Infectious diseases found commonly in animal shelters, including feline immunodeficiency virus (FIV), feline leukaemia virus (FeLV), feline herpesvirus (FHV-1), feline calicivirus, canine parvovirus (CPV), feline panleukopenia virus (FPV), giardiasis and Tritrichomonas foetus in cats. Mark also has a strong interest in animal welfare and behaviour, including the effects of animal hoarding and other stressful environments such as high density shelters.