FELINE MEDICAL CURIOSITIES: FACIAL DEFORMITIES

Hydrocephaly, Anencephaly etc



Text copyright 2001 - 2018, Sarah Hartwell

Note: Contrary to suggestions on some bulletin boards, the images here are not photoshop. With the exception of those labelled as artist's impressions these are photos of medical conditions. These pages are intended as a medical reference site. Offsite links to images on these pages is not supported - bandwidth costs money!

HYDROCEPHALY

The peculiar shaped face of this five week old black-and-white kitten is due to hydropcephaly and anophthalmia.

Hydrocephaly means fluid accumulating inside the skull. It causes a distinctive domed appearance. While the kitten is young, the skull grows increasingly domed or bulbous to accommodate the fluid. The tall forehead is characteristic of the condition. Later, the skull cannot stretch and the build-up of fluid causes pressure on the brain, increasing brain damage and eventually death. Nicknamed "the dog-faced kitten", the black-and-white kitten (above) was put to sleep at about 8 weeks old because of increasing fluid pressure and poor prognosis. In hydrocephalic humans, shunts are used to drain the fluid; at present shunts are not available for cats with the condition.

Some case of hydrocephaly do survive. "Moon" (pictured left) was a hydrocephalic kitten with hare lip and cleft palate and is owned by Leila in Sao Paulo, Brazil, who sent these photos. According to Leila, Moon was found abandoned at 4 months old. He has undergone surgery to repair his hare lip and cleft palate and, at the time of writing, was a year old and doing well. I believe this to be hypertelorism (wide face) rather than hydrocephaly as the head is wide, rather than domed.

Helen Simpson (Cambridgeshire, UK) provided these photos and details of her hydrocephalic kitten, Josh. Josh's case was not too severe and he has survived kittenhood and is doing well. When Helen got Josh from a rescue in Kent, he he was due to be put to sleep because of the shape of his head and the organisation he was with said no-one would want him. Luckily someone told Helen about Josh's case. His head is quite domed and to begin with the vets were not sure if he would live because affected kittens rarely survive as their mothers reject them or they have far more severe cases of hydrocephaly. As he's grown older he has "grown into" his head (it is less out of proportion) although it is still very domed. As a small kitten, his head resembled a balloon on his tiny body.

Josh was a strange kitten with "no real sense of reason but bags of personality." To begin he often ran into things and when running, his brakes didn't work. When working out how to do things, for example how to jump on a bed, he squeaks and chatters to himself about it. He was 8-9 months old in April 2007 and has been neutered (using a different anaesthetic from normal due to his condition).

MENINGOENCEPHALOCELE

(Incomplete skull with protrusion of meninges and brain)

Squeak (owned by Tigger Browne) was a rescue kitten with a cranial abnormality. By 4 months her skull did not cover her brain properly and her face is twisted from just above her nose. Leading from the top of her nose is a very big V-type groove which leads to a soft lump on the top of her head. The soft lump on her head is a meningoencephalocele - the protrusion of her brain through the gap in her skull. Usually kittens with meningoencephalocele are stillborn, die very early or are put to sleep, so Squeak may be unique in having survived to 4 months. A skull x-ray would determine how much skull is missing and how much brain is protruding through the gap. In addition, Squeak's gender is ambiguous and s/he has a small umbilical hernia (Squeak will be referred to as "she" for convenience).

Because the brain had developed and was growing abnormally resulted in seizures and abnormal behaviour: panic attacks involving foaming at the mouth and wetting herself and showing signs of terror. Seizures lasted for 2 - 3 minutes after which she became very clingy and loving and tried to clean herself obsessively (she had problems cleaning her head and her rear end). In general, her behaviour was scatty, but not intellectually retarded. She appeared to hallucinate, morseso that cats that normally chase invisible prey. Her movement tended to swing when she walked and she frequently missed her target when jumping or pouncing; her owner believed Squeak may have had some impairment of vision or spatial awareness. The seizures were are likely to get worse, eventually leading to ataxia (lack of co-ordination), possibly blindness and probably increasing paralysis. The brain is also very easily damaged where it protrudes; any trauma could cause swelling. It's not possible to give a prognosis in months or years because Squeak is unusual in surviving this far. In some cats, this is inherited (American Shorthair Craniofacial Defect, Burmese Head Defect), though it can occur at random through mutation or developmental abnormality.

