Cat Diseases – Feline Infectious Peritonitis
Feline Infectious Peritonitis
Feline Infectious Peritonitis (FIP) is a chronic progressive infectious disease of cats caused by feline coronavirus. It is characterized by peritonitis, ascites and high fatality rate.
Feline infectious peritonitis virus (FIPV) belongs to the feline coronavirus of the coronavirus family Coronavirus. The genome of the virus is composed of single-stranded RNA, and the virus particles are pleomorphic, with irregular fibrous protrusions on the surface, with a size of 90-100 nm and spiral symmetry.
FIPV has poor resistance to the external environment. It can lose its activity in 1 day at room temperature. General disinfectants such as 0.2% formalin solution, 1% to 5% bleaching powder solution, 0.1% neocleansing solution and heating can kill it. But the virus is more resistant to phenol, low temperature and acidic environment.
FIPV can proliferate in the primary cells of cats, as well as in the group culture of cat lung cells and ascites cells.
Etiological studies have shown that feline coronaviruses are similar to porcine transmissible gastroenteritis viruses and human and canine coronaviruses in different degrees of antigenic structure.
Feline coronavirus can infect cats of all ages. Cats between 1 and 2 years old and elderly cats have the most incidence. Cats of different breeds and genders have no obvious susceptibility to the disease, but the incidence of purebred cats is higher than that of ordinary cats.
The main route of infection of the disease is infection through the digestive tract, or transmission by vector insects, and it can also be transmitted vertically through the placenta.
Serological investigations on the disease in foreign countries show that 9% to 60% of cats in different regions are positive for coronavirus antibodies, but most of them do not show clinical symptoms. Once a cat becomes ill, the fatality rate is almost 1.0%.
At the beginning of the onset, the symptoms are not obvious. The sick cats gradually lose weight, lose appetite or intermittent anorexia, and are in poor physical condition. subsequently, the body temperature rose to 39.7°C~41.10°C, and the number of white blood cells in the blood increased. After 1 to 6 weeks, abdominal swelling can be seen. When a female cat becomes ill, it is often mistaken for pregnancy. Abdominal palpation is generally painless, but there is obvious fluctuating feeling. The sick cat has difficulty breathing, gradually weakens, and shows symptoms of anemia, and finally died.
In some cases, the eyes, central nervous system, kidney and liver are mainly affected, and the symptoms of ascites are not obvious. Corneal edema can be seen from eye infection, and there is a fibrin clot in the anterior chamber of the eye. When the central nervous system is damaged, it manifests as hindquarters dyskinesia, dyskinesia, and even body spasms, and low back feeling. Cases of liver damage show symptoms of jaundice. When the kidney is invaded, the kidney is often palpated in the abdomen, and the sick cat has symptoms of progressive renal failure.
There is a large amount of fluid in the abdominal cavity of sick cats. The fluid is colorless, transparent or light yellow and egg white, and it is easy to solidify after contact with air. The peritoneum is cloudy and rough, covered with fibrin- like exudate. Fibrin is attached to the surface of liver, spleen, kidney and other organs, and small necrotic foci with a diameter of 1 to 3 mm can be seen in the liver. The cut surface penetrates deeply into the liver parenchyma. In some cases, there is also an increase in pleural fluid.
In cases of infringement on the eyes and central nervous system, there is almost no increase in ascites. Dissection showed brain edema, kidneys were uneven, granulomatous changes, and liver necrosis.
According to epidemiological characteristics, clinical symptoms and pathological changes, a preliminary diagnosis can be made. The diagnosis should be combined with laboratory inspections.
(1) Neutralization test method, immunofluorescence antibody method and enzyme-linked immunosorbent method are commonly used in serological examination. The antigen can be liver tissue infected with porcine transmissible gastroenteritis virus, feline coronavirus, and feline coronavirus. During fluorescent antibody examination, the antibody titer of cats can reach 1:100~1:3200.
(2) Virus isolation: Ascites cells and cat lung cells can be cultured and separated successfully.
At present, there is no effective vaccine available. For prevention, attention should be paid to the environmental sanitation of the cattery, and the blood-sucking insects and rodents in the cattery should be eliminated. Use 0.2% formaldehyde or 0.5% chlorhexidine to thoroughly disinfect the contaminated cattery.
There is no specific treatment for this disease, and the prognosis of sick cats with ascites symptoms is poor.mmunosuppressants such as corticosteroids can be used for treatment in the early stage of the disease, and certain effects can be achieved. Once diagnosed with infectious peritonitis, it is best to euthanize the sick cat.