Does Ebola Fear Justify Involuntary Detention?

Let’s cut the crap … from the CDC website:
http://www.cdc.gov/animalimportation/bringinganimaltous.html

Bringing an Animal into the United States

CDC regulations govern the importation of animals and animal products capable of causing human disease. Pets taken out of the United States are subject upon return to the same regulations as those entering for the first time.

Example:

If the horse is not known to carry any diseases transmissible to humans, no CDC regulations would apply. However, the United States Department of Agriculture (USDA) requires various periods of quarantine depending on the country of origin of the horse. In countries with prevalent screwworm, the quarantine period is 7 days. Horses coming from countries with African horse sickness are quarantined for 60 days.

Why should we be more concerned with equine disease vectors than human vectors ?