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Comparison of the effects of local and systemic dry cow therapy for staphylococcal mastitis control
PREVENTIVE VETERINARY MEDICINE Preventive Veterinary Medicine 25 ( 1995) 63-67
Comparison of the effects of local and systemic dry cow therapy for staphylococcal mastitis control M. Bolourchi”,
P. Hovareshti, A.H. Tabatabayi
Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453, Tehran, Iran
Accepted 3 May 1995
Abstracl. The therapeutic effects of systemic injections of enrofloxacin or tylosin and intramammary infusions of an ointment containing naficillin, penicillin and dihydrostreptomycin were compared in the dry period against staphylococcal intramammary infection (IMI) in a large Holstein dairy herd. The frequency of IMI was 26.7% and samples were all negative for Mycoplusma spp. At the time of treatment, the prevalence of staphylococcal IMI in the three groups: ( 1) enrofloxacin (EN), (;I) tylosin (TY) and (3) naficillin, penicillin and dihydrostreptomycin (DC) were 29.8%, 28.5% and 21.7%, respectively. The difference between the three figures were not statistically significant (P = 0.17). The cure rates in the EN, TY and DC groups were 85.2%, 77.4% and 92.3%, respectively, which were also not significantly different (P = 0.15). New infection rates in EN, TY and DC groups, after treatment, were 6.1%. 7.5% and 4.4%, respectively, showing no statistically significant difference between the three groups (P = 0.46). We co:ncluded that systemic dry cow therapy using enrofloxacin or tylosin can be an alternative to the conventional local method for elimination of staphylococcal IMI during the dry period, although, local dry cow therapy (using partially inserted cannulas) is still the most effective method when considering IMI at calving. Keywords Mastitis; Staphylococcus; Local systemic; Therapy
1. Intmduction The main cost, to the farmer, of Stu~hyZococc~~ aureus (S. aureus) is due to the milk production loss in chronic infections (Amstutz, 1980; Blood et al., 1983; National Mastitis Council, 1987; Faull et al., 1991). Although dry cow therapy increases the cure rate in * Corresponding author. 0167-5877/95/$09.50 0 1995 Elsevier SSDIO167-5877(95)00508-O
Science B.V. All rights reserved
64
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
staphylococcal udder infections, the pattern of sensitivity of the bacteria to certain antibiotics varies by area and herd (Tyler et al., 1993; Vestweber, 1994). In addition, it is often impossible to find a reasonable association between the antibiotic sensitivity test and treatment results (Vestweber, 1994). Resistance to antibiotics is due to existence of the microorganisms in macrophages and polymorphonuclear neutrophilic leukocytes; only a few antibiotics (e.g. penicillin, tylosin and enrofloxacin) can produce sufficient intracellular concentration to kill the bacteria (Soback et al., 1990; Ziv, 1992). About 12% of the quarters that are infected at drying off are still infected after parturition if dry cow therapy is not practiced (Nickerson, 1990). Few studies have been conducted on systemic treatment of the subclinical staphylococcal intramammary infections in the dry period. However, Soback et al. ( 1990) have found norfloxacin nicotinate (a fluoroquinolone derivative) to give encouraging results. In our study, effects of parenteral injection of enrofloxavin (another derivative of the fluoroquinolone family) and tylosin (a macrolide) were compared with routine intramammat-y partially-inserted-cannula infusion of an ointment containing sodium naficillin, procaine benzylpenicillin and dihydrostreptomycin.
2. Materials and methods In a large Holstein dairy herd that was previously reported to have staphylococcal intramammary infection (IMI) , a study was carried out on 547 cows during one year ( 19931994). The herd was fed a ration of corn silage, dry alfalfa and a concentrate including crushed barley grain, wheat bran, cottonseed meal, beet pulp, minerals and vitamins during the year. Cows were kept in free stalls. The average milk production days and the average total lactation milk yield for the herd were 326 + 73 and 8109 f 1988 kg respectively. Cows were randomized by the systematic method into three groups gradually throughout the year as they were dried off. A standard teat sanitation method was practiced using 70% ethanol (National Mastitis Council, 1987) and a composite milk sample was collected from each cow when the milk had a honey-coloured appearance. The administered drug were selected by lottery, and there was a similarity among groups regarding the seasons of the year, at dry off.
