Yes, rabbits can become sterile or experience reduced fertility if exposed to excessively high temperatures for prolonged periods. Rabbits are highly sensitive to heat stress due to their thick fur and inability to regulate their body temperature effectively. Heat stress can negatively impact their reproductive system and overall health.

Here are some ways in which heat stress can affect rabbit fertility:

1. **Decreased Sperm Quality**: High temperatures can affect the quality of sperm in male rabbits, leading to reduced fertility or even temporary sterility. Heat stress can impair sperm production, motility, and viability.

2. **Decreased Ovulation and Egg Quality**: Heat stress can also impact the reproductive system of female rabbits. It can lead to irregular or suppressed ovulation, resulting in fewer viable eggs. The quality of the eggs may also be affected, reducing the chances of successful fertilization.

3. **Reduced Libido**: Heat stress can decrease the libido and sexual activity of both male and female rabbits, leading to reduced mating behavior and lowered fertility.

4. **Increased Resorption of Embryos**: Pregnant rabbits exposed to high temperatures may experience increased resorption of embryos, resulting in reduced litter sizes or even early pregnancy loss.

To prevent heat stress and its impact on fertility, it is essential to provide proper heat management for rabbits, especially during hot weather. Here are some measures to help prevent heat-related fertility issues:

- Ensure rabbits have access to shade and well-ventilated areas.
- Provide ample fresh water at all times to keep them hydrated.
- Use fans, misters, or cooling pads to create a comfortable environment.
- Avoid breeding during extreme heat periods.
- Monitor rabbits closely for signs of heat stress, such as lethargy, panting, or loss of appetite.

By implementing appropriate cooling measures and prioritizing the rabbits' welfare during hot weather, you can help maintain their fertility and overall health.