Swayback refers to abnormal bent-back postures in humans and in quadrupeds, especially horses.

Swayback posture in humans is characterised by the posterior displacement of the rib cage in comparison to the pelvis. It looks like the person has a hyperextension of the natural lordosis, however this is not necessarily the case. Most sway-back exhibits a posteriorly tilted pelvis; the lumbar region is usually flat (too flexed) and not hyperlordotic (too extended).

Signs and symptoms may include:

- fever

- severe headache

- muscle aches (myalgia)

- chills and shaking, similar to the symptoms of influenza

- nausea

- vomiting

- loss of appetite

- unintentional weight loss

- abdominal pain

- cough

- diarrhea,

- aching joints

- sensitivity to light

- weakness

- fatigue

- change in mental status (extreme confusion, memory loss, inability to comprehend environment- interaction, reading, etc.)

- temporary loss of basic motor skills

Symptoms may be minor, as evidenced by surveillance studies in high-risk areas. Gastrointestinal tract symptoms occur in less than half of patients and a skin rash is seen in less than 10% of patients. It is also characterized by a low number of platelets, a low number of white blood cells, and elevated serum transaminase levels in the majority of infected patients. Even though people of any age can get HGA, it is usually more severe in the aging or immune-compromised. Some severe complications may include respiratory failure, kidney failure, and secondary infections.

Human granulocytic anaplasmosis (HGA) is a tick-borne, infectious disease caused by "Anaplasma phagocytophilum", an obligate intracellular bacterium that is typically transmitted to humans by ticks of the "Ixodes ricinus" species complex, including "Ixodes scapularis" and "Ixodes pacificus" in North America. These ticks also transmit Lyme disease and other tick borne diseases.

The bacteria infect white blood cells called neutrophils, causing changes in gene expression that prolong the life of these otherwise short-lived cells.

Porocephaliasis is a condition associated with species in the closely related genera "Porocephalus" and "Armillifer". (The term "pentastomiasis" encompasses all diseases of Pentastomida, which includes Porocephaliasis and Linguatulosis.)

Porocephaliasis is associated with contact with snakes. (This is in contrast with Linguatulosis, which is associated with contact with dogs or wolves.)

It has been reported from Africa, Malaysia and the Middle East. Its occurrence has been rare in Europe and North America where it has been found in immigrants and travelers.

People with ASPD are unable to stay awake until their desired bedtime and unable to stay asleep until their desired waking time. They will complain to a sleep clinician of early morning insomnia and falling asleep early in the evening. When someone has advanced sleep phase disorder their melatonin levels and core body temperature will cycle hours earlier than an average person. These symptoms must be present for at least three months in order to be correctly diagnosed.

Advanced sleep phase disorder (ASPD), also known as the advanced sleep-phase type (ASPT) of circadian rhythm sleep disorder or advanced sleep phase syndrome (ASPS), is a condition in which patients feel very sleepy and go to bed early in the evening (e.g. 6:00–8:00 p.m.) and wake up very early in the morning (e.g. around 3:00 a.m.).

Berserk llama syndrome or berserk male syndrome (as it is more pronounced in males) is a psychological condition suffered by human-raised llamas and alpacas that can cause them to exhibit dangerously aggressive behavior toward humans. The term has been overused, however, and is sometimes inappropriately applied to llamas with aggressive personalities that are not truly "berserk".

The condition is a result of the llama imprinting on its human handlers to such a degree that it considers them to be fellow llamas. Imprinting can be caused by bottle feeding and by isolation from other llamas. Adult male inter-llama interaction can be rough, including chest-ramming and biting, and they are strongly territorial. Male llamas suffering from this condition become dangerous when this behavior is directed toward humans and they usually have to be euthanised. Female llamas can also suffer from berserk llama syndrome but their behavior is usually limited to spitting and difficult handling.

Berserk llama syndrome can be prevented in males through castration before puberty.

Many species of arthropods (insects, arachnids and others) regularly or occasionally bite or sting human beings. Insect saliva contains anticoagulants and enzymes that cause local irritation and allergic reactions. Insect venoms can be delivered by their stingers, which often are modified ovipositors, or by their mouthparts. Insect, spider and scorpion venom can cause serious injury or death. Dipterans account for the majority of insect bites, while hymenopterans account for the majority of stings. Among arachnids spider bites are the most common. Arthropods bite or sting humans for a number of reasons including feeding or defense. Arthropods are major vectors of human disease, with the pathogens typically transmitted by bites.