3. Cultures Blood Agar and MacConkey’s agar media were used to isolate the bacteria. Differential media were used to identify the isolates according to the standard practices (Carter and Cole, 1990). To isolate mycoplasma, about 1 ml of each composite milk sample was filtered through a millipore filter (0.45 pm) and was cultured in 4 ml of Bacto, PPLO broth (with 20% sterile horse serum, 0.5% yeast extract and l/2000 thalium acetate) for 72 hours. About 0.5 ml of the culture was then recultured in an enriched PPLO agar. Observations of the cultures was continued for 14 days. Paired cultures were incubated in 37-37.5”C in both an ordinary environment and one containing 5-10% CO*.
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
65
4. Treatments Each cow was treated after sampling (with no reference to the results of cultures), as it reached the dry off stage, in the following fashion: ( 1) Group EN; this group consisted of 181 cows, receiving 2.5 mg kg-’ BW enrofloxacin (Baytril, Bayer, Bayer Leverkusen) subcutaneously daily for 3 days at the time of dry cow therapy. (2) Group TY; this group of 186 c:ows received 5 mg kg-’ BW tylosin 200 solution (Tylan, Elanco Animal Health, Eli Lilly) intramuscularly daily for 3 days at the time of dry cow therapy. (3) Group DC; this group of 180 cows received an intramammary infusion of an ointment containing sodium naficillin ( 100 mg), procaine benzylpenicillin (300 mg) and dihydrostreptomycin ( 100 mg), (Nafpenzal DC, Intervet International, Boxmeer) in each quarter at the time of last milking. About 3 mm of the cannula was inserted into the teat canal. All three groups were subjected to teat dipping using iodophor solution as a part of routine mastitis control program. Immediately after parturition a composite colostrum sample was collected from each cow and was cultured for bacteria. Data were subjected to Chi-square tests, (most with two degrees of freedom) for statistical analysis.
5. Results The most common bacterium isolated at the time of dry off, was S. aureu~ which was obtained in pure culture from 146 out of 547 composite milk samples (26.7%). The prevalence of staphylococcal IMI was reduced to 4.2% at calving. Prior to the treatment (at drying off) the prevalence of staphylococcal IMI in groups EN, TY and DC were 29.8% (54/181), 28.5% (531186) and 21.7 (391180) respectively which at freshening were reduced to 4.4% (8/181), 6.5% (12/186) and 1.7% (3/180) respectively excluding new infections. Table 1 The results of the therapeutic effects of the local and the systemic dry cow therapy for staphylococcal udder infections in Iranian Holstein cows
Group
Number
Number
Prevalence
Number of
Cure
Number of
Number of
New
Total
Prevalence
of cows
of inf. at
at drying
infection
rate
negative at
new
infection
number
at calving
drying
off(%)
elimination
(%)
drying off
infection
rate
of
Off
during dry
during
Period
period
dry
(%)
infection at calving
EN
181
54
29.8
46
85.2
127
11
6.1
19
10.5”
TY
186
53
28.5
41
77.4
133
14
7.5
26
14.w
DC
180
39
21.7
36
92.3
141
8
4.4
11
6.1b
Overall P-value for difference
0.17
0.15
0.045
0.46
between the three groups “bGroups wilh different superscripts are significantly different i.e. P <0.05. EN, systemic enrofloxacin; TY, systemic tylosin; DC, inaamammaq drostreptomycin
ointment containing natkillin,
benzylpenicillin,
and dihy-
66
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
The cure rates for EN, TY and DC groups were 85.2%, 77.4% and 92.3% respectively and new infection rates were 6.1% (11/181), 7.5% (14/186) and 4.4% (8/180) respectively (Table 1) . All of the milk samples were negative for Mycopkzsma spp. However, Corynebacterium bouis (30 isolations), coliforms ( 18 isolations) and Streptococcus spp. (4 isolations) were also isolated. These microorganisms were equally distributed between the three groups and no mixed infections were encountered.
