1. The characteristics of infectious diseases are usually caused by pathogenic microorganisms, with certain incubation period and symptoms. Infectious diseases are called infectious diseases. It is characterized by the interaction between pathogenic microorganisms and dogs. Without canine distemper virus, there would be no canine distemper. It is contagious and popular. For example, canine distemper virus discharged from a dog suffering from canine distemper invades another susceptible healthy dog, which can cause canine distemper with the same symptoms and spread among dogs in a certain area, and infected dogs will have specific reactions; Resistant dogs can obtain specific immunity; There are typical symptoms.
2. The types of infection can be divided into endogenous infection and exogenous infection according to the occurrence of infection; According to the types of pathogens, it can be divided into simple infection, mixed infection and secondary infection; According to the severity of the disease, it can be divided into benign infection and malignant infection; According to the course of disease, it can be divided into the most acute, acute, subacute and chronic infections.
3. Epidemic of Infectious Diseases Dogs Infectious diseases spread directly between dogs or indirectly through the media, which constitutes an epidemic. Generally, it needs to go through a process: sick dogs excrete pathogenic microorganisms, transmission routes and the invasion of new susceptible dogs. This shows that the spread of infectious diseases in dogs must have three links: the source of infection, the route of transmission and susceptible dogs.
(1) The source of infection is the source of infection, including infectious dogs, dogs with drugs and dogs with bacteria.
(2) Transmission route The route that pathogenic microorganisms are discharged from the source of infection and then invade new susceptible dogs in a certain way is called transmission route. There are two modes of transmission: direct contact and indirect contact. Direct contact transmission refers to the mode of transmission in which pathogenic microorganisms contact susceptible dogs (mating, licking, playing, etc.). ) through the source of infection, there is no external factor. Indirect contact transmission is a mode of transmission in which pathogenic microorganisms cause diseases in newly susceptible dogs through the media with the participation of external factors. Media usually include: water droplets and dust in the air; Contaminated feed, drinking water, bedding, utensils, toys, soil, etc. ; Parasites with pathogenic microorganisms, livestock and poultry, wild animals, humans, etc.
(3) Susceptibility refers to the sensitivity of dogs to infectious diseases. The susceptibility of dogs to pathogens is not only related to the types and virulence of pathogens, but also related to the internal factors, external factors and specific immune status of dogs. The internal factors of dogs are determined by heredity, and different breeds of dogs will have different symptoms when the same pathogen invades. The external factors of dogs refer to feed quality, kennel hygiene, feces and urine treatment, dog density, hunger, exercise status, neat appearance, vaccination and so on. Dog-specific immunity refers to the specific immunity of surviving dogs, tolerant dogs and asymptomatic dogs after the epidemic of an infectious disease. The offspring of dogs with this immunity often have innate immunity, and they also have certain immunity in infancy.
When the source of infection, the route of transmission and susceptible dogs are connected, the epidemic of infectious diseases will occur.
The epidemic of infectious diseases shows that as long as any one of these three links is eliminated, the route of transmission is cut off, and the disease resistance of dogs is enhanced (susceptibility is eliminated), the chain of infection process will be broken and infectious diseases will not occur. This provides a clear theoretical basis for preventing and controlling the occurrence and epidemic of infectious diseases in dogs. Common infectious diseases of pet dogs are discussed as follows:
(1) canine distemper
Canine distemper is a highly contagious disease. The disease is distributed all over the world, mainly harming puppies, with extremely high morbidity and mortality.
[Pathogen] Puppies have no innate specific immunity, poor preventive measures, no vaccination, no resistance, and are attacked by canine distemper virus. The pathogen belongs to RNA paramyxovirus with a diameter of 100 ~ 300 nm. Strong resistance to drying and cold, but sensitive to ether, chloroform and alkali. Sick dogs are the main source of infection of the disease.
