Dog Diseases – Canine Herpes Virus Infection
Canine Herpes Virus Infection is mainly an acute and fatal infectious disease of young dogs. Affect the reproduction of dogs and often cause serious economic losses. The disease has attracted people’s attention only after the virus was first isolated in the United States and the United Kingdom in 1965 and its pathogenicity was determined. The puppies are characterized by systemic hemorrhage and necrosis after infection, and when dogs over 3 weeks of age are infected, they mainly show symptoms of upper respiratory tract infection.
The causative agent of this disease is canine herpes virus type I, which has weak resistance to high temperature. 56U can kill the virus in 4 minutes. But the resistance to low temperature is stronger. In an acidic environment (pH 4.5), the virus can lose its pathogenicity after 30 minutes. The virus can be excreted through saliva, nasal juice, and urine. The disease is mainly infected by droplets, and the fetus can also be infected when it comes into contact with the vaginal secretions of a virulent female dog during delivery.
(1) Epidemiological characteristics Canine herpes virus only infects dogs, and mainly causes fatal infections in puppies less than 2 weeks old. Puppies and adult dogs over 3 weeks old have mild symptoms and mainly show non-dominant infections.
(2) Clinical features After being infected with this disease, puppies within 2 weeks of age often do not increase their body temperature and are mentally retarded. Poor appetite or stop breastfeeding. Difficulty breathing, abdominal pain, vomiting, discharge of yellow-green stools. Sick dogs often howl continuously, and most often die within 24 hours after the onset of clinical symptoms. Individual puppies who have been tolerated often have neurological symptoms such as ataxia, circular motions to one side, and blindness. After 3 to 5 weeks of age, puppies and adult dogs often do not show systemic symptoms, but only cause mild rhinitis and pharyngitis, mainly showing upper respiratory symptoms such as runny nose, sneezing, and dry cough. Tests have proved that the virus can mildly multiply on the mucous membranes of the respiratory and reproductive tracts of these sick dogs and become a source of infection.
(3) Characteristics of pathological necropsy The typical lesions of young dogs are scattered on the surface of the parenchymal organs with a large number of gray-white necrotic foci and small bleeding points with a diameter of about 2 to 3 mm, especially the changes in the kidneys and lungs. Bloody serous fluid accumulates in the chest and abdominal cavity. The spleen is enlarged and the intestinal mucosa is bleeding a little.
A preliminary diagnosis can usually be made based on the above-mentioned clinical characteristics and pathological changes in necropsy, combined with epidemic characteristics. The final diagnosis depends on virus isolation or serological tests.
There is currently no specific vaccine for this disease. Therefore, comprehensive measures should be taken to prevent this disease, such as not buying dogs from a group of dogs that frequently suffer from respiratory diseases; quarantine dogs that are found to be sick, and apply broad-spectrum antibiotics to prevent secondary infections; strengthen disinfection; strengthen feeding management, etc.