Salomonella saintpaul septicemia in an adult Asian elephant
Location: Italy (zoo)
Submitted by: Fieke Molenaar DVM and Pasqualino Silvestre DVM
Three months after the move to another zoo, a 37 year-old female Asian elephant (Elephas maximus) presented mild lethargy and a reduction of food and water intake. Mild colics were suspected and the elephant was treated with non-steroidal anti-inflammatories (NSAID, meloxicam i.m. ~ 0.2 mg/kg) and spasmolytics (metamizole and butylscopolamine bromide i.m., ~ 80 and 5mg/kg). As no improvement was noticed on Day 2, a standing sedation was carried out (detomidine i.m., ~ 0.018 mg/kg, and butorphanol (i.m., ~ 0.017 mg/kg). Rectal fluids (20 L of hand-warm tap water) and i.v. fluids (4 L of 0.9% saline solution) were administered, as well as i.m. injections with amoxicillin (~ 15 mg/kg), vitamin B-complex and vitamin E/selenium. Flunixin meglumine was given in the auricular vein. Sedation was reversed using atipamezole (i.m., ~ 0.05 mg/kg). Blood was collected during this procedure.
Unfortunately, the elephant collapsed 9 hours later in lateral recumbency. The animal was unresponsive and could be approached while it kept its eyes wide open (see videos). The araol mucosa was very pale. After 25 minutes it managed to stand up without any assistance but remained lethargic. Respiration was shallow. During the night the elephant went down in lateral recumbency again.
During the following 5 days, the elephant was sedated every day for treatment and blood collection.
Collapsed Asian elephant due to septicemia caused by Salmonella saintpaul. Note the pale oral mucosa. The state of paralysis very much looks like the paralysis seen in botulism (see case report).
Leucopenia was evident on the first blood smear that was made, with a clear increase of bands and a reduction of matured heterophils. An interesting finding was the presence of immature granulocytes (myelocytes) that could not be identified exactly. The platelet count was low and schistocytes (fragments of erythrocytes) were observed in each view. The presence of schistocytes is suggestive for the presences of a coagulopathy.
In conclusion: based on the hemogram, a diffuse intravascular coagulopathy (DIC) was suspected, most likely associated with septicemia caused by a bacterial infection or a toxicosis.
Interestingly, EEHV 3/4 was detected by a combined PCR test for subtype 3 and 4 in a blood sample and in trunk swabs. The elephant had been tested PCR positive for EEHV4 previously. A trunk swab taken from the conspecific that shared the enclosure was PCR-negative.
For photos of elephant heterophils, bands, platelets and schitsocytes: click here.
Human myelocyte, containing both primary (azurophilic) and secondary/specific (pink or lilac) cytoplasmic granules. The proportion of secondary granules increases as the cell matures. The nucleus is round and lacks a nucleolus. Courtesy: ASH Image Bank
Myelocyte of the Asian elephant in this case report. The quality of this photo is poor as it was taken with a cell-phone through the ocular lens of the microscope.
Daily urine samples were taken and analyzed using a dipstick and refractometer from Day 3 onwards. Initially a high specific gravity with a low pH was determined, suggestive for severe dehydration and metabolic acidosis.
A fecal sample collected on Day 3 was submitted for bacteriology.
The treatment plan focused on the suspected septicemia. Treatment with NSAID was continued and the antimicrobial treatment was switched to enrofloxacin (per rectum, ~ 2.5 mg/kg) and metronidazole (per rectum, ~ 11 mg/kg). Administration of vitamin B-complex and E/selenium was repeated on day 4 and day 5.
In an attempt to find the causative agent of the suspected septicemia, stored hay was inspected for mould and other conditions that favor (an)aerobic growth of toxin producing bacteria, more specifically Clostridium spp.
All sand in the enclosure was replaced; drains and surfaces were disinfected with 5% sodium hypochlorite before new sand was brought in.
On Day 9 Salmonella saintpaul sensitive for enrofloxacin was isolated from the feces.
Until Day 6, dehydration was getting worse, based on hematological findings (increased Ht) and urinalysis (increased specific gravity). On Day 7 no feces were produced (probably caused by the anorexia and repeated administration of detomidine) and diphteric necrotic tissue was observed during the administration of rectal fluids. In the mean time, hematology results started to show evidence of recovery from the septicemia: bands had dropped from 36% (Day 5) to 11%, while platelets increased from 320 (Day 2) to 437 x109/L. WBCs increased from 3.3 (Day3) to 10.5 x 106/L. Interestingly, the number of myelocytes increased to 35% on Day 7, but sharply dropped to 5% on Day 8 and they totally disappeared after that day.
All hematological parameters were normal when checked again on Day 48 and 55.
In order to stimulate the appetite and the intake of fibrous food, daily sedations were discontinued as from Day 8, and the focus of treatment moved to provide gastro-protection and stimulation of the duodenal motility by the administration of ranitidine (oral, ~ 0.25 mg/kg) twice daily. Water soaked bran and hay ad lib, bamboo browse and banana tree-trunks were offered as much as possible. Sugar-containing food items were restricted to treats for compliance to vocal commands by the keepers in order to get cooperation from the elephant for the necessary treatment procedures.
The animal regained its strength and body condition over the 3 month-period following this clinical episode.
The presence of EEHV3/4 in the blood and trunk swab can be explained by a virus reactivation due to the sudden deficiency of the immune system as a result of the septicemia and DIC. No clinical impact is to be expected from this finding, as the animal known to be a carrier of EEHV4.
Molenaar, F.M. and Silvestre S. 2021. Clinical approach to colic and collapse in an Asian elephant (Elephas maximus) with Salmonella saintpaul septicaemia and subsequent ileus. Vet Rec Case Rep. 2021;e214. https://doi.org/10.1002/vrc2.214.