The course of fasciolosis in humans has 4 main phases:

- Incubation phase: from the ingestion of metacercariae to the appearance of the first symptoms; time period: few days to 3 months; depends on number of ingested metacercariae and immune status of host

- Invasive or acute phase: fluke migration up to the bile ducts. This phase is a result of mechanical destruction of the hepatic tissue and the peritoneum by migrating juvenile flukes causing localized and or generalized toxic and allergic reactions. The major symptoms of this phase are:

- Fever: usually the first symptom of the disease;

- Abdominal pain

- Gastrointestinal disturbances: loss of appetite, flatulence, nausea, diarrhea

- Urticaria

- Respiratory symptoms (very rare): cough, dyspnoea, chest pain, hemoptysis

- Hepatomegaly and splenomegaly

- Ascites

- Anaemia

- Jaundice

- Latent phase: This phase can last for months or years. The proportion of asymptomatic subjects in this phase is unknown. They are often discovered during family screening after a patient is diagnosed.

- Chronic or obstructive phase:

This phase may develop months or years after initial infection. Adult flukes in the bile ducts cause inflammation and hyperplasia of the epithelium. The resulting cholangitis and cholecystitis, combined with the large body of the flukes, are sufficient to cause mechanical obstruction of the biliary duct. In this phase, biliary colic, epigastric pain, fatty food intolerance, nausea, jaundice, pruritus, right upper-quadrant abdominal tenderness, etc., are clinical manifestations indistinguishable from cholangitis, cholecystitis and cholelithiasis of other origins. Hepatic enlargement may be associated with an enlarged spleen or ascites. In case of obstruction, the gall bladder is usually enlarged and edematous with thickening of the wall (Ref: Hepatobiliary Fascioliasis:

Sonographic and CT Findings in 87 Patients During the InitialPhase and Long-Term Follow-Up. Adnan Kabaalioglu, Kagan Ceken, Emel Alimoglu, Rabin Saba, Metin Cubuk, Gokhan Arslan, Ali Apaydin. AJR 2007; 189:824–828). Fibrous adhesions of the gall bladder to adjacent organs are common. Lithiasis of the bile duct or gall bladder is frequent and the stones are usually small and multiple.

Cynanthropy (sometimes spelled "kynanthropy") is, in medicine, the pathological delusion of real persons that they are dogs and in anthropology and folklore, the supposed magical practice of shape-shifting alternately between canine and human form, or the possession of combined canine and human anatomical features, a form of therianthropy.

The Greeks spoke of cynanthropy ("kyon", dog). The term existed by at least 1901, when it was applied to myths from China about humans turning into dogs, dogs becoming people, and sexual relations between humans and canines (De Groot, 184). After lycanthropy, cynanthropy is the best known term for a specific variety of therianthropy.

Anthropologist David Gordon White called Central Asia the "vortex of cynanthropy" because races of dog-men were habitually placed there by ancient writers. Hindu mythology puts races of "Dog Cookers" to the far north of India, the Chinese placed the "Dog Jung" and other human/canine barbarians to the extreme west, and European legends frequently put the dog men called Cynocephali in unmapped regions to the east. Some of these races were described as humans with dog heads, others as canine shapeshifters (White, 114-15).

The weredog or cynanthrope is also known in Timor. It is described as a human/canine shapeshifter who is also capable of transforming other people into animals against their wills. These transformations are usually into prey animals such as goats, so that the cynanthrope can devour them without discovery of the crime (Rose, 390).

Patients can present with fever, headache, myalgias, and malaise. Laboratory tests may reveal thrombocytopenia, leukopenia, and evidence of liver damage.

Eastern equine encephalitis (EEE), commonly called Triple E or, sleeping sickness (not to be confused with "Trypanosomiasis") is a zoonotic alphavirus and arbovirus present in North, Central and South America and the Caribbean. EEE was first recognized in Massachusetts, United States in 1831 when 75 horses died mysteriously of viral encephalitis.

Epizootics in horses have continued to occur regularly in the United States. It can also be identified in asses and zebras. Due to the rarity of the disease its occurrence can cause economic impact in relation to the loss of horses and poultry. EEE is found today in the eastern part of the country and is often associated with coastal plains. It can most commonly be found in east and gulf coast states. In Florida about one to two human cases are reported a year although over sixty cases of equine encephalitis are reported. Some years in which there are favorable conditions for the disease there number of equine cases are over two-hundred. Diagnosing equine encephalitis is challenging because many of the symptoms are shared with other illnesses and patients can be asymptomatic. Confirmations may require a sample of cerebral spinal fluid or brain tissue although CT scans and MRI scans are used to detect encephalitis. This could be an indication that the need to test for Eastern Equine Encephalitis is necessary. If a biopsy of the cerebral spinal fluid is taken it is sent to a specialized laboratory for testing.

