Zoophilia and health
This article describes the health implications of sexual contact with animals (see: Zoophilia). Areas of possible concern are infection, physical injury and allergic reaction.

# Zoonoses acquired via sexual contact
Infections that are transmitted from animals to humans are called zoonoses. A few of zoonoses may be transferred through casual contact, but others are much more readily transferred by activities that expose humans to the semen, vaginal fluids, urine, saliva, feces and blood of animals. This means that sexual activity with animals is sometimes a high risk activity. It is advisable for practitioners of bestiality to assess their relative risk, since risk varies for each species involved, for each disease mentioned below (and others not mentioned), and for each region in the world. Some of the more common zoonoses are listed at the National Agricultural Safety Database (NASD) and the Centers for Disease Control (CDC).

## List of zoonoses
 May occur in other areas but at a lower rate.
 Not a definitive list. Not medical advice.

## Brucellosis
Brucellosis in humans is a potentially life-threatening multisystem disease that can be extremely difficult to treat. There are several varieties of Brucellosis, all caused by bacteria of the genus Brucella, the most notable being B. abortus and B. melitensis which affect larger species of domestic animals, and B. canis which infects dogs and other canids. All are widely spread around the world. The most severe infections are thought to be associated with B. melitensis which primarily infects goats, sheep, and camels in the Mediterranean, Asia, Latin America, parts of Africa and some southern European countries. Humans can catch B. canis through contact with the body fluids of infected dogs, especially semen. urine and vaginal fluids. Dogs can be infected with Brucellosis without showing any signs or symptoms, and infection can only be diagnosed with specific blood tests. The typical symptoms of the type of brucellosis contracted from dogs are: fever that comes and goes, loss of appetite, fatigue, weakness, malaise, sore joints, low back pain, spine pain, headache, depression, abdominal pain, constipation, diarrhoea, vomiting, weakness, dizziness, unsteadiness of gait, and urinary retention. Heart and lung complications can occur. Infected people exhibit only some of these symptoms. Other forms of brucellosis can be more severe.
With approximately 500,000 zoonotic infections a year worldwide (source:CDC), brucellosis places a large burden on humanity. Brucellosis has been reduced to rare disease status in North America (excluding Mexico) and northern Europe through vaccination and eradication programs, but it remains rife throughout the rest of the world. In most countries up to 10% of dogs carry this bacterium, and even up to 42.7% in some provinces of China, representing a major threat to the health of veterinarians and people who handle the blood or semen of infected animals. In the USA, there are only about 100 cases of human brucellosis diagnosed per year, although some sources consider it underdiagnosed and underreported. Most other countries have much higher rates, with high risk areas including the Mediterranean Basin (Portugal, Spain, Southern France, Italy, Greece, Turkey, North Africa), South and Central America (including Mexico), Eastern Europe, Asia, Africa, the Caribbean, and the Middle East.

## Emerging zoonoses
New diseases that can jump from animals to humans are called emerging zoonoses. The emerging zoonosis situation changes constantly, in an upward trend. An example from the equine species is the rare Hendra virus, originally passed from flying foxes to horses.  The implications for zoophilic sexual contact of each emerging disease should be carefully assessed by practitioners.

## Zoophilia and human sexually transmitted diseases

### HIV / AIDS
HIV (the "AIDS" virus) was originally a zoonosis acquired from primates (notably monkeys) in Africa, probably via hunting and eating but possibly via animal bite. It only lives in primates (humans, apes and monkeys) and is not believed to survive long in other species or away from the human body and fluids. The myth that sex with an animal can cure AIDS is false.

### Other STDs
Human sexually transmitted diseases ("STDs") are not carried or transmitted by animals.
However, many human pathogens can survive in animal fluids for a limited time, and therefore STDs may theoretically be transmitted by an animal that has multiple consecutive human sexual partners in a short enough time frame to allow pathogen survival.

# Bites and other physical injury
Humans may be at substantial physical risk and seriously harmed by sexual activity with animals.  Larger animals may have the strength and defensive attributes (e.g. teeth, hooves, horns, claws) to injure a human, either in rejecting physical or sexual contact, or during sexual arousal.

## Bites
Many animals bite as part of sexual excitement and foreplay. Animals carry numerous bacteria in their mouths capable of causing disease after a bite. The most common risk after an animal bite is simple infection (infection risk approximately 15-20% in the USA, may be higher elsewhere), and for dogs and other large animals injury from the force of the bite. Bacterial bite infections are usually fully curable,
although dog bites may cause Pasteurella and Capnocytophaga canimorsus infections, which may have severe consequences.

## Other injury
The sexual organs of other species may not safely conform to the human anatomy. For example, the penis of a sexually aroused dog has a broad bulb at the base which can cause injury if forcibly pulled from a body orifice, and equines can thrust suddenly and "flare". In 2005, Kenneth Pinyan, a resident of WA state died from internal injury after being anally penetrated by a stallion. In 2002, a 62-year-old farmer in Bulgaria was treated for a torn rectum after sex with a boar (male pig). In 1976, a 46-year-old French farmer underwent surgery for peritonitis after sex with a boar.

# Allergic reactions
Sensitization and allergic reactions to animal saliva and semen may occur, ranging from mild irritation to anaphylaxis. Although dried skin flakes, known as dander, are the most commonly cited allergen, dog saliva is a more potent allergen than dander. An estimated 10% of people are allergic to animals in general, rising to 20-30% amongst asthma sufferers; the percentage of people allergic to animal secretions in particular is currently unknown. Repeated exposure to secretions after sensitization has already occurred may subsequently provoke an anaphylactic reaction, which can be life-threatening, and should be avoided.