Blackleg in cattle in the state Mato Grosso do Sul, Brazil: 59 cases

Heckler, Rubiane F.; Lemos, Ricardo A.A. de; Gomes, Danilo C.; Dutra, Iveraldo S.; Silva, Rodrigo O.S.; Lobato, Francisco C.F.; Ramos, Carlos A.N.; Brumatti, Ricardo C.

doi:10.1590/1678-5150-PVB-4964

ABSTRACT:

This study aimed to review cases of blackleg (Clostridium chauvoei infection) diagnosed in cattle from Midwestern Brazil from 1994 to 2014 considering epidemiological, clinical, necropsy and histopathological findings. Also the following laboratory tests were used for the diagnosis of some cases of blackleg: microbiological culture and identification of the agent, microbiological culture and identification of the agent by the polymerase chain reaction (PCR), and identification of the agent in formalin fixed paraffin embedded tissues (FFPE). Criteria for presumptive diagnosis of blackleg included necrohemorrhagic emphysematous myositis consisting of inflammatory infiltrate, coagulative necrosis of myofiber, interstitial edema, hemorrhage, and gas bubbles between myofibers. Fifty nine cases from 51 outbreaks of blackleg were found, which corresponded to 1.1% of 5,375 cattle deaths investigated. In five of those outbreaks, samples of affected muscles cultures for the identification of pathogenic clostridia were made. Another three samples of similar material were cultured for clostridia with subsequent identification of the isolate by PCR. Twelve samples of FFPE affected muscle fragments were submitted to PCR for identification of the etiological agent. Except for January, cases were observed in each month of the year, with higher numbers in July-October. Most affected cattle were in the age of 7-12 years, but calves younger than 6 month-old and older than 24 months were also observed. Vaccination histories were scarce. In 32 outbreaks some vaccination history was available, but only in two of those vaccination has been carried out properly. In 56 six cases the skeletal muscles were involved. Muscles of the hind limbs were the most affected. In ten cases muscles of the tongue, myocardium and diaphragm were also affected. In three of the cases the visceral form was observed. Deaths occurred after a clinical course of 6-24 hours, but in most cases cattle were found death. Sudden death was the outcome in visceral cases (cardiac) blackleg. Clostridium chauvoei was confirmed to be the cause by culturing in 5 cases, and by PCR and histopatology in 8 cases. Bacterial culture followed by PCR did not demonstrate C. chauvoei. Calculation of the economic impact indicates that blackleg is a frequent disease in the state of Mato Grosso do Sul (MS) that inflicts significant economic loss. The amount of these losses would be reduced through proper vaccination programs against the prevalent strains of C. chauvoei in the region.

INDEX TERMS:
Blackleg; diseases of cattle; clostridial myositis; Clostridium chauvoei

