Veterinary treatment or an improved and more stimulating environment may help birds suffering from feather-plucking. Organic bitter sprays are sold in pet stores to discourage plucking, especially of newly grown feathers, although this may make general beak-based grooming difficult for the animal. This is not recommended since it does not address the real reason why the bird is picking feathers.

In orange-winged amazon parrots, a heritability estimate of 1.14 ± 0.27 was found for feather-plucking, indicating that a genetic basis exists. This study, however, only involved analysis of full siblings and a small number of birds, explaining the heritability value of greater than 1. Quantitative trait loci (QTL) analysis could provide more insight in possible genetic markers that are involved in feather-plucking.

Feather duster budgerigars ("Melopsittacus undulatus"), sometimes called budgerigar mops, are budgerigars that have a condition characterised by overly long feathers that do not stop growing at usual periods, giving the bird the appearance of a feather duster. This condition is sometimes known as chrysanthemum feathering. The contour, tail and flight feathers do not stop growing, and they do not have the necessary barbs and barbules for the feather's structure to interlock. The shaft (calamus) is also curved, and so the feathers appear deformed and fluffed out. Individuals with this condition often appear less alert than nest mates. In addition, they are small and some have other defects such as microphthalmia. They lack vigour, often cannot fly and die within a year of hatching. There is no treatment for the condition; birds are often euthanized in the nest.

The condition may be a genetic disorder, caused by a herpesvirus, or perhaps caused by both.

There is no cure for CPL; the aim of treatment is to relieve the signs of the disease, and to slow the progression. Management requires daily care to prevent infection of the affected skin. The first step is to trim the feather from the lower leg, to ensure no affected areas are missed, and to allow application of treatments directly to the affected skin. Bacterial infections can be treated by gentle washing and drying of the skin. Topical treatments are required to treat chorioptic mange (caused by the mite "Chorioptes equi"), as the mites are not vulnerable to oral or systemic treatments when they are within the crusts on the skin. Daily exercise assists with the flow of lymph. Combined decongestive therapy involves massage of the leg to move the lymph, followed by specialized compression bandaging which creates a pressure gradient up the leg.

Horses with CPL often have poor-quality hoof, so regular trimming is required to help keep the hoof healthy.

There is currently no specific treatment for the virus. A vaccine is available, but only experimentally. It has not been released to the public due to the risk it poses to already exposed birds.

Therapeutic intervention is limited to treating secondary infections. The individual bird can sometimes recover, but this is rare. If only the feathers are affected and the bird suffers no other symptoms, it can usually experience an acceptable quality of life. But if the bird's beak or nails are affected, veterinarians will recommend euthanasia.

The management of the disease lies thus mostly in prevention. Every new bird that enters a pen with other birds should be quarantined first and be tested for BFDV. Birds which are known carriers should not be introduced into new pens, especially not if those contain young birds.

Affected breeds include the Shire, Clydesdale, Belgian, Gypsy cob, and Friesian. Signs are usually only seen in horses older than two years. Both sexes are affected.

There is currently no definitive way to cure the sneezing fits brought on by the photic sneeze reflex. Photic sneezing can be combated by shielding one's eyes with hats or sunglasses. There are many remedial fixes for sneezing, such as placing a finger horizontally below the nose or holding the nose closed when the beginnings of a sneeze are felt.

Another remedy is to deliberately cause the onset of sneezing in a safe environment before moving into an environment where the condition could be a danger. The person will then be protected as long as the refractory period lasts.

The most helpful way to avoid the risks stated above is to be aware of any inclination to sneeze in response to strange stimuli. If a pilot knows he or she is at risk for experiencing a photic sneeze during a flight, he or she can wear polarized goggles to block the sun, or at the very least be prepared for a sneeze and have measures planned to minimize the risk from such a sneeze. Any patient with a history of uncontrollable sneezing who requires periocular surgery should tell the doctor or anesthesiologist, so that they can take appropriate measures to minimize the risk of injury in case of a sneeze during the surgical procedure. People who know they have a tendency to experience sneezing fits after consuming a large meal can make an effort to reduce the size of their meals, since snatiation seems to occur only as a result of an extremely full stomach.

