Heat cycle is actually indication of achieving puberty in some animals like dogs and cats. In all dogs including Mini fox terrier get their first heat cycle at the age of 6-9 months. At this age, dogs are not physically mature enough to handle stress of pregnancy and labor, so, it is recommended that dogs should not be breed after their first heat cycle but ideal age is after 2 years. It is more better to get spay your dog to avoid many problems in future.
