How does the dangerous dogs act accommodate guard dogs ?
If an uninvited person enters your property (by trespassing) and the dog threatens or bites that person surely the dog is proptecting its own property and home and therefore no actions should be taken .
Especially if the property is fenced and secure and there are signs to warn people that dogs are loose .
Micah

Under the Guard Dogs Act 1974 a licence is required to keep a guard dog in certain situations under s 2. Otherwise a warning has to be posted under s 1:

(1) A person shall not use or permit the use of a guard dog at any premises unless a person ('the handler') who is capable of controlling the dog is present on the premises and the dog is under the control of the handler at all times while it is secured so that it is not at liberty to go freely about the premises.
(2) The handler of a guard dog shall keep the dog under his control at all times while it is being used as a guard dog at any premises except:
(a) while another handler has control over the dog; or
(b) while the dog is secured so that it is not at liberty to go freely about the premises.
(1) A person shall not use or permit the use of a guard dog at any premises unless a notice containing a warning that a guard dog is present is clearly exhibited at each entrance to the premises.

http://www.defra.gov.uk/animalh/welfare/domestic/dogs.htm

The owner of a guard dog may be liable for any injury to a person under s 2(2) of the Animals Act 1971, unless they come within one of the exceptions in s 5.

Hi Im not to sure on this one. The law says any dog that is on the dda list should be on a lead and muzzled in public and in control by a person of 16 and have insurance for 3rd party liability and be tatoo'd and chipped. It also says that any dog that is known to be (likely to be)dangerous is covered by this law and must be on a lead in a public place etc. When it comes to private property that is well fenced and sign posted etc I am not to sure. The law in Scotland for tresspassing is totally different to Englands laws.
You can also be charged with assault with a weapon if you allow the dog free to attack. Mick

Im just asking - if a police dog pursues a suspect and grabs him can the suspect sue for being scratched or whatever?

The answer is yes sadly & it has been done