Problems and Challenges with Analysis of Short Tandem Repeats (STRs) in Animal DNA.

The number of households with pets has been steadily increasing in recent years, highlighting the growing social and economic importance of companion animals. The increasing role of animals in human life and the need for biodiversity protection have contributed to growing interest in animal DNA analysis, although it still remains less developed than human forensic genetics. Current research focuses on genetic identification, parentage verification, biodiversity monitoring, and wildlife forensic investigations. DNA identification methods have evolved from restriction fragment length polymorphism (RFLP) to short tandem repeat (STR) analysis, which is currently one of the most widely used approaches due to its high sensitivity, discriminatory power, and the possibility of multiplex amplification. Recent advances include the implementation of massively parallel sequencing (MPS/NGS), sequence-based STR typing, and integrated SNPSTR systems, which significantly improve the interpretation of complex and degraded samples. Despite challenges associated with PCR artefacts, stutter formation, allelic imbalance, and interpretation of low-template DNA, STR markers remain valuable tools in forensic analyses, conservation genetics, and combating illegal wildlife trade. Continued development of new marker panels, standardized nomenclature systems, and bioinformatic approaches is essential for improving the effectiveness and reliability of animal genetic identification.