PESQUISA VETERINÁRIA BRASILEIRA

Abstract in English:

ABSTRACT.- Coneglian M.M., Flaiban K.K.M.C. & Lisbôa J.A.N. 2014. [Non-parturient hypocalcaemia in lactating dairy cows grazing in oat and perennial ryegrass pasture: study of predisposing factors.] Hipocalcemia não puerperal em vacas leiteiras sob pastejo de aveia e azevém: estudo de fatores predisponentes. Pesquisa Veterinária Brasileira 34(1):15-23. Departamento de Clínicas Veterinárias, Centro de Ciências Agrárias, Universidade Estadual de Londrina, Campus Universitário, Cx. Postal 10011, Londrina, PR 86057-970, Brazil. E-mail: janlisboa@uel.br Non-parturient hypocalcaemia (NPH) is a rare and poor understood condition. There are no studies that explain its relationship with winter pasture intake. The aim of this study was to describe clinical aspects of two natural cases of NPH, and to study the mineral and electrolyte balance of high and medium producing dairy cows feeded with winter pasture in different growing stages. Two cases of NPH in lactating dairy cows, grazing in oat grass and perennial ryegrass in Francisco Beltrão, PR, Brazil, were described. Healthy lactating high producing Holstein cows (n=11) and medium producing Holstein (n=8) and Jersey (n=9) cows were selected from three farms located in the same municipality. They were maintained in a mixing pasture of oats and perennial ryegrass from June to October, and supplemented with corn silage. Blood, urine and ingested food samples were collected before treatment started (May), and during initial (June), intermediate (July) and final stages (September) of the grass maturation cycle. Serum and urinary concentrations of Ca, P, Mg, Na+, K+, Cl- and creatinine were determined, and their fractional excretion were calculated. Dry matter and Ca, P, Mg, Na, K, Cl and S concentrations were determined in food samples, and the dietary cation-anion difference was calculated. Based on clinical evidence we can assure that lactating dairy cows maintained in oat and perennial ryegrass pastures during the winter months can develop hypocalcaemia, showing signs and responding to treatment similar to classic puerperal hypocalcaemia, even in non-parturient period. Partial substitution of corn silage to oat and perennial ryegrass pasture did not cause electrolyte imbalances and did not interfere with the calcemia, phosphatemia or magnesemia of high and medium producing lactating dairy cows. Using winter forage as the only or main source of roughage in the diet can be the triggering factor for the disease, which can be related to excessive cation intake due to increased K concentration, especially during early stages of pasture growing.

• Hyocalcemia calcium metabolism Avena sativa Lolium multiflorum hipocalcemia metabolismo de cálcio

Abstract in Portuguese:

