Epizootology and symptoms of leptospirosis in cattle, treatment and prevention

Leptospirosis often affects many animals, but cattle are most often affected. The situation requires the immediate intervention of a veterinarian, because the infection spreads at a reactive speed, and the consequences of the disease can become fatal, so you cannot delay treatment. A serious approach to vaccination and compliance with sanitary and hygienic rules will help avoid trouble.

Characteristics of leptospirosis

Leptospirosis affects many animal species.This infectious natural focal disease affects the internal vessels, gastrointestinal tract, skin and mucous membranes. The disease is accompanied by fever, involuntary abortions or the appearance of sick offspring. The productivity of a sick pet is noticeably reduced.

The causative agent of this dangerous disease is microscopic parasites - Leptospira (Genus Leptospira). With multiple magnifications, you can see that the pests look like thin silvery threads.

Leptospira live in an aquatic environment, so they thrive in lakes, rivers and even gutters, but quickly die on land. Thus, in open reservoirs, parasites can live up to 200 days, but in dry soil they cannot survive even 12 hours. An outbreak of the disease can occur at any time of the year. Young pets aged 1-1.5 years suffer from leptospirosis more severely than adult animals. For them, the probability of death reaches 25%.

Epizootology shows that mainly cattle and pigs become victims of the disease. Leptospirosis often affects sheep, goats, dogs, horses and poultry. Arctic foxes, foxes, mice and other rodents are susceptible to infection. Livestock and wild animals become carriers of Leptospira. In most cases, the source of infection is small rodents.

Pathogens are excreted in milk, excrement or secretions from the genitals of animals. Most individuals suffer the disease without pronounced symptoms and are only reservoirs for parasites. Such animals are especially dangerous for pets. Leptospira live in cattle for up to 6 months.

Causes of disease in cattle

Thanks to animal carriers of Leptospira, parasites easily enter food, water bodies and soil.

1. In most cases, infection of livestock occurs during watering. Parasites live and reproduce safely in lakes, ponds and rivers. Sources of increased danger are bodies of water filled with standing water (swamps and deep puddles).
2. Leptospira often lives in humus, moist soil with neutral acidity. Infection occurs through damaged skin or cracks in the hooves.
3. Pets get the infection through food. Rodents infected with leptospirosis leave traces of their vital activity in prepared food.
4. Calves contract the disease while still in utero or when fed milk from infected cows.
5. Often, infection occurs during mating of a pet with an infected individual.

Parasites easily enter the cow's body through wounds, scratches, bites, as well as the mucous membranes of the nose, eyes, mouth, genital tract and gastrointestinal tract. Within an hour, leptospira easily enters the blood and internal organs of pets.

The spread of leptospirosis is facilitated by poor living conditions for animals (unsanitary conditions, poor nutrition, lack of vitamins), and incorrectly chosen places for pasture and watering places.

Symptoms of pathology

Symptoms of the pathology depend on the form of leptospirosis. The course of the disease can be acute, mild and chronic. Depending on the symptoms, the disease can be typical or atypical. The incubation period for the development of an infectious disease, on average, ranges from 5 to 20 days.

Acute development of the disease:

1. Sudden increase in temperature (40-41 degrees).
2. A depressed state, weakness, or vice versa – extreme excitement.
3. Impaired coordination of movements, the animal spends time in a lying position.
4. Abrupt refusal to eat, lack of chewing gum.
5. The pulse becomes rapid, breathing becomes difficult.
6. On the third day after the onset of the disease, the mucous membranes acquire a yellow tint.
7. Urine mixed with blood. Attempts to empty the bladder cause the animal severe pain.
8. Some individuals develop conjunctivitis.
9. The amount of milk decreases.
10. Constipation, intestinal atony of the pet.

Young animals, under the age of 1.5 years, are more likely to develop acute disease. Animal pregnancy often ends in abortion. The cow's milk production decreases, or even stops altogether. It takes on a saffron hue. The coat becomes dull and disheveled. Necrotic formations appear on the mucous membrane of the oral cavity and skin in the back and tail of the neck. As a result, the pet's body becomes covered with ulcers. The disease lasts no more than 10 days. In the absence of medical care, in 50% of cases the animal runs the risk of dying from asphyxia.

The chronic form of the disease is accompanied by significant weight loss, fluctuations in body temperature, enlarged inguinal lymph nodes, and the appearance of blood in the animal’s urine. The pet is tormented by a frequent urge to urinate and rapid breathing. Animals hide from bright light and shed heavily. As a result, the pet's skin becomes covered with bald spots. Sick cows experience difficulties with the reproductive system. Pregnancy in pets often ends in abortion or the birth of sick offspring. Postpartum complications often occur.

The atypical form of leptospirosis begins with a short-term, slight increase in temperature (0.5-1 degree).The animal becomes a little lethargic. The pet's mucous membranes acquire a yellowish tint. Hemoglobin appears in urine (hemoglobinuria). This condition lasts from 12 to 96 hours, then the pets fully recover.

How to make a diagnosis

First of all, the veterinarian examines the animal to see the clinical picture of the sick pet’s condition. The specialist takes into account not only the external signs of the pet’s illness, but also its behavior. At the next stage, blood, urine and samples of other physiological secretions are taken from the animal for analysis. The resulting samples are examined to detect antibodies to the parasites Leptospira. Specialists perform bacteriological culture on suitable, selective media, and also conduct a general hematological study.

An indicator of the disease is a significant decrease in the number of red blood cells in the pet’s blood, a sharp drop in sugar levels, and changes in hemoglobin levels.

Additional studies are carried out using the PCR method. DNA and RNA contained in leptospira are detected in the samples. If a pet dies in the herd, the veterinarian will order a pathological examination. Confirmation of the disease are:

1. Yellow tint to the skin and mucous membranes.
2. Necrosis and edema.
3. Bloody accumulations in the chest and abdomen.
4. Enlarged liver.

How to properly treat the disease

Treatment includes 2 courses: antimicrobial therapy and elimination of symptoms of the disease. First of all, sick pets are separated from the herd. Infected animals are injected with anti-leptospirosis serum. The product is administered subcutaneously, and after 2 days the procedure is repeated. A dose of 20-60 ml is sufficient for calves; adult pets are given 50-120 ml of serum.

Antimicrobial therapy

To destroy infectious agents, the following drugs are used: “Streptomycin” (subcutaneous injection 10-12 units per kg of pet’s weight), “Kanamycin” (intramuscular injection 15 units per kg of animal’s weight). Tetracycline and Biomycin products cope effectively with the task. They are given to animals 2 times a day for 4 days.

Symptomatic treatment

Simultaneously with antimicrobial therapy, the animal is administered Urotropin, a 40% glucose solution and caffeine. The consequences of intestinal atony are eliminated with the help of Glauber's salt. The pet's oral cavity is regularly treated with a solution of potassium permanganate. The animal's diet is supplemented with vitamin supplements and microelements. Supplements in the form of fish meal or fish oil will benefit your pet.

Prevention and vaccines

To prevent infectious diseases, the modern VGNKI vaccine is used. The polyvalent agent protects pets from the acute form of leptospirosis. For a lasting effect, revaccination must be carried out regularly. One-year-old calves are vaccinated once every six months, adult animals - once a year.

Other preventive measures include monthly treatment of areas where animals are kept with antibacterial agents and preventive examination of pets. Cattle are not recommended to graze in wet meadows and nearby areas.