I have found some few anecdotal accounts and medical reports and surprisingly little folklore. Perhaps folklore has, rather unusually considering its usual inventiveness, adhered to the general biological rule of thumb with modern creatures is that predators may have fangs and claws, but horns or antlers are only found in prey animals. There have been reports of a peculiar feline creature inhabiting the tiny isles of Alor and Solor, part of the Lesser Sundas chain of Indonesian islands. Cryptozoologists have collected the limited available information from local people who describe this beast as the size of a domestic cat, but having short, but conspicuous, horn-like knobs on its forehead. Most likely the horned Alor and Solor "cat" is a known species, but has a hereditary condition causing these nodules. Such mutations may be perpetuated on small islands due to the limited gene pool.

Drew Hendricks, from Olympia Washington wrote in 2005 of his housecat "Squirrel". Squirrel has a 1 cm long keratinous horn growing from just behind the midline between her ears on top of her head. She began growing the horn a few months earlier (while living in Minneapolis) after a cat fight left her with an injury in the area affected. The growth appears to be an unusual response to injury, or due to a cyst. There are no details on who won the cat fight, but a horn might just give Squirrel the advantage next time!

In Middle Ages Europe, horns were sometimes added to depictions of everyday creatures - including humans - to indicate that the creatures were demons or were otherwise linked to the devil. Horns and a forked tail have long been associated with the devil so this convention allowed poorly literate individuals could understand the pictures. This does not suggest the existence of horned cats in real life.

In more recent years, fantasy writers and role-play game writers/players have invented many fabulous beasts. Some are purely imaginative while others are peculiar amalgams of real life creatures. No doubt horned cats or horned big cats appear somewhere or other in books and games.

"Horns" have been widely reported in humans with a number of cases in historical medical literature and in books of human curiosities ("freaks"), but what of reports of horned cats? Given their association with witchcraft in Europe, there appear to be tales of bat-winged cats but seemingly none of horned cats? I am not familiar enough with Eastern mythology to know if horned cats appear there.

There seem to be surprisingly few horned cats in folklore. One horned cat of folklore is the "Cactus Cat" documented by some cryptozoologists. The Cactus Cat has its origins in 19th Century campfire tales of the American West. Many odd tales came out of the American West at that time. These were either purely the invention of frontiersmen or based on a poor understanding of the unfamiliar and often frightening wildlife mixed with isolation, alcohol and a love of storytelling. These tales were passed on orally, passing into folklore and giving rise to a menagerie of bizarre and impossible animals. The spined "Cactus Cat" was one of many "fearsome critters" invented by 19th century frontiersmen.

The Cactus Cat had thorny hair, especially exaggerated on its ears. Its tail was branched. Its front legs were equipped with savage, sharp blades of bone, which it used to slash open the giant saguaro cacti to get at the sap within. The cactus sap fermented, the cat then drank it and became intoxicated, and then ran off uttering horrible screams. The Cactus Cat was most likely inspired by the unearthly night-time screams of Pumas and possibly by the spiny skins (or discarded quills) of porcupines. Although credulous people might once have taken it at face value ("here be dragons") there is no serious suggestion that such a creature really exists.

Noel Mollinedo from Bolivia has provided descriptions of the Supay (Bolivian Andes) and Simpira (Peru). The Supay is an evil genie that owns all the silver in the world and all the precious metal mines. It has the power to transform a rich mine of gold into common dirt or vice versa. The Supay is depicted as a having ram’s horns, the head of a jaguar and the body and paws of a puma and the smell of brimstone. It is also able to transform itself into a handsome man, a beautiful woman, a domestic cat, an owl, or into nature disasters such as hailstorms, hurricanes or earthquakes. The Simpira is the lord of “panshin nete” (a place similar to hell) and has the form of a black jaguar with deer horns, one of his paws has the form of a corkscrew and can grow large enough to catch wrongdoers and drag them into panshin nete where they are transformed into into jungle beasts to serve the Simpira.

I have heard of reports of cats with spiky tails. Damage to the caudal (tail) vertebrae could lead to the growth of bony spurs. Most often these have the external appearance of lumps and bumps and the growth bony spurs is detected by x-ray. It is conceivable that in severe cases, bony spurs might grow through the flesh and skin of the tail to give the appearance of spines and necessitating surgery. While this is not beyond the bounds of medical possibility, I have no veterinary/medical confirmation of this.

Humans who have undergone spinal surgery (e.g. removal of crumbling vertebral disk) may develop bony overgrowth of vertebrae in later life. Damage done to the bone during surgery triggers the body's repair function, but for some reason bone continues to be formed around the injury site. This forms a bony process or spur which can interfere with nearby nerves and with articulation of the spine. If the damage is in the area of the spine not thickly covered with muscle, the bony lumps can be felt through the skin.