It is difficult to gain an accurate picture of incidence and prevalence of self-harm. This is due in a part to a lack of sufficient numbers of dedicated research centres to provide a continuous monitoring system. However, even with sufficient resources, statistical estimates are crude since most incidences of self-harm are undisclosed to the medical profession as acts of self-harm are frequently carried out in secret, and wounds may be superficial and easily treated by the individual. Recorded figures can be based on three sources: psychiatric samples, hospital admissions and general population surveys.

The World Health Organization estimates that, as of 2010, 880,000 deaths occur as a result of self-harm. About 10% of admissions to medical wards in the UK are as a result of self-harm, the majority of which are drug overdoses. However, studies based only on hospital admissions may hide the larger group of self-harmers who do not need or seek hospital treatment for their injuries, instead treating themselves. Many adolescents who present to general hospitals with deliberate self-harm report previous episodes for which they did not receive medical attention. In the United States up to 4% of adults self-harm with approximately 1% of the population engaging in chronic or severe self-harm.

Current research suggests that the rates of self-harm are much higher among young people with the average age of onset between 14 and 24. The earliest reported incidents of self-harm are in children between 5 and 7 years old. In the UK in 2008 rates of self-harm in young people could be as high as 33%. In addition there appears to be an increased risk of self-harm in college students than among the general population. In a study of undergraduate students in the US, 9.8% of the students surveyed indicated that they had purposefully cut or burned themselves on at least one occasion in the past. When the definition of self-harm was expanded to include head-banging, scratching oneself, and hitting oneself along with cutting and burning, 32% of the sample said they had done this. In Ireland, a study found that instances of hospital-treated self-harm were much higher in city and urban districts, than in rural settings. The CASE (Child & Adolescent Self-harm in Europe) study suggests that the life-time risk of self-injury is ~1:7 for women and ~1:25 for men.

Navel fetishism, belly button fetishism, or alvinophilia is a partialism in which an individual is sexually attracted to the human navel.

According to a study, it is a moderately prevalent fetish among individuals. While in 2012, it was the second most popular fetish search on Google as per their global monthly averages.

There are many movements among the general self-harm community to make self-harm itself and treatment better known to mental health professionals, as well as the general public. For example, March 1 is designated as Self-injury Awareness Day (SIAD) around the world. On this day, some people choose to be more open about their own self-harm, and awareness organizations make special efforts to raise awareness about self-harm. Some people wear an orange awareness ribbon or wristband to encourage awareness of self-harm.

Uncontrollable fits of sneezing are common in patients under propofol sedation who undergo periocular or retrobulbar injection. A sneeze by a sedated patient often occurs upon insertion of a needle into or around their eye. The violent and uncontrollable movement of the head during a reflexive sneeze has potential to cause damage within the patient's eye if the needle is not removed before the sneeze occurs.

"Knemidocoptic mange" [neʺmĭ-do-kopʹtik mānj]

From the Latin "manducare" (to itch), mange is a skin disease caused by mites in domestic and wild animals. Knemidocoptic, from the Greek "knemid" (greave, a piece of armor that protects the leg) and "koptein" (to cut), refers to the morphology and pathogenesis of mites of the genus "Knemidocoptes", which are burrowing mites of birds.

Scaly foot, or knemidocoptiasis is a bird ailment that is common among caged birds and also affects many other bird species. It is caused by mites in the genus "Knemidocoptes" which burrow into the bird's flesh. The tunnels made by the mites within the skin cause dermatitis and scaly lesions. Scaly face is caused by the same mite responsible for scaly foot and other related mites cause depluming. The condition is transmitted from one bird to another by direct prolonged contact.

PBFD is usually acquired by nestlings from their parents (vertical transmission) or from other members of the flock (horizontal transmission). The immature immune system of young birds makes them susceptible to the PBFDV. The virus may be transferred in crop secretions, in fresh or dried feces, and in feather and skin particles.

Adult birds coming into contact with the virus usually (but not always) develop resistance to it, but the virus is retained in their body and, in most cases, is excreted in feces and feather debris for the rest of their lives.