6. Discussion Staphylococcal IMI prevalence were not significantly different between the three groups at the time of drying off. All of the treatments worked effectively to eliminate IMI during the dry period, reducing it significantly from 26.7% at the time of last milking to 4.2% at freshening (P < 0.0005) and they also showed to have equal cure rates. New infection rates were also equal between the groups. Boddy and Nickerson (1986) clearly show that the partially inserted cannula infusion method is more effective in preventing IMI than the fully inserted cannula infusion method. This may explain the disagreement between our results and those of Soback et al. (1990) who showed that the systemic dry cow therapy by norfloxacin is more effective than the locally, fully inserted cannula infusion at the time of drying off. Although the difference in the cure rates were not statistically significant during the dry period and also no significant difference could be found in new staphylococcal IMI at the freshening between the three groups, the prevalence of infection at calving was significantly higher in EN and TY groups compared with that of the DC group (P = 0.045). This was due to the cumulative effects of the slightly higher cure rate and slightly lower rate of new infections in the DC group. In conclusion our study showed that local dry cow therapy (using partially inserted cannulas) is still the most effective method.
Acknowledgement We are indebted to the research secretariate of the Tehran University without whose help this work could not have taken place. We also thank Sepahan Dairy Farm Managers and personnel for their cooperation. Finally, we thank the executive managers of Bayer and Cot-pa companies for contributing the drugs used in this study.
References Amstutz, H.E., 1980. Bovine Medicine and Surgery. 2nd edn., Am. Vet. Publ. Inc., pp. 1049-1086. Blood, D.C., Radostits, O.M. and Henderson, J.A., 1983. Veterinary Medicine. 6th edn., Bailliere Tindall/W.B. Saunders, London, pp. 451-492. Boddie, R.L. and Nickerson, SC., 1986. Dry cow therapy: effect of method of drug administration on occurrence of intramammary infection. J. Dairy Sci., 69: 253-257.
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
67
Carter, G.R. and Cole, J.R., 1990. Diagnostic Procedures in Veterinary Bacteriology and Mycology. 5th edn., Academic Press, 620 pp. Faull, W.B., Hughes, I.W. and Ward, W.R., 1991. A Mastitis Handbook for the Dairy Practitioner. 5th edn., Liveqpool University Press, Liverpool, pp. 17-23. National Mastitis Council, 1987. Laboratory and Field Handbook of Bovine Mastitis. Hoard, W.D. Hoards and Sons (Co., USA, 7 pp. Nickerson, S.C., 1990. Mastitis and its Control in Heifers Dry Cow. Int. Symp. Bovine Mastitis, 13-16 September 1990, Indianapolis, National Mastitis Council and American Association of Bovine Practitioners, pp. 82-91. Soback, S., Ziv, G., Wikler, M. and Saran, A., 1990. Systemic dry cow therapy-a preliminary report. J. Dairy Sci., 73: 661-666. Tyler, J.W., Wilson, C.R. and Dowling, P., 1992. Treatment of subclinical mastitis. Vet. Clinics of North Am. Food Anim. Pratt., 8( 1): 17-28. Vestweber, J.G., 1994. Staphylococcusaureus mastitis. Part II. Diagnostic aids, therapy, and control, compendium. Cont. Ed. Vet. Med. Pratt., 16(2): 217-222. Ziv, G., 1993. Treatment of peracute and acute mastitis. Vet. Clinics of N. Am. Food Anim. Pratt., 8( 1): 1-15.
