Every state in the United States has regulations prohibiting acts of neglect and cruelty against animals. Local law enforcement and animal control agencies are responsible in many communities to enforce these statutes. As society's perception of horses has changed from their origin as livestock to companion animals in modern times, owners have transitioned their care and management. The goal of this study was to identify the role and capacities of local animal control services in the United States that investigate equine neglect, cruelty, and abandonment investigations and to identify challenges and outcomes of the investigations. A 128-question online survey was accessible for animal agencies to complete. Comprehensive questions included their capacity for investigating equine cases, funding, housing for horses, and causes and outcomes of investigations. Respondents also were asked to select a single case and provide detailed information on the condition of horses, seizure and custody procedures, costs, and prosecution proceedings. A total of 165 respondents from 26 states completed all or the majority of the questions. A total of 6,864 equine investigations were initiated between 2007 and 2009 by 90 agencies, which extrapolates to 38 investigations annually per agency. A typical agency has an average annual budget of $740,000, employs 7 animal control officers, and spends about $10,000 annually on equine cases. Neglect was ranked as the most common reason for investigation. Owner ignorance, economic hardship, and lack of responsibility were the highest ranked causes of neglect and cruelty. Individual cases were provided by 91 agencies concerning 749 equines. The physical condition of the horse was the primary factor of investigation, and low body condition, parasite infestation, and compromised dental condition were present in most seized horses. Over half of the equine owners previously had been investigated or charged with neglect or cruelty of animals or were identified with cruelty or abuse offenses to people. Less than 3% of the cases advanced to adjudication, and these were likely to be decided by a judge rather than a jury. Judgments of guilty verdicts and pleas were 9 times more common than acquittal. Challenges for equine investigations cases included lack of funding, limited availability of facilities for horses, and providing educational materials for horse owners to aid in prevention and resolution of neglect cases.