Therapy of Canine Deep Pyoderma with Cephalexins and Immunomodulators

Š p r u č e k F. , M . S v o b o d a , M . To m a n , M , F a l d y n a F. Š p r u č e k J r : Therapy of Canine Deep Pyoderma with Cephalexins and Immunomodulators. Acta Vet. Brno 2007, 76: 469-474. Pyodermas are among bacterial skin diseases often resisting antibiotic therapy. We therefore examined how the dogs with deep pyoderma (n = 29) respond to therapeutic effect of antibiotic cephalexins (Ceporex, 30 mg·kg-1 p.o., once a day for 9 – 11 weeks) combined with immunomodulators (Baypamune®, once a week i.m. pro toto). The dogs with the fi rst occurrence of pyoderma (n = 11) were treated by antibiotics alone, whereas the dogs with recurrent pyoderma (n = 18) were treated by either antibiotics alone (n = 8) or antibiotics combined with Baypamune® (n = 10). Of 11 dogs with the fi rst occurrence of disease, 8 (73%) were successfully cured. However, only 5 of them (45%) stayed recovered after a period of two months that elapsed from the completion of therapy. Of the 8 dogs with recurrent pyoderma treated by antibiotics only, 6 (75%) recovered quickly but only 3 of them (38%) stayed healthy after 2 months elapsing from the therapy termination. Of the 10 dogs treated by antibiotics combined with immunomodulators, 8 (80%) regained health within a therapeutic period and 7 of them (70%) remained completely cured after 2 months from completion of therapy. The durations of treatment in dogs with the fi rst occurrence of pyoderma and those with recurrent pyoderma were 8.4 and 10.5 weeks, respectively, the difference begin signifi cant. Hair lenght and percentage of the skin area affected had no effect on the therapy duration. The disappearance of pruritus preceded the successful treatment. The results suggest that the joint treatment of deep pyodermas in dogs by antibiotics and immunomodulators may be superior to the purely antibiotic therapy, because of a stronger suppressive effect on the disease relapse. Cephalexin, Baypamune®, Staphylococcus intermedius, deep pyoderma Pyoderma represents a large group of canine skin diseases that are diffi cult to treat. These are mostly infl ammations of secondary nature linked to coagulase-positive Staphylococcus spp. Purulent skin infl ammation is not a defi nitive diagnosis, but only a clinical symptom, which masks the main (primary or secondary) cause of the disease; sometimes several factors can play a role in triggering the disease. A major problem consists in increased pruritus which prevents the skin from healing. Self-mutilation due to the pruritus causes other infective skin changes (Rybníček 1999; Chabanne et al. 2000; De Boer and Marsella 2001; Craig 2003). Suitable antibiotics may be selected based on experience and observation, especially in case of surface pyoderma after cytological examination of pus and positive bacterial cultivation from an intact pustule. Bacteriological testing and sensitivity to antibiotics must be carried out in case of deep pyoderma, recurrent pyoderma, or if the antibiotic therapy proves to be unsuccessful. Tests may be repeated during the therapy (Scott et al. 2001). Antibiotics with bacteriostatic effect are suitable for superfi cial pyoderma. Antibiotics with bactericide effect are the drug of choice for cases of recurrent deep pyoderma and for weakened individuals (Lloyd and Grant 1996). Recommended ACTA VET. BRNO 2007, 76: 469-474; doi:10.2754/avb200776030469 Address for correspondence: MVDr. František Špruček, Ph.D. Small Animal Clinic Tylova 3, 77900 Olomouc Czech Republic Phone:+ 420 585 226 008 Fax: +420 585 226 008 Email: sprucek@email.cz http://www.vfu.cz/acta-vet/actavet.htm doses for individual antibiotic groups according to individual authors are shown in Table 1. Cephalexin dosed at 15 30 mg·kg-1 p.o. q 12 – 24 h has a quick effect, and it also kills staphylococci located on mucosal membranes (Lloyd and Grant 1996). Dosing according