RESUMO.- Coneglian M.M., Flaiban K.K.M.C. & Lisbôa J.A.N. 2014. [Non-parturient hypocalcaemia in lactating dairy cows grazing in oat and perennial ryegrass pasture: study of predisposing factors.] Hipocalcemia não puerperal em vacas leiteiras sob pastejo de aveia e azevém: estudo de fatores predisponentes. Pesquisa Veterinária Brasileira 34(1):15-23. Departamento de Clínicas Veterinárias, Centro de Ciências Agrárias, Universidade Estadual de Londrina, Campus Universitário, Cx. Postal 10011, Londrina, PR 86057-970, Brazil. E-mail: janlisboa@uel.br A Hipocalcemia Não Puerperal (HNP) é uma condição rara e pouco compreendida. Não há estudos que expliquem a sua relação com a ingestão de pastagens de inverno como base da alimentação volumosa. Os objetivos deste trabalho foram descrever aspectos clínicos de dois casos naturais de HNP, e estudar o balanço mineral e eletrolítico de vacas leiteiras de alta e de média produção alimentadas em pastagem de inverno em diferentes estágios de evolução. Foram acompanhados dois casos de HNP em vacas leiteiras, mantidas em pastagens de aveia ou de azevém no município de Francisco Beltrão, PR. De três propriedades localizadas no mesmo município, foram selecionadas vacas lactantes hígidas de alta produção da raça Holandesa (n=11) e de média produção das raças Holandesa (n=8) e Jersey (n=9), mantidas em pastagem mista de aveia e azevém, de junho a outubro de 2011, e complementadas com silagem de milho. Amostras de sangue, de urina e dos alimentos ingeridos foram colhidas antes do ingresso na pastagem (maio), e nos estágios inicial (junho), intermediário (julho) e final (setembro) do ciclo de maturação da forragem. Foram determinadas as concentrações séricas e urinárias de Ca, P, Mg, Na+, K+, Cl- e creatinina e calculada as excreções fracionadas. Nas amostras de alimento foram determinadas a matéria seca (MS) e as concentrações de Ca, P, Mg, Na, K, Cl e S, e calculou-se a diferença entre cátions e ânions da dieta (DCAD) nos diferentes momentos. Com base nas evidências pode-se afirmar que vacas leiteiras em lactação mantidas em pastagem de aveia e/ou de azevém nos meses de inverno podem desenvolver hipocalcemia e exibir sinais clínicos e resposta ao tratamento similares aos da hipocalcemia puerperal clássica, mesmo não sendo recém paridas. A ingestão de aveia e azevém, substituindo parcialmente a silagem de milho como volumoso da dieta, não provoca desequilíbrio eletrolítico e não interfere com a calcemia, a fosfatemia ou a magnesemia de vacas lactantes de alta e de média produção. A utilização das forrageiras de inverno como a única ou principal fonte de volumoso da dieta parece ser o fator desencadeante da doença e pode estar relacionada com o excesso de cátions ingeridos devido à elevada concentração de K, principalmente, quando a planta é jovem.

Abstract in English:

ABSTRACT.- Lemos G.C., Costa R.M., Neto M.G. & Malafaia P. 2013. [Weight gain of Nelore cattle supplemented with different phosphorus sources.] Desempenho ponderal de bovinos Nelore suplementados com fontes alternativas de fósforo. Pesquisa Veterinária Brasileira 33(2):188-192. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23851-970, Brazil. E-mail: malafaia_ufrrj@yahoo.com.br Weight gain and possible interference of fluoride on animal health was investigated in Nellore cattle supplemented during 866 days with alternative sources of phosphorus with different phosphorus:fluor (P:F) ratios. The five treatments were: (1) Negative control (NC, without any supplemental P), (2) dicalcium phosphate (DCP 120:1, DCP 30:1 and DCP 10:1), (3) monodicalcium phosphate (MDCP 60:1), (4) triple superphosphate (TSF 30:1), and (5) cajati rock phosphate (RP 10:1). We used 49 oxen weaned with 8 months of age and an average weight of 230 kg, distributed into seven paddocks with water and mineral mixture formulated without P. A standard diet consisting of sugar cane bagasse (0.03% P) as roughage and a concentrate containing 0.239% P was provided on 1% of live weight to allow a weight gain of about 0.50 kg/day. Until day 134, there was no statistical difference between the various groups, including the treatment NC which received no supplemental phosphorus in the diet and gained weight of 71.6 kg or 0.633 kg/day. After 866 days of confinement (2.37 years), the oxen supplemented with dicalcium phosphate standard (120:1) gained less weight than those supplemented with sources MDCP 60:1, DCP 30:1 and TSF 30:1. Up to one year of supplementation with dicalcium phosphate artificially fluoridated with NaF or with rock phosphate did not result in damage to health or in weight gain of the animals. Analyses of phosphorus in bones showed statistical difference between treatments, and group NC that did not receive any supplemental P showed the lowest values. The concentration of fluoride in bones proved to be closely related to the amount of fluoride available in the sources used. As the ratio P:F in the diet decreased, characteristic signs related to dental fluorosis became more evident, and the animals that received P supplies with 10:1 ratio showed at the end of the experiment permanent malformed incisor teeth, brittle and whitish stained.

