It is clear that ultrasonography has multiple applications when breeding a range of animals, some of which have been discussed in previous articles. There are numerous issues that must be taken into consideration prior to breeding, which will form the basis of this discussion.

Age is always a factor when breeding, especially in dogs. Puppies are able to be registered from a bitch aged at least 12 months by the UK Kennel club, although moral issues may come into question here. Furthermore, it has been argued that some dog breeds are best to be mated sooner rather than later, although this is disputed. For example, Bulldogs may be best mated younger, as older dogs are more likely to be overweight, complicating the whelping process.

In contrast, cats are recommended to start breeding no younger than 10 months, although it is dependent on the specific breed, and breeding from cats aged 12 months may be better, particularly from an ethical viewpoint. Very interestingly, guinea pigs must be bred before they reach 12 months of age due to pelvic mineralisation preventing their ability to give birth. In the event that a guinea pig is bred at an older age, a Caesarean section may be required.

Finally, in sheep, the location of the animals can affect breeding. In the UK, one farmer can lamb a few hundred sheep in a season when compared to New Zealand, where one farmer can lamb thousands of sheep due to selective breeding. In addition, in New Zealand, sheep are selected that possess wider birthing canals, and bred with rams that do not have broad shoulders allowing the sheep to have an unassisted birth. Financial implications are also partly responsible here, as government-provided subsidiaries still available to UK famers are no longer available for NZ farmers, resulting in the latter having to become more frugal and economical.

When deciding to start breeding, a number of factors should be taken into account. In addition to the breeding guidelines, it is likely that each individual breeder also takes into account the needs of each individual animal. In conclusion, ensuring the right conditions for breeding are met, ultrasound imaging can aid in the establishment of pregnancy and any potential problems that may arise during gestation, and throughout the birthing process.