EEEV is closely related to Venezuelan equine encephalitis virus and Western equine encephalitis virus.

Rabies is a viral disease that exists in Haiti and throughout the world. It often causes fatal inflammation of the brain in humans and other mammals, such as dogs and mongooses in Haiti. The term "rabies" is derived from a Latin word that means "to rage"; rabid animals sometimes appear to be angry. Early symptoms can include fever and tingling at the site of exposure, followed by one or more of the following symptoms: violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, death is nearly always the outcome. The time period between contracting the disease and showing symptoms is usually one to three months; however, this time period can vary from less than a week to more than a year. The time between contraction and the onset of symptoms is dependent on the distance the virus must travel to reach the central nervous system.

Haiti is one of five remaining countries in the Americas where canine rabies is still a problem. It has the highest rate of human rabies deaths in the western hemisphere with an estimated two deaths each week. Only about seven deaths are reported to health authorities each year due to poor surveillance, limitations in diagnostic capacity, and lack of awareness and education about the disease among Haitians.

Clinical signs of fasciolosis are always closely associated with infectious dose (amount of ingested metacercariae). In sheep, as the most common definitive host, clinical presentation is divided into 4 types:

- Acute Type I Fasciolosis: infectious dose is more than 5000 ingested metacercariae. Sheep suddenly die without any previous clinical signs. Ascites, abdominal haemorrhage, icterus, pallor of membranes, weakness may be observed in sheep.

- Acute Type II Fasciolosis: infectious dose is 1000-5,000 ingested metacercariae. As above, sheep die but briefly show pallor, loss of condition and ascites.

- Subacute Fasciolosis: infectious dose is 800-1000 ingested metacercariae. Sheep are lethargic, anemic and may die. Weight loss is dominant feature.

- Chronic Fasciolosis: infectious dose is 200-800 ingested metacercariae. Asymptomatic or gradual development of bottle jaw and ascites (ventral edema), emaciation, weight loss.

In blood, anemia, hypoalbuminemia, and eosinophilia may be observed in all types of fasciolosis. Elevation of liver enzyme activities, such a glutamate dehydrogenase (GLDH), gamma-glutamyl transferase (GGT), and lactate dehydrogenase (LDH), is detected in subacute or chronic fasciolosis from 12 to 15 weeks after ingestion of metacercariae. Economical effect of fasciolosis in sheep consists in sudden deaths of animals as well as in reduction of weight gain and wool production. In goats and cattle, the clinical manifestation is similar to sheep. However, acquired resistance to "F. hepatica" infection is well known in adult cattle. Calves are susceptible to disease but in excess of 1000 metacercariae are usually required to cause clinical fasciolosis. In this case the disease is similar to sheep and is characterized by weight loss, anemia, hypoalbuminemia and (after infection with 10,000 metacercariae) death. Importance of cattle fasciolosis consist in economic losses caused by condemnation of livers at slaughter and production losses especially due to reduced weight gain.

In sheep and sometimes cattle, the damaged liver tissue may become infected by the "Clostridium" bacteria "C. novyi" type B. The bacteria will release toxins into the bloodstream resulting in what is known as black disease. There is no cure and death follows quickly. As "C. novyi" is common in the environment, black disease is found wherever populations of liver flukes and sheep overlap.

The most common symptoms include headache, muscle aches, and fatigue. A rash may occur, but is uncommon. Ehrlichiosis can also blunt the immune system by suppressing production of TNF-alpha, which may lead to opportunistic infections such as candidiasis.

Most of the signs and symptoms of ehrlichiosis can likely be ascribed to the immune dysregulation that it causes. A "toxic shock-like" syndrome is seen in some severe cases of ehrlichiosis. Some cases can present with purpura and in one such case the organisms were present in such overwhelming numbers that in 1991 Dr. Aileen Marty of the AFIP was able to demonstrate the bacteria in human tissues using standard stains, and later proved that the organisms were indeed Ehrlichia using immunoperoxidase stains.

Experiments in mouse models further supports this hypothesis, as mice lacking TNF-alpha I/II receptors are resistant to liver injury caused by ehrlichia infection.

3% of human monocytic ehrlichiosis cases result in death; however, these deaths occur "most commonly in immunosuppressed individuals who develop respiratory distress syndrome, hepatitis, or opportunistic nosocomial infections."

It is prevalent in parts of Africa and Asia where eating snake meat is common. In Africa it has also been associated with groups who use the snake as a totem. Unlike linguatuliasis, humans are only ever an accidental intermediate host for "Armillifer", i.e. the larvae establish themselves in the visceral organs causing human visceral pentastomiasis, but adults do not occur in the human respiratory system. After a while the larvae die within the host and sometimes calcify, leaving characteristic crescent-shaped structures seen in X-ray. In extreme cases a heavy parasite burden can have serious medical consequences and can even be fatal.