to Mason and Kietzmann (1999) is Cefaseptin® 20 mg·kg-1 p. o.q 8 h, Rilexine® 15 mg·kg-1 p.o.q 24 h or 30 mg·kg-1 p.o.q 24 h; even this dose was clinically highly effective. Both medications have identical pharmacokinetic profi le, but we do not know their action mechanism in such different dosing. Cephalexin (Rilexin®) dosed at 15 mg·kg-1 p.o. q 12 h (Guaguere et al. 1998) had the success rate of 92% of cured dogs in 28 days compared to co-amoxiklav (Synulox®) dosed at 12.5 mg·kg-1 p. o. q 12 h, with 72% of cured in 35 days. Synulox® acts more slowly, it is given for a longer period of time and it is less effective (Guaguere et al. 1998). Post-antibiotic effect of cephalexin lasted for 3 h and 20 min (Bousquet et al. 1999). In the study dealing with pharmacokinetics of cephalexin after administration of Rilexin® in tabs dosed at 15 mg·kg-1 p.o. q 12 h and Cefaseptin® in coated tablets dosed at 25 mg·kg-1, quick absorption was observed. No signifi cant difference in the pharmacokinetics between both preparations was observed (Ehinger and Kietzmann 2002). 470 Table 1. Survey of orally administered antibiotics and sulfonamides in the treatment of deep pyoderma in dogs in recommended dosage according to individual authors. Administration period is 5 – 7 weeks (depending on clinical symptoms) 1sulfa. – sulfadiazine or sulfametoxazol2. When administered for a long period of time and high dosing it may cause hypothyroidism, KCS and bone marrow suppression Antibiotic/Sulfonamids Dose (mg·kg-1) Daily frequency Authors Amoxycilin 10-20 2 Lloyd and Grant 1996 Oxacilin 20 3 Lloyd and Grant 1996 Co-amoxiklav (Synulox®) 12.5 2-3 Lloyd and Grant 1996 Cephalexin (Ceporex®) 15-30 1-2 Lloyd and Grant 1996 Cephalexin 15 2 Guaguere et al.1998 Cephalexin (Rilexin®) 15 2 Mason and Kietzmann 1999 Cephalexin (Rilexin®) 30 1 Mason and Kietzmann 1999 Cefadroxil (Cafadrox®) 10 2 Mason and Kietzmann 1999 Enrofloxacin 5 1 Ihrke et al. 1999 Enrofloxacin 10-20 1 Hnilica and May 2004 Orbifloxacin 5 1 Ihrke et al.1999 Orbifloxacin 7,5 1 Hnilica and May 2004 Difloxacin 5 1 Ihrke et al. 1999 Marbofloxacin 2 1 Ihrke et al. 1999 Marbofloxacin 5 1 Hnilica and May 2004 Erytromycin 10-20 3 Hnilica and May 2004 Linkomycin 15-33 2–3 Hnilica and May 2004 Tylosin 20 2 Hnilica and May 2004 Clindamycin 10 2 Hnilica and May 2004 Rifampicin 5-10 1 Hnilica and May 2004 Ormetoprim + sulfa1 27.5 2 Hnilica and May 2004 Trimethoprim + sulfa2 15-30 1-2 Hnilica and May 2004 Baquiloprim + sulfa 30 1 in 2 days Hnilica and May 2004 Materials and Methods Twenty nine dogs of various breeds were included in the therapy of deep pyoderma study group (Labrador Retriever, English Bulldog, Golden Retriever, Shar-pei, Bernese Mountain Dog, etc.), the average age of dogs was 6 years (from 2 to 10 years) and sex representation was 13 females and 16 males. Dogs with deep pyoderma (n = 29) formed a group (n = 18) with idiopathic recurrent deep pyoderma (they were previously treated with antibiotics, antibiotics combined with glucocorticoids, and glucocorticoids); while another group consisted of dogs (n = 11) with the fi rst episode of deep pyoderma, that were never treated before. According to the therapy method, 29 dogs with deep pyoderma were divided into three groups. The fi rst group of dogs with recurrent deep pyoderma (n = 10) received cephalexin (Ceporex®) dosed at 30 mg·kg-1 p.o. q 24 h combined with Baypamune® i. m. pro toto, 1 × per week. The second group of dogs with recurrent deep pyoderma (n = 8) received cephalexin (Ceporex®) dosed at 30 mg·kg-1 p.o. q 24 h and the third group of dogs (n = 11) with the fi rst episode of deep pyoderma without previous treatment were also given cephalexin (Ceporex®) dosed at 30 mg·kg-1 p.o. q 24 h. The treatment length ranged between 9 11 weeks. Their health status was continuously monitored. The group of dogs with i. m. administration of Baypamune® was checked once per week, while other groups once per