Cat Diseases – Feline Viral Rhinotracheitis
Feline Viral Rhinotracheitis
Feline Viral Rhinotracheitis is an acute contact respiratory infectious disease in cats caused by Feline Herpes Virus Type I (FHV-1). Its main clinical features are sneezing, tearing, catarrhal rhinitis and conjunctivitis.
Feline herpesvirus type I (FHV-I) belongs to the Herpesviridae family and the herpesvirus subfamily A. It has the general morphological characteristics of herpesviruses. The virus genome is double-stranded DNA with a particle diameter of 126~167nm and has cysts. membrane .
FHV-1 has strong resistance to the external environment, and can survive for about 12 hours under dry conditions after leaving the host. It loses activity for 4 to 5 minutes at 56V. The virus is sensitive to fat-soluble solvents such as acetone and chloroform, and formaldehyde can kill the virus.
FHV-I can proliferate on cat kidney, lung, testis and rabbit kidney cells, producing cytopathic and eosinophilic intranuclear inclusion bodies. The virus can adsorb and agglutinate cat red blood cells, and there is only one serotype.
FHV-I mainly infects cats, and other animals in the feline family can be infected. Serological investigations show that a considerable number of cats carry FHV-I. Sick cats and recovered cats can carry and detoxify for a long time and are the main source of infection of this disease. In the early stage of onset, the virus pollutes the environment through nose, eye secretions, sputum, and excretion. Susceptible cats are infected through the respiratory tract by inhaling virus-containing droplets. The disease has the characteristics of latent infection. FHV-1 may be a common virus in the upper respiratory tract of cats. When the cat’s resistance is strong, the virus does not multiply, and the poisoned cat does not show any symptoms; some stress factors (transportation, crowding, wading, estrus or childbirth, etc.) can cause the virus to multiply and be discharged, and tears, tears, etc. Clinical symptoms such as sneezing.
The incubation period is 2 to 5 days, and the artificial infection is 1 to 2 days. At the beginning of the disease, the body temperature rises, sneezing, watery eyes, coughing, and nasal secretions increase. It is serous at first and mucopurulent later. Some cats have foamy nasal fluid, depressed, and lose appetite. Some cats have ulcerative stomatitis, skin ulcers and vaginitis. Young cats have more severe symptoms than adult cats, and the mortality rate can reach 50%. If a secondary infection causes pneumonia, the mortality rate is even higher. Acute cases of this disease have a course of 7-10 days, and chronic cases have a course of 2 to 3 weeks, with chronic rhinitis, ulcerative conjunctivitis and corneal ulcers. In severe cases, it can lead to blindness. The kittens of female cats with poison are weak, lethargic, have difficulty breathing, and die easily.
Acute cases of nasal cavity, turbinate bones, tonsils, epiglottis cartilage, larynx, trachea, bronchial mucosa diffuse bleeding, severe cases of focal necrosis; chronic cases of turbinate deformation, sinusitis. Histological examination: tissues around the bronchi and bronchiole are necrotic, and eosinophilic intranuclear inclusion bodies appear in the epithelial cells of the respiratory tract.
The clinical symptoms of this disease are very similar to feline infectious rhinoconjunctivitis and feline chlamydia pneumoniae infection, and it is difficult to distinguish it. The diagnosis must be confirmed by etiological examination.
Virus isolation and identification Take swabs from the nasal cavity, tonsils, throat and conjunctiva of sick cats, and inoculate them on cat kidney, lung or testicular cells after treatment with double antibodies. After incubating for 2 hours at 37°C, replace with new maintenance solution and observe daily for presence or absence After 7 days of cytopathic disease, after 3 generations of breeding, neutralization test was performed with FHV-I serum to identify the virus.
Inclusion body examination Take sick cat’s eye conjunctival epithelium or upper respiratory tract mucosal epithelium to prepare slices, and use FHV-1 fluorescent antibody staining to examine the eosinophilic nuclear inclusion bodies in the epithelial cells.
Hemagglutination inhibition test According to FHV-1’s ability to adsorb and agglutinate cat red blood cells, the hemagglutination inhibition test can be used for antibody testing.
The prevention of this disease can use the cat quadruple vaccine.
Get immunizations. Immunization program: The cat is immunized for the first time at 50-60 days after birth, and then immunized for 2 consecutive times with an interval of 14-21 days. You need to immunize 3 times in the first year and 2 times a year thereafter. Adult cats will be immunized once every 3 to 4 weeks, and twice a year. In normal times, strengthen feeding management, improve environmental sanitation, and avoid various stress factors. Newly introduced cats must be quarantined and observed for 2 to 3 weeks. Confirm that there are no abnormalities, and then inject them. Only 7 days after the second vaccine injection can they be fed in groups.
There is no special treatment for this disease, symptomatic treatment, the use of vaccine antiviral drugs and the control of secondary infection have a certain effect.