【 Symptoms 】 The incubation period of canine distemper is 3-6 days, and the body temperature is typical biphasic fever. Different symptoms and course of disease show different pathological symptoms, and the length of course of disease is also inconsistent. At the initial stage, the body temperature rose above 39.5℃, and the body was depressed, with loss of appetite, conjunctival inflammation, tears, sneezing and runny nose, and the high fever subsided after 1 ~ 3 days. The sick dog seems to be getting better. After a few days, his body temperature rose for the second time, reaching 4 1℃. In the middle stage, the dog was devastated, anorexia, and severe respiratory, gastrointestinal and nervous system symptoms appeared. Such as dyspnea, frequent cough, and poor nasal breathing; Sometimes vomiting, diarrhea, emaciation, limb weakness, blurred eyes, gingival hypertrophy and so on. Late lip trembling, foaming at the mouth, * * * ataxia, walking in ecstasy, barking constantly, fell to the ground and died of convulsions. In addition to the characteristics of the disease course, different dogs often have different symptoms and characteristics for individuals.
Pneumonia type: mainly respiratory symptoms, such as runny nose, sneezing, coughing, dirty nostrils, cracked or dry nose, poor breathing, abdominal breathing and other symptoms.
Enteritis type: mainly manifested as gastrointestinal symptoms, loss of appetite, even abandonment of food, or good or bad appetite, drinking more water during high fever, sometimes vomiting, mucus or bloodshot stool, bubbles, unpleasant smell, oral ulcer, white tongue coating, weakness and emaciation.
Skin type: skin symptoms are the main manifestations. Red blisters, sores and purulent lesions the size of rice grains, peas and soybeans are scattered on the inner skin of the lower abdomen and thighs, and the area gradually expands from less to more. Later, blisters, sores and pustules disappeared, and symptoms such as scabbing and lazy skin appeared.
Neurotype: sudden onset, mainly manifested as nervous system symptoms, lip trembling, foaming at the mouth, walking like drunkenness, ignoring competition, jumping blindly, screaming from time to time, even limb twitching, ataxia, falling to the ground, incontinence, lethargy and death.
In addition to the above symptoms, the foot pad skin of canine distemper dogs often becomes excessively keratinized, rough, hard and yellow; Eyelid swelling, conjunctival inflammation, gingival suppuration, corneal ulcer perforation.
【 Prevention 】 Although canine distemper is the main infectious disease in dogs, it can be controlled as long as corresponding epidemic prevention measures are taken. In addition to general prevention, puppies under 3 months old should be injected with canine distemper vaccine 2 ~ 3 times, the first time at weaning, and then the second and third times every half month; Puppies and puppies over 3 months old should be vaccinated once a year. Commonly used gallnut seedlings.
Once a dog suffers from canine distemper, it is particularly difficult to cure. Even with a specific antiviral serum, it cannot effectively prevent the disease from developing in depth. In order to prevent or control bacterial infection, some antibiotics, sulfonamides, antiviral traditional Chinese medicine preparations or Virulin can be used in combination. Measures such as supportive therapy, symptomatic therapy and improving autoimmune can be taken for the weak.
(2) Canine parvovirus disease
Canine parvovirus disease is an acute infectious disease in dogs, which is prevalent all over the world, with high morbidity and mortality, especially in puppies.
[Pathogen] The prevention work is weak, and the dog itself has no immunity and is not vaccinated, so it is invaded by canine parvovirus. This virus belongs to RNA virus, with a size of about 20 nm and icosahedral symmetry. Strong ability to resist environmental factors, stable at 60℃ 1 hour, but can be inactivated by formalin, oxides and ultraviolet rays.
Sick dogs and poisonous dogs are the main sources of infection of this disease. Viruses are discharged with feces, urine, vomit and saliva, polluting the environment. The feces of rehabilitation dogs may be toxic for a long time. The virus is infected through the digestive tract of healthy dogs. Puppies are most susceptible to infection before and after weaning, and often erupt in the same nest, which is endemic.
【 Symptoms 】 The incubation period of canine parvovirus disease is 7 ~ 14 days, showing hemorrhagic enteritis or non-suppurative myocardial inflammation.
Hemorrhagic enteritis type: dogs suddenly have depressive symptoms, loss of appetite, stubborn vomiting, rapid diarrhea, or discharge thin feces in the form of spray, with mucus and false membrane, and then tomato juice, which is particularly smelly, dehydrated quickly and emaciated. Puppies under 3 months old are easy to die, and the mortality rate of adult dogs is 10% ~ 15%.
Myocarditis type: 1 month-old puppies often suffer from myocarditis, with mild initial manifestations, mild diarrhea, occasional vomiting, pale conjunctiva, slow movement, arrhythmia, hypothermia, heart failure and death. The mortality rate was 40% ~ 100%.