[1] *Corresponding author: ricardo.lemos@ ufms.br

Case number	Montth of occurrence	Age in months	Total number of cattle	Cattle at risk	Sick cattle	Dead cattle	Vaccination	Protocol of vaccination
1	March	8	NI	NI	8	8	Inadequated	A^d
2	March	30	NI	NI	1	1	Inadequated	Vaccinated at 4-year-old
3	June	8	60	60	11	3	Yes	Protocol 1^e
4	June	12	50	50	1	1	NI	NI
5	June	18	2000	NI	1	1	Yes	Protocol 1
6	July	4	NI	NI	NI	NI	NI	NI
7	July	6	200	200	1	1	NI	NI
8	July	2	NI	6	2	2	NI	NI
9, 10^a	August	12	300	150	16	16	No	-
11	August	18	3500	NI	16	16	NI	NI
12	August	8	NI	NI	5	5	NI	NI
13, 14^a	October	11	NI	78	8	8	Inadequated	A
15	November	12	NI	NI	1	1	NI	NI
16	September	11	600	600	5	5	NI	NI
17	April	12	NI	156	6	6	Yes	NI
18	June	7	16	16	1	1	NI	NI
19	September	14	26	26	1	1	NI	NI
20, 21, 22^b	June	7	1000	940	11	11	Yes	Protocol 2^f
23	August	8	160	NI	10	8	Inadequated	A^f
24	May	36	100	NI	3	3	No	NI
25	September	6	NI	4	1	1	No	NI
26	September	4	400	30	1	1	NI	NI
27	October	8	100	100	7	6	Yes	NI
28	December	4	200	40	1	1	NI	NI
29	February	NI^c	NI	NI	NI	NI	NI	NI
30	June	4	NI	NI	2	2	No	-
31	March	14	813	367	17	17	Yes	NI
32	March	18	600	NI	1	1	No	-
33	April	24	700	NI	1	1	Yes	NI
34	May	9	1943	29	2	2	Inadequated	B^g
35	June	6	70	12	2	2	No	-
36	September	10	NI	NI	9	9	Yes	Protocol 2
37	July	NI	NI	NI	3	3	Inadequated	B
38	August	12	2000	800	7	6	No	-
39, 40^a	September	12	693	200	5	5	Yes	Protocol 2
41	August	9	NI	NI	NI	NI	Inadequated	B
42	October	12	206	206	4	4	No	-
43	April	10	NI	NI	11	11	NI	NI
44, 45^a	May	7	1500	NI	3	3	No	-
46	August	10	110	110	2	2	No	-
47	August	14	1053	534	13	13	Inadequated	A
48	June	36	1200	125	2	2	No	-
49	October	10	248	138	1	1	Yes	NI
50	October	8	600	NI	1	1	NI	NI
51	March	8	80	80	2	2	NI	NI
52, 53, 54^b	Dezember	18	310	80	4	3	Yes	NI
55	September	11	480	68	2	2	NI	NI
56	October	12	115	115	5	5	NI	NI
57	November	30	700	NI	NI	NI	No	-
58	July	12	160	40	1	1	NI	NI
59	September	8	1500	NI	3	3	Yes	NI

Age in months	Total cases	%
0-6	8	13.6
>6-12	35	59.3
13-18	9	15.3
19-24	1	1.7
> 24	4	6.8
Not informed	2	3.4

Clinical sign	Number of cases (%)
Lameness	23 (56.10)
Prostation	14 (34.15)
Muscle swelling	12 (29.27)
Crepitation in affected muscle	7 (17.07)
Edema	7 (17.07)
Muscle tremors	4 (9.76)
Stiff gait	2 (4.88)
Anorexia	1 (2.44)
Tachypnea	1 (2.44)

Affected muscle		Number of cases	%
	Skeletal muscle	46/59	77.97
	Right hind limb	9/46	19.56
	Left hind limb	15/46	32.61
	Right fore limb	5/46	10.87
	Left for limb	5/46	10.87
	Psoas	1/46	2.17
Anatomical site not informed		11/46	23.91
Myocardium and skeletal muscles		6/59	10.17
Myocardium		3/59	5.08
Myocardium, tongue and skeletal muscles		1/59	1.69
Tongue and skeletal muscles		1/59	1.69
Tongue, diaphragm, and skeletal muscles		1/59	1.69
Diaphragm and skeletal muscles		1/59	1.69

Lesion	Number of cases	%
Dark red discoloration of affected muscle area	34	87.18
Crepitation of affected muscle area	23	58.97
Edema tinged with blood	16	41.03
Good nutritional plane	15	38.46
Butyric smell from the lesion	10	25.64
Affected muscle floating in formalin	6	15.38
Splenomegaly	6	15.38
Blood-stained froth flowing from the nose	5	12.82
Poorly circumscribed swelling in the affected area	4	10.26
Fibrinohemorrhagic pericarditis	1	0.39
Fibrinohemorrhagic pleuritis	1	0.39

