CLINICAL ASPECTS OF BOVINE PNEUMOPATHIES TREATMENT OF BOVINE RESPIRATORY SYNDROME (S.R.B.)
PRIZES BIOVET 1999 – Mateu Torrent i MollevÃ
My professional performance in the field of the bovine clinic comprises two fairly well defined stages, which are:
1Âª. From 1950 to 1970 dedicated especially to dairy cows. It was the time when I wrote all the medical records of my patients and carefully filed them.
2Âª. From 1971 to 1999, dedicated mainly to the visit and consultation of large holdings of bait logs, with a range of action of more than 60 km around Lleida, corresponding, therefore, a wide strip of the province of Huesca, Spain, whose zone can be considered as the one of greater concentration in Spain in farms of calves bait.
As will be understood throughout these years my services have not only been requested to make a visit to the sick animals, but I have been consulted in multiple occasions in which the cattleman had exhausted his means to take his animals forward.
Since the farmer wants immediate actions and results, without waiting for laboratory tests, I have had to limit myself to adequately interpreting the symptoms and injuries found in patients and necropsies performed by careful observation and macroscopic examination of the lesions in The respiratory tree (congestion or not of the rhinotracheal mucosa, localization and extension of emphysematous, hepatic or necrotic areas, etc.).
Bovine respiratory syndrome (S.R.B.) has also been called Transport Fever or Shipment Fever.
In practice we find that patients from the same batch may be affected by different pathogens, as well as among different feedlots.
There are also etiological differences of the disease concurrent several predisposing factors, which I synthesize in the next picture.
Pasteurella haemolityca: the most frequent and the most resistant to antibiotics
Pasteurella multocida: less frequent and more sensitive to antibiotics.
Parainfluenza-3 virus (PI-3)
Bovine viral diarrhea virus (BVD)
Infectious bovine rhinotracheitis virus (IBR)
Rhinovirus, adenovirus, enterovirus, reovirus, calicivirus
Respiratory syncytial virus (BRSV)
Haemophilus somnus (sensitive to antibiotics)
RISK FACTORS TO BE TAKEN INTO ACCOUNT IN THE PRESENTATION OF S.R.B.
Transport of livestock in poor conditions (without water, without food)
Environmental conditions (climate, accommodation, microbial change)
Management practices (feeding, little colostrum, changes of milk or feed)
Acquisition of animals at fairs and markets (especially if they have been in more than one)
Mixture of animals of different origins
Introduction of new animals to the farm
Density of cattle or very close contact (overcrowding)
Hygienic-sanitary conditions of the farm in general and of the particular ship.
Introduce seropositive animals on the farm
Immunity level of very low cattle (few antibodies)
High level of stress (state of immuno-depression)
Pathogenic power of strains of attacking viruses
Degree of bacterial complication
Animals with virus in latency
Congenital infection or hereditary predisposition.
Metabolic Disorders (Acidosis Status)
Bacterial toxins (endotoxic shock)
Treatment of corticosteroids
State of respiratory insufficiency (asphyxia, pulmonary emphysema)
Constitutional diathesis of the calf
Narrow air ducts
Too tight rib cage
Very compartmentalized lung structure
Low pulmonary volume in relation to the total weight of the animal
Lower amount of pulmonary macrophages.
In any case, I have always valued the following:
Ã Temperature:> / = 40 Â° C (pyrexia)
Ã Respiratory symptoms:> / = 40 breaths / minute, dyspnea, nasal discharge, tearing, cough
Ã Depression: absent, moderate or severe
Ã Ruminal filling: normal, hard or semi-empty
Ã Concurrent diseases: gastroenteritis, arthritis, lameness, encephalitis, vulvogaginitis
Ã Weight loss (sick animals are delayed and skinny)
Ã Clinical disease index: slightly, moderately or very seriously ill
Ã Mortality (percentage)
Ã Necropsy: macroscopic lesions in the respiratory tree, sometimes in the intestines and liver
Relapse or reinfection
Ã Success or failure of the first medication
Ã Adverse reactions to treatments: decreased defenses, pain and / or inflammation at the point of inoculation, irritation, twisted neck
CHOICE OF ANTIBIOTIC
The main considerations to consider are:
– To be effective
– Fast action
– Easy to administer
– Well tolerated
– Make it a good price
Characteristics of some antibiotics:
– Oxytetracycline: 10 mg / kg.p.v in young cattle. It is still a useful product
– Ceftiofur: has no action against mycoplasmas
– Tilmicosin: effective in single dose
– Florfenicol: safe and useful with two or three doses in 48-hour intervals
– Cefquinoma: requires a daily application
– Enrofloxacin: also of daily application, with the advantage of acting on enteric complications.
– Baquiloprim: oral boluses for 2-4 days, with enteric and respiratory efficiency. Also injectable.
– Marbofloxacin: broad spectrum, rapid serum peak reach, safety and tolerance, single daily dose of low volume.
INDIVIDUAL OR COLLECTIVE TREATMENT
The group treatment is advised in the initial state of the disease, before the problem is increased and spread throughout the herd.
In deciding whether or not to treat the group, I consider the following:
– Identification of diseased animals by rectal temperature (cumbersome procedure)
– The observation of consumption habits and the amount of feed they consume
– The observation of the behavior of the animals (way of walking, cornering in the ship)
In any case, the choice of antibiotic or antimicrobial for collective metaphylaxis should be different from that used or to be used in clinical or systemic treatment.
– Non-steroidal anti-inflammatory agents. Flunixin, ketoprofen, etc. They prevent the negative development of the inflammatory response of the lung before the lesions.
– Agent to combat acidosis of the belly: calcium saccharate and carbonate.
– Bronchodilators, rapid effect on bronchial diameter and on resistance to respiration: clenbuterol injection, methylxanthines (caffeine, theophylline, theobromine), aminophylline, epinephrine.
– Diuretics, such as flurosemide or methenamine, which allow better lung function by contributing to the elimination of accumulated fluid in the respiratory tree.
– Mucolytic agents, expectorants or antitussives: bromhexine, noscapine, atropine.
– Decongestants: ephedrine.
– Antihistamines: Promethazine, Diphenhydramine.
– Analgesics and / or antipyretics: phenylbutazone, dipyrone, acetylsalicylic acid.
– Cardio-respiratory stimulants: digital or digitalina, estrophantin …
– Vitamins and trace elements (to strengthen their contribution)
– Use of Vitamin B1 (intravenous injection of 1 g of thiamine) for when there are nervous system disorders.
STAGES OF ANTIMICROBIAL THERAPEUTICS
The treatments that I have been practicing in this clinic have been in line with the therapeutic advances in veterinary medicine. And so we have:
1Âª. Time when I started using sulphamides (sodium sulfamethazine) and penicillin – streptomycin, with a success rate above 90%, according to my medical records from the 50’s and 60’s
2Âª. Generalized use of spectinomycin-lincomycin + sulfamethoxipiridazine + trimethoprim + tylosin, with remarkable success, perhaps somewhat less than in the first stage, to begin to complicate the disease.
3Âª. Use of chloramphenicol + tetracycline, and of amoxicillin, in whose antibiotics a great hope was coded.
Dexamethasone is no longer used as an adjuvant, since it reduces the animal’s defenses and contributes to the reactivation of latent viruses. Instead, I choose non-steroidal anti-inflammatory drugs such as benzidine, dipyrone, isopyrine, indomethacin, or aminopyrine.
4Âª. The widespread use of drug associations or “porros”, as they were baptized by cattlemen, began to spread (around 1975).