Which marking on a cavy is considered not desirable?

The presence of a bare spot on a cavy is considered not desirable. This is because a bare spot can indicate health issues, such as skin conditions, parasites, or inadequate nutrition, which may affect the overall well-being and appearance of the cavy. In show settings, judges look for a healthy, well-groomed animal, and any unsightly bare patches can detract from the animal's presentation.

In contrast, markings like a blaze, bonnet strings, and a collar are specific to certain breeds and can actually be considered desirable traits that contribute to the cavy's overall appearance based on breed standards. These features can enhance the aesthetic appeal of the animal and may even be sought after in specific breeds, thereby having a positive effect in a show context. Understanding the implications of each marking helps in recognizing what is valued in showmanship and breeding standards for cavies.