Helminthiases are common diseases that cause significant harm to cattle and other farm animals. Especially a lot of troubles can be expected from dictyocaulosis of ruminants - a helminthic infestation that affects the respiratory tract - the bronchi and lungs of the victim. Due to infection with worms, animals develop slowly, enter puberty late, reproduce poorly and die early.
What kind of disease is this
Dictyocaulosis of ruminants is a type of helminthiasis provoked by the penetration of nematodes of two varieties belonging to the same family into the lungs, trachea and bronchi of animals:
- Dictyocaulus filarial, parasitizing small ruminants such as sheep and goats.
- Dictyocaulus viviparous, causing cattle diseases.
With this helminthic infestation, the parasites cause severe irritation of the respiratory tract, leading to a deterioration in the health of the livestock, which causes significant losses for farmers and large agricultural producers.
What is the economic damage from the pathology?
Dictyocaulosis of ruminants is easily transmitted from sick animals through food, therefore, the larger the herd, the higher the risks of mass destruction and death of a large number of livestock. Treating ruminant animals sick with dictyocaulosis is difficult, time-consuming and expensive; this affects productivity, the rate of weight gain when it comes to beef cattle breeding, and a decrease in milk yield in dairy production.
In addition, livestock begins to lag in growth and later reaches the breeding season, which also causes enormous material damage to breeders, both small owners and farmers, and mass producers.
Causes of the disease
The causative agent of ruminant dictyocaulosis is a type of nematode - thread-like helminths that settle in the lower respiratory tract of ruminants. They are resistant to environmental influences, so they can remain on the grass, in the ground and on other objects for a long period. From here, the parasites get on food, mainly on grass, which is eaten by ruminant cattle on pastures, so the incidence starts in spring, early summer, and peaks in the middle of the warm season until October.
In the respiratory tract of the victim, mature individuals of the parasite lay eggs, which are released into the oral cavity with cough, saliva, and sputum. The animal swallows eggs, which turn into larvae in the intestines, which are in the first stage of development. They are excreted together with the droppings. However, some eggs and larvae may land on grass and surrounding objects due to sneezing or coughing.
If the ambient temperature is below 10 degrees or above 30 degrees, the helminths will remain dormant. But if the heat level rises above the lower mark and does not “exceed” the upper limit, the air is sufficiently humid and the oxygen level is high, the nematodes have every chance of molting twice and continuing to develop to the state of invasive larvae.
By ingesting them with food and/or water, animals become infected with ruminant dictyocaulosis and can carry the parasites within them for 3 months to a year. They, as well as wet meadows and pastures, and water sources become foci of infection and can lead to massive infections of the entire livestock.
Symptoms and signs of the problem
At the first stage of dictyocaulosis in ruminants, the animal exhibits blurred signs that resemble indigestion. They are accompanied by lethargy, loss of appetite, and frequent loose stools. Then, after 3 weeks to a month, cattle infected with dictyocaulosis develop a slight cough, gradually becoming dry, difficult, and causing severe discomfort. Weakness gradually increases, the animal becomes depressed.
Young individuals suffer from nasal discharge, fever, exhaustion, and secondary infections.Choking may also occur due to the accumulation of parasites in the respiratory tract. Dictyocaulosis of ruminants has a wide range of effects on large and small livestock:
- The mechanical effect is associated with the accumulation of eggs and larvae in the trachea and bronchi, as well as in the lungs. This causes breathing problems and an acute lack of oxygen, which has a depressing effect on the general well-being, appetite and development of the young.
- The presence of helminths causes inflammatory processes in the surrounding tissues, which leads to a rise in temperature and deterioration of well-being.
- The vital activity of nematodes provokes intoxication, which aggravates the course of the disease.
Signs of dictyocaulosis will be more obvious and noticeable in the case of weakened, unhealthy, old or very young animals.
Diagnostic methods
In living animals, the diagnosis of “dictyocaulosis” can be made based on obtaining the results according to Vaid or Berman-Orlov and comparing them with the clinical picture of the disease. Before the larvae are fixed in the secretions of ruminant animals with dictyocaulosis, an intradermal allergy reaction can be performed. With it, the allergen is introduced into the fold under the tail using a subcutaneous injection. Infection can be detected no earlier than 21 days after infection.
Posthumously, to identify the cause of death of the animal, an autopsy of ruminant internal organs affected by dictyocaulosis is performed. When analyzing animal feces, it is necessary to distinguish nematodes from other larvae with similar features and sizes.
Treatment of dictyocaulosis in cattle
For timely detection of invasion, the following drugs are used:
- "Ditrazine." This drug has an excellent effect on the pathogens of dictyocaulosis in ruminants.Small cattle are given single injections for the purpose of prevention, and repeated injections for treatment. Dosage – 4 milliliters per 10 kilograms of animal weight. The injection is made into the area of the withers or elbow joint, in the form of a warm, freshly prepared solution. For cattle, the dose is 2 milliliters per 10 kilograms of body weight, administered three times, on the first, second and fourth day.
- A solution of iodine in water is prepared as follows: 1 gram of iodine in crystalline form, 1.5 grams of potassium iodide are dissolved in 1.5 liters of boiled or distilled water. In this proportion, the drug is administered to young small livestock. For calves and other cattle, a more concentrated preparation is made by diluting the same amount of iodine and potassium iodide in 1 liter of water.
- "Cyazide" in the form of injections is used three times at intervals of 0.025 milliliters intramuscularly or subcutaneously per day.
The following drugs are also used for therapeutic and prophylactic purposes: Levamisole 75, Ivermek, Dictifug (which is a complete analogue of Cyazide), Loxuran, Nilverm and many others. In Ukraine, a method of fumigating herds with an aerosol of aluminum iodide has been developed and is being used.
It is extremely important to strictly follow the dosage indicated on a specific drug or calculated by a veterinarian for a sick animal. Medicines are toxic, and exceeding the dosage can negatively affect the health of infected livestock.
During treatment, cattle are not allowed to pasture, and excrement is carefully collected and destroyed. The premises must be kept perfectly clean.
Disease prevention
It is impossible to reduce the risk of infection with dictyocaulosis in ruminants by 100%, however, with a competent approach to the problem, the risk of mass casualties can be significantly reduced. To do this, it is best to choose stall housing for young and adult animals, separate grazing of herds up to a year old and older representatives, the use of specially prepared cultivated pastures rather than random walking, as well as maintaining cleanliness in the premises where the herd or individual animals live. For preventive purposes, pastures are treated with Phenothiazine. The drug is served with food and/or water so that the animals eat it on their own.
Equally important is the quarantine of newly purchased animals, separation from the general group of representatives with signs of infection, as well as timely injections against the disease, especially during an outbreak of dictyocaulosis on surrounding farms, household plots and pastures. It is also necessary to pay attention to the quality of water and food, as well as methods of storing them. Cleanliness can protect cattle and small ruminants not only from ruminant dictyocaulosis, but also from a variety of other invasive diseases.