Brasil

Brasil

Blackleg in cattle in the state Mato Grosso do Sul, Brazil: 59 cases

Carbúnculo sintomático em bovinos em Mato Grosso do Sul: 59 casos

ABSTRACT:

Lesion	Number of cases	%
Neutrophilic infiltrate	55	93.22
Hemorrhage	52	88.14
Fibrin	37	62.71
Coagulative segmentar necrosis	32	54.24
Separation of myofibers	30	50.85
Gas bubbles between myofibers	17	28.81

Sample	Bacterial culture	Bacterial culture followed by PCR^a of the isolate	PCR in FFPE^b
3	Clostridium chauvoei	NP	NP
9	Clostridium chauvoei	NP	NP
12	Clostridium chauvoei	NP	NP
25	Clostridium chauvoei	NP	NP
29	Clostridium chauvoei	NP	NP
48	NP^c	NP	Negative
49	NP	NP	Clostridium chauvoei
50	NP	NP	Negative
51	NP	NP	Negative
52	NP	Clostridium septicum	Clostridium chauvoei
53	NP	NP	Clostridium chauvoei
54	NP	Clostridium septicum	Clostridium chauvoei
55	NP	NP	Clostridium chauvoei
56	NP	NP	Clostridium chauvoei
57	NP	NP	Negative
58	NP	NP	Clostridium chauvoei
59	NP	Negative	Clostridium chauvoei

Case number	Cattle at risk	Cattle dead	Vaccination	Value of the herd (R$)	Losses (R$)	Losses (%)	Cost of vaccine (R$)	Cost/loss rate
57	80	22	No	107,600	29,590	27.50%	129	0.44%
25	4	1	No	5,044	1,261	25.00%	6	0.51%
35	12	2	No	15,132	2,522	16.67%	19	0.77%
9, 10a	150	16	No	183,000	19,520	10.67%	242	1.24%
13, 14^a	78	8	No	95,160	9,760	10.26%	126	1.29%
34	29	2	No	35,380	2,440	6.90%	47	1.91%
47	534	13	No	651,480	15,860	2.43%	860	5.42%
48	125	2	No	218,750	3,500	1.60%	201	5.75%
46	110	2	No	147,950	2,690	1.82%	177	6.58%
42	206	4	No	251,320	4,880	1.94%	332	6.80%
38	800	6	No	1,076,000	8,070	0.75%	1,288	15.96%
8	6	2	NI	5,346	1,782	33.33%	10	0.54%
18	16	1	NI	20,176	1,261	6.25%	26	2.04%
56	115	5	NI	140,300	6,100	4.35%	185	3.04%
19	26	1	NI	34,970	1,345	3.85%	42	3.11%
55	68	2	NI	82,960	2,440	2.94%	109	4.49%
28	40	1	NI	50,440	1,261	2.50%	64	5.11%
58	40	1	NI	48,800	1,220	2.50%	64	5.28%
26	30	1	NI	26,730	891	3.33%	48	5.42%
4	50	1	NI	64,125	1,283	2.00%	81	6.28%
51	80	2	NI	71,280	1,782	2.50%	129	7.23%
16	600	5	NI	732,000	6,100	0.83%	966	15.84%
7	200	1	NI	178,200	891	0.50%	322	36.14%
27	100	6	Yes	126,100	7,566	6.00%	161	2.13%
31	367	17	Yes	493,615	22,865	4.63%	591	2.58%
3	60	3	Yes	64,560	3,228	5.00%	97	2.99%
17	156	6	Yes	200,070	7,695	3.85%	251	3.26%
52, 53, 54^b	80	3	Yes	97,600	3,660	3.75%	129	3.52%
39, 40*	200	5	Yes	244,000	6,100	2.50%	322	5.28%
20, 21, 22^b	940	11	Yes	1,011,440	11,836	1.17%	1,513	12.79%
49	138	1	Yes	185,610	1,345	0.72%	222	16.52%