Yes, it appears that Solenodons and some shrews are the only other venomous mammals.

yes, these creatures have been around nearly as long as man. extraordinarily venomous to mankindness in many ways too numerous to mention. These entities have hipnotic effect on the unwary innocent. Draw the poor soul into a labrinyth of hemlock glee. Only to scathe away ones idea of health and happiness while diverting ones attention to estacy of the ass. Women need I say more.

I thought the cuddly Koala also had poisonous spurs on its hind legs and therefore had to be handled with care.

Yes. Only four mammals besides the platypus are poisonous (but not lethal to humans). They are all insectivores: two types of shrews (the Blarina and Neomys species) and two types of the rare shrew-like solendons. The short-tailed shrew (Blarina species) — a small mousy-looking insectivore — paralyzes insects and other prey with a poison that is both a neurotoxin (damages nerves) and a hemotoxin (destroys blood cells). The poisoned insects stay alive and immobile for three to five days as fresh food. The short-tailed shrew is the only poisonous mammal in North America. The water shrew (Neomys species) of Eurasia weakens its aquatic prey (snails, mollusks, and freshwater insects) with a similar saliva poison. Both species (Solenodon paradoxus and Solenodon cubanus) of the solenodon of the West Indies also are poisonous. In the dark of the night, the rat-size slow-moving animals sniff with their long tubular snouts for ants, insects, grubs, and small reptiles that venture forth. A solenodon or shrew kills by biting her victim. She stores the poison with her saliva in glands. When she bites a prey, the venomous saliva oozes down ducts to the base of her lower incisors, thence along side channels grooved in the teeth, and into the wound. Her teeth serve as a poison hypodermic — piercing the victim’s hide and injecting the venom. http://www.wonderquest.com/shark-dolphin-buddies-toxic-mammals-soap-germs.htm#toxic