Comparison of the effects of local and systemic dry cow therapy for staphylococcal mastitis control M. Bolourchi”,
P. Hovareshti, A.H. Tabatabayi
Department of Large Animal Clinical Sciences, Faculty of Veterinary Medicine, University of Tehran, P.O. Box 14155-6453, Tehran, Iran
Accepted 3 May 1995
Abstracl. The therapeutic effects of systemic injections of enrofloxacin or tylosin and intramammary infusions of an ointment containing naficillin, penicillin and dihydrostreptomycin were compared in the dry period against staphylococcal intramammary infection (IMI) in a large Holstein dairy herd. The frequency of IMI was 26.7% and samples were all negative for Mycoplusma spp. At the time of treatment, the prevalence of staphylococcal IMI in the three groups: ( 1) enrofloxacin (EN), (;I) tylosin (TY) and (3) naficillin, penicillin and dihydrostreptomycin (DC) were 29.8%, 28.5% and 21.7%, respectively. The difference between the three figures were not statistically significant (P = 0.17). The cure rates in the EN, TY and DC groups were 85.2%, 77.4% and 92.3%, respectively, which were also not significantly different (P = 0.15). New infection rates in EN, TY and DC groups, after treatment, were 6.1%. 7.5% and 4.4%, respectively, showing no statistically significant difference between the three groups (P = 0.46). We co:ncluded that systemic dry cow therapy using enrofloxacin or tylosin can be an alternative to the conventional local method for elimination of staphylococcal IMI during the dry period, although, local dry cow therapy (using partially inserted cannulas) is still the most effective method when considering IMI at calving. Keywords Mastitis; Staphylococcus; Local systemic; Therapy
1. Intmduction The main cost, to the farmer, of Stu~hyZococc~~ aureus (S. aureus) is due to the milk production loss in chronic infections (Amstutz, 1980; Blood et al., 1983; National Mastitis Council, 1987; Faull et al., 1991). Although dry cow therapy increases the cure rate in * Corresponding author. 0167-5877/95/$09.50 0 1995 Elsevier SSDIO167-5877(95)00508-O
Science B.V. All rights reserved
64
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
staphylococcal udder infections, the pattern of sensitivity of the bacteria to certain antibiotics varies by area and herd (Tyler et al., 1993; Vestweber, 1994). In addition, it is often impossible to find a reasonable association between the antibiotic sensitivity test and treatment results (Vestweber, 1994). Resistance to antibiotics is due to existence of the microorganisms in macrophages and polymorphonuclear neutrophilic leukocytes; only a few antibiotics (e.g. penicillin, tylosin and enrofloxacin) can produce sufficient intracellular concentration to kill the bacteria (Soback et al., 1990; Ziv, 1992). About 12% of the quarters that are infected at drying off are still infected after parturition if dry cow therapy is not practiced (Nickerson, 1990). Few studies have been conducted on systemic treatment of the subclinical staphylococcal intramammary infections in the dry period. However, Soback et al. ( 1990) have found norfloxacin nicotinate (a fluoroquinolone derivative) to give encouraging results. In our study, effects of parenteral injection of enrofloxavin (another derivative of the fluoroquinolone family) and tylosin (a macrolide) were compared with routine intramammat-y partially-inserted-cannula infusion of an ointment containing sodium naficillin, procaine benzylpenicillin and dihydrostreptomycin.
2. Materials and methods In a large Holstein dairy herd that was previously reported to have staphylococcal intramammary infection (IMI) , a study was carried out on 547 cows during one year ( 19931994). The herd was fed a ration of corn silage, dry alfalfa and a concentrate including crushed barley grain, wheat bran, cottonseed meal, beet pulp, minerals and vitamins during the year. Cows were kept in free stalls. The average milk production days and the average total lactation milk yield for the herd were 326 + 73 and 8109 f 1988 kg respectively. Cows were randomized by the systematic method into three groups gradually throughout the year as they were dried off. A standard teat sanitation method was practiced using 70% ethanol (National Mastitis Council, 1987) and a composite milk sample was collected from each cow when the milk had a honey-coloured appearance. The administered drug were selected by lottery, and there was a similarity among groups regarding the seasons of the year, at dry off.
