Detailed Explanation of Canine Distemper Prevention and Treatment Techniques: Scientific Methods for Preventing and Treating Dog Diseases

Canine distemper is a highly contagious infectious disease caused by the canine distemper virus, affecting dogs and some economic animals and wildlife. The clinical features include biphasic fever, rhinitis, inflammation of the respiratory and digestive tracts, and in some cases, symptoms involving the skin and nervous system. Secondary bacterial infections frequently occur clinically.

1. Pathogen The pathogen of this disease is the canine distemper virus, which has strong resistance to dryness and cold. It can survive at room temperature for 7 to 8 days.

2. Epidemiological characteristics Diseased dogs, mink, and other affected animals and virus-carrying animals are the most important sources of infection. This disease is mainly transmitted through direct contact between diseased dogs and healthy dogs via the respiratory tract; droplets are of particular significance in the spread of this disease, and infection can also occur through the digestive tract and mating. Dogs of different ages, sexes, and breeds can all be infected, with puppies under 1 year of age being the most susceptible. In addition, wolves, jackals, and foxes in the Canidae family, mink in the Mustelidae family, and raccoons, white-nosed coatis, and red pandas in the Procyonidae family are all susceptible. However, humans and other domestic animals are not susceptible to this disease.

3. Clinical symptoms The incubation period of this disease is 3 to 7 days in dogs and 9 to 14 days in mink. At the beginning of the illness, dogs mostly show serous discharge from the eyes and nose, listlessness, and reduced appetite. The initial body temperature rises to 39.5 to 41 degrees C, lasts for about 2 days, then drops to normal temperature and remains so for 2 to 3 days; at this time the sick dog seems to improve and has an appetite. The second rise in body temperature can last for several weeks, presenting typical biphasic fever. At this point the condition further deteriorates, showing an acute course, with listlessness, refusal to eat, and mucous-purulent discharge from the eyes and nose, followed by symptoms of pneumonia, and vomiting often occurs. Severe cases may show foul-smelling diarrhea with watery stools mixed with mucus or blood. Sick dogs rapidly lose weight, become depressed, and have a very high mortality rate. In some sick dogs, neurological symptoms predominate after onset, showing depression, paroxysmal muscle spasms, ataxia, circling, convulsions, or coma. Sick dogs that develop convulsions mostly die. In some cases, after other symptoms disappear, chorea-like symptoms and paralysis remain. In puppies with this disease, some develop papules on the skin of the abdomen, inner abdomen, or other areas, which often develop into pustules. After recovery, the pus dries up and disappears.

4. Anatomical and pathological changes The respiratory tract mucosa shows catarrhal inflammation, with mucous or purulent exudate, pneumonia, and pulmonary edema. The digestive tract mucosa shows catarrhal hemorrhagic inflammatory changes, with swelling of the gastrointestinal mucosa, increased mucus, mucosal hemorrhage, and hemorrhagic ulcers. In some cases, in the later stage of the disease, vesicular or pustular dermatitis appears on the skin. In some cases, the epidermal stratum corneum of the toe pads proliferates and becomes thickened (so-called hard pad disease).

5. Diagnosis Typical cases can be diagnosed based on clinical symptoms and epidemiological data; for confirmation, typical cytoplasmic inclusion bodies should be found in the epithelial cells of affected tissues. Differential diagnosis: canine infectious hepatitis commonly shows temporary corneal opacity, prolonged clotting time after bleeding, and on necropsy characteristic lesions of the liver and gallbladder and blood-like exudate in the body cavities, whereas canine distemper does not have these changes.

6. Prevention and treatment (1) Prevention: Comprehensive epidemic prevention measures are mainly adopted. Sick dogs should be isolated and treated as early as possible, with strict disinfection to prevent mutual infection and further spread. Attenuated canine distemper vaccine is used for preventive vaccination: the first immunization at 9 weeks after birth, the second immunization at 15 weeks, and then once every year thereafter. For those that have not suckled after birth, vaccinate within 2 weeks, with a second immunization after 10 to 15 days. (2) Treatment: At present, antibiotic injections combined with symptomatic therapies such as cardiac stimulation and fluid supplementation for sick dogs, especially treatment in the early stage, to control secondary bacterial infections, have achieved good results. Where conditions permit, injection of canine distemper antiserum for treatment has a relatively good effect.