Respiratory diseases

Respiratory syndrome is the cause of reduced growth and cessation of development in young animals

Acute respiratory diseases of viral etiology have recently become widespread among cattle in Ukraine, namely: infectious rhinotracheitis; viral diarrhoea - mucous membrane disease; parainfluenza-3; rota- and coronavirus infection; as well as mycoplasmosis and chlamydia, whose causative agents occupy an intermediate place between viruses and bacteria. These infections cause damage to the mucous membrane of the upper respiratory tract and create conditions for the development of pathogenic and opportunistic bacterial microflora, which, in turn, cause a complication - bronchopneumonia. The results of clinical and epizootological examination of farms, virological, bacteriological and serological monitoring show that several infectious agents can occur in one herd or even in individual animals. This explains the development of viral and viral-bacterial mixed infections. In addition, associations of several viruses or viruses with mycoplasmas, chlamydia or other bacteria have been reported. Under practical conditions, the veterinary welfare of livestock farms for pneumoenteritis of mixed etiology is primarily complicated by the lack of specific means of active prophylaxis, rapid methods of laboratory diagnosis, and the inability to prevent contact between healthy animals and virus- and bacteria-carriers due to loose housing, frequent movements and regroupings.

Positive results in the prevention and control of acute respiratory and intestinal diseases in cattle are achieved by compliance with general organisational and management measures and the use of specific prophylactics.

If prophylactic vaccinations, which provide animals with active immunity, have not been carried out or have not been effective and an outbreak of respiratory and intestinal diseases on the farm has not been prevented, serum preparations (immune serum, serum-reconvalescent or immune globulin) are used for the prevention and treatment of complicated infectious respiratory diseases in calves, which are made from blood of productive farm animals with specific antibodies to pathogens that are circulating in the farm.

One of these products is "Immune serum against respiratory and intestinal diseases of calves". The product is a serum containing specific antibodies against respiratory and intestinal diseases of calves. The content of specific antibodies therein corresponds to positive S/P% in ELISA for the pathogens of IRT, VD, PI-3, Rota and coronavirus infection. The specific antibodies in the serum block the pathogen, thus preventing colonisation on the mucosal epithelium and neutralising the exotoxins of the pathogen, resulting in no or no disease. To prevent gastrointestinal and respiratory infections, the serum is administered intramuscularly or subcutaneously to animals from one day of age to 5 months at a dose of 0.5 cm³/kg. For therapeutic purposes the serum is administered intramuscularly or subcutaneously, twice at 24-hour intervals to animals up to 5 months of age at a dose of 1.0 cm³/kg.

Figure 1. Indices of cellular immunity in white rats after administration of "Immune serum against animal respiratory and intestinal diseases" (experimental group)

Figure 2. Indices of cellular immunity in white rats after administration of "Immune serum against respiratory and intestinal animal diseases" (control group)

The effect of the veterinary immunobiological preparation "Immune serum against animal respiratory and intestinal diseases" on such indicators of the immune status of white mice and white rats as: macrophage transformation index, phagocytic index, phagocytic number, CIC, complement, T-lymphocytes, B-lymphocytes was studied. For this purpose, ten white mice of the experimental group (Fig. 1) were injected with the immunobiological preparation subcutaneously at a dose of 1.0 ml/head. The control group (10 animals) was injected with isotonic sodium chloride solution subcutaneously (Fig. 2). Studies were carried out on the 2nd, 7th and 21st days after a single injection of the drug. From the data presented in the diagrams, in experimental animals up to seven days after the drug administration there was a tendency for the immune system activity to increase, until the 14th day after the administration the immune status indicators stabilized.

High efficacy of immune serum against respiratory-intestinal diseases of calves is proved at treatment of diseased animals at introduction of serum in complex with antibacterial preparations that is shown at bacterial complications of viral infections.

Two groups consisting of 100 calves aged 5 months each with signs of respiratory and intestinal diseases were selected for the study. Calves in the first group were injected subcutaneously, twice at 24 h intervals at a dose of 1.0 cm³/kg. The observation period lasted 14 days.

This was followed by antimicrobial, pathogenetic and symptomatic therapy according to the antibiotic chart and the traditional regimen for the treatment of respiratory and intestinal diseases in calves. Calves in the second group received antimicrobial, pathogenetic and symptomatic therapy according to the antibiotic chart and the traditional scheme of treatment of respiratory and intestinal diseases, but without the administration of immunobiological drugs. In the first group, a reduction in clinical signs of respiratory and intestinal diseases was recorded within 14 days, and no adverse local reactions or abnormal general reactions were detected, and the temperature was within normal limits.

In the second group, a delayed disappearance of clinical manifestations and exacerbation of the disease was observed. Bronchopneumonia became chronic in 45% of calves. Exacerbation was recorded in 40% of calves in the second group. Only 15% of calves recovered clinically.

Thus, the immune serum against respiratory and intestinal diseases of calves is harmless and induces passive immunity in animals after two injections with an interval of 24 hours, which lasts for a fortnight. When a disease occurs, specific antibodies in the serum block the pathogen, thus preventing colonisation on the epithelium of the mucous membranes, and neutralise exotoxins of the pathogen, which results in disease absence or halting its development. Due to this effect, the serum is recommended for use in calves from the age of one day to 5 months for prophylactic and therapeutic purposes against respiratory and intestinal diseases.