3. Cultures Blood Agar and MacConkey’s agar media were used to isolate the bacteria. Differential media were used to identify the isolates according to the standard practices (Carter and Cole, 1990). To isolate mycoplasma, about 1 ml of each composite milk sample was filtered through a millipore filter (0.45 pm) and was cultured in 4 ml of Bacto, PPLO broth (with 20% sterile horse serum, 0.5% yeast extract and l/2000 thalium acetate) for 72 hours. About 0.5 ml of the culture was then recultured in an enriched PPLO agar. Observations of the cultures was continued for 14 days. Paired cultures were incubated in 37-37.5”C in both an ordinary environment and one containing 5-10% CO*.
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
65
4. Treatments Each cow was treated after sampling (with no reference to the results of cultures), as it reached the dry off stage, in the following fashion: ( 1) Group EN; this group consisted of 181 cows, receiving 2.5 mg kg-’ BW enrofloxacin (Baytril, Bayer, Bayer Leverkusen) subcutaneously daily for 3 days at the time of dry cow therapy. (2) Group TY; this group of 186 c:ows received 5 mg kg-’ BW tylosin 200 solution (Tylan, Elanco Animal Health, Eli Lilly) intramuscularly daily for 3 days at the time of dry cow therapy. (3) Group DC; this group of 180 cows received an intramammary infusion of an ointment containing sodium naficillin ( 100 mg), procaine benzylpenicillin (300 mg) and dihydrostreptomycin ( 100 mg), (Nafpenzal DC, Intervet International, Boxmeer) in each quarter at the time of last milking. About 3 mm of the cannula was inserted into the teat canal. All three groups were subjected to teat dipping using iodophor solution as a part of routine mastitis control program. Immediately after parturition a composite colostrum sample was collected from each cow and was cultured for bacteria. Data were subjected to Chi-square tests, (most with two degrees of freedom) for statistical analysis.
5. Results The most common bacterium isolated at the time of dry off, was S. aureu~ which was obtained in pure culture from 146 out of 547 composite milk samples (26.7%). The prevalence of staphylococcal IMI was reduced to 4.2% at calving. Prior to the treatment (at drying off) the prevalence of staphylococcal IMI in groups EN, TY and DC were 29.8% (54/181), 28.5% (531186) and 21.7 (391180) respectively which at freshening were reduced to 4.4% (8/181), 6.5% (12/186) and 1.7% (3/180) respectively excluding new infections. Table 1 The results of the therapeutic effects of the local and the systemic dry cow therapy for staphylococcal udder infections in Iranian Holstein cows
Group
Number
Number
Prevalence
Number of
Cure
Number of
Number of
New
Total
Prevalence
of cows
of inf. at
at drying
infection
rate
negative at
new
infection
number
at calving
drying
off(%)
elimination
(%)
drying off
infection
rate
of
Off
during dry
during
Period
period
dry
(%)
infection at calving
EN
181
54
29.8
46
85.2
127
11
6.1
19
10.5”
TY
186
53
28.5
41
77.4
133
14
7.5
26
14.w
DC
180
39
21.7
36
92.3
141
8
4.4
11
6.1b
Overall P-value for difference
0.17
0.15
0.045
0.46
between the three groups “bGroups wilh different superscripts are significantly different i.e. P <0.05. EN, systemic enrofloxacin; TY, systemic tylosin; DC, inaamammaq drostreptomycin
ointment containing natkillin,
benzylpenicillin,
and dihy-
66
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
The cure rates for EN, TY and DC groups were 85.2%, 77.4% and 92.3% respectively and new infection rates were 6.1% (11/181), 7.5% (14/186) and 4.4% (8/180) respectively (Table 1) . All of the milk samples were negative for Mycopkzsma spp. However, Corynebacterium bouis (30 isolations), coliforms ( 18 isolations) and Streptococcus spp. (4 isolations) were also isolated. These microorganisms were equally distributed between the three groups and no mixed infections were encountered.