• Fluorosis dicalcium phosphate rock phosphate superphosphate phosphoric supplementation fluorose fosfato bicálcico fosfato de rocha superfosfato triplo suplementação fosfórica

Abstract in Portuguese:

RESUMO.- Lemos G.C., Costa R.M., Neto M.G. & Malafaia P. 2013. [Weight gain of Nelore cattle supplemented with different phosphorus sources.] Desempenho ponderal de bovinos Nelore suplementados com fontes alternativas de fósforo. Pesquisa Veterinária Brasileira 33(2):188-192. Departamento de Nutrição Animal e Pastagem, Instituto de Zootecnia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ 23851-970, Brazil. E-mail: malafaia_ufrrj@yahoo.com.br O desempenho produtivo e a possível interferência do flúor sobre a saúde dos animais foram investigados em bovinos Nelore suplementados, por 866 dias, com distintas fontes alternativas de fósforo com diferentes relações fósforo:fluor (P:F). Os tratamentos experimentais foram: Controle negativo (CONTNEG, sem qualquer suplementação com P), fosfato bicálcico (FB 120:1, FB 30:1 e FB 10:1), fosfato monobicálcico (FMBC 60:1), superfosfato triplo (SFT 30:1) e fosfato de rocha de Cajati (FR 10:1). Foram utilizados 49 novilhos, desmamados aos oito meses de idade, castrados e com 230 kg de peso médio, distribuídos em sete piquetes com água e mistura mineral formulada sem P. A dieta padrão foi feita com bagaço de cana (0,03% de P) como volumoso e um concentrado contendo 0,239 % de P oferecido na base de 1% do peso dos animais para permitir um ganho de peso aproximado de 0,50 kg/dia. Até o dia 134, não houve diferença estatística entre os diversos lotes, inclusive para o tratamento CONTNEG, que não recebeu fósforo suplementar na dieta e ganhou 71,6 kg de peso ou 0,633 kg/dia. Após 866 dias de confinamento (2,37 anos), os animais suplementados com o fosfato bicálcico padrão (120:1) ganharam menos peso que os suplementados com as fontes FMCB 60:1, FB 30:1 e SFT 30:1. Até um ano de suplementação fosfórica com fosfato bicálcico padrão (120:1) artificialmente fluoretado com NaF ou com o fosfato de rocha não se detectou danos à saúde ou ao ganho de peso dos animais. As análises de fósforo nos ossos mostraram diferença estatística apenas entre o tratamento CONTNEG e os que tinham fosfato bicálcico. As concentrações de flúor nos ossos se mostraram intimamente associadas à quantidade de flúor disponível nas fontes utilizadas. Conforme a proporção P:F na dieta foi diminuindo, características relacionadas à fluorose dentária ficaram mais evidentes, sendo que os animais que receberam fontes com relação 10:1, apresentaram, ao final do experimento, dentes incisivos permanentes mal formados, quebradiços e com manchas esbranquiçadas.

Abstract in English:

ABSTRACT.- Martínez P.P. & Carvalho M.B. 2010. [Participation of renal excretion of calcium, phosphorus, sodium and potassium on the homeostasis in healthy dogs and in dogs with chronic kidney disease.] Participação da excreção renal de cálcio, fósforo, sódio e potássio na homeostase em cães sadios e cães com doença renal crônica. Pesquisa Veterinária Brasileira 30(10):868-876. Departamento de Medicina Veterinária, Área de Clínica Médica de Pequenos Animais, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP 14870-000, Brazil. E-mail: pedromartinezpadua@hotmail.com In chronic kidney disease (CKD), the first problem to be solved by the organism is to maintain water and sodium homeostasis and, with the worsening of the renal injuries, other severe problems related to the calcium and phosphorus homeostasis emerge. The