1. What is the causative agent of rabies?
2. How can animals pick up the virus of rabies?
3. How does rabies affect the salivary glands?
4. How do rabies viruses work?
5. Is the virus of rabies spread through the air?
6. How many types of rabies are there?
7. What are the clinical signs of rabies in a) cattle b) dogs?
8. What neurological symptoms of rabies can be observed?
9. What is the prognosis for this disease?
10. Are there any tests available for rabies in live animals?
11. Which animals are at risk of contracting the virus of rabies from an infected animal?
12. Can animals be vaccinated for rabies?
Exercise 26. Britons are a nation of animal lovers, and it's quite natural that animals should be represented in their proverbs and sayings. Read the proverbs, pay attention to the verbs denoting the sounds the animals make. Give Russian equivalents to the proverbs.
1.A bellowingcow soon forgets her calf. – (An excessive show of grief quickly passes).
2. A sheep that bleats loses a mouthful. – (You can’t talk and eat at the same time (or you might choke).
3.Barking dogs seldom bite. – (People who make themselves appear threateningrarely do any harm).
4. From the bull, expect a bellow. – (Don't expect anything from a narrow-minded person).
5. If the hen did not cackle, you would not know she had laid an egg. – (Noise proves nothing).
6. It is not the cow that moos the most that gives the most milk. – (It’s the empty can that makes the most noise).
7. The little pig grunts as the old sow leads. – (The old one does, the young one learns).
8. Pigs gruntabout everything and nothing. – (You cannot make people keep silent and not spread rumours).
VOCABULARY LIST TO TEXT D
|anorexicadj||[anəˈreksɪkl]||страдающий отсутствием аппетита|
|phocineadj||[ˈfɒˌsiːn]||относящийся к тюленям|
|rinderpestn||[ˈrɪndəpest]||чума крупного рогатого скота|
Canine distemper is a contagious and serious viral illness with no known cure. The disease affects dogs, and certain species of wildlife, such as raccoons, wolves, foxes, and skunks. The common house pet, the ferret, is also a carrier of this virus. Canine distemper belongs to the Morbillivirusclass of viruses, and is a relative of the measles virus, which affects humans, the Rinderpestvirus that affects cattle, and the Phocinevirus that causes seal distemper. All are members of the Paramyxoviridaefamily. The virus of distemper is actually quite a short-lived virus in the environment (around 20 minutes up to 180 minutes in warm climates). It is a fragile enveloped virus and this enveloped structure means that the distemper organism is very susceptible to heat, sunlight, desiccation(drying out) and most soaps and disinfectants. In conditions close to freezing (4°C or less), the virus may survive for weeks in the environment.
Young, unvaccinated puppies and non-immunized older dogs tend to be more susceptible to the disease. The virus, which is spread through the air and by direct or indirect (i.e. utensils, bedding) contact with an infected animal, initially attacks a dog’s tonsils and lymph nodes and replicates itself there for about one week. After the virus has replicated to massive numbers within the lymphatic and bone marrow tissues, it distributes throughout the body, settling within the cells of the nervous system, the eye and the cells that line the gastrointestinal tract, urinary tract, uterus, respiratory tract, mucous membranes (gums and conjunctiva) and skin. It is during this second phase of replication (replication within these new sites) 8-14 days after initial infection that the main clinical signs of distemper are seen. It is also during this time that newly made virus particles are shed from the body, ready to infect other animals.
In the initial stages of canine distemper, the major symptoms include high fever (≥103.5 ° F, or 39.7° C), reddened eyes, and a watery discharge from the nose and eyes. An infected dog will become lethargic and tired, and will usually become anorexic. Persistent coughing, vomiting, and diarrhea may also occur. In the later stages of the disease, the virus starts attacking the other systems of the dog’s body, particularly the nervous system. The brain and spinal cord are affected and the dog may start having fits, seizures, paralysis, and attacks of hysteria.
Canine distemper is sometimes also called “hard pad disease” because certain strains of the virus can cause an abnormal enlargement or thickening of the pads of an animal’s feet. In dogs or animals with weak immune systems, death may result two to five weeks after the initial infection.
Canine distemper is diagnosed with biochemical tests and urine analysis, which may also reveal a reduced number of lymphocytes, the white blood cells that function in the immune system in the initial stages of the disease (lymphopenia). A serology test may identify positive antibodies, but this test cannot distinguish between vaccination antibodies and an exposure to a virulent virus. Viral antigens may be detected in urine sediment or vaginal imprints. Haired skin, nasal mucous, and the footpad epithelium may be tested for antibodies as well. Radiographs can only be used to determine whether an infected animal has contracted pneumonia. Computed tomography (CT) and magnetic resonance imaging (MRI) scans can be used to examine the brain for any lesions that may have developed.
Unfortunately, there is no cure for canine distemper. Treatment for the disease, therefore, is heavily focused on alleviating the symptoms. If the animal has become anorexic or has diarrhea, intravenous supportive fluids may be given. Pus-like discharge from the eyes and nose must be cleaned away regularly to prevent crust-formation. There are no antiviral drugs that are effective in treating the disease.
A dog's chances for surviving canine distemper will depend on the strain of the virus and the strength of the dog’s immune system. Recovery is entirely possible, although seizures and other fatal disturbances to the CNS may occur two to three months after recovery. Fully recovered dogs do not spread or carry the virus.
The best prevention for canine distemper is routine vaccinations and immediate isolation of infected animals. Special care must be taken to protect new-born pups from exposure, since they are especially susceptible to the disease.
EXERCISES TO THE TEXT
Exercise 27. Look through the text and find information about:
- distemper causative agent;
- symptoms of distemper in dogs;
- causes of distemper in dogs;
- diagnosis of canine distemper;
- treatment for distemper in dogs;
- chances for survival;
-prevention of distemper in dogs.