Polycoria is a disease which affects many species of animals, including humans. It is caused by a fungus called Pseudomonas aeruginosa (PAS). PAS infects the respiratory tract and causes pneumonia in humans and other mammals. Pneumonia kills up to one third of those infected with it. Cats are most susceptible to this infection because they have shorter respiratory tracts than do humans or other mammals. The bacteria that cause pneumonia are killed off by the cat’s natural immunity. However, some of these bacteria survive and multiply in the lungs. These bacteria produce toxins that damage cells in the lung tissue, causing scarring and eventually leading to death.
The symptoms of polycoria vary from animal to animal. Some animals develop no signs at all, while others die within days after being infected.
The disease may affect any part of the body, but is most common in the lungs and heart. Death usually occurs within two weeks of infection. Animals that survive infection often suffer from severe breathing difficulties and require intensive care for months before recovery takes place. In rare cases, animals recover completely without suffering any ill effects.
In an animal with full-blown polycoria, the disease causes the immune system to produce more antibodies and inflammatory cells in an attempt to fight off the infection. This leads to a release of various cytokines, which are signalling molecules that tell white blood cells how to behave.
These signalling molecules cause the white blood cells to mature into T-lymphocytes and macrophages. These cells then attack and destroy the PAS infection. Unfortunately, this also causes them to mistakenly attack the animal’s own tissue. When this happens, the animal’s body thinks it is under attack by PAS again, and releases more cytokines that cause the T-lymphocytes and macrophages to multiply even further. This leads to inflammation in the respiratory tract which gets worse over time. The inflammation and tissue damage caused by the T-lymphocytes and macrophages kills many of the bacteria, but also causes permanent scarring of the lungs. Eventually, this leads to emphysema and respiratory failure.
The cytokines released during a polycoria infection also cause the immune system to attack the heart. Cytokines cause the heart muscle to go into spasms, which prevents adequate blood flow to the body.
Eventually, this will lead to the animal’s death.
Because the disease affects the lungs and heart, animals with polycoria can show a range of symptoms depending on which organs are most affected. Animals may cough, wheeze or have difficulty breathing.
They may also have a swollen abdomen from fluid buildup (pleural effusion) in the chest. The infection can also lead to an increased heart rate (tachycardia), irregular heart rhythms (arrhythmias), or a decrease in the strength of the heartbeat (heart failure), which will lead to death.
There is no cure for animals infected with PAS. Any treatment focuses on alleviating the symptoms and giving palliative care.
Antibiotics are useless against PAS, as the infection is caused by a virus and antibiotics only work against bacterial infections. As such, giving an animal antibiotics will not improve its condition and may even cause harm due to unwanted side effects.
Bleeding the animal may help if it suffers from bleeding disorders, and a tracheostomy may be necessary to help animals with breathing difficulties. Oxygen supplementation may also be used, as well as fluid drainage to reduce the buildup of fluid in the chest.
In severe cases, cardiopulmonary resuscitation (CPR) may be necessary to keep an animal alive.
Other possible treatments include:
Because of the severe symptoms, animals with PAS rarely recover. In most cases, death will occur within days or even hours after the first symptoms become apparent.
The rate of mortality is around 90%. Of the 10% that survive, most will die within a year.
There is no risk of humans getting polycoria; the disease only affects animals. Humans can, however, spread the disease to other animals and cause an outbreak.
Great care must be taken to ensure that no human comes into contact with an animal with this disease.
The disease is most commonly spread through direct contact with an infected animal’s bodily fluids, but it may also be caught by inhaling bacteria from the air (aerosols) or by consuming infected food or water. It spreads most easily in crowded areas with poor ventilation, such as pet stores and animal shelters.
Any location where animals are present has the potential to be a hotspot for polycoria infection, but the disease affects cats in particular due to their tendency to crowd together.
Despite the high mortality rate, there have been no known cases of humans getting polycoria from animals. However, scientists are concerned about the possibility that the virus may mutate into a form that can infect humans and spread from human to human.
Such a scenario is very unlikely, but possible – especially since the first human case of PAS is already thought to have occurred. As such, strict guidelines are in place to prevent the transmission of the disease from animals to humans.
Once an animal is diagnosed with PAS, it is put down to prevent it from spreading the disease. If no humans have come into contact with the infected animal, the carcasses may be burned or at least safely discarded.
The surrounding areas are also disinfected as a precaution. Great care is taken to ensure that no humans come into contact with the bodily fluids or remains of the dead animal.
Should humans have had contact with the infected animal, they may be ordered to undergo a series of medical tests and observations to ensure that they do not contract polycoria through casual contact with the infected animal. Aggressive treatment with antibiotics is given during this time.
Mostly found in shelter or pet store animals, this disease takes the form of a skin infection in many animals. This includes cats and dogs.
A skin infection caused by the bacterium pseudolysimatis, PAS causes large and small boil-like rashes to appear all over the body of the infected animal. These rashes sometimes ooze a thin yellow fluid.
Other symptoms include fever and lethargy. The infection is very resistant to antibiotics and as such there is no cure. Owners of animals diagnosed with PAS are required by law to have them put down.
