Canine Parvovirus Prevention

The primary viral disease is an acute infectious disease in dogs. Clinically, sick dogs are mostly characterized by hemorrhagic enteritis or non-suppurative myocarditis. Sometimes the infection rate can be as high as 100%, and the fatality rate is 10% to 50%.
Sick dogs are the main source of infection of this disease, and their feces, urine, vomitus and saliva contain the highest levels of poison. Sick dogs continue to excrete viruses and infect other healthy dogs. The feces of recovered dogs carry poison for a long time. Therefore, once the disease occurs in a group of dogs, it is extremely difficult to completely eliminate it. In addition to dogs, wolves, foxes, and cats can also be naturally infected. The disease is mainly contracted through direct or indirect contact. Canine parvovirus is highly resistant to external factors and can survive for 1 hour in an environment of 60°C. The virus is still infectious in an environment that is either acidic or alkaline. Viruses can survive on feces and solid contaminants for months to years. In low temperature environment, its infectivity can be maintained for a long time. D. 5% formalin, 0.5% peracetic acid, 5% to 6% sodium hypohydrite, etc. can be used as disinfectants for this virus.

[Clinic Key Points]

(1) Epidemiological characteristics There is no obvious seasonality in the prevalence of this disease, but it is more common in cold winter. Newly weaned puppies are more likely to suffer from myocarditis syndrome, while puppies are more likely to suffer from enteritis syndrome.

(2) Clinical characteristics: This disease mainly appears in two clinical forms, namely enteritis type and myocarditis type.
① Enteritis type has an incubation period of 7 to 14 days, usually with vomiting first and then diarrhea. The stool is yellow or gray-yellow and contains a large amount of fluid and pseudomembrane. 2 to 3 days after the illness, the feces will be like tomato juice, mixed with blood, and have a special fishy smell. The sick dog soon showed symptoms of dehydration. At this time, the sick dog was depressed, had no appetite, its body temperature rose to above 40°C, and its thirst increased. In the later stages, the body temperature of some sick dogs is lower than normal, and the visible mucous membranes are pale. The tail and rear abdomen are often contaminated with feces. In severe cases, the anus is loose and dilated.
②Myocarditis type: Puppies have difficulty breathing, hyperpalpitations, pale mucous membranes, physical failure, and often sudden death. Usually, a preliminary diagnosis can be made based on the above-mentioned popular characteristics and clinical symptoms. Clinically, attention should be paid to observe whether the sick man has vomiting and diarrhea. If further diagnosis is required, diarrhea from sick dogs should be taken early, mixed with 0.5% porcine red blood cell suspension in proportion at 4°C, and observed for its agglutination effect on red blood cells. If necessary, stool samples can also be sent to the testing unit for electron microscopy to confirm the diagnosis.

[Preventive and Control Measures]

First, we must do a good job in immunization. Domestic inactivated canine parvovirus vaccine is used in combination with other vaccines. Dogs aged 30-90 days should be injected three times, and dogs over 90 days old should be injected twice, spaced 2-4 weeks apart. One dose (2 ml) is given each time, followed by boosters every six months. However, maternal antibodies in puppies can affect the immune effect of the vaccine. The canine pentane vaccine developed by the Chinese People's Liberation Army Agriculture and Animal Husbandry University isolated parvovirus from mink and has strong resistance to female dog antibodies and does not cause immune interference. Therefore, it can be based onImmunize according to the canine distemper vaccination program.

