Hi, Heather,
According to work published by Profesoor Woodruff many years ago there is a host of diseases- zoonoses- which throretically
can be transmitted from dog to man.
In fact however, there are remakably few.
By far the most common is flea infestation - troublesome, but not life threatening! Sarcoptic mange in the dog is also capable of infecting humans in close contact, as is another form of mange, chyletiella, both of ehich can produce intensely itchy spots.
In certain parts of the country - parts of Wales and Scotland - Hydatidosis
can be a serious problem. Echinococcus granulosus is a small tapeworm living in dogs' intestines, and its eggs when eaten by other animals - mainly sheep - produce cysts in that animal, which when eaten by another dog complete the life cycle. However, if a human - particulary a child - fondle a dog which has these tapeworms, he/she may unewittingly swallow some of the taperwom eggs which grow into 'hydatid cysts' in the body - the liver, lungs, brain etc, and may prove fatal.
The common roundworm of the dog -Toxocara -(and the cat, and the fox) lays eggs which after 2-3 weeks lying in the ground, if swallowed by a human, can produce a condition called 'visceral toxocara migrans' which received a lot of publicity some years ago. The egs hatch in the bowel into larvae and move about the body. It can be serious if one of these larvae ends up in the back of the eye, where it can be mistaken for a cancer of the retina, which may result in the eye being unnecessarily removed.
Leptospirosis either L canicola or L incterohaemorragica are contagious disease which dogs may contract, and for a time they pass the organisms in their urine, and if humans come into contact with it, they may become infected. A far commoner source of infection in humans is rat urine - oven found in ponds where children amay swim.
With the ending of quarantine for dogs, whilst the risk of rabies is so low as to be virtually non-existent, there may be other diseases such as Leishmania which an imprted dog may be carrying, and is capable of infecting inc-contact humans.
There is also, of course, the risk of a dog bite, which may produce a serious local infection, or, in extreme cases, tetanus.
I hope that that is enough for you to be going on with.
What exactly is your interest?
Walter