【 Prevention 】 Comprehensive epidemic prevention measures should be taken for canine parvovirus, and health work should be done well at ordinary times. Regular injection of canine parvovirus vaccine or pentavaccine, once every half a month before and after weaning, 2 ~ 3 times in a row, and once a year thereafter. After the sick dogs are found, they should be kept in isolation and treated, and the environment should be disinfected with 10% ~ 20% bleaching powder.
There is no specific treatment for canine parvovirus. At present, the use of specific immune serum combined with drug therapy is a widely used comprehensive treatment measure. Inject 3 ~ 10 ml high immune serum of parvovirus disease into sick dogs every day, and take symptomatic treatment and supportive therapy at the same time. For example, a large number of ringer's solution and physiological sugar saline (5% glucose solution) are supplemented 300 ~ 500ml/ time; Intramuscular injection of Luo 'an blood 5mg/ time or Aiqi 2ml/ time to stop bleeding and vomiting; Lincomycin 20mg/kg/ time, 1 ~ 3 times/day. Diet and oral administration are prohibited. Dogs can be given blood transfusion treatment if conditions permit, and the effect is better.
(3) Canine infectious hepatitis
Canine infectious hepatitis, commonly known as blue eye disease, is an acute septic infectious disease in dogs. It occurs all over the world, regardless of season, sex, breed and age, but the morbidity and mortality of dogs under 1 year old are high.
[Pathogen] The prevention work is weak, the dog has no resistance, and the canine infectious hepatitis vaccine has not been injected, which is caused by the attack of canine infectious hepatitis virus. The virus belongs to DNA adenovirus, its size is 70 ~ 80 nanometers, and it has strong resistance to the environment, and it can survive for about 100 days at room temperature.
Sick dogs and poisonous dogs are the sources of infection of this disease. The vomit, secretion and excrement of sick dogs contain viruses, and rehabilitation dogs can detoxify through urine for a long time. The disease is a contact infection, mainly caused by digestive tract infection.
【 Symptoms 】 The incubation period of this disease is 2-8 days. Puppies often die suddenly within 1 ~ 2 days, and adult dogs can be cured if they can stand it for more than 2 days. The course of disease is about 15 days, and the mortality rate is 25% ~ 40%.
Subclinical type: most puppies are of this type, with no obvious symptoms, some of them die quickly and have mild dysfunction.
Light: limited to anorexia, depression, fever, lethargy, emaciation, etc.
Severe: persistent high fever, body temperature 465438 0℃, vomiting, occasional jaundice, abdominal pain, groaning, unable to sleep.
Severe type: abdominal pain, diarrhea, vomiting and bleeding, dehydration and emaciation, high fever, and death in about one day.
In the late stage of the disease, corneal inflammation and edema, unilateral or bilateral blue eyes.
[Prevention] Do a good job in health and epidemic prevention at ordinary times, and start to inject canine infectious hepatitis vaccine or canine pentavaccine after weaning. In case of emergency, intramuscular injection of immune serum 5 ~ 10 ml can be used. You can also inject immunoglobulin, interferon, thymosin and other immune preparations at the same time, each 10mg/ animal, and inject it into muscle once for prevention.
In the early stage of the disease, a large dose of high immune serum, antiviral drugs, supplemented by antibiotics and other drugs can achieve certain curative effects. Inject 3 ~ 10 ml of canine infectious hepatitis serum and appropriate amount of immune preparation into muscle every day; Intravenous infusion of glucose, vitamin C, coenzyme A, etc. Regulate the metabolism of water, electrolyte and sugar; In order to control the secondary infection, some antibiotics and antiviral traditional Chinese medicine preparations can be selected, such as Radix Isatidis, Folium Isatidis, Flos Lonicerae, Fructus Forsythiae, etc. , supplemented by hormone drugs; For the treatment of blue eyes, you can choose to drop eye drops 3 ~ 4 times a day.
(4) Canine coronavirus disease
Canine coronavirus disease is a canine infectious disease characterized by gastroenteritis. It is popular all over the world, mostly in winter, and dogs of different breeds, ages and genders are susceptible.
