appeared in the promotional literature for Cerberus dog food. “Obesity is a great problem among pet dogs, just as it is among their human owners. Obesity in humans is typically caused by consuming more calories than the body needs. For humans, a proper diet for losing weight is a reduced-calorie diet that is high in fiber and carbohydrates but low in fat. Therefore, the best way for dog owners to help their dogs lose weight in a healthy way is to restrict the dog’s diet to Cerberus reduced-calorie dog food, which is high in fiber and carbohydrates but low in fat.” Discuss how well reasoned... etc.(下文思路单一，两段都是谈类比错误。还可以谈人即使与狗有可比性，这种狗食也未必是“最好”的治疗方案！)
In this argument the makers of Cerberus dog food recommend their reduced-calorie product as the best way for dog owners to help their obese dogs lose weight. Their reasoning in support of this recommendation is simple. To begin with, they point out that the best way to treat obesity in humans is by a reduced-calorie diet that is high in fiber and carbohydrates but low in fat. Second, they indicate that reduced-calorie Cerberus dog food is high in fiber and carbohydrates but low in fat. The conclusion drawn from this information is that Cerberus dog food is the best way to treat obesity in dogs. This argument is unconvincing for a couple of reasons. In the first place, the makers of Cerberus dog food assume that the cause of obesity in dogs is the same as the cause in humans. Given the vast differences between the exercise patterns and basic diets of humans and dogs, this assumption is highly dubious. Lacking evidence to support this claim, the argument is unacceptable. In the second place, the author assumes that the gastrointestinal systems of dogs and humans are sufficiently similar to ensure that treatment that is effective on humans will be equally effective on dos. Again, this is a highly dubious assumption due to the obvious physiological differences between humans and dogs. Since no evidence has been offered to support this assumption, it too can be rejected. In conclusion, this argument is unconvincing. To strengthen the argument evidence is required to substantiate the assumption that dogs and humans are sufficiently similar in both their diets and their physiology to warrant similar treatment.