Apart from the seizures and strange behaviour, Squeak weaned quickly and ate and drank normally and was quick to learn to use the litter tray. She was fully housetrained except when having a seizure. She was underweight when adopted, but grew to a healthy 2 kg (4.4 lbs) and was a lively, happy, inquisitive little soul that loved playing with feet or running around like any other kitten causing mayhem wherever she went. Tigger is experienced with epileptic animals and rescue cats and monitored Squeak's condition. It wasn't known whether anti-epileptics would control the seizures. As Squeak (still sexually ambiguous, but possibly developing as a male) grew her fits initially decreased in frequency and intensity. She went through the normal shedding of kitten teeth and the dome-shaped swelling on Squeak's head became less pronounced, especially on the right side, as she grew. She also became able to clean herself. Unfortunately on Saturday 13th December 2008, Squeak became hyperactive and had 3 increasingly violent fits in succession. As her fits were becoming continuous and more distressing due to the pressure on the brain, she was put to sleep aged approximately 5 months old. Squeak appears to be the oldest recorded survivor of meningoencephalocele.

UNEVEN FACIAL DEVELOPMENT

Sarah Saylor provided these photos of a 5 and a half week old kitten "Batty Cat" with facial deformites. It appears that one side of Batty's face hasn't developed as fully as the other side - giving him a smaller eye and twisting his nose and mouth to one side. As long as he can eat and drink normally and the rest of his body is unaffected by developmental deformities, Batty should have a normal life. The cleft lip is cosmetic and there is no cleft palate; the lip could be repaired surgically if it caused any problems. The twisting of the nose could cause noisy or obstructed breathing, but that could be helped by surgery. One eye is under-developed and appears to have limited sight. As Batty grows, a vet will need to check his jaw alignment (it may grow unevenly) in case there's any twisting or under-development on one side in which case he might need some adult teeth removed to avoid over-crowding. Batty was otherwise in good health and had a good appetite, though it has been a little harder for him to move onto soft food due. He was bottle-fed from birth.

FACIAL DERMOIDS

A dermoid cyst is a type of teratoma that frequently consists of skin, hair follicles, and sweat glands (larger cysts can contain teeth or other mature tissue). Visually they appear as abnormally located patches of skin or whisker pad. In cats, dermoid cysts are associated with the Burmese and American Shorthair craniofacial defect where cats were bred for domed heads. They can also occur randomly, either due to a developmental anomaly in the embryo or as part of a genetic condition where there may also be asymmetrical facial development, crooked nose or jaw, cleft lip, severe cleft palate or duplicated or wrongly-placed canine teeth.

They can occur when skin cells and things like hair, sweat glands, oil glands or fatty tissue get trapped in the skin as they embryo develops. In many of the cases shown here, the face is abnormally broad at the midline which shows that the cysts are linked to other issues and not simply to trapped skin cells. Extreme broadening can lead to duplication of facial structures e.g. eyes, nose bridge, but a single lower jaw.

TERATOMA ON FOREHEAD OF PUMA CONCOLOR

Deformities also occur in big cats. A mountain lion shot in southeast Idaho, in 2015, had a partial jawbone and set of teeth growing out of its forehead. In December 2015, Tyler Olson reported that a mountain lion had attacked his dog at his rural Weston Canyon home. A group of mountain lion hunters and neighbours quickly tracked the cougar through Weston Canyon (about 8 miles southwest of Preston near the Idaho/Utah border) and shot it (this is legal). The hunter reported the animal's deformity to the authorities when reporting the kill. A conservation officer inspected the kill and sent photos of the lion’s deformity to Idaho Fish and Game’s Southeast Regional Office in Pocatello. The year-old lion had a partial jawbone and fully-formed teeth, including what appeared to be small whiskers, growing out of hard, fur-covered tissue on the left side of its forehead, an abnormality that local Fish and Game biologists had never seen before.