two weeks. In our study of 29 tested dogs with deep pyoderma, we bacteriologically examined (n = 10) randomly selected dogs. Statistical analysis Dogs with deep pyoderma were tested with t-test, amended with the test of equality of variances of compared selections. If the selection variances were not equal, the Welch’s analysis of variance was used as a signifi cance test. Percentage differences were tested with Wilcoxon’s non-parametric test. If the variances were unequal (heteroskedasticity), we again used the Welch’s modifi cation of variance analysis. The relation between two quantitative variables was analyzed using the linear regression method. We used the JMP program (SAS Institute Inc. 2005) for all statistical examinations.

Pyodermas are among bacterial skin diseases often resisting antibiotic therapy.We therefore examined how the dogs with deep pyoderma (n = 29) respond to therapeutic effect of antibiotic cephalexins (Ceporex ® , 30 mg•kg -1 p.o., once a day for 9 -11 weeks) combined with immunomodulators (Baypamune ® , once a week i.m. pro toto).The dogs with the fi rst occurrence of pyoderma (n = 11) were treated by antibiotics alone, whereas the dogs with recurrent pyoderma (n = 18) were treated by either antibiotics alone (n = 8) or antibiotics combined with Baypamune ® (n = 10).Of 11 dogs with the fi rst occurrence of disease, 8 (73%) were successfully cured.However, only 5 of them (45%) stayed recovered after a period of two months that elapsed from the completion of therapy.Of the 8 dogs with recurrent pyoderma treated by antibiotics only, 6 (75%) recovered quickly but only 3 of them (38%) stayed healthy after 2 months elapsing from the therapy termination.Of the 10 dogs treated by antibiotics combined with immunomodulators, 8 (80%) regained health within a therapeutic period and 7 of them (70%) remained completely cured after 2 months from completion of therapy.The durations of treatment in dogs with the fi rst occurrence of pyoderma and those with recurrent pyoderma were 8.4 and 10.5 weeks, respectively, the difference begin signifi cant.Hair lenght and percentage of the skin area affected had no effect on the therapy duration.The disappearance of pruritus preceded the successful treatment.The results suggest that the joint treatment of deep pyodermas in dogs by antibiotics and immunomodulators may be superior to the purely antibiotic therapy, because of a stronger suppressive effect on the disease relapse.

Cephalexin, Baypamune ® , Staphylococcus intermedius, deep pyoderma
Pyoderma represents a large group of canine skin diseases that are diffi cult to treat.These are mostly infl ammations of secondary nature linked to coagulase-positive Staphylococcus spp.Purulent skin infl ammation is not a defi nitive diagnosis, but only a clinical symptom, which masks the main (primary or secondary) cause of the disease; sometimes several factors can play a role in triggering the disease.A major problem consists in increased pruritus which prevents the skin from healing.Self-mutilation due to the pruritus causes other infective skin changes (Rybníček 1999;Chabanne et al. 2000;De Boer and Marsella 2001;Craig 2003).
Suitable antibiotics may be selected based on experience and observation, especially in case of surface pyoderma after cytological examination of pus and positive bacterial cultivation from an intact pustule.Bacteriological testing and sensitivity to antibiotics must be carried out in case of deep pyoderma, recurrent pyoderma, or if the antibiotic therapy proves to be unsuccessful.Tests may be repeated during the therapy (Scott et al. 2001).Antibiotics with bacteriostatic effect are suitable for superfi cial pyoderma.Antibiotics with bactericide effect are the drug of choice for cases of recurrent deep pyoderma and for weakened individuals (Lloyd and Grant 1996).Recommended doses for individual antibiotic groups according to individual authors are shown in Table 1.
