obsolete infectious myxomatosis

Myxomatosis: A Viral Disease in Rabbits

Myxomatosis, also known as infectious myxomatosis, is a viral disease that affects domestic rabbits and European rabbits (Oryctolagus cuniculus). The disease is caused by the Myxoma virus, which belongs to the Poxviridae family.

Definition and Symptoms

The disease is characterized by a severe and usually fatal infection in European rabbits. In contrast, the natural hosts of the virus, such as tapeti (Sylvilagus brasiliensis) in South and Central America, experience only a mild disease [15].

The symptoms of myxomatosis in European rabbits include:

• A viral infectious disease that results in infection located in eyes or located in upper respiratory tract
• Mucinous skin lesions on incision
• Severe and usually fatal disease

History and Outbreaks

Myxomatosis was first described following an outbreak in laboratory rabbits in Uruguay in 1896 [12]. Since the 1950s, the virus has been circulating constantly in wild and farmed populations of lagomorphs, causing outbreaks of the disease [13].

Vaccine Development

Modified live virus vaccines prepared from fibroma virus or modified Myxoma virus strains are available for immunization of rabbits. These vaccines can help prevent the spread of the disease.

References:

• [1] Definition of myxomatosis
• [4] Material basis of myxomatosis in domestic rabbits
• [5] Pathogen causing infectious myxomatosis in rabbits
• [12] First description of myxomatosis in laboratory rabbits
• [13] Circulation of the virus since the 1950s
• [15] Natural hosts and symptoms of the disease

Myxomatosis in Rabbits: A Review of Signs and Symptoms

Myxomatosis, a highly infectious viral disease, has been a significant threat to rabbit populations worldwide. The symptoms of this disease can be severe and often lead to high mortality rates if left untreated.

Early Warning Signs

The early signs of myxomatosis in rabbits include:

• Swelling and redness of eyelids and ear margins
• White eye and nasal discharge
• Ear droop
• Purple/blue spots on the skin
• Skin nodules/lumps up to 1 cm in diameter, often on eyelids, face, nose, ears, and genitals, which can scab [3][5]

Severe Symptoms

As the disease progresses, rabbits may exhibit more severe symptoms, including:

• Swelling of the lips, eyelids, and genitals
• High temperature (pyrexia)
• Lethargy and anorexia
• Blindness caused by eye inflammation
• Respiratory problems
• Appetite loss [5][6]

Clinical Signs

The most commonly reported clinical signs of myxomatosis are:

• Swellings of the eyelids and genitals
• White ocular discharge
• Pyrexia
• Lethargy and anorexia [4]

It is essential to note that these symptoms can vary depending on the strain of the virus and the individual rabbit's health.

References

[1] Symptoms of myxomatosis. Depending on the strain of the virus, it can take between one to three weeks for symptoms of myxomatosis to show. [2] Myxomatosis is a highly infectious viral disease that has a high mortality rate in infected rabbits. [3] Symptoms of Myxomatosis in Rabbits. Early signs of myxomatosis include: Swelling and redness of eyelids and ear margins, and genitals. White eye and nasal discharge. Ear droop. Purple/blue spots on the skin. Skin nodules/lumps up to 1 cm in diameter, often on eyelids, face, nose, ears, and genitals, which can scab. [4] The most commonly reported clinical signs of myxomatosis are: Swellings of the eyelids and genitals. White ocular discharge. Pyrexia. Lethargy and anorexia. [5] Severe symptoms of myxomatosis include: Swelling of the lips, eyelids, and genitals. High temperature (pyrexia). Lethargy and anorexia. Blindness caused by eye inflammation. Respiratory problems. Appetite loss. [6] Within hours or days of contracting the myxoma virus, rabbits will show signs of feeling unwell, such as food refusal or lethargy, and their eyes will become inflamed.

Note: Myxomatosis is an obsolete infectious disease in many parts of the world due to successful vaccination programs. However, it still poses a significant threat to rabbit populations in some areas.

Understanding Myxomatosis in Rabbits

Myxomatosis is a fatal disease caused by the myxoma virus, which affects rabbits worldwide. The symptoms include mucinous skin lesions, tumors, edema, and conjunctivitis with serous and mucoid discharge.