Clinical diagnosis can be made with the naked eye using the ABCD guideline or by using dermatoscopy. An online-screening test is also available to help screen out benign moles.

Although infection of avian reovirus is spread worldwide, it is rarely the sole cause of a disease. For chickens, the most common manifestation of the disease is joint/limb lameness. Confirming infection of avian reovirus can be detected through an ELISA test by using and observing the expression of σC and σB proteins. However, isolating and identifying reoviruses from tissue samples is very time consuming. Isolation is most successfully attained through inoculation of material into chick embryo cultures or fertile chicken eggs. Inoculation of embryonic eggs through the yolk sac has shown that the virus usually kills the embryos within 5 or 6 days post inoculation. Analyzing the samples, the embryos appeared hemorrhagic and necrotic lesions on the liver were present. (Jones, Onunkwo, 1978). There have also been approaches to identify avian reoviruses molecularly by observing infected tissues with dot-blot hybridization, PCR, and a combination of PCR and RFLP. This combination allows for the reovirus strain to be typed.

A navel fetishist can be sexually aroused by a variety of stimuli, including key words, thoughts or specific forms of physical interaction with the navel.

In order to determine the relative prevalence of different fetishes, scientists obtained a sample of at least 5000 individuals worldwide, in 2007, from 381 Internet discussion groups. The relative prevalences were estimated based on (a) the number of groups devoted to a particular fetish, (b) the number of individuals participating in the groups and (c) the number of messages exchanged. Of the sampled population, 7 percent were sexually aroused by hair (as opposed to 12 for underwear, but only 4 for genitals, 3 for breasts, 2 for buttocks, and less than one for body hair).

Poena cullei (from Latin 'penalty of the sack') under Roman law was a type of death penalty imposed on a subject who had been found guilty of parricide. The punishment consisted of being sewn up in a leather sack, sometimes with an assortment of live animals, and then being thrown into water. The punishment may have varied widely in its frequency and precise form during the Roman period. For example, the earliest fully documented case is from ca. 100 BCE, although scholars think the punishment may have developed about a century earlier (earlier than that, murderers, including parricides, would be handed over to the aggrieved family for punishment, rather than punishment being enacted by Roman state officials). Inclusion of live animals in the sack is only documented from Early Imperial times, and at the beginning, only snakes are mentioned. At the time of Emperor Hadrian (2nd century CE), the most well known form of the punishment was documented, where a cock, a dog, a monkey and a viper were inserted in the sack. However, at the time of Hadrian "poena cullei" was made into an optional form of punishment for parricides (the alternate being thrown to the beasts in the arena). During the 3rd century CE up to the accession of Emperor Constantine, "poena cullei" fell out of use; Constantine revived it, now with only serpents to be added in the sack. Well over 200 years later, Emperor Justinian reinstituted the punishment with the four animals, and "poena cullei" remained the statutory penalty for parricides within Byzantine law for the next 400 years, when it was replaced with the punishment for parricides to be burnt alive instead.

"Poena cullei" gained a revival of sorts in late medieval and early modern Germany, with late cases of being drowned in a sack along with live animals being documented from Saxony in the first half of the 18th century.

Diagnosis of lymphoid tumors in poultry is complicated due to multiple etiological agents capable of causing very similar tumors. It is not uncommon that more than one avian tumor virus can be present in a chicken, thus one must consider both the diagnosis of the disease/tumors (pathological diagnosis) and of the virus (etiological diagnosis). A step-wise process has been proposed for diagnosis of Marek’s disease which includes (1) history, epidemiology, clinical observations and gross necropsy, (2) characteristics of the tumor cell, and (3) virological characteristics

The demonstration of peripheral nerve enlargement along with suggestive clinical signs in a bird that is around three to four months old (with or without visceral tumors) is highly suggestive of Marek's disease. Histological examination of nerves reveals infiltration of pleomorphic neoplastic and inflammatory lymphocytes. Peripheral neuropathy should also be considered as a principal rule-out in young chickens with paralysis and nerve enlargement without visceral tumors, especially in nerves with interneuritic edema and infiltration of plasma cells.