Cephalexin dosed at 15 -30 mg•kg -1 p.o. q 12 -24 h has a quick effect, and it also kills staphylococci located on mucosal membranes (Lloyd and Grant 1996).Dosing according to Mason and Kietzmann (1999) is Cefaseptin ® 20 mg•kg -1 p. o.q 8 h, Rilexine ® 15 mg•kg -1 p.o.q 24 h or 30 mg•kg -1 p.o.q 24 h; even this dose was clinically highly effective.Both medications have identical pharmacokinetic profi le, but we do not know their action mechanism in such different dosing.Cephalexin (Rilexin ® ) dosed at 15 mg•kg -1 p.o. q 12 h (Guaguere et al. 1998) had the success rate of 92% of cured dogs in 28 days compared to co-amoxiklav (Synulox ® ) dosed at 12.5 mg•kg -1 p. o. q 12 h, with 72% of cured in 35 days.Synulox ® acts more slowly, it is given for a longer period of time and it is less effective (Guaguere et al. 1998).Post-antibiotic effect of cephalexin lasted for 3 h and 20 min (Bousquet et al. 1999).In the study dealing with pharmacokinetics of cephalexin after administration of Rilexin ® in tabs dosed at 15 mg•kg -1 p.o. q 12 h and Cefaseptin ® in coated tablets dosed at 25 mg•kg -1 , quick absorption was observed.No signifi cant difference in the pharmacokinetics between both preparations was observed (Ehinger and Kietzmann 2002).

Materials and Methods
Twenty nine dogs of various breeds were included in the therapy of deep pyoderma study group (Labrador Retriever, English Bulldog, Golden Retriever, Shar-pei, Bernese Mountain Dog, etc.), the average age of dogs was 6 years (from 2 to 10 years) and sex representation was 13 females and 16 males.Dogs with deep pyoderma (n = 29) formed a group (n = 18) with idiopathic recurrent deep pyoderma (they were previously treated with antibiotics, antibiotics combined with glucocorticoids, and glucocorticoids); while another group consisted of dogs (n = 11) with the fi rst episode of deep pyoderma, that were never treated before.According to the therapy method, 29 dogs with deep pyoderma were divided into three groups.The fi rst group of dogs with recurrent deep pyoderma (n = 10) received cephalexin (Ceporex ® ) dosed at 30 mg•kg -1 p.o. q 24 h combined with Baypamune ® i. m. pro toto, 1 × per week.The second group of dogs with recurrent deep pyoderma (n = 8) received cephalexin (Ceporex ® ) dosed at 30 mg•kg -1 p.o. q 24 h and the third group of dogs (n = 11) with the fi rst episode of deep pyoderma without previous treatment were also given cephalexin (Ceporex ® ) dosed at 30 mg•kg -1 p.o. q 24 h.The treatment length ranged between 9 -11 weeks.Their health status was continuously monitored.The group of dogs with i. m. administration of Baypamune ® was checked once per week, while other groups once per two weeks.In our study of 29 tested dogs with deep pyoderma, we bacteriologically examined (n = 10) randomly selected dogs.

Statistical analysis
Dogs with deep pyoderma were tested with t-test, amended with the test of equality of variances of compared selections.If the selection variances were not equal, the Welch's analysis of variance was used as a signifi cance test.Percentage differences were tested with Wilcoxon's non-parametric test.If the variances were unequal (heteroskedasticity), we again used the Welch's modifi cation of variance analysis.The relation between two quantitative variables was analyzed using the linear regression method.We used the JMP program (SAS Institute Inc. 2005) for all statistical examinations.