For most people, bony spurs growing from damaged bones do not qualify as horns. Horns or horny plates may grow from any part of the body, but in popular imagination horns grow on heads e.g. goat or cow horns.

According to medical texts as far back as the 1890s, horny outgrowths from the skin are surprisingly common in humans. They grow not only from the head but from the limbs and body and horns have even been recorded growing from the genitals. Many are cutaneous horns - outgrowths of the skin which grow hard and which may fall off and even re-grow. Bony horn-like protrusions may also be the result of bone-growth disorders. In humans there are a variety of conditions which cause bony overgrowth and distortion, including lumps and bumps, if not horns in the classical sense.

One condition affecting bone growth is acromegaly, where the long bones and facial bones continue to grow during adulthood resulting in distortion of features, limbs, hands and feet. Although the skull becomes distorted, horns are not normally associated with acromegaly. Proteus syndrome can cause subcutaneous lumps, thickened skin, bony lumps on the head, spinal curvature and hemi-hypertrophy (one side of the body grows bigger than the other). This is the condition which afflict Joseph Merrick (the Elephant man) . Although it can cause massive bony growths, it is not associated with horns. Various bone cancers also cause overgrowth of areas of bone, these result in nodules and lumps but not in well-defined horns. Several medical conditions can therefore result in blunt horn-like bony nodules growing from the head. Perhaps the goat-like horns depicted in early medical texts are imaginative interpretations of bony lumps.

So far I've considered bony lumps. True horns are not made of bone, they are made of the same stuff as hair and nails - keratin, and are called cutaneous horns. It is possible for hair follicles to multiply and malfunction, growing horn-like material instead of normal hair. One cause is a cyst where the contents exude very slowly and harden on contact with the air. The cyst is a pocket containing skin cells which are trapped in the pocket when they are shed. These horns grow from the base as the cyst contents are slowly released. Although these horns can be knocked off accidentally, they will continue to grow until the underlying cyst sac (which sheds the cells) is removed.

Most commonly, in cats at least, cutaneous horns are an overgrowth of keratin and affect one or multiple paw-pads. They usually resemble second claws or close to the true claws. These generally don’t cause any discomfort unless they are on a weight-bearing part of the paw-pad, but they can cause clicking sounds when the cat walks on hard surfaces such as floorboards. If they occur on a weight-bearing part of the pad they can cause lameness. Cutaneous horns tend to occur spontaneously on the paw pad. In outdoor cats they are probably worn away as fast as they grow and go unnoticed. If they resemble second claws just below the true claws the vast majority are harmless. If the horns are not causing lameness they can be ignored or periodically trimmed. If they cause discomfort or lameness the vet will advise on whether the growth can be removed without adversely affecting the paw pad.

Some types of cutaneous horns are also associated with papillomavirus infection, actinic keratosis, FeLV, and squamous cell carcinoma. These are rare and look different from the horned pads shown here. FeLV-related paw pad horns occur in the centres of the paw pads, while non FeLV-related horns grow on the toe pads, just below the nails. If you are worried, FeLV can be ruled out easily by a test. Single horns in combination with scaly skin lesions should be biopsied to rule out squamous cell carcinoma.

A reason that reports horned or spined cats are rare is that, excepting pampered pets, cats with bone deformities have reduced survival chances and those sprouting rigid keratinous horns are disadvantaged. Where the skull is affected, their ability to eat becomes compromised. Where the limbs or spine are affected, they may be unable to hunt.

Many of the conditions described here have a variety of effects, not just horns. It is possible that reports of horned humans have ignored those other effects and concentrated solely on the horns. This is not uncommon where real-life cases are selectively reported (or even misreported) so that they tie in with an existing body of folklore. I would imagine this to be the case with any reports of horned cats.

HORNED SKIN

In July 2002, Jane McCard in the UK provided additional information on "horned cats". She adopted "Willow" some three years previously from a rescue shelter. He had gone to the shelter with a considerable number of cats which had been allowed to inter-breed and become inbred. Inbreeding can throw up anomalies as normally rare genes become more numerous among the inter-breeding cats.

Willow was not considered as re-homable as the other cats, as he had an unusual skin condition, which was worst around his ears. There was a thick, nobbly build up of skin, that very much resembled little horns. Despite tests, the vet remained unsure of the cause of Willow's skin condition. Steroid injections eliminated the growths completely, but with the risk of diabetes as a side-effect if they are used long term.

Since Willow is not actually bothered by his "horns", Ms McCard opted to discontinue the steroid treatment. She did notice that the condition seems stress related to some extent. It improved considerably once Willow had fully settled into his new home. He no longer has his "horns", but has little "nobbles" around his ears and on some other areas of his body.

For cats with "horned paws" or "horned paw pads" see Horned Paws

I welcome further information about horned cats in early folklore, mythology or veterinary texts.