Pediculosis is an infestation of lice (blood-feeding ectoparasitic insects of the order Phthiraptera). The condition can occur in almost any species of warm-blooded animal (i.e. mammals and birds), including humans. Although "pediculosis" in humans may properly refer to lice infestation of any part of the body, the term is sometimes used loosely to refer to "pediculosis capitis", the infestation of the human head with the specific head louse.

Short stature refers to a height of a human being which is below typical. Whether a person is considered short depends on the context. Because of the lack of preciseness, there is often disagreement about the degree of shortness that should be called "short".

In a medical context, short stature is typically defined as an adult height that is more than two standard deviations below the mean for age and gender, which corresponds to the shortest 2.3% of individuals. In developed countries, this typically includes adult men who are shorter than tall and adult women who are shorter than tall. By comparison, the median or typical adult height in these populations (as the widely abundant statistics from these countries clearly state) is about for men and for women.

There are two ways in which the virus can progress, systematic and encephalitic, depending on the person's age. Encephalitic involves swelling of the brain and can be asymptomatic while the systemic illness occurs very abruptly. Those with the systemic illness usually recover within one to two weeks. While the encephalitis is more common among infants in adults and children it usually manifests after experiencing the systemic illness. Symptoms include high fever, muscle pain, altered mental status, headache, meningeal irritation, photophobia, and seizures, which occur three to 10 days after the bite of an infected mosquito. Due to the virus's effect on the brain, patients who survive can be left with mental and physical impairments such as personality disorders, paralysis, seizures, and intellectual impairment

"Taenia saginata" infection is asymptomatic, but heavy infection causes weight loss, dizziness, abdominal pain, diarrhea, headaches, nausea, constipation, chronic indigestion, and loss of appetite. It can cause antigen reaction that induce allergic reaction. It is also a rare cause of ileus, pancreatitis, cholecystitis, and cholangitis.

To diagnose infestation, the entire scalp should be combed thoroughly with a louse comb and the teeth of the comb should be examined for the presence of living lice after each time the comb passes through the hair. The use of a louse comb is the most effective way to detect living lice.

The most characteristic symptom of infestation is pruritus (itching) on the head which normally intensifies 3 to 4 weeks after the initial infestation. The bite reaction is very mild and it can be rarely seen between the hairs. Excessive scratching of the infested areas can cause sores, which may become infected.

Nephropathia epidemica ("NE" or epidemic nephropathy) is a type of viral haemorrhagic fever with renal syndrome (HFRS) caused by the Puumala virus. The incubation period is three weeks. Nephropathia epidemica has a sudden onset with fever, abdominal pain, headache, back pain and gastrointestinal symptoms. More severe symptoms include internal hemorrhaging. Although fatal in a small percentage of cases, nephropathia epidemica is generally milder than the HFRS that is caused by hantaviruses in other parts of the world. The bank vole is the reservoir for the virus, which humans contract through inhalation of aerosolised vole droppings.

The majority of infected individuals are asymptomatic or develop only mild symptoms, and the disease is not known to spread from human to human.

This infection is known as "sorkfeber" in Swedish and "myyräkuume" in Finnish (vole fever). In Norway, it is called "musepest" (mouse plague).

The portal of entry is the gastrointestinal tract. The organism is acquired usually by insufficiently cooked pork or contaminated water, meat, or milk. Acute "Y. enterocolitica" infections usually lead to mild self-limiting enterocolitis or terminal ileitis and adenitis in humans. Symptoms may include watery or bloody diarrhea and fever, resembling appendicitis or salmonellosis or shigellosis. After oral uptake, "Yersinia" species replicate in the terminal ileum and invade Peyer's patches. From here they can disseminate further to mesenteric lymph nodes causing lymphadenopathy. This condition can be confused with appendicitis, so is called pseudoappendicitis. In immunosuppressed individuals, they can disseminate from the gut to the liver and spleen and form abscesses. Because "Yersinia" species are siderophilic (iron-loving) bacteria, people with hereditary hemochromatosis (a disease resulting in high body iron levels) are more susceptible to infection with "Yersinia" (and other siderophilic bacteria). In fact, the most common contaminant of stored blood is "Y. enterocolitica". See yersiniosis for further details.

Ehrlichiosis ewingii infection is an infectious disease caused by an intracellular bacteria, "Ehrlichia ewingii". The infection is transmitted to humans by the tick, "Amblyomma americanum". This tick can also transmit "Ehrlichia chaffeensis", the bacteria that causes human monocytic ehrlichiosis (HME).