Results
From the total number of 29 dogs with deep pyoderma, 22 animals were cured at the end of therapy (76%), and after two months the success rate of the therapy decreased due to recurrence, to 15 patients (52%).In individual groups of dogs divided according to therapy, the situation was as follows: after two months from the end of therapy, there were relapses in three cases in the group of dogs (n = 11) with the fi rst episode of the disease and treated with antibiotics Cephalexin (Ceporex ® 30 mg•kg -1 p.o. q 24 h for 9 -11 weeks), so the relative number of cured dogs decreased from 73% to 45% (Fig. 1).
In the group of dogs (n = 8) with relapses, treated also with antibiotics cephalexin (Ceporex ® 30 mg•kg -1 p.o., 1 × per day for 9 -11 weeks) there were three recurrent cases, the relative number of cured dogs decreased from 75% to 38%.One relapse was recorded in the group of dogs (n = 10) with recurrent pyoderma treated with antibiotics combined with immunomodulators cephalexin (Ceporex ® dosed at 30 mg•kg -1 p.o. q 24 h in combination with Baypamune ® i. m. pro toto, 1 × per week), where the relative number of cured dogs decreased from 80% to 70% (Table 2).
The success rate of the therapy of dogs with recurrent deep pyoderma (n = 18), treated with antibiotics cephalexin (Ceporex ® 30 mg•kg -1 p.o. q 24 h) and antibiotics in combination with immunomodulators (Baypamune ® 1 × per week i. m.) increased by 56% compared to the previous treatment with antibiotics (Synulox ® 12.5 mg•kg -1 p.o. q 12 h) and glucocorticoids (Prednison 2 mg•kg -1 p.o. q 24 h).After the end of therapy, we had an 80% (i.e. 8 cured of 10 dogs) success rate in dogs (n = 10) treated with antibiotic in combination with immunomodulators, in contrast to the group of dogs treated with antibiotics only (n = 19), where the success rate of the therapy was 70% (i.e. 14 cured of 19 dogs).After two months, the success rate of the therapy in the group of dogs treated with antibiotics and immunomodulators decreased due to relapse to 70% (i.e. 7 of 10 dogs), and in dogs treated with antibiotics only there was a signifi cant decrease in the therapy success rate due to relapse to 41% (i.e. 8 cured of 19 dogs).
The average length of therapy with antibiotics and antibiotics in combination with immunomodulators was 9.6 weeks.Differences in the length of therapy between sexes were not found (t-test males 9.8 weeks, females 9.4 weeks, P = 0.51).Hair length and the percentage of affected skin surface had no effect on the length of treatment (P = 0.79), and neither did animal weight (P = 0.19).Dogs with recurrent deep pyoderma (n = 18) healed 14 days longer than the patients with the fi rst episode of the disease (n = 11), treated only with cephalexin.In dogs with relapse, the treatment period was 10.5 weeks and in dogs with the fi rst episode of the disease it was 8.4 weeks (P < 0.001).The period of pruritus resolution had a signifi cant predictive effect on the total length of treatment (Fig. 2).Earlier disappearance of pruritus indicated shorter treatment (P = 0.004).No signifi cant relation between age and length of treatment was established (P = 0.64).
In our study of 29 tested dogs with deep pyoderma, we randomly chose 10 dogs for bacteriological examination.In (n = 7) dogs we diagnosed Staphylococcus intermedius (70%), one E. coli, Streptococcus spp.and Actinomyces spp.

Discussion
Available studies on pharmacokinetics of cephalexin after oral administration (Rilexin ® dosed at 15 mg•kg -1 p.o. q 12 h in tablets and Cefaseptin ® in coated tablets in the dose of 25 mg•kg -1 ) observed rapid absorption in the affected tissue.and Kietzmann 2002).In our study, we used cephalexin in Ceporex ® 30 mg•kg -1 p.o. q 24 h for 9 -11 weeks (Guaguere et al. 1998).This dosage, compared to 15 mg•kg -1 p.o. q 12 h, reportedly has a similar therapeutic effect and administration of the preparation × 1 per day is more convenient for the animal owners.Baypamune ® activates NK (natural killer) cells, stimulates lymphocytic proliferation, and activates macrophages and production of interleukins and antiviral interferon.Baypamune ® is suitable for modulation of non-specifi c immunity reaction and to stimulate suppressed immunity after the end of administration of immunosuppressive doses of steroids (Winnicka et al. 2000).
