More important is a low fence to keep out diseased rodents which can infect dogs by carrying parasites.
The fungus has a major natural reservoir in rodents, but can also infect pet rabbits, dogs and horses.
This happened in 1994 when the canine distemper virus, which normally infects only dogs, suddenly jumped to lions.
A virus that infects dogs will not infect cats, for example.
It can also infect wild birds, domestic ruminants, dogs, cats and horses.
Giardia affects humans, but is also one of the most common parasites infecting cats, dogs and birds.
It can also infect dogs and humans, however.
Pythium occupies swamps in late summer and infects dogs who drink water containing it.
It does not infect humans or dogs.
Tests in Thailand have shown that the virus has infected dogs without causing apparent symptoms.
