Early Canine Distemper Symptoms & Origin Explained

Section 1: What is Canine Distemper?

As humans wage battles against diseases, it's equally crucial to prioritize the health of our canine companions. Among the fierce infectious diseases that have taken a toll on countless dogs' lives are canine distemper and parvovirus. Canine distemper, in particular, is a highly contagious illness caused by the canine distemper virus. This disease ranks among the top in terms of its transmission intensity, severity, and mortality rate among dogs.

Section 2: The Transmission Process of Canine Distemper Virus

The canine distemper virus progresses through the following stages: it enters the upper respiratory mucosa, where it multiplies within macrophages. It then spreads to the tonsils and bronchial lymph nodes. After 24 days, the virus replicates in the bone marrow, thymus, and spleen's monocytes. Four to six days later, it invades the gastrointestinal tract, multiplying in the mucosa of the stomach, small intestine, mesenteric lymph nodes, and Kupffer cells in the liver. This leads to a rise in body temperature and a decrease in white blood cells (primarily lymphocytes). By the 89th day, the virus spreads to epithelial cells and neural tissues. After 14 days, most of the virus is cleared, but it can still survive in neurons and the skin.

Section 3: The Progression of Canine Distemper

In 1905, Carre proposed that canine distemper is caused by a highly virulent virus. In 1951, Dedy was the first to culture the canine distemper virus using tissue culture methods. By the late 1970s, researchers in China, including Hua Guoyin, isolated several vaccine strains from imported attenuated canine distemper virus strains. Studies have confirmed that the canine distemper virus belongs to the genus Morbillivirus within the family Paramyxoviridae, sharing close antigenic relationships with rinderpest and measles viruses. Both Morbillivirus and Measlesvirus are classified as singlestranded RNA viruses. The genus includes measles, rinderpest, and other similar viruses. There is a close antigenic relationship between measles, rinderpest, and canine distemper viruses. Most cases of canine distemper are accompanied by secondary bacterial infections, which means we cannot categorize it as a bacterial disease. Additionally, in traditional Chinese veterinary medicine, canine distemper is considered a type of pestilence and is not classified as a bacterial disease. For a long time, traditional Chinese veterinary medicine has regarded canine distemper as a pestilence and included it within its theoretical framework.

Tip: For more information about canine distemper, click "What Are the Symptoms of Canine Distemper?" to learn more.