There are hundreds of different pathogenic viruses and diseases caused by them in the world. But smallpox in cows is a kind of legend, since it was precisely its causative agent that was used to create the world's first vaccine. Today this ailment is not so common, but still it is worth remembering to all owners of these animals.
What it is?
Cowpox is a viral disease that manifests itself in the appearance of small ulcers and pustules on the skin, accompanied by a short-term and insignificant increase in the total body temperature of the animal. Skin lesions usually disappear on their own (over time). However, if the animal’s immune system is suppressed by drugs or another disease, the infection can proceed in a severe manner, which is fraught with unpleasant consequences.
Causes of the disease
There are many rash-causing viruses that can infect many different kinds of animals. Despite the fact that the cowpox virus infects cattle, there have been many cases of its transmission to other pets, since cows are not a natural reservoir for this pathogen. In particular, the virus has repeatedly been described as being infected with domestic cats and even cheetahs, cattle and (very often) people working with cows.
In addition, the disease can occur in dogs, elephants and horses. Surprisingly, many scholars have suggested that the small hosts of the smallpox virus are the natural hosts for the vaccinia virus ...
Veterinarians are convinced that smallpox epidemics in isolated herds of cows (in separated villages) are possible solely due to the actions of peddlers. These may include: bank vole (Clethrionomys glareolus), common vole (Microtus agrestis), and house mouse (Apodemus sylvaticus).
When examining more than 1.5 thousand rodents, researchers determined that at least 27% of them are natural carriers of the virus. Typically, such “reservoirs on the legs” do not show any signs of infection. Cases of smallpox (and regular ones) have been reported in many European countries, including Austria, Belgium, France, Germany, the Netherlands, Great Britain, Scandinavia, and throughout the former Soviet Union.
What happens in some countries of the Asian region and Africa, one can only guess. However, regular essays by naturalists and ethnographers indicate that they are more than regular with cowpox in these parts.
Disease spread
The spread of infection among cows and other domestic animals is thought to be fairly small, but there are variations depending on the geographical location of a particular area. There is no pedigree, age or gender predisposition, but the risk of infection increases markedly in the seasons when rodents massively enter the farm buildings (for example, autumn).
Most often, smallpox in cows occurs where animals are kept on free-range housing, that is, in one way or another they come in contact with the environment. In the conditions of modern automated complexes where livestock are not walking and where deratization is regularly carried out, outbreaks of the disease are not recorded at all (with very rare exceptions).
Clinical signs of infection
As a rule, the virus enters the body alimentary by eating contaminated food or drinking contaminated water. In addition, cases of the disease after bites of rats and mice were recorded. How does smallpox occur in cows? Her symptoms are quite characteristic. A viral infection becomes apparent after a few days, when small wrinkled nodules (papules) appear on the skin of the udder. This can be accompanied by a secondary bacterial infection, up to the formation of abscesses, so that smallpox in cows is not such a harmless disease, as some owners think.
In addition, viremia (a virus in the blood) develops. It spreads very quickly across all organs and tissues of the body, which often leads to dire consequences. Cases of ulcerative lesions in the gastrointestinal tract were described. In milder situations, rhinitis, pneumonia, and diarrhea develop. Fortunately, this is far from always reaching. As a rule, the maximum that a cow faces is a short-term increase in body temperature, a slight digestive upset, and a short-term refusal to feed.
Further infection
About ten days after the virus enters the body, more numerous, diffuse skin lesions develop in the form of papules and pustules. This is smallpox in cows on the udder. Their shape can vary from oval to almost perfectly round, the diameter of the lesions rarely exceeds a centimeter. Most often, although this phenomenon is described in veterinary literature, in practice the animal does not experience severe itching.
After a few days, the pustules begin to become covered with crusts, which subsequently dry out and finally fall off the skin. These lesions can be observed on any part of the body, but they are best seen on the udder. Cases of development of papules and pustules on the skin of the nasal mirror of cows were described (although this is unusual).
When can a disease be deadly?
After about six to eight weeks, the infection “spontaneously” declines. Important! If for some reason the animal was receiving glucocorticoids (steroids) at that time, which have an extremely significant deficiency expressed in suppressing the immune system, or if it has any significant problems with the immune system (for example, leukemia), septic lesion of all body systems. So if you see that there is smallpox on the udder of a cow, treatment should under no circumstances require corticosteroids!