Experts have not been able to agree on the cause of the unusual mutation. It could be the remnants of a conjoined twin which died in the womb, or incomplete duplication of facial features; the fact that the tissues are well organised into a lower jaw tends to support this. They feel that a more likely explanation is that it is a teratoma, a type of tumour that can grow other body tissues such as hair, teeth, bones - even eyes. Though extremely unusual, there are well-documented cases of teratomas in humans, dogs and horses, however the tissues are often disorganised. Less likely is that the mountain lion suffered a jaw injury that healed in an abnormal. There is no evidence of an injury to the mouth, and it appears to have a normal set of teeth in its mouth. Idaho Fish and Game's Southeast Regional Office, in Pocatello, had hoped to bring the carcass in for examination. X-rays and analysis could have revealed the cause of the abnormal growth. Officials asked the hunter to bring the cougar in for testing. However, the hunter never brought the animal in and is not required to do so by state law. According to rumour, the cougar is now a taxidermy specimen in somebody’s home.

MISCELLANEOUS CRANIAL AND CRANIOFACIAL DEFECTS

Cranial refers to head and skull defects that affect the braincase. Craniofacial defects affect the head and face: the soft tissues and the bones forming the front of the skull i.e. the face and jaws. These abnormalities are often related to other conditions such as dwarfism, hydrocephaly or metabolic disease. These include extreme over-bite/under-bite, hare lip (cleft lip) and cleft palate.

Craniofacial anomalies are an intrinsic part of some breeds such as the modern ultra-typed Persian and the now-extinct Peke-Face Red Persian (extreme brachycephaly) and the extremely elongated head of the modern Siamese. The Peke-Face Persian is different from the modern "piggy" Persian and the last known true Peke-face Persians was registered in 2002, and only about 100 such cats were ever registered. Their skull structure differed greatly from the standard Persian: a very round head with a very strong chin and very wide-set eyes. The muzzle was wrinkled and the nose pushed inward and indented between the eyes, plus there there was an additional horizontal break located between the usual nose break and the top dome of the head. This second break created half-moon boning above the eyes (brow ridge and double dome) and an additional horizontal indentation (dimple) in the center of the forehead. These features were part of the breed standard and caused a lot of problems. Kittens tended to have heads too large for them to be born without a caesarian section. Their palates could be too high so that they couldn't suckle. Their tear ducts were malformed and did not drain (a problem seen in extreme Persians today). In the wild, the kittens and their mother would not have survived, so this was a deferred lethal mutation. Probably multiple genes were involved rather than a single gene, and these genes were combined together because of inbreeding.

Inbreeding is a problem in cats with small gene pools. Yoda, below, has thickened facial skin giving a puffy appearance. The thickened facial skin does not have working hair follicles, so Yoda lacks fur on his face and lacks whiskers.

A dwarf cat named Tardar Sauce (born April 4, 2012), Tabatha Bundesen, became an internet meme in the guise of “Grumpy” because her condition gives her a flat face, protruding eyes, an under-bite and a grumpy facial expression. Tardar Sauce (a colourpoint with white) and her brother (black-and-white bicolour), also a dwarf, called Pokey were born to normal parents. As well as their distinctive faces, they are undersized and have limb deformities associated with feline dwarfism.

Tabby and white Lil Bub (2013), owned by owner Michael Bridavsky, had a serious and rare bone condition that caused her paws to be deformed and her tongue permanently protruding due to a very short lower jaw. Lil Bub's face had a distinct "stop" (change of angle) between the wide set eyes, an extremely under-developed mandible (lower jaw) and she lacked teeth. She was also a polydactyl with six toes on her paws. She stopped growing at 7 months old and weighed only 1 kg throughout her life. She died in 2019, aged 8 years old, still looking like a kitten.