Second, after the disease breaks out in a group of dogs, they should be isolated in time, and the kennels and feeding equipment should be treated with 2% to 4% caustic soda, 1% formalin, 0.5% peracetic acid or 5% to 6% Repeated disinfection with sodium hypochlorite. Dogs that are unlikely to be cured should be killed as soon as possible, burned and buried deeply. Third, the treatment of sick dogs. Dogs suffering from myocarditis have a severe course of disease, worsen rapidly, and often die before treatment. If dogs with enteritis type disease can be treated promptly and reasonably, the mortality rate can be significantly reduced. In the early stage of the disease, the cure rate can be improved by applying hyperimmune serum and taking measures such as cardiotonic, rehydration, antibacterial, anti-inflammatory, anti-shock and intensive nursing care.
(1) Using high immune serum early can improve the efficacy. Once a dog is diagnosed with this disease, other sick dogs should be given immune serum or recovered dog serum immediately. The dosage of hyperimmune serum is 0.5 to 1 ml/kg of body weight, and that of recovered dog serum is 0.5 to 2 ml/kg of body weight, for 3 to 5 days. If hyperimmune serum is used together with other antibacterial and anti-inflammatory drugs, the efficacy can be improved.

(2) Dogs suffering from rehydration disease often die of dehydration, so rehydration is the main treatment for the disease. Determine the composition and volume of fluid based on the dog's degree of dehydration and general condition. The total volume of intravenous fluids should be 60 ml/kg body weight.

① Intravenous rehydration: 5 to 40 ml of 25% glucose solution, 2/10 ml of vitamin C, 5 to 20 ml of energy mixture, and infused slowly intravenously 1 to 2 times a day. 50 to 500 ml of 5% sugar saline, 2 to 10 ml of vitamin C, 0.5 to 2 ml of adenosine triphosphate (ATP) injection, 50 to 100 ml of 5% sodium bicarbonate, antibiotics, etc., one slow intravenous infusion , 2 times/day. During infusion, the infusion volume and infusion speed should be strictly controlled, and attention should be paid to the functional status of the heart, otherwise it may easily lead to treatment failure. When sick dogs show severe vomiting and diarrhea, dehydration, electrolyte imbalance and acid-base balance need to be corrected. 50 to 500 ml of lactated Ringer's solution, 5 to 40 ml of 25% glucose solution and 0.0 ml of Santos hydrochloride injection can be given intravenously. 3~1ml, 2 times/day.
② Oral rehydration method: When the sick dog shows no appetite, rapid heart rate, no vomiting, and appetite or desire to drink, oral rehydration salts can be given: 3.5 grams of sodium chloride, 2.5 grams of sodium bicarbonate, 1.5 grams of potassium chloride, 20 grams of glucose, and 1000 ml of water. Allow the dog to drink freely or give it a deep enema.
③Peritoneal cavity rehydration If the sick dog has difficulty with intravenous drip, peritoneal cavity rehydration is possible, and the dosage is 70 ml/kg of body weight.

(3) Antibacterial and anti-inflammatory drugs can be used in conjunction with various broad-spectrum antibiotics, but they are not suitable for long-term use to prevent intestinal flora imbalance, but they can delay the recovery of intestinal digestive function. Antituberculosis freeze-dried powder and antitoxin injection (produced by Heilongjiang Provincial Veterinary Drug Factory No. 1) have good curative effects on this disease. Generally, dogs under 15 kg are injected with freeze-dried powder ampoules every day, dogs over 15 kg are injected with 2 ampoules per day, and No. 1 needle is injected with 10-30 ml per day.. Zhixieling tablets are broad-spectrum antibacterial and antiviral preparations prepared from active ingredients extracted from a variety of traditional Chinese medicines. It has a very good effect on this disease. Usage and dosage: 1-2 tablets each time for dogs weighing 2-4 kg, 2-4 tablets each time for dogs weighing 5-10 kg, beans 2-2 times a day. The amount of diarrhea caused by the virus has doubled.

(4) Vomiting: For severe vomiting, 0.3 to 2 ml of Aimol and metoclopramide (metoclopramide) can be injected intramuscularly.
(5) Anti-shock For those with obvious shock symptoms, 5 to 15 mg of dexamethasone (flumetasone) can be injected intramuscularly, or 0.3 to 1 ml of Santosine Hydrochloride Injection.
(6) Strengthen care and pay attention to keeping sick dogs warm. During diarrhea, high-protein and high-fat feeds such as milk, eggs, and meat should be stopped and easy-to-digest feeds should be given to reduce the burden on the gastrointestinal tract and improve the cure rate.