In such cases, severe purulent pneumonia often develops, usually ending in the death of the animal. When signs of respiratory tract damage appear, it is recommended to slaughter the cow for meat. So if your cow has smallpox on the udder (photos of pustules are on the pages of this material), you should not be frivolous about the disease.
Diagnostics
To confirm / deny the diagnosis, the veterinarian will take pieces of skin and samples of the contents of the papules. They are used to check for the presence of certain antibodies or the vaccinia virus itself. Infection can be confirmed using the following methods:
- Positive antibody titer in blood tests. This test is carried out using serological reactions. Important! Antibodies are initially detected no earlier than 7-10 days after the pathogen enters the body (when the first clinical signs appear). If analyzes are done before, their results will be false negative.
- The cultivation of the virus in cell culture, as well as the polymerase chain reaction (PCR). Detection of the genetic material of the pathogen with its subsequent identification. The test sample is taken from the crusts that have appeared on the skin of the udder, since there are a lot of viral bodies in them. These types of tests are considered the gold standard for diagnosis, but they require a well-equipped clinic and an experienced veterinarian. However, smallpox in cows (the treatment of which we will discuss later) usually does not require such complicated diagnostic methods.
- A biopsy of the skin from the affected areas also shows characteristic changes in infected cells and, if necessary, the virus can be detected by these indirect signs (although this method is less reliable, it is much simpler).
Information about the treatment of sick animals
So how to treat smallpox in cows? In most cases, the lesions will heal without intervention within a few weeks after the onset of infection, and in moderate cases, often no treatment is required. Of course, this does not mean that the disease can be treated through the sleeves. If there are a lot of rashes on the skin of the udder, and the immunity of the cow is already weakened by some kind of infection, the consequences can be the most unfavorable, up to the development of sepsis with a massive bacterial lesion.
In the case when signs of deterioration are visible, the sick animal must be treated. Specific therapy, as with many other viral pathologies, does not exist. The treatment is symptomatic, supportive. Thus, smallpox in cows, the treatment (a photo of the consequences of the pathological process is in the article) which we are discussing, has no specific features, in comparison with other viral ailments,.
What to use for processing the affected areas of the udder?
Udder skin is treated using zinc ointment. It allows you to dry the lesions and accelerates the regeneration process. Moisturizing ointments should not be used, as they may well contribute to maceration (softening) of the skin and simplify the pathogenic microflora's task of introducing into its thickness. Because of this, smallpox in cows on the udder (treatment, photo - all this is in our material) can become fatal due to the rather high probability of sepsis.
Other recommendations
If the cow eats poorly, appetite-stimulating drugs and, if necessary, mild laxatives (like glauber's salt) are used. With increasing temperature, the appointment of intravenous buffer formulations and glucose solutions is indicated, which help relieve intoxication and contribute to lowering the temperature. It is vital to avoid the administration of glucocorticoids, because the clinical signs can become much worse.
We emphasize once again that in severe cases, when it comes to damage to the lower respiratory tract and lungs, it is recommended to slaughter the meat. In this regard, smallpox in cows on the udder (treatment, photos - all this you will find in our article), the disease is quite dangerous.
As a rule, antibiotics for this disease are not prescribed, since such drugs do not act on viruses in principle. But at the slightest risk of developing secondary bacterial infections, the appointment of antimicrobials is fully justified. However, the decision on this should be made exclusively by the veterinarian. Here's how to treat smallpox in cows.
Infection spread and risks to people
Transmission from animal to animal is extremely rare, but in general it is possible, since you can easily infect a cow by simply rubbing the contents of its diseased “commodity” papules into its udder. For people, infection with cowpox is quite rare, but such cases still occur. In particular, it was on the basis of observations of milkmaids that the world's first vaccine was developed at one time, so that smallpox in cows (the photo of which is in the article) can be recognized as a zooanthroponic disease.
If possible, work with sick cows of people with weakened immunity should be limited. In addition, contact of sick animals with children is undesirable. Again, many pediatricians believe that it is useful for young people to get smallpox: despite its eradication in the world and the absence of infection in our country, the epidemiological situation in Central Asia is difficult, and there is a chance of infection.
Disinfection measures
Use disposable medical gloves when caring for sick animals; be sure to disinfect the care items, as the virus is able to remain alive for a long time at room temperature. For effective disinfection, any means based on
sodium hypochlorite (whiteness, other bleach bleaches) can be used. Thus, smallpox in cows is not the most dangerous disease of cattle, but nevertheless certain measures should be taken when it occurs.