【 Pathogen 】 This virus often leads to the epidemic of canine diarrhea together with canine parvovirus. Canine coronavirus is a single-stranded RNA virus with a size of 80 ~ 100 nm, which can be easily inactivated by heating and ultraviolet rays.
Sick dogs and poisonous dogs are the main sources of infection of this disease. Viruses are discharged with feces, polluting feed and drinking water. , and through the digestive tract infection. Viruses can survive for 6 ~ 9 days in feces, and pollutants can remain infectious for several days in water. Therefore, once the disease occurs, it is difficult to control infection and epidemic, which often leads to dens and outbreaks.
【 Symptoms 】 The incubation period of this disease is 1 ~ 3 days. It spreads quickly, and it can spread to the whole group within a few days. Some people have watery diarrhea, while others have no clinical symptoms. Sick dogs have anorexia, lethargy, vomiting and emaciation, and excrete foul-smelling, soft and sticky feces. Vomiting usually lasts for a few days until diarrhea begins, and the frequency of vomiting decreases. After that, the feces changed from mushy and semi-mushy to watery, and the color changed from orange to green, containing mucus and bloodshot. Sick dogs dehydrate quickly, generally do not have a fever, weaken and die quickly, and recover in 7 ~ 10 days.
【 Prevention 】 At present, there is no vaccine to prevent canine coronavirus disease. Usually only do general epidemic prevention work to enhance the dog's physique and resistance. Once the disease occurs, the source of infection should be controlled or eliminated, and the source of infection should be blocked to protect healthy dogs from infringement.
There is no specific medicine to treat this disease. According to the common methods of treating infectious diseases, secondary infection can be controlled, and symptomatic treatment and supportive therapy can be adopted.
(5) rabies
Rabies, also known as mad dog disease's phobia, is an infectious disease of people and animals. It occurs all over the world, the incidence rate is well controlled, but the mortality rate is extremely high.
[Pathogen] Animals such as people, cats and dogs who have not been injected with rabies vaccine are attacked by rabies virus. Rabies virus belongs to RNA rhabdovirus with a size of 75× 180 nm. Infect all warm-blooded animals and people. In nature, dogs, cats, bats, etc. It is the storage host of this virus and the source of rabies infection for people and livestock. Viruses mainly exist in the central nervous system, salivary glands and saliva of humans and animals. The mode of transmission is infection after being bitten by sick animals and drug carriers, and the virus can also infect saliva and droplets (aerosol) through respiratory tract, digestive tract and wound. The virus is sensitive to disinfectants such as acid, alkali, carbolic acid, formalin and mercuric chloride, and can be inactivated by various fatty solvents, 70% alcohol, iodine solution, sunlight, X-rays and boiling.
【 Symptoms 】 The incubation period ranges from 2 to 8 weeks, the shortest is 8 days, and the elderly are months or years. This is related to the susceptibility of animals, the distance from the wound to the central nervous system, and the virulence and quantity of invasive viruses. The course of the disease is divided into three stages: prodromal stage, exciting stage and paralysis stage.
Precursor period: also known as depression period, about 1 ~ 2 days. The sick dog is depressed and often hides in the dark. They don't want to get close to people or answer the phone. If they are forced to lead, they will bite their master. Abnormal appetite, like to eat foreign bodies, laryngeal paralysis, dysphagia. Pupils dilated, hyperreflexia, excitability, increased saliva secretion, roaring in the sky, sexual excitement, licking the reproductive organs.
Excitement period: also known as violence period, about 2 ~ 4 days. Sick dogs are highly emotional and violent, attacking people and animals, and often appear alternately in rage and depression, then lie down tired and get up with peace of mind. Horrified strabismus, self-biting limbs, tail, genitals. Wandering in the wild for dozens of kilometers a day, I don't know the way home. Emaciation, hoarseness, sunken eyes, jaw paralysis, etc.
Paralysis period: this period is about 1 ~ 2 days. Mandibular drooping, tongue hanging out of mouth, drooling. Tetraplegia, unable to lie down, convulsion failed and died. Some animals are sick. They are afraid of water.
【 Prevention 】 Now susceptible animals such as dogs are widely inoculated with attenuated vaccines and inactivated vaccines. Poisonous animals and rabies animals are culled and treated harmlessly. When people and animals are bitten by suspicious animals (dogs, cats) or rabies animals, it is best to let the wound bleed and detoxify first, then wash it with soapy water, and then disinfect it with 5% iodine tincture. Emergency rabies vaccine should be given within 24 hours and immune serum should be injected at the same time.