Diagnostic Tests for Myxomatosis

Several diagnostic tests can identify the viral genome in RNA extracted directly from feces or other samples. These include:

• Polyacrylamide gel electrophoresis
• Polymerase chain reaction (PCR)
• Enzyme-linked immunosorbent assay (ELISA)
• Haemagglutination (HA) tests
• Electron microscopy

Clinical Signs and Confirmation

The clinical signs of myxomatosis are very classic, making it easy for veterinarians to diagnose the disease based on these symptoms. However, confirmation can be found using diagnostic tests such as PCR or ELISA.

Eradication and Outbreaks

Myxomatosis was definitively eradicated in some areas due to repeated sampling of sera and naso-conjunctival swabs to detect antibodies by cELISA and viral RNA by PCR. However, outbreaks have been reported in wild and farmed populations of lagomorphs since the 1950s.

References

• [1] Diagnostic tests that identify the viral genome in RNA extracted directly from feces include polyacrylamide gel electrophoresis, ...
• [2] Myxomatosis should be suspected in any rabbit with edema of the eyelids and anogenital region, and a definitive diagnosis is best achieved via PCR of swollen ...
• [3] Polymerase chain reaction testing on conjunctival swabs was performed on the first 5 rabbits in the study; however, only one of the swabs was positive for ...
• [4] Myxomatosis is a fatal disease in rabbits caused by the myxoma virus, which leads to mucinous skin lesions, tumors, edema, and conjunctivitis with serous and ...
• [5] Eyelid biopsies from all rabbits (11/11) were positive for myxoma virus by qualitative PCR followed by Sanger sequencing (100% nucleotide ...
• [6] Possible tests include polymerase chain reaction (PCR), enzyme-linked immunosorbent assay (ELISA), haemagglutination (HA) tests, and electron microscopy.
• [7] Myxomatosis was definitively eradicated in some areas due to repeated sampling of sera and naso-conjunctival swabs to detect antibodies by cELISA and viral RNA by PCR.

Treatment Options for Obsolete Infectious Myxomatosis

Myxomatosis, a viral disease affecting rabbits, has no specific treatment available. However, supportive care and antibiotics can be used to alleviate symptoms and prevent secondary infections.

• Antibiotics: While ineffective against the myxoma virus itself, antibiotics can be used to treat secondary bacterial infections that may arise as a result of the disease [6][9].
• Pain relievers: Pain management is essential in managing the symptoms associated with myxomatosis, such as pain and discomfort [4].
• Isolating the rabbit: Isolation of the infected rabbit from other animals can help prevent the spread of the disease [4].

It's worth noting that no specific treatment exists for myxomatosis, and the focus is on prevention through vaccination and maintaining a healthy environment [1][2].

Differential Diagnoses for Obsolete Infectious Myxomatosis

Obsolescent infectious myxomatosis, a disease caused by the myxoma virus (MV), presents with distinct clinical signs that can be confused with other conditions. The differential diagnoses for obsolete infectious myxomatosis include:

• Fibromatosis: This condition causes localized fibroma and is less severe than myxomatosis [2].
• Bacterial upper respiratory tract infections: These can cause similar symptoms to myxomatosis, such as anorexia and serous nasal secretion [1].
• Other viral diseases: Although not specifically mentioned in the context, other viral diseases could potentially be considered in the differential diagnosis.

Key Clinical Signs

The clinical signs of obsolete infectious myxomatosis include:

• Subcutaneous swellings that exude a mucoid secretion when sectioned [4]
• Mucinous skin lesions or myxedema of the head [7]

These symptoms can help differentiate myxomatosis from other conditions.

Importance of Accurate Diagnosis

Accurate diagnosis is crucial in distinguishing obsolete infectious myxomatosis from other diseases. This is because myxomatosis is a fatal disease, whereas fibromatosis is less severe [2].

References:

[1] Context 1: Differential diagnosis. Clinical signs of classic myxomatosis are fairly clear-cut, although bacterial upper respiratory tract infections and bacterial ...

[2] Context 2: Differential Diagnoses. Rabbits of the genus Sylvilagus ... Myxomatosis causes severe to fatal disease, whereas fibromatosis causes a localized fibroma.

[4] Context 4: Myxomatosis is a fatal disease of the European rabbit. It is characterized by subcutaneous swellings that exude a mucoid secretion when sectioned.

[7] Context 7: Myxomatosis is called “big head” and is characterized by mucinous skin lesions or myxedema of the head.