Liability for keeping animals 'mansuetae nature'
For an owner to be held liable for harm caused by domestic or naturally harmless animals classified as mansuetae naturae (such as dogs, cats, cows, and horses), a plaintiff must establish two key elements: that the individual animal possessed an abnormally vicious propensity not typical of its species, and that the owner had actual knowledge of this dangerous disposition.
As detailed by Bankes, L.J. in Buckle v. Holmes, domestic animals are not inherently dangerous, so owners are not liable when the animal acts on ordinary natural instincts—such as a cat hunting birds (Buckle v. Holmes) or a mare kicking another horse in a shared field (Manton v. Brocklebank).
However, once an owner receives indication of a dangerous habit, the animal transitions into a class kept at the owner’s peril; thus, owners were held liable in Hudson v. Roberts when a known aggressive bull attacked a pedestrian wearing red, and in Read v. Edwards when a dog with a known habit of destroying game killed a plaintiff’s pheasants.
A significant statutory exception exists under Section 1(1) of the Dogs Act, 1906, which creates strict liability for dog owners if their dog injures livestock (“cattle”) or poultry, completely waiving the requirement to prove prior mischievous propensity, owner knowledge, or negligence, though general common law principles continue to govern all other non-livestock harm.
CATTLE TRESPASS
Apart from the scienter rule, the doctrine of Cattle Trespass imposes strict liability on livestock owners when their animals enter another person’s land, without requiring proof of negligence or prior knowledge of vicious traits.
“Cattle” includes bulls, cows, sheep, pigs, horses, donkeys, and poultry, but excludes dogs and cats; therefore, in Buckle v. Holmes, a cat owner was not liable for cattle trespass when the cat killed a neighbour’s birds.
Any physical boundary crossing, such as a horse biting another through a fence in Ellis v. Loftus Iron Co., constitutes trespass, making the owner liable for direct consequences, including disease transmission or personal injury, as shown in Thayer v. Purnell and Wormald v. Cole.
Importantly, an action for cattle trespass can only be brought by the lawful occupier of the land.
Non-occupiers, such as pedestrians or guests, cannot claim under this doctrine; in Cox v. Burbidge, a child injured by a horse on a highway had to prove negligence or prior knowledge under the scienter rule.
ORDINARY LIABILITY IN TORT
Under ordinary tort law, liability can arise when animals are used as the instrumentality of torts such as nuisance (excessive barking, foul odours, or path obstructions), assault and battery (setting a dog on a person), or negligence.
For naturally attracted wild pests, as in Stern v. Prentice Bros., landowners are generally not liable for crop damage caused by escaping rats unless they create an excessive or unusual hazard.
Regarding public roads, Searle v. Wallbank established that an owner is not liable when a domestic animal accidentally strays onto a highway and causes an accident without negligence.
However, two exceptions apply: first, an owner who intentionally brings an animal onto a public road must exercise reasonable control and may be liable for negligence if control fails, as in Gomberg v. Smith, though not where full care was exercised, as in Tillet v. Ward and Holmes v. Mather.
Second, under the scienter rule, owners remain strictly liable when an animal is ferae naturae or a domestic animal known to have vicious tendencies, if it escapes onto a highway and causes damage.