Pseudomonas aeruginosasepsis in an adult horse with enteric Salmonellosis

Abstract

Objective: To report a case of enteric Salmonellosis and Pseudomonas aeruginosa bacteremia in an adult horse. Case summary: A 7-year-old mare presented for signs of acute abdominal pain. Exploratory laparotomy allowed surgical correction of right dorsal displacement of the large colon with a 1801 volvulus at the cecocolic ligament. Postoperatively, the mare developed fevers, leukopenia, and diarrhea. Salmonella newport was cultured from the feces and P. aeruginosa from 2 consecutive blood cultures. The mare responded well to intensive medical therapy. New or unique information provided: Bacteremia associated with colitis is unusual in an adult horse, although the percentage of animals that may be bacteremic is unknown. The bacteria isolated, P. aeruginosa, a common pathogen of other sites in the horse, has not, to our knowledge, been previously reported as a cause of bacteremia and septicemia in an adult horse. (J Vet Emerg Crit Care 2006; 16(3): 219-223)A 7-year-old, approximately 550 kg, Warmblood mare presented to the George D. Widener Hospital for Large Animals, New Bolton Center, for evaluation of abdominal pain of approximately 18 hours duration. On presentation, the mare was bright and alert, with a heart rate of 40 beats per minute (bpm), respiratory rate of 12 breaths per minute, and temperature of 38.3 1C (100.9 1F). Routine hematology and serum biochemistry were unremarkable. Rectal palpation revealed a large gas-distended viscus in the left dorsal quadrant of the abdomen that prevented palpation of the nephrosplenic ligament. Entrapment of the left colon over the nephrosplenic ligament was suspected, and the mare was treated medically with intravenous (IV) fluids, phenylephrine a (30 mg IV) once over 15 minutes, and exercise. The mare exhibited further signs of abdominal pain despite therapy, and an exploratory laparotomy was performed. Pre-operative antimicrobial therapy with ceftiofur b (2.5 mg/kg IV q 12 h) and gentamicin c (8.8 mg/kg IV q 24 h) was initiated. The horse

Blood culture status in mature horses with diarrhoea: A possible association with survival

“…Although strict definitions for SIRS are not available in equine medicine, extrapolation from human medicine suggests that not all blood culture positive horses met the criteria for SIRS. The contribution of the bacteraemia to morbidity in horses with diarrhoea is difficult to ascertain, as the clinical syndromes associated with both diarrhoea -with accompanying endotoxaemia -and bacteraemia can be similar (Johns et al 2006). Horses with positive blood cultures did not differ from blood culture negative horses with respect to the presence or absence of SIRS or development of complications.…”

“…Hollis, unpublished data), the incidence in mature subjects with GI mucosal compromise has been considered to be low (Murray 2002;Roy 2004). Evidence to support this hypothesis has, however, been limited to single case reports (Hondulas and Johnson and Goetz 1993;Johns et al 2006) and anecdotal information.…”

“…Bloodstream infections are recognised in human medicine as a major cause of morbidity and mortality (Bearman and Wenzel 2005). Bacteraemia is generally thought to be an uncommon sequela to diarrhoea in mature horses (Divers 2002;Roy 2004;Johns et al 2006). If clinically significant bacteraemia is diagnosed, prompt and appropriate antimicrobial therapy is indicated to reduce sepsis-associated morbidity and mortality (Leibovici 1998).…”

Current controversies in equine antimicrobial therapy

“…Ten percent of normal human adults with uncomplicated enteric salmonellosis develop transient bacteraemia that is cleared by the body's own defence mechanisms without the need for specific antimicrobial therapy (Pitout and Church 2004); the clinical importance of bacteraemia in the mature horse, where detected, is unclear. Clinically important bacteraemia responsive to specific antimicrobial therapy has been reported in a horse with enteric salmonellosis, and should be considered in horses with colitis that are unresponsive to typical supportive therapy (Johns et al 2006). The authors recommend collection of multiple blood cultures from all mature horses with diarrhoea that are not responsive to general supportive care, and consideration of specific treatment in those that are bacteraemic with potentially pathogenic organisms.…”