What aspect of a cavy’s health is directly assessed during a show?

The aspect of a cavy's health that is directly assessed during a show is weight. Maintaining a healthy weight is crucial for the overall well-being and performance of the cavy. Judges look for cavies that are neither underweight nor overweight, as this can indicate their health and care. A healthy weight range ensures the animal has adequate muscle tone, energy levels, and is likely to be free from obesity-related issues or malnutrition.

Other factors such as coat condition, ear size, and tail length do contribute to the overall presentation and breed standards, but they do not directly assess the health of the cavy in the same way that weight does. Coat condition reflects grooming rather than health, ear size is primarily a breed characteristic, and tail length is also part of breed standards. Therefore, while they are important in evaluating a cavy, weight is the primary health-related measurement scrutinized during shows.