The development of foot rot in sheep occurs due to infection of the animal with a gram-negative bacterium. The disease is contagious and leads to serious complications. The course of the pathology is accompanied by rotting and destruction of the tissues that make up the hooves. In the absence of adequate treatment, the disease leads to the death of the infected animal. Moreover, after the end of therapy, immunity in sheep to this bacterium does not develop.
History of the disease. Economic damage
The first cases of domestic animals being infected with foot rot were recorded more than 300 years ago.Initially, this pathology was not identified as a separate group, since the causes of the development of the disease were not established. Some researchers have suggested that foot rot is a symptom of necrobacteriosis. Officially, this pathology was identified as a separate disease in 1938 by a British scientist. This happened due to the fact that the researcher identified the causative agent of hoof rot.
The disease is considered highly contagious. In the Soviet Union, during the 50-70s of the last century, mass infection of livestock with foot rot was recorded several times. More often, cases of infection were detected in the southern regions of the country.
The disease causes significant economic damage because:
- reduces the amount of meat and wool obtained from sheep;
- makes the offspring weak;
- disrupts normal reproduction of livestock;
- weakens the immunity of young animals to other pathologies.
If the livestock is infected, the volume of meat produced decreases by 20-40% compared to earlier indicators, milk - by 20-60%, wool - by 10-40%.
Causes of the disease
The disease develops after infection with the anaerobic bacterium Bacteroides nodosus. Infection occurs mainly during open grazing. The pathogen remains viable in grass for two weeks and in hooves for one year. Therefore, infection of animals is possible in the pen.
The following factors can provoke the development of disease in a herd:
- high humidity;
- unsanitary conditions of detention;
- insufficient space in the pen, due to which animals are constantly in contact with each other;
- lack of a hard surface in the walking area;
- rare change of litter;
- hoof damage;
- weakening of immune defense.
Infection occurs more often in autumn and spring, when precipitation increases. Therefore, in order to avoid infection, it is recommended that after grazing, treat the hooves with bleach, phenol or formaldehyde, which destroy the pathogen.
Symptoms of the disease
Symptoms of the disease, depending on the nature of the accompanying factors, appear 5-20 days after infection. The pathology at the initial stage is acute, but over time it becomes chronic. This means that symptoms of foot rot may reappear several months after the animal has recovered.
This pathology at the initial stage of development causes:
- redness of tissue at the site of infection;
- swelling;
- hair loss;
- formation of mucus in the interhoof gap;
- detachment of the horn shoe;
- the appearance of a foul odor from the affected hoof;
- discharge of purulent masses.
The infected animal becomes restless and stops stepping on the affected leg. In some cases, the horny shoe falls off. More often these symptoms appear on one or two legs, less often on four.
Foot rot develops in three stages: mild, moderate and severe. Often the disease is cured in the first or second stage. If the pathology can be cured, then the affected tissue is restored. However, after this, deformation of the hooves is noted. One of the characteristic features of this pathology is that the animal’s body temperature does not rise, while the affected area remains hot.
Establishing diagnosis
The primary diagnosis is made based on an external examination of the animal and collection of information about symptoms. To confirm the preliminary conclusion, material is taken from the affected area and a bacteriological examination of the scraping is carried out.The final diagnosis is made subject to the identification of pathogenic microflora in the samples taken.
Treatment methods for foot rot
The above recommendation regarding the treatment of hooves with formaldehyde and other substances concerns primarily the prevention of infection. But the same solutions are also applicable to the treatment of pathology.
As part of the treatment of foot rot, the affected area is treated with 10% formaldehyde or 5% paraform. At the same time, the affected areas are removed with a scalpel and other instruments. After each such procedure, baths with a 10% formaldehyde solution are recommended. It is recommended to cut off the affected tissue and then treat it every 2 days until the symptoms disappear completely.
In order to prevent the spread of the disease and the addition of a secondary infection, these drugs must be combined with broad-spectrum antibiotics: Bicillin-5, Biomycin or Nitox 200. It is not recommended to carry out these manipulations at home. This is due to the fact that in order to completely cure the animal, it is necessary to completely remove the affected tissue.
Possible danger
In the absence of adequate and timely treatment, foot rot leads to the following complications:
- tissue necrosis of the affected limb;
- the formation of fistulas in different parts of the body, including the oral cavity and udder;
- endometriosis;
- exhaustion of the animal.
In advanced cases, hoof rotting provokes extensive sepsis, due to which the animal dies.
Prevention and immunity
In order to prevent infection of sheep with foot rot, it is recommended:
- regularly remove manure and change bedding in the pen;
- keep animals in well-ventilated areas;
- do not allow humidity in the pen to increase;
- provide adequate nutrition for sheep;
- Clean the hooves every 2 months;
- Every six months, treat the hooves with a 10% formaldehyde solution or a 20% copper sulfate solution.
As noted, after treatment, the animal’s body does not develop stable immunity to the pathogen. Therefore, re-infection is possible. An artificial vaccine, which is periodically used by veterinarians, gives a good effect for a limited period of time.