The presence of nodules on the internal organs may also suggest Marek's disease, but further testing is required for confirmation. This is done through histological demonstration of lymphomatous infiltration into the affected tissue. A range of leukocytes can be involved, including lymphocytic cell lines such as large lymphocyte, lymphoblast, primitive reticular cells, and occasional plasma cells, as well as macrophage and plasma cells. The T cells are involved in the malignancy, showing neoplastic changes with evidence of mitosis. The lymphomatous infiltrates need to be differentiated from other conditions that affect poultry including lymphoid leukosis and reticuloendotheliosis, as well as an inflammatory event associated with hyperplastic changes of the affected tissue.

Key clinical signs as well as gross and microscopic features that are most useful for differentiating Marek’s disease from lymphoid leukosis and reticuloendotheliosis include (1) Age: MD can affect birds at any age, including 5% in unvaccinated flocks; (4) Potential nerve enlargement; (5) Interfollicular tumors in the bursa of Fabricius; (6) CNS involvement; (7) Lymphoid proliferation in skin and feather follicles; (8) Pleomorphic lymphoid cells in nerves and tumors; and (9) T-cell lymphomas.

In addition to gross pathology and histology, other advanced procedures used for a definitive diagnosis of Marek’s disease include immunohistochemistry to identify cell type and virus-specific antigens, standard and quantitative PCR for identification of the virus, virus isolation to confirm infections, and serology to confirm/exclude infections.

The World Organisation for Animal Health (OIE) reference laboratories for Marek’s disease include the Pirbright Institute, UK and the USDA Avian Disease and Oncology Laboratory, USA.

It often requires a dermatologist to fully evaluate moles. For instance, a small blue or bluish-black spot, often called a blue nevus, is usually benign but often mistaken for melanoma. Conversely, a junctional nevus, which develops at the junction of the dermis and epidermis, is potentially cancerous.

A basic reference chart used for consumers to spot suspicious moles is found in the mnemonic A-B-C-D, used by institutions such as the American Academy of Dermatology and the National Cancer Institute. The letters stand for asymmetry, border, color, and diameter. Sometimes, the letter E (for elevation or evolving) is added. According to the American Academy of Dermatology, if a mole starts changing in size, color, shape or, especially, if the border of a mole develops ragged edges or becomes larger than a pencil eraser, it would be an appropriate time to consult with a physician. Other warning signs include a mole, even if smaller than a pencil eraser, that is different from the others and begins to crust over, bleed, itch, or become inflamed. The changes may indicate developing melanomas. The matter can become clinically complicated because mole removal depends on which types of cancer, if any, come into suspicion.

A recent and novel method of melanoma detection is the "ugly duckling sign" It is simple, easy to teach, and highly effective in detecting melanoma. Simply, correlation of common characteristics of a person's skin lesion is made. Lesions which greatly deviate from the common characteristics are labeled as an "ugly duckling", and further professional exam is required. The "little red riding hood sign", suggests that individuals with fair skin and light colored hair might have difficult-to-diagnose melanomas. Extra care and caution should be rendered when examining such individuals as they might have multiple melanomas and severely dysplastic nevi. A dermatoscope must be used to detect "ugly ducklings", as many melanomas in these individuals resemble non-melanomas or are considered to be "wolves in sheep clothing". These fair skinned individuals often have lightly pigmented or amelanotic melanomas which will not present easy-to-observe color changes and variation in colors. The borders of these amelanotic melanomas are often indistinct, making visual identification without a dermatoscope very difficult.

People with a personal or family history of skin cancer or of dysplastic nevus syndrome (multiple atypical moles) should see a dermatologist at least once a year to be sure they are not developing melanoma.

