Regarding diet, canines thrive most on proteins and animal fats and less on carbohydrates or vegetables. The highest concentration of these elements is found in food that contains mostly meat, poultry, and their byproducts. A working dog's diet should consist mostly of fat, with a slightly smaller proportion of proteins and a small percentage of carbohydrates. Working dogs must be conditioned to work in all types of weather and strenuous situations, which requires regular and rigorous physical training that includes a strict schedule of exercises that relate to the tasks the dog must perform in work assignments. Canines may suffer injuries and wounding on the job, as well as a variety of illnesses. The most common illnesses in patrol dogs are bloat, heatstroke, and dehydration. K-9 officers should gain knowledge of canine anatomy and the symptoms of various conditions, so that referral to veterinarians will be timely. An appropriately stocked first-aid kit should be kept in the patrol car at all times. In retirement, canine partners continue to need special care from the officer and his/her family. The handler must make clear to family members what behaviors will trigger aggression in the dog. Although no longer officially a working dog, the dog will continue to behave according to the training and conditioning given for police work. A veterinarian should be consulted about treatment for painful changes in musculature and joints that comes from aging.