(6) Pseudorabies
Pseudorabies is an acute infectious disease in dogs, which is distributed all over the world. The disease is characterized by itching and encephalomyelitis.
[Pathogen] Dogs are attacked by pseudorabies virus. The virus belongs to herpes virus, and its double-stranded DNA is spherical with the size of 100 ~ 150 nm. Viruses have strong resistance to the external environment. It can survive for 30 ~ 46 days in a kennel at 8 ~ 24℃, and can only be inactivated at a temperature above 56℃ in ultraviolet light, formalin, ether and sodium hydroxide. Dogs, cats, rats, pigs and cows are all susceptible to infection through digestive tract and skin wounds. Mostly in spring and autumn.
【 Symptoms 】 The incubation period is 3 ~ 10 day. At the beginning of the disease, the sick dog showed indifference to the surrounding things, then became restless, refused to eat, curled up and slept, and often changed his crouching place. I often vomit, stare at the skin wound and lick it. The more I lick it, the more itchy it becomes, so that I scratch, lick and bite, and the wound is torn, the tissue is swollen and I moan from time to time. Barking uneasily, attacking people and animals, running around, jumping over walls, drooling in the mouth, unable to swallow, similar to rabies, so it is called pseudorabies. Most animals have spasms in the neck and lips and have difficulty breathing. Often died within 24 ~ 36 hours, and the mortality rate was as high as 100%.
【 Prevention 】 Pay attention to killing rats in kennels to prevent dogs from contacting other susceptible animals. Dog meat should be cooked and disinfected. Suspected sick dogs should be treated in isolation. The dead bodies of sick dogs should be treated harmlessly.
At present, there is no specific treatment for pseudorabies, and it is effective to inject pseudorabies immune serum in the early stage of the disease with symptomatic treatment. Sichuan Agricultural University has successfully developed pseudorabies vaccine.
(7) canine tuberculosis
Canine tuberculosis is a chronic infectious disease of humans and animals. Its pathological feature is the formation of granuloma in various tissues and organs, showing caseous and calcified nodular lesions with pearl-like appearance, so it is also called pearl disease.
[Pathogen] The dog is infected with mycobacterium tuberculosis. Mycobacterium tuberculosis is a gram-positive bacterium, which belongs to strict aerobic bacteria, and the optimum growth and reproduction temperature is 37 ~ 38℃. Because bacteria are rich in lipids, they have strong viability in the external environment and strong resistance to dryness and wetness. They can survive in water for 5 months and in soil for 7 months. The heat resistance is poor, and it takes 4 hours to kill with disinfectant, but it will die quickly in 70% alcohol and 10% bleaching powder.
This kind of bacteria can infect more than 70 kinds of livestock and humans, and the infection routes are mostly digestive tract and respiratory tract. Dogs are often infected by licking patients' spit, inhaling air containing bacteria and contacting patients with open tuberculosis. Dog diseases can be transmitted to people, cats and so on. And human diseases can be transmitted to dogs, cats, etc.
【 Symptoms 】 The incubation period of tuberculosis is different, ranging from ten days to dozens of days, even several years, which varies greatly due to the variety, age, nutrition, management and health.
Tuberculosis in dogs is mostly chronic infection with subacute symptoms. The initial symptoms of the sick dog are not obvious, but the appetite is jet lag, weak and inactive, listless and progressive emaciation.
The clinical symptoms of tuberculosis are different in different parts:
Laryngeal nodule: mainly manifested as hoarseness, spasmodic cough, aphonia and so on.
Pulmonary tuberculosis: mainly manifested as dyspnea, bad breath, cough pain, runny nose, abdominal breathing, frequent sitting and rest, sensitivity to touching the chest and abnormal voice.
Hepatic tuberculosis: mainly manifested as jaundice, yellow urine, yellow skin, no food, thirst, sensitivity between palpation of right costal arch and xiphoid cartilage, palm patting, etc.
Uterine tuberculosis: the abdominal circumference is getting bigger and bigger, and the vulva often flows out with bloodshot yellowish viscous exudate, and it is not estrus. Even the entire reproductive organs appear tuberculosis, breast ulceration, and pregnant dogs miscarry. Male dogs have epididymis, testicular swelling and penile erosion.
