Evaluation of Activated Charcoal as an Alternative to Antimicrobials for the Treatment of Neonatal Calf Diarrhea

Figures & data

Table 1 Treatment Groups and Dosing Regimen

Group	Route	Dosage	Product^b	Active Ingredient(s)
A (Antimicrobials) n=86	Oral	2 boluses per 50 kg of body weight twice daily the first day, and 1 bolus per 50 kg of body weight twice daily for 2 days	Cocci Scour Bolus	250 mg neomycin, 2000 mg sulfamethazine per bolus
B (Antimicrobials + Charcoal) n=86	Oral	Antimicrobials as above (A) Charcoal as below (C)	Cocci Scour Bolus as above (A) and Charcoal as below (C)
C (Charcoal) n=86	Oral	30 mL/calf; twice per day (separated by 2–4 hrs) for 2 days	Charcoal-Kaolin Oral Paste	100 mg Activated Charcoal, 197 mg Kaolin per mL
Electrolytes n=104^a	Oral	1 pouch in 2 L, repeat treatment twice daily as necessary	Electrolyte powder	Per 76 g pouch: 41.734 g dextrose, 3.507 g sodium chloride, 6.756 g glycine, 1.940 g potassium chloride, 13.125 g sodium acetate, 0.6 g sodium phosphate monobasic, 0.349 g dipotassium phosphate, 0.012 g calcium d-pantothenate
Meloxicam n=258 (all animals)	Oral Drench	5 mL, once per calf	Meloxicam Oral Suspension	15 mg/mL Meloxicam, USP

Notes: ^aElectrolytes given to dehydrated calves according to facility protocols. ^bAll products were obtained from Alberta Veterinary Laboratories Ltd.

Table 2 Mortality of Animals Treated with Antimicrobials (A), Charcoal (C), or Both (B)

Treatment	Number of Animals	Number of Deceased Animals (Percent)
A	86	1 (1.16%)^a
B	86	8 (9.30%)^a
C	86	7 (8.14%)
Total	258	16 (6.20%)

Notes: ^aA vs B: P=0.03; B vs C: P>0.99; A vs C: P=0.06; A vs Total: P=0.08; B vs Total: P=0.33; C vs Total: P=0.62. P values were Calculated using Fisher’s Exact Test.

Table 3 Recovery of Animals Treated with Antimicrobials (A), Charcoal (C), or Both (B)

Treatment	Number of Animals	Number of Recovered Animals (Percent)
A	86	83 (96.5%)
B	86	78 (90.7%)
C	86	75 (87.2%)
Total	258	236 (91.5%)

Notes: A vs B: P=0.21; B vs C: P>0.99; A vs C: P=0.13; A vs Total: P=0.22; B vs Total: P=0.65; C vs Total: P=0.50. P values were Calculated using Fisher’s Exact Test.

Figure 1 Kaplan–Meier curves of survival (A) or recovery (B) for animals treated with antimicrobials, charcoal, or antimicrobials + charcoal. A=antimicrobials (n=86); C=charcoal (n=86); B=both (n=86). For panel B, animals were censored when they died, as were animals that failed to recover over the 7-day period. Overall P-values were 0.0594 and 0.0063 for panels A and B, respectively (calculated using a Log rank test). The indicated P-values (A vs B, A vs C, and B vs C) were adjusted for multiple comparisons using the Holm-Šídák method and a family-wise significance level of 0.05. *P<0.05; **P<0.01.

Table 4 Pathogens Detected in Fecal Samples from Diarrhetic Calves

Method of Detection	Organism	Mean log10 CFU/mL or Oocysts/g Feces ±SD	Number of Positive Animals^a	Positivity Rate (%)
Enterichek	Rotavirus	N/A	159	61.9
	Coronavirus		5	1.95
	E. coli K99 (F5)		2	0.778
	C. parvum		198	77.0
	Rotavirus + C. parvum		116	45.1
Plating on chromogenic agar	Campylobacter spp.	4.25 ± 0.83^b	4	1.56
	Total E. coli	5.90 ± 1.23	256	99.6
	Total coliforms	4.99 ± 1.86	237	92.2
Fluorescence microscopy	C. parvum oocysts^c	3.40 ± 1.47	223	86.8

Notes: ^aThe total number of animals sampled was 257. ^bOnly calculated for the 4 positive samples. ^c2/257 (0.78%) of samples yielded false positives (ie, Enterichek was positive but the oocyst count was 0); 27/257 (10.5%) of samples yielded false negatives (ie, Enterichek was negative but oocysts were counted).

Abbreviations: SD, standard deviation; N/A, not applicable.

Table 5 Enterichek Positivity Rate for Rotavirus at Days 0 and 7, Organized by Treatment Group

Treatment	Number of Samples	Number of Positive Samples (Percent)		P (Day 0 vs 7)^a
		Day 0	Day 7
A	85	54 (63.5%)	1 (1.2%)^b	<0.0001
B	80	45 (56.3%)	7 (8.8%)^b	<0.0001
C	78	49 (62.8%)	2 (2.6%)	<0.0001
Total	243	148 (60.9%)	10 (4.1%)	<0.0001

Notes: ^aCalculated using Fisher’s Exact Test. ^bFor A vs B on Day 7, P=0.03. For all other pairwise comparisons, P≥0.17.

Table 6 Enterichek Positivity Rate for C. parvum at Days 0 and 7, Organized by Treatment Group

Treatment	Number of Samples	Number of Positive Samples (Percent)		P (Day 0 vs 7)^a
		Day 0	Day 7
A	85	70 (82.4%)	33 (38.8%)	<0.0001
B	80	66 (82.5%)	37 (46.3%)	<0.0001
C	78	54 (69.2%)	39 (50.0%)	0.0220
Total	243	190 (78.2%)	109 (44.9%)	<0.0001

Notes: ^aCalculated using Fisher’s Exact Test. For B vs C on Day 0, P=0.06; for A vs C on Day 0, P=0.07; for A vs C on Day 7, P=0.16; for all other pairwise comparisons, P≥0.35.

Table 7 Enterichek Positivity Rate for E. coli K99 (F5) at Days 0 and 7, Organized by Treatment Group

Treatment	Number of Samples	Number of Positive Samples (Percent)		P (Day 0 vs 7)^a
		Day 0	Day 7
A	85	0	0	>0.9999
B	80	2 (2.5%)	0	0.4969
C	78	0	0	>0.9999
Total	243	2 (0.8%)	0	0.4990

Notes: ^aCalculated using Fisher’s Exact Test. For A vs B on Day 0, P=0.23; for all other pairwise comparisons, P≥0.50.

Table 8 Enterichek Positivity Rate for Coronavirus at Days 0 and 7, Organized by Treatment Group

Treatment	Number of Samples	Number of Positive Samples (Percent)		P (Day 0 vs 7)^a
		Day 0	Day 7
A	85	1 (1.2%)	0	>0.9999
B	80	0	0	>0.9999
C	78	3 (3.8%)	0	0.2452
Total	243	4 (1.6%)	0	0.1235

Notes: ^aCalculated using Fisher’s Exact Test. For B vs C on Day 0, P=0.12; for all other pairwise comparisons, P≥0.35.