In the clinical study dealing with dogs with deep pyoderma, Baypamune ® was administered simultaneously with antibiotics cephalexin (Ceporex ® ) in all cases of recurrent deep pyoderma that were previously treated with antibiotics and steroids.After the end of therapy, no signifi cant difference was observed in the success rate of treatment between the group treated with antibiotics and immunomodulators -80% (i.e. 8 of 10 dogs), and the group treated with antibiotics only -70% (i.e. 14 of 19 dogs).In dogs with deep pyoderma whose clinical status during treatment did not improve, the primary cause might have been an autoimmune disease.After two months, the success rate of therapy in the group of dogs treated with antibiotics and immunomodulators decreased due to relapse to 70% (i.e. 7 of 10 dogs) and in dogs treated only with antibiotics to 41% (i.e. 8 of 19 dogs).Signifi cant decreasing of the number of recurrent cases indicates a positive effect of immunomodulators on the long-term stabilization of immunity status, which may be partly responsible for the resulting clinical condition.Shorter treatment in dogs treated with antibiotics combined with immunomodulators, as quoted by Winiarzcyk et al. (1998) in his studies, was not observed.The success rate of the therapy in dogs with relapse treated with antibiotics and antibiotics in combination with immunomodulators increased by over 50% compared to the previous treatment with antibiotics and glucocorticoids, and in dogs with relapse that were treated with antibiotics and immunomodulators it was successful in over 70%.This result indicates a good choice of antibiotics (dosage and period of administration) and the effect of immunomodulator on clinical improvement.Dogs with recurrent deep pyoderma were treated 14 days longer than patients with the fi rst episode of deep pyoderma.There was a signifi cant decrease in the number of relapses in affected dogs that received Baypamune ® combined with cephalexin (Ceporex ® ).This combination and the effect of Baypamune ® confi rms the immunomodulation effect as it Fig. 2. Dependence between treatment period in weeks and the resolution of clinical symptoms of pruritus in dogs treated with deep pyoderma has been reported after intravenous administration of immunoglobulins, which suppress infl ammatory reaction mediated by the complement, activate counter-infl ammatory cytokines, affect the activity of endothelial cells, neutralize microbial toxins and decrease requirements for corticosteroids (Foster 2004).Due to diffi cult diagnostics of primary causes of deep pyoderma and inconsistent etiology, immunomodulation therapy in autoimmune diseases may cause (contrary to immunodefi ciencies) adverse effects with subsequent clinical worsening of the overall health condition, leading to relapse.

Fig. 1
Fig. 1. a) Relative values for cured dogs with deep pyoderma after the end of therapy b) Relative values for cured dogs in 2 months from the end of treatment, decreased due to relapse during the monitored period.Dogs treated for the fi rst time with ATB (n = 11), dogs with relapse treated with ATB (n = 8), dogs with relapse treated with ATB combined with immunomodulators (n = 10), dogs treated with deep pyoderma total (n = 29)

Table 1 .
Survey of orally administered antibiotics and sulfonamides in the treatment of deep pyoderma in dogs in recommended dosage according to individual authors.Administration period is 5 -7 weeks (depending on clinical symptoms) 1 sulfa.-sulfadiazine or sulfametoxazol 2 .When administered for a long period of time and high dosing it may cause hypothyroidism, KCS and bone marrow suppression

Table 2 .
(Ehinger and Kietzmann 2002)ative numbers of treated and cured dogs with deep pyoderma after the end of treatment and relapses after 2 months 1 cured / abs.-absolute numbers of cured dogs with deep pyoderma / from the total number of dogs in the group plasma was achieved in 1.5 h after administration(Ehinger and Kietzmann 2002).No visible difference in the pharmacokinetics of both preparations was determined (Ehinger