Bites and claw wounds from infected animals are the most common way of transmission. If an animal has PAS, it is likely to have very sore and swollen areas on their skin due to the boils.
Because of this, owners of animals with PAS are required by law to put their animals down even if their animal is asymptomatic.
The virus is spread through contact with the bodily fluids of an infected animal or through an open wound. Due to this, bites and claw wounds are very dangerous as the virus can easily infect the area and enter the bloodstream.
Antibiotics are effective against the infection if treatment is caught early on.
Due to its nature, PAS only affects mammals. Humans are susceptible to it, as are dogs and cats.
Birds, rodents and other animals are not affected nor are they carriers of the virus.
The virus attacks skin cells and causes them to grow at a much faster rate than normal. This eventually leads to the development of boils on the skin.
The reason why animals that get PAS tend to have large bumps is because their fur grows into the boils and gets infected as well, thus worsening the condition.
PAS is an acronym for Paramyxovirus associated with Acquired B-cell Lymphoma. It was originally called P-MLV, as it was the virus that caused most cases of B-cell lymphoma in pet hamsters.
After it was discovered to be the cause of a pet hamster disease known as “fluff disease”, its role in the development of lymphoma was discovered and it was given its current name.
PAS is a virus with no known cure. It causes a rapid growth of cancerous cells that form tumors in the host’s body.
This is known as an hyperacute tumor necrosis condition and results in the death of the host animal within a few hours of the first symptoms appearing.
The tumors that grow cause necrosis, or cell death, of the vital organs the animal needs to survive. Because of this, animals with PAS often die as a result of their body shutting down very suddenly.
Due to the blood carrying so much cancer, it affects the mind of the animals as well.
An effective means of treatment is not yet known due to the short life span of the infected organism. It’s recommended to owners of animals with PAS to put their animals down before they begin suffering.
This virus causes the animal’s blood cells to grow out of control. As a result, the animal suffers from anemia and dies as a result of blood loss.
Owners of animals with this condition are not required by law to put their animals down, but it is recommended under any circumstances.
The virus affects the bone marrow of the animal and causes their blood cells to grow out of control. This results in severe anemia, or a deficiency of red blood cells, and the animal’s body begins to shut down as a result of this.
As infected animals suffer from severe anemia, they become very weak and are unable to move about. They suffer from frequent nose bleeds which often leads to death.
It’s common for infected animals to die within a week of infection due to organ failure.
It is illegal by law to own an animal with this condition. Owners are required by law to report their infected animals and must put them down immediately.
The virus causes extreme swelling of the animal’s body. Minor swelling such as that of the belly and joints can result in death, while more extreme swelling of the head can cause the animal’s skull to explode.
Either way, death is almost always certain once the virus takes hold.
Due to the gruesome and horrific effects of this condition, it is not owned by many. Those who do own it often use it as a scare tactic to threaten their enemies.
Due to the short life span of the infected organism, there are no long-lasting affects. The virus causes the animal’s body to swell up, and this intense swelling causes the cells to burst and die.
As such, there is no pain involved with this condition other than the few hours it takes for the animal to die. There is no cure for animals afflicted with this virus. Owners of infected animals must put them down to end their suffering.
This virus is the result of two other viruses which combined to form one. The first virus is known as ECOS, and causes extreme swelling of the body tissues and organs.
This leads to a slow and painful death as the body tissues become so swollen they begin to burst. The second virus is known as SKIN, and causes large skin growths and tumors to appear all over the infected organism.
The virus causes a slow build up of fluid in the lungs. This leads to difficulty breathing, and the host often begins to make severe coughing noises.
Owners of infected animals are required by law to put them down before this happens.
If untreated, this virus will cause the animal’s internal organs to fail and shut down, leading to death. Most owners choose to have their animals put down before this happens.
Sources & references used in this article:
True polycoria by NS Jaffe, P Knie – American Journal of Ophthalmology, 1952 – ajo.com
True polycoria or pseudo‐polycoria? by N Islam, JS Mehta, GT Plant – Acta Ophthalmologica Scandinavica, 2007 – academia.edu
Congenital Nonattachment of the Retina: With Hydrophthalmia, Hypoplastic Vitreous Body and True Polycoria by RY Foos, RJ Kiechler, RA Allen – American journal of ophthalmology, 1968 – ajo.com
Posterior polymorphous dystrophy with polycoria and corectopia by AK Patel, RSK Loh, AJ Morrell – Eye, 2004 – nature.com
A Case of Congenital Binocular Polycoria. by KH Han – Journal of the Korean Ophthalmological Society, 1974 – wprim.whocc.org.cn
Polycoria, miosis, and amblyopia by GT Hofeldt, JW Simon – Journal of American Association for Pediatric …, 2002 – jaapos.org
Congenital polycoria, trichomegaly, and hereditary congenital cataract by H Bhattacharjee, K Bhattacharjee, P Tahiliani – Journal of American …, 2013 – Elsevier
A Case of Binocular Polycoria Due to Extensive Persistence of the Pupillary Membrane. by BS Chae, JH Yoo, JH Kim – Journal of the Korean …, 1969 – wprim.whocc.org.cn