Stereotypies also occur in non-human animals. It is considered an abnormal behavior and is sometimes seen in captive animals, particularly those held in small enclosures with little opportunity to engage in more normal behaviors. These behaviors may be maladaptive, involving self-injury or reduced reproductive success, and in laboratory animals can confound behavioral research. Examples of stereotypical behaviors include pacing, rocking, swimming in circles, excessive sleeping, self-mutilation (including feather picking and excessive grooming), and mouthing cage bars. Stereotypies are seen in many species, including primates, birds, and carnivores. Up to 40% of elephants in zoos display stereotypical behaviors. Stereotypies are well known in stabled horses, usually developing as a result of being confined, particularly with insufficient exercise. They are colloquially called stable vices. They present a management issue, not only leading to facility damage from chewing, kicking, and repetitive motion, but also lead to health consequences for the animal if not addressed.

Stereotypical behaviors are thought to be caused ultimately by artificial environments that do not allow animals to satisfy their normal behavioral needs. Rather than refer to the behavior as abnormal, it has been suggested that it be described as "behavior indicative of an abnormal environment." Stereotypies are correlated with altered behavioral response selection in the basal ganglia. As stereotypies are frequently viewed as a sign of psychological distress in animals, there is also an animal welfare issue involved.

Stereotypical behavior can sometimes be reduced or eliminated by environmental enrichment, including larger and more stimulating enclosures, training, and introductions of stimuli (such as objects, sounds, or scents) to the animal's environment. The enrichment must be varied to remain effective for any length of time. Housing social animals with other members of their species is also helpful. But once the behavior is established, it is sometimes impossible to eliminate due to alterations in the brain.

Hair fetishism, also known as hair partialism and trichophilia, is a partialism in which a person sees hair most commonly, head hair as particularly erotic and sexually arousing. Arousal may occur from seeing or touching hair, whether head hair, pubic hair, axillary hair, chest hair or fur. Head-hair arousal may come from seeing or touching very long or short hair, wet hair, certain colors of hair or a particular hairstyle. Pubic hair fetishism is a particular form of hair fetishism.

Haircut fetishism is a related paraphilia in which a person is aroused by having their head hair cut or shaved, by cutting the hair of another, by watching someone get a haircut, or by seeing someone with a shaved head or very short hair.

A stereotypy (, or ) is a repetitive or ritualistic movement, posture, or utterance. Stereotypies may be simple movements such as body rocking, or complex, such as self-caressing, crossing and uncrossing of legs, and marching in place. They are found in people with intellectual disabilities, autism spectrum disorders, tardive dyskinesia and stereotypic movement disorder, but may also be encountered in neurotypical individuals as well. Studies have shown stereotypies associated with some types of schizophrenia. Frontotemporal dementia is also a common neurological cause of repetitive behaviors and stereotypies. Several causes have been hypothesized for stereotypy, and several treatment options are available.

Stereotypy is sometimes called "stimming" in autism, under the hypothesis that it self-stimulates one or more senses. Related terms include "punding" and "tweaking" to describe repetitive behavior that is a side effect of some drugs.

Among people with frontotemporal lobar degeneration, more than half (60%) had stereotypies. The time to onset of stereotypies in people with frontotemporal lobar degeneration may be years (average 2.1 years).

Vaccination is the only known method to prevent the development of tumors when chickens are infected with the virus. However, administration of vaccines does not prevent transmission of the virus, i.e., the vaccine is not sterilizing. However, it does reduce the amount of virus shed in the dander, hence reduces horizontal spread of the disease. Marek's disease does not spread vertically. The vaccine was introduced in 1970 and the scientist credited with its development is Dr. Ben Roy Burmester and Dr. Frank J Siccardi. Before that, Marek's disease caused substantial revenue loss in the poultry industries of the United States and the United Kingdom. The vaccine can be administered to one-day-old chicks through subcutaneous inoculation or by "in ovo" vaccination when the eggs are transferred from the incubator to the hatcher. "In ovo" vaccination is the preferred method, as it does not require handling of the chicks and can be done rapidly by automated methods. Immunity develops within two weeks.

The vaccine originally contained the antigenically similar turkey herpesvirus, which is serotype 3 of MDV. However, because vaccination does not prevent infection with the virus, the Marek's disease virus has evolved increased virulence and resistance to this vaccine. As a result, current vaccines use a combination of vaccines consisting of HVT and gallid herpesvirus type 3 or an attenuated MDV strain, CVI988-Rispens (ATCvet code: ).