Cian White and James Orr
Cats vs Dogs: Who Would Win in a Fight?
The age old question of which is better, cats vs dogs, has now been answered. Which of these two families of carnivora (Canidae or Felidae) has evolution moulded into the perfect predator? Which specific physiological hunting adaptations separate these two groups? Or to put it simply: who would win in a fight? The main areas where these two groups diverge in terms of their hunting adaptations are locomotion, weaponry (pow pow), and special senses. Obviously these predators have been fine tuned by natural selection so that they fit perfectly into their own niches and so are excellently adapted to the various styles of predation that they practice. So determining which group are ‘better’ predators is subjective and meaningless. But hypothetically, who would win in a fight down a dark alleyway – a dog or a cat?
Fast twitch muscle fibres and a flexible spine allow the cheetah to reach speeds of 100km/hr. Image Source
In a 100m sprint the furry felids would dominate against man’s best friend with time to spare for Usain Bolt-esque celebrations crossing the line. Why is this? Science has the answer! Felids like the cheetah, the fastest land animal quite capable of topping 100km/hr, have a higher proportion of fast twitch muscle fibres in their hind limbs than a tiger or lion1 , which in turn have a higher proportion of these fast twitch Type IIx fibres than a beagle2. All of the felids are ambush hunters, stalking their prey until close enough to launch a surprise attack. These specialised muscle fibres have more myosin cross bridges allowing for the powerful contraction needed for the violent acceleration3. Canids on the other hand are cursorial hunters; they tend to chase down their quarry and rely on their stamina, exhausting their prey. Think of wolves or the African Hunting Dog , the Mo Farahs of the canid world. They have a higher proportion of slower twitch muscle fibres: type I and Type IIa. These duracell muscles can keep going all3 day but don’t generate the contractile force seen in the felids. So in a typical alleyway brawl, well the cats would come out on top; they are simply stronger pound for pound.
Weaponry is another area where cats seem to have the edge. Although felids have fewer teeth than canids (on average 30 compared to 42) these teeth are sharper and more adapted to meat eating (scary sabre tooth cats of the pleiostocene) than to the diverse dentistry of dogs. Cats’ teeth have no flat surfaces for grinding plants while dogs’ teeth do. There are also specialized bone crushing premolar cusps found in felids but not in canids4. These contrasting dental structures can be explained by the various diets of cats and dogs. The feline family are obligate carnivores while the canids tend to be scavengers and so have more of an omnivorous diet
A young Lion yawns.
As well as their more specialized carnivorous teeth, cats have a second weapon that they use to deadly effect. Because the felids’ claws are retractable (except cheetah’s semi retractable claws) they remain sharp. Dogs have non-retractable, blunt claws which cannot be used as weapons4. As well as teeth that are more adapted to meat eating and retractable, sharp claws cats have a number of other weapons in their arsenal that dogs lack. Rough tongue papillae help cats tear apart meat and flexible wrists5 allow for cats to hold prey in place while they unleash powerful bites. The cats will certainly be better armed for this street rumble than the dogs.
Retracted (a) and extended (b) claw in felid.
Both groups, cats and dogs, have developed specialized senses that are key to their hunting success. Olfaction is primarily used by canids, whereas felids rely more so on their vision. But who has the upper paw in the snout department? And are dogs really the underdog of sight? While cats and dogs both have superficially similar eye structure you may notice Rover isn’t finishing his dinner and this is probably because due to the relatively large pupils, lenses and cornias of canids he is near sighted i.e. dogs can’t focus on objects that are too close to them6.Both groups have a highly reflective layer of tissue behind the retina called the tapetum lucidum that increases night vision7. The combination of the tapetum lucidum along with a high density of rods in the centralis7 area mean that cats have superb night vision that enables them to hunt anytime, day or night.
Felids mainly use vision to hunt and so their eyes are extremely sensitive.
Comparably Canidae skulls are adapted to accommodate for approximately 225 million olfactory receptors8, with longer snouts than their felid counterparts. Felids have between 50 and 80 million total odour receptors. Canids use this extreme sense of smell in conjunction with the auxiliary vomeronasal organ to hunt their prey.
Scent processing takes up a much larger proportion of a canid’s brain. The structure of the nose is much better specialised for smell detection, and the act of ‘sniffing’ enhances canine sense of smell9. Only a minor part of a felid’s brain is concerned with processing scents. Essentially cats see the world whereas dogs smell it. So, in a dark alleyway beside Coppers the felines night vision and acuity would overcome the distracting smells of beer, vomit and kebabs! But in the land of constant darkness the nasally gifted canids are kings.
So which is better? Well neither. Canids and felids fill different niches in today’s world so it is impossible to say which is ‘better’. The dogs are cursorial and chase down their prey and so have adaptations to that way of hunting; stamina, a good sense of smell and an efficient running anatomy. The felines are ambush predators which surprise their prey relying on good vision, sharp claws and powerful muscles to catch their dinner.
A wolf snarls. The longer snout holds more scent processing receptors than a felids’. Image Source
But there was a situation during the mid-Cenozoic when cats and dogs were competing for the exact same niche space – they were put in a cage and the nature was chanting ‘fight fight fight’. An international study published this year10 showed that when cats migrated from Asia to North America 18 million years ago two of the three subfamilies of canids went extinct. There was a particularly strong correlation between felid diversification and the extinction of the Borophaginae – a large group of canids that were probably ambush hunters. This is important because there was direct competition for the exact same niche (large ambush carnivore) and cats won. As felids had a strong negative effect on the survival of dogs the inverse was not true. This implies that cats out-competed dogs due to their superior physiological adaptations to hunting. So with this historical evidence as well as the physiology of the two groups – our money is on the cats.
Written by Cian White and James Orr with contributions from Anna Whitaker and Alice de Burca
- Hyatt, JP., Roy, RR., Rugg, S., Talmadge RJ. (2010) Myosin heavy chain composition of tiger (Panthera tigris) and cheetah (Acinonyx jubatus) hindlimb muscles. Journal of Experimental Zoology, 313(1), pp. 45-57.
- Goto, M., Kawai, M., Nakata, M., Itamoto, K., Miyata, H., Ikebe, Y., Tajima, T. and Wada, N. (2013). Distribution of muscle fibers in skeletal muscles of the cheetah (Acinonyx jubatus). Mammalian Biology – Zeitschrift für Säugetierkunde, 78(2), pp.127-133
- Westerblad, H., Bruton, J., Katz, A. (2010). Skeletal muscle: Energy metabolism, fibre types, fatigue and adaptability. Experimental Cell Research 316, pp.3093-3099.
- Martin, Larry D., “Functional Morphology and the Evolution of Cats” (1980). Transactions of the Nebraska Academy of Sciences and Affiliated Societies. Paper 287.
- Andersson, K. (2004). Elbow-joint morphology as a guide to forearm function and foraging behaviour in mammalian carnivores. Zool J Linn Soc, 142(1), pp.91-104
- Lawson, M.J. et al. 2012. “A computational study of odorant transport and deposition in the canine nasal cavity: implications for olfaction.” Chemical Senses 37(6): 553-566.
- Silvestro, Daniele et al. ‘The Role Of Clade Competition In The Diversification Of North American Canids’. Proceedings of the National Academy of Sciences 112.28 (2015): pp. 8684-8689.