Heap of Hippos at Hannover, 23/03/13

But I guess here my dog just smelled the glass like regular glass

This is definitely something you won't see in the US, with the sole exception of seeing-eye dogs. Even with seeing-eye dogs, zoos will get a little jumpy when they are on grounds, and extra notifications must go out to all employees.

I actually worked at a zoo once that allowed leched dogs on the grounds. I never saw it as a problem form animal welfare reasons. Most zoo animals get used to what ever is around them very quickly. This wasn't a very modern zoo and many enclosures where simple wire netting but we never had a veterinary issues either, that I'm aware of.

Yes, they cause hippos to stack

I do wish one of our UK zoos exhibited Hippos with underwater viewing- the zoos that have them are certainly missing a trick by not doing this- though of course the expense-to-build is the major prohibitive factor obviously. But the UK zoo that eventually does it would have a major 'first'.

Dogs- I've seen them in one or two European zoos also. Of the larger UK collections only Cotswold seem to allow it- probably to attract people who might otherwise not want to leave their dog in a (hot) car so might be put off visiting otherwise as the only(practical) way to get there is by car.

Though I believe Twycross, another car-access only Zoo, may not allow them at all now -even when left in cars?

Whether dogs are allowed in Zoos seems to run the gamut from quite acceptable to totally unacceptable, according to the country/location.

Cotswold don't allow dogs throughout the site. The semi-walkthrough area with waterfowl, capybara and tapirs is barred to them, which means that interaction between domesticated and wild Canis lupus is not possible.

From a veterinary point of view that is probably very wise, from an animal-watching point of view I find it mildly frustrating!!

Almost exactly 1/2 of Czech zoos allow visitors´ dogs into their areal. Also zoo employees, including animal keepers, are allowed to take their pet dog with them to the job if they don´t cause problems or break hygienic norms.

Negative expriences exist, of course. Prague had to set a limit of 1 dog per person. The zoo also strongly discourages big-scale meetings of dog breeds clubs within their areal.

According to BALAI directive it is not at all possible to let the dogs into the zoo. Therre is a risk of loosing BALAI approval immediately what would further complicate any exports and imports for a given institution.

I think water supply/treatment is another major expense. The volume of water in a decently sized pool and the amount of hippo waste added daily mean that a major filtration system is required to keep the water clear enough for underwater viewing and a high energy bill. It might be more feasible if the hippo exhibit was the last one in series of underwater exhibits for diving birds and mammals such as otters and capybara.

Alan