The number of horses seized by Dublin City Council is likely to reach 400 by year's end.
So far this year 310 horses have been taken away by council officials on animal welfare or public safety grounds.
An Oireachtas committee was told today that the cost of a seizure is €1,000.
Figures supplied to the committee indicate that the overall number of horse seizures is increasing across the country.
Philip Maguire from Dublin City Council said some of the animals are being bought for as little as €20, and in one case a horse was traded for a mobile phone.
He said the current legislation dealing with the matter does not go far enough.
Louis Duffy from Cork County Council said finding homes for unclaimed horses is also a problem.
He said there is anecdotal evidence that some horses were later stolen, allegedly by their original owners.
As a result, he said, it is now considered an unacceptable risk to give custody of a seized horse to another private individual.