Simple SummaryGuinea pigs are common pets but are susceptible to a range of diseases, some of which can be rapidly fatal without prompt veterinary attention. Bacterial infections are one cause of respiratory and gastrointestinal disease in guinea pigs, but few studies have reported how commonly these infections occur in pet guinea pigs or which types of bacterial infection are most often seen. A survey of guinea pig owners was conducted to assess the types of infections and signs of illness pet guinea pigs had suffered from. From the 524 responses it was determined that just under 40% of owners reported that their guinea pig had been diagnosed with a bacterial infection by their veterinarian. Upper respiratory tract infections were most common followed by urinary tract infections and gastrointestinal infections. Guinea pigs may not tolerate some antimicrobial drugs well due to disruption of the bacteria within their gut, therefore treatment of these types of infection can be challenging even if diagnosed early. Based on the frequency of bacterial infections reported by owners in this study, it is suggested that guinea pig owners practice good hygiene and husbandry and remain vigilant for signs of ill health in their pets.AbstractDomestic guinea pigs suffer morbidity and mortality due to a range of bacterial infections amongst other causes. Microorganisms such as Bordetella bronchiseptica and Streptococcus pneumoniae are commonly implicated in respiratory disease; however, there is a lack of research surrounding the prevalence of these bacterial infections. The aim of this study was to investigate the frequency with which owners reported bacterial infections in pet guinea pigs and to assess owner knowledge of correct husbandry practices to inform prevention of the development of bacterial infections. An online questionnaire, consisting of 30 questions was promoted to guinea pig owners. Of all respondents (n = 524), 39.39% reported that their guinea pig(s) had been clinically diagnosed with a bacterial infection, with upper respiratory tract infections the most commonly reported (46.95%), followed by urinary tract (15.49%) and then gastrointestinal infections (11.73%). Owners demonstrated knowledge of correct husbandry practices and there was no significant effect (p = 0.475) of owner knowledge on having owned a guinea pig with a bacterial infection. Bacterial infections may be more common in guinea pigs than was previously thought. Further research is required to understand why bacterial infections are common in pet guinea pigs and to help owners to prevent and recognize these infections.