Cattle theelaziosis: symptoms and developmental biology, treatment and prevention

Cattle thelaziosis is understood as a dangerous pathology that can provoke the blindness of the animal. The causes of the development of the disease are parasites. They affect the eyes of an infected individual, which provokes the development of purulent conjunctivitis. In addition to visual impairment, the invasion causes a general decrease in productivity and a violation of the quality of milk. They carry the cow fly disease, so preventing its development can be quite problematic.

Causes of thelaziosis in cattle

To understand the principle of cattle infection, you need to familiarize yourself with the developmental biology of parasites. Before entering the body of an animal, the larva goes through a series of stages:

1. At first, the female telazia produces a certain number of larvae, which are considered non-invasive. They are not dangerous to animals.
2. Then the larvae are consumed by cowflies, in which their development begins. Due to short modifications, which take about a month, the larva becomes invasive. At this stage, it can develop in the body of the carrier.
3. Cowflies fly up to individual animals and sit on the site, which is located as close as possible to the eyes. After that, they distribute the larvae along the eyelids and near the palpebral fissure. Many young calves can be detected already in early July.
4. After infection, the so-called incubation period begins. At this time, the larvae are gaining strength to take part in reproduction.

Telyazia that have reached puberty live for a maximum of 1 year and then die. They are able to remain active in winter. However, during this period, parasites do not produce offspring. Related to this is the absence of disease outbreaks during the cold season.

Symptoms of the problem

Treatment of thelaziosis of cattle is characterized by a specific development. Moreover, each stage is distinguished by certain stages. At the initial stage, pathology is rarely noticeable. At the first stage, the following signs appear:

• increased lacrimation, glitter in the eyes of infected animals;
• inflammation of the conjunctiva, the appearance of a red tint.

The second stage of the disease is more obvious than the first. Many ranchers detect pathology at this stage. It is characterized by the following symptoms:

• swelling and enlargement of the inflamed conjunctiva;
• discharge of a whitish fluid from the eyes - this includes mucus and pus that seeps from the tear duct.

In the second stage, thelaziosis is easily confused with conjunctivitis. Drug treatment provides results only in the first two stages.

Sometimes it is possible to cure an animal even when moving to the next stage. However, the longer the parasites stay in the cow's eyes, the worse the prognosis.

At the third stage, irreversible changes begin in the animal's body, which can cause final blindness. The following manifestations testify to the neglect of the process:

• clouding of the cornea - it may protrude or perforate;
• general animal oppression;
• temperature increase.

At this stage, many animals develop a purulent form of conjunctivitis. In infected animals, a decrease in milk yield is observed and the quality of milk deteriorates significantly. If calves are affected by calves, they lag behind in development and slowly gain body weight. There is an opinion that the younger the animal, the worse it tolerates thelaziosis, therefore, treatment should be started at the first symptoms.

How to diagnose a disease

It is possible to make a diagnosis after a veterinary study of the anamnesis. Diagnostic methods depend on the stage of the disease. When primary symptoms appear, a laboratory study of the lacrimal fluid is performed. In some individuals, the first stage is almost asymptomatic. In this case, it is impossible to identify the disease by external examination. In the laboratory, under a microscope, specialists examine the tear fluid. In the presence of pathology, it is possible to identify sexually mature nematodes and their larvae.

When they are detected, the veterinarian selects therapy. If the disease is more advanced, there is no need for laboratory procedures.

Differential diagnosis is required. Telaziosis is recommended to be distinguished from rhinotracheitis, rickettsial keratoconjunctivitis, vitamin A deficiency. It should also be differentiated from non-contagious conjunctivitis and herpes virus infection.Pathology is characterized by the following pathoanatomical changes:

• development of keratitis and conjunctivitis;
• clouding of the cornea;
• formation of ulcers on the cornea.

Methods of treating the disease

Taking into account the severity of the disease, the veterinarian will select a therapy regimen. It should be comprehensive and include antibiotics, broad-spectrum anthelmintics, and immunomodulators. Also, cattle are often prescribed homeopathy, medicinal ointments and drops.

Antibiotics

Antibacterial agents from the group of macrolides help to get good results in the therapy of thelaziosis.They are recommended to be placed once in the cavity of the conjunctival sac. It costs 5 days to use the remedy. The most common remedy is Azithromycin. For cattle, the dosage is 0.9-1.1 grams. At the first symptoms of thelaziosis, you should immediately contact a veterinarian, without waiting for the appearance of subsequent stages.

Drops, ointments

To speed up recovery, you should use special solutions and drops.

The most effective drugs include:

1. Iodine solution with potassium iodide. To prepare it, you need to mix 1 gram of crystalline iodine with 1.5 grams of potassium iodide. Dilute the resulting composition with 2 liters of purified water. Wash the affected eye three times a day. It is recommended to do this with a syringe with a rubber tip. For 1 procedure, 75 milliliters of solution is required.
2. Boric acid solution with a concentration of 3%. It is recommended to moisten a cotton swab in it and wipe the walls of the eye cavity and the inner corner of the eye. Carry out the procedure three times a day for 5-7 days.
3. Antibacterial penicillin drops for 50 thousand units. They are used by prescription from a veterinarian.
4. Novocaino-penicillin ointment. This remedy is used when ulcerative defects appear on the cornea. Before use, it is recommended to hold the composition for 5-7 days at a temperature of +2-4 degrees.
5. Infusions of chamomile, wild rosemary, calendula in a ratio of 1:100.

In addition, the main therapy is supplemented with retrobulbar blockade using novocaine solution. To do this, 15-30 milliliters should be injected from the bottom and top of the eye. It is recommended to do this for at least 5 days until the symptoms pass.

Antiparasitics

To completely eliminate the pathology and prevent the occurrence of thelaziosis in other animals, antiparasitic treatment is carried out for the entire herd. The most effective antiparasitics include:

1. "Ivomek" - injected once. In this case, it is recommended to use 1 milliliter of medicine per 50 kilograms of an individual's weight.
2. "Levamisole" - injected once. For 1 kilogram of body weight, 0.0075 grams of the product should be used.
3. "Rivertin" - it is worth entering 2 days at 0.2 grams per 1 kilogram of weight.
4. "Fascoverm" - injected once. In this case, it is recommended to use 0.005 grams per 1 kilogram of weight.
5. Ditrazine-citrate solution with a concentration of 25% - it is administered subcutaneously with an interval of a day. The dosage is 0.016 grams per 1 kilogram of weight.

Prevention of thelaziosis of cows

To avoid thelaziosis, it is recommended to perform preventive deworming and try to exterminate pasture flies. Prophylactic deworming is performed on animals at the time of placement in the stall and before pasture.

To exterminate flies, it is recommended to use the following:

• "Ectomin" at a concentration of 0.1%;
• "Neostomazan" at a concentration of 0.25% with an interval of 2-3 weeks;
• "Neocidol" at a concentration of 0.1%.

To fight flies indoors, it is recommended to use "Ectomin" at a concentration of 1-2%. You can also use the Neocidol emulsion at a concentration of 0.5%. For 1 square meter, use 50-100 milliliters of the product. Animals are recommended to enter the room no earlier than 2 hours later.

Cattle thelaziosis is a rather dangerous pathology that can provoke complete blindness. It is almost impossible to cope with advanced forms of the disease. Therefore, at the first sign, it is worth consulting with a veterinarian.

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