Intestinal tuberculosis: In addition to indigestion and loss of appetite, it often causes intractable diarrhea, dehydration and rapid weight loss.
Anatomy of common thoracic cavity, abdominal cavity, pelvic mucosa and corresponding organs and lymph nodes showed white, grayish white and yellow pearl-like nodules of different sizes. The cut nodule shows caseous necrosis and some calcification.
[Prevention] Comprehensive epidemic prevention measures should be taken to prevent tuberculosis. As long as dogs are checked regularly, suspicious and sick people should be isolated. Dogs with open pulmonary tuberculosis have no therapeutic value, so they should be culled as soon as possible and their bodies should be burned. Avoid feeding dogs raw milk and raw meat to prevent infection through the digestive tract. Some countries have developed tuberculosis vaccine, taking preventive injection as the best policy and strengthening disinfection.
Dogs with unopened tuberculosis can be treated in isolation. Commonly used drugs are: isoniazid, 4 ~ 8 mg/kg body weight, taken orally 2 ~ 3 times a day. Streptomycin 10 mg/kg body weight intramuscular injection, 2 ~ 3 times/day; Kanamycin, 5 ~ 10 mg/kg body weight, twice a day. Scutellaria baicalensis Georgi, Bletilla striata, Stemona Stemona, Akebia Akebia, Flos Lonicerae, Radix Astragali, Atractylodis Rhizoma, and Fructus Crataegi are orally decocted, three times a day.
(8) Canine salmonellosis
Salmonella canis, also known as canine paratyphoid fever, is a zoonotic infectious disease. It is a conditional infectious disease, which is prevalent all over the world.
[Pathogen] Dogs were attacked by Salmonella. Salmonella is a gram-negative bacterium, generally, it is 1 ~ 3 microns long and 0.4 ~ 0.6 microns wide. There are many kinds of bacteria, most of which have flagella, can exercise and need oxygen. It has certain resistance to dryness, corruption and sunlight, and can survive for weeks to months in nature, but its resistance to chemical disinfectants is not strong, and general disinfection methods can achieve the purpose of disinfection.
Salmonella typhimurium is the main cause of canine diseases, which is widely distributed in nature and easy to spread in animals, people and the environment. Patients and carriers are the source of infection. Pollutants, dust and water are the media of transmission. It is mainly transmitted through digestive tract and respiratory tract. Living in the intestine, when the conditions are bad or mutate, it invades the internal organs and produces toxins to cause pathological process, so it is called conditional infectious disease.
【 Symptoms 】 Symptoms vary with the breed, age, nutrition, physical condition, bacterial count and virulence of dogs.
Subacute type: Strong dogs have strong resistance, and a small amount of salmonella does not necessarily cause clinical symptoms, or it may pass at once.
Acute septicemia: When the dog is weak, the bacteria are large and virulent, and the bacteria multiply rapidly, producing a large amount of toxins, causing severe gastroenteritis, splenomegaly and lymphadenopathy, leading to septicemia and death. Clinically, dogs usually have fever, aversion to cold, fatigue, no food, vomiting, abdominal pain, diarrhea, dehydration, emaciation and other symptoms, and eventually die of exhaustion.
【 Prevention 】 Pay attention to the environmental sanitation of kennels at ordinary times, often kill rats and flies, and disinfect and clean dog utensils. It is forbidden to feed raw meat and milk and put an end to unhealthy eating habits. Dead dogs should be burned and buried. Disinfect with 10% bleaching powder, 20% carbolic acid milk and 5% ammonia water.
Early treatment is effective. Antibiotics, sulfonamides and furans can all be selected. Chloramphenicol, 50 mg/kg body weight, once orally, 4 times a day for 5 days, and the injection dose was halved. Synergistic sulfanilamide 50 mg/kg body weight twice a day, 1 week. Furazolidone 5 mg/kg body weight, twice a day, 1 week. Chinese herbal medicines, such as Coptidis Rhizoma, Mume Fructus, Alismatis Rhizoma, Akebia Caulis, Pulsatilla, and Gentiana Decoction, are taken orally, 2-3 times a day, with 65,438 0 doses per day. Combine symptomatic treatment with supportive therapy.