6. Discussion Staphylococcal IMI prevalence were not significantly different between the three groups at the time of drying off. All of the treatments worked effectively to eliminate IMI during the dry period, reducing it significantly from 26.7% at the time of last milking to 4.2% at freshening (P < 0.0005) and they also showed to have equal cure rates. New infection rates were also equal between the groups. Boddy and Nickerson (1986) clearly show that the partially inserted cannula infusion method is more effective in preventing IMI than the fully inserted cannula infusion method. This may explain the disagreement between our results and those of Soback et al. (1990) who showed that the systemic dry cow therapy by norfloxacin is more effective than the locally, fully inserted cannula infusion at the time of drying off. Although the difference in the cure rates were not statistically significant during the dry period and also no significant difference could be found in new staphylococcal IMI at the freshening between the three groups, the prevalence of infection at calving was significantly higher in EN and TY groups compared with that of the DC group (P = 0.045). This was due to the cumulative effects of the slightly higher cure rate and slightly lower rate of new infections in the DC group. In conclusion our study showed that local dry cow therapy (using partially inserted cannulas) is still the most effective method.
Acknowledgement We are indebted to the research secretariate of the Tehran University without whose help this work could not have taken place. We also thank Sepahan Dairy Farm Managers and personnel for their cooperation. Finally, we thank the executive managers of Bayer and Cot-pa companies for contributing the drugs used in this study.
References Amstutz, H.E., 1980. Bovine Medicine and Surgery. 2nd edn., Am. Vet. Publ. Inc., pp. 1049-1086. Blood, D.C., Radostits, O.M. and Henderson, J.A., 1983. Veterinary Medicine. 6th edn., Bailliere Tindall/W.B. Saunders, London, pp. 451-492. Boddie, R.L. and Nickerson, SC., 1986. Dry cow therapy: effect of method of drug administration on occurrence of intramammary infection. J. Dairy Sci., 69: 253-257.
M. Bolourchi et al. /Preventive
Veterinary Medicine 25 (1995) 63-67
67
Carter, G.R. and Cole, J.R., 1990. Diagnostic Procedures in Veterinary Bacteriology and Mycology. 5th edn., Academic Press, 620 pp. Faull, W.B., Hughes, I.W. and Ward, W.R., 1991. A Mastitis Handbook for the Dairy Practitioner. 5th edn., Liveqpool University Press, Liverpool, pp. 17-23. National Mastitis Council, 1987. Laboratory and Field Handbook of Bovine Mastitis. Hoard, W.D. Hoards and Sons (Co., USA, 7 pp. Nickerson, S.C., 1990. Mastitis and its Control in Heifers Dry Cow. Int. Symp. Bovine Mastitis, 13-16 September 1990, Indianapolis, National Mastitis Council and American Association of Bovine Practitioners, pp. 82-91. Soback, S., Ziv, G., Wikler, M. and Saran, A., 1990. Systemic dry cow therapy-a preliminary report. J. Dairy Sci., 73: 661-666. Tyler, J.W., Wilson, C.R. and Dowling, P., 1992. Treatment of subclinical mastitis. Vet. Clinics of North Am. Food Anim. Pratt., 8( 1): 17-28. Vestweber, J.G., 1994. Staphylococcusaureus mastitis. Part II. Diagnostic aids, therapy, and control, compendium. Cont. Ed. Vet. Med. Pratt., 16(2): 217-222. Ziv, G., 1993. Treatment of peracute and acute mastitis. Vet. Clinics of N. Am. Food Anim. Pratt., 8( 1): 1-15.