Sick dogs

[Dubhead]

Hi, someone might be able to help.My neighbour has 2 sick dogs, both are working farm dogs, though not overly used. 1 is a 12 year old blue heeler and the other a 9 year old hunterway they are exibiting symptoms such as vomiting,loss of apetite,unstable on feet, moaning,glassy eyedness, unusually quiet,and general lethargy. Both dogs never seem to be sick at the same time, but both have taken to eating dirt at the cow shed and cow dung.Their diet it is fairly well rounded with dog biscuits and brown bread and boiled potatoes though their meat diet has slipped a little in the last 12 months.Any ideas greatly appreciated.