Salmonellosis In Calves Research Articles

The epidemiology of salmonella in calves: the role of markets and vehicles

Environmental contamination has been shown to be an important aspect of the epidemiology of salmonellosis in calves. Markets and transport vehicles are important links in the calf marketing chain and these were investigated to determine the level of salmonella contamination. Salmonellas were isolated from 7 of the 14 markets surveyed, with 31 of 838 samples (3.7%) being positive. Nine different salmonella serotypes, of which the commonest was Salmonella typhimurium, were isolated. Four different phage types of S. typhimurium were detected, the commonest being DT204C. Salmonellas were isolated from 22 of the 107 vehicles (20.6%) examined before washing and from 4 of the 62 vehicles (6.5%) examined after cleaning. Twelve different salmonella serotypes were isolated, of which the most frequent was S. typhimurium. The commonest of the six different S. typhimurium phage types was DT204C. These results indicate that improved cleaning and disinfection routines both for vehicles and markets are necessary to control salmonellosis in calves.

Epidemiology of Salmonella typhimurium infection in calves: persistence of salmonellae on calf units

Salmonella typhimurium DT204C infection is the commonest cause of salmonellosis in calves. On five calf rearing farms a distinct strain, as indicated by plasmid profile analysis, was found to have persisted on the premises for periods ranging from four months to two years, the average being 14 months. The persistence of salmonellae in the environment appears to be an important factor in the epidemiology of calf salmonellosis and clearly indicates the inadequacy of many cleaning and disinfection routines.

STUDIES ON CALVES SALMONELLOSIS 1. INCIDENCE OF SALMONELLA SEROTYPE IN CALVES

With a view to determine the prevalence of salmonellosis in calves in Baghdad, a systematic survey was conducted, involving calves herds located in two different regions of Baghdad. This study, though limited, revealed that the overall incidence of salmonellosis was 29.01 % (33.33 % in white Gold herd and 24.30% in AL-Futhalia herd). This study also revealed that out of 57 isocates, 14 different serotype was obtained. Of these, S. dublin and S. typhimurium were the commonest serotype isolated from calves (26.32% and 17.54 %respectively).

The epidemiology of salmonella infection of calves: the role of dealers

Salmonellas were detected in the environment of 10 of the 12 calf dealers' premises studied. The cleaning and disinfection routines were often ineffective and salmonellas were isolated from 7.6% and 5.3% of the wall and floor samples before disinfection and 6.8% and 7.6% afterwards. Eight different salmonella serotypes were detected, of which the commonest were Salmonella typhimurium, predominantly phage type DT204C, and S. dublin. Plasmid profiles were used to fingerprint S. typhimurium DT204C and the results indicated that with the exception of one of the premises, prolonged salmonella-persistence in the environment was not occurring. Three separate epidemics of salmonellosis in calves were studied by use of plasmid profile analysis. The results illustrated the role of delers, and their subcontractors, in the dissemination of salmonellas. The study concludes with suggestions for methods to reduce the spread of salmonellas in the calf marketing chain.

Induction of circulating tumor necrosis factor cannot be demonstrated during septicemic salmonellosis in calves

The concentration of tumor necrosis factor in the circulation of calves, which were infected with Salmonella typhimurium and exhibited septicemia as indicated by clinical signs and blood culture, was measured with a radioimmunoassay. These levels were compared with those in calves before infection and in other calves that had received an intravenous dose of gram-negative endotoxin. The tumor necrosis factor levels measured in samples taken during septicemia were not different from those in samples from infected nonsepticemic calves or samples from calves before infection. In contrast, the levels of tumor necrosis factor rose rapidly in calves after treatment with endotoxin by intravenous injection.

