JANUARY is always a sad and difficult time for staff at the Hawkesbury Companion Animal Shelter, as they become inundated with lost and unwanted dogs and cats.

The first seven days of January are usually the busiest, as dogs frightened by fireworks or left home alone while their owners go on holidays end up in the pound.

The shelter took in 73 dogs in the first week of January this year, and now the shelter is full up. Hawkesbury City Council's manager of regulatory services, Garry Baldry, said there were about 80 dogs and 10 cats impounded at present.

"Unfortunately the scene at the Shelter at the moment is similar to this time every year, with limited space to accommodate additional dogs and cats," Mr Baldry said.

"The shelter finds that larger animals are the most difficult to adopt out.

"The high number of dogs coming through the facility and not being reunited with their owners relates directly to the majority of them not being microchipped or registered, which is a requirement under the law, but is also a means to return the dogs to their home.

"Unfortunately as there are so many of them, it is hard to find homes for all of them."

But Mr Baldry said Council usually exceeds the requirements of the NSW Companion Animal Act in its procedures for managing companion animals at the Shelter.

"Rather than euthanising animals within the seven days (if not microchipped) or 14 days (if they have been microchipped) specified in the Act, the shelter keeps all suitable pets for as long as practicable," Mr Baldry said.

"The major constraints are the availability of kennels in the facility and the ability of the animal welfare organisations that work with Council to assist in placing pets."

Mr Baldry said many dogs are surrendered around Christmas time simply because people do not want to pay for boarding for their dogs while they go away on holidays.

"They seem to treat their dogs as disposable items rather than the loyal companions that they are," Mr Baldry said.