Salmonellosis in Calves

Despite the efforts of both physicians and veterinarians, the number of cases of salmonellosis per year has held steady or risen. The ability of the organism to live in many different animal species and under inhospitable environmental conditions is likely responsible for Salmonella's prevalence today. Diverse clinical signs occur in salmonellosis; they range from unthriftiness to explosive, necrotizing diarrheas with high mortality. Secondary complications of pneumonia, bone and joint infections, and meningoencephalitis can result from calfhood infections. Treatment of enteric salmonellosis is chiefly aimed at maintaining fluid, acid-base, and electrolyte balance. Bacteremic or septicemic calves also require systemic antibiotics. The control measures for salmonellosis are based on sanitation and management. Individual calf hutches or pens provide adequate isolation if sufficient spacing and good sanitation are maintained. The Salmonella vaccines presently available provide limited protection; however, live vaccines made from auxotrophic strains of Salmonella appear to be more efficacious.

Chemiluminescence of bovine alveolar macrophages as an indicator of developing immunity in calves vaccinated with aromatic-dependent Salmonella

Chemiluminescence of bovine alveolar macrophages was used to study the development of opsonins in calves vaccinated parenterally with live aromatic-dependent strains of either S. dublin or S. typhimurium. These calves responded by producing Salmonella-specific opsonins detected by increased chemiluminescent responses, and were able to survive oral challenge with live virulent organisms of either serotype. Non-vaccinated calves of the same age lacked Salmonella-specific opsonins and were not able to survive challenge. Thus it was concluded that the ability to produce opsonins is among the immunological responses that are associated with protection against salmonellosis in calves. Antigenic similarities between S. dublin and S. typhimurium were shown by the ability of either organism to absorb significant amounts of opsonic capacity from the sera of calves vaccinated with either of the two vaccines. These antigenic similarities are thought to explain in part the ability of either vaccine to protect against challenge with either the homologous or heterologous Salmonella serotype.

Appraisal of the suitability of a disease model of acute salmonellosis in calves for chemotherapeutic studies

When young calves were dosed orally with 10(10) organisms of a culture of Salmonella dublin, typical symptoms of acute salmonellosis followed with a death rate of 86 per cent. Peak mortality occurred six days after infection. As a result of a statistical appraisal of the consistency of mortality in groups of untreated calves a model is proposed for the therapeutic evaluation of antibacterial compounds, which compares the number of survivors in groups of seven or eight calves with a minimum of four needed for significant indication of efficacy. Bacteriological and pathological investigations showed that the experimental disease was initially an acute systemic infection followed by severe enteritis. Measurements of plasma concentrations of enzymes and other constituents did not achieve the desired objective of establishing a method of quantitative evaluation of the clinical status of individual animals, although some changes occurred which were consistent with the pathology of the disease and suggested possible mechanisms by which jaundice occurred.

Use of a calf salmonellosis model to evaluate the therapeutic properties of trimethoprim and sulphadiazine and their mutual potentiation in vivo

Using an established disease model of acute salmonellosis in calves, and basing the evaluation of chemotherapeutic efficacy on mortality, trimethoprim and sulphadiazine were shown to exhibit marked synergism in vivo. Both parenteral and oral methods of administration were effective and daily intravenous doses were shown to have high efficacy in spite of the short plasma half-life (one hour) of trimethoprim in the calf. Blood levels of trimethoprim were thus shown to be of little value as a prediction of efficacy.

Acute phase responses to experimental salmonellosis in calves and colibacillosis in chickens: Serum iron and caeruloplasmin

Calves and chickens were artificially infected with virulent strains of S. dublin or E. coli and changes in serum iron and caeruloplasmin concentration were studied in order to investigate whether the changes in these constituents described in laboratory animals after the injection of endotoxins also occurred in response to induced bacterial infection in farm animals. Salmonella infection in calves resulted in an acute and significant hypoferraemia, which correlated closely with the onset and severity of clinical signs but was not influenced by the immune status of the calf. Colibacillosis in chickens also resulted in an acute and significant hypoferraemia, which differed from that seen in infected calves in the duration of the response (over 7 days and approx. 2 days respectively). The unbound iron-binding capacity of the serum in calves showed a moderate increase 24 h after infection and then decreased rapidly in unison with the restoration of serum iron concentration, whereas in chickens there was a progressive increase from 6 h after infection extending beyond 4 days after infection. It is suggested that the demonstrated differences between calves and chickens reflect true variation in this antibacterial defence mechanism between host species. Changes in serum caeruloplasmin concentration after infection were slower in onset than the hypoferraemic response in both species. The concentration increased from about 2 days after infection, was maximal at 4 days and showed a sharp decline in calves and a moderate decrease in chickens at 7 days. The demonstrated difference in duration of the response between host species may indicate that caeruloplasmin is associated with restoration of serum iron concentration at the end of the hypoferraemic response. Conversely the increase in caeruloplasmin concentration may be a change mediated by pathogenic bacteria to overcome the host hypoferraemic response.

Control of Salmonellosis in Calves

Calfhood salmonellosis continues to be a major source of economic loss for dairies and commercial calf growers in Southern California. Almost all dairies in our area are drylot operations ranging in size from 200 to 1,200 milking cows. Replacement heifers are raised on the premises or by a commercial calf grower in our area until they are four to eight months old, at which time they are usually shipped out of Southern California. The two most significant health problems our calf growers experience are: (1) neonatal calf diarrhea ("colibacillosis," calf septicemia, reo-, and/or corona virus), and (2) salmonellosis. Salmonellosis may be slightly less prevalent than "colibacillosis," but may represent an equal or greater economic loss since it affects older calves, is resistant to therapy, and is extremely difficult to control.

TheSalmonellaexcretor incidence of dogs in Hawke's Bay

Abstract Extract Dogs have occasionally been implicated in the spread of Salmonella infection, particularly with respect to the transmission of the disease to man. Evidence of such transfer is difficult to obtain and few actual cases have been reported (Wolff et at., 1948 Wolff, A. H., Henderson, N. D. and McCallum, Grace L. 1948. Salmonella from dogs and the possible relationship to salmonellosis in man. Am. J. publ. Hlth, 38: 403–408. [Crossref], [PubMed] , [Google Scholar]; Gibson, 1961 Gibson, E. A. 1961. Salmonellosis in calves. Vet. Rec, 73: 1284–1296. [PubMed] , [Google Scholar]; Kaufmann, 1966 Kaufmann, A. F. 1966. Pets and Salmonella infection. J. Am. vet. med. Ass., 149: 1655–1661. [Web of Science ®] , [Google Scholar]). Buxton (1955 Buxton, A. 1955. Salmonellosis. Proc. R. Soc. Med., 48: 636–638. [PubMed] , [Google Scholar]) considers that the potential danger to humans is slight unless the dog is suffering from clinical disease.

Oral and parenteral neomycin as a treatment for scours and salmonellosis in calves.

Oral and parenteral neomycin as a treatment for scours and salmonellosis in calves.

Salmonellosis in calves--the effect of dose rate and other factors on transmission.

Abstract Extract Salmonella infections in domestic animals in New Zealand have been reported by Josland (1950 Anderson, E. S., Galbraith, N. S. and Taylor, C. E. D. 1961. Lancet, 1(7182): 854–854. [Google Scholar]) and Salisbury (1958 Fey, H., Lanz, E., Margadant, A. and Nicolet, J. 1962. Dtsch tierärztl. Wschr., 69: 581–581. [Google Scholar]), while Nottingham (1961 Jamieson, J. E. 1962. J. Hyg. (Camb.), 60: 193–193. [Google Scholar]) has drawn attention to the high incidence of Salmonella in animals slaughtered at meat works. The latter found Salmonella in 15% of dairy cattle, 4% of beef cattle, 15% of sheep, and 13% of calves. If these figures reflect the true incidence of Salmonella in domestic animals in New Zealand, it is surprising that outbreaks of salmonellosis are not diagnosed more often in the field. In fact, the number of isolations of Salmonella from material submitted to Wallaceville Animal Research Centre for confirmation of a diagnosis of salmonellosis was only 158, or 3.9% of 3,978 cases examined over a period of eight years. These figures suggest that the incidence of Salmonella in the field may not be nearly as high as that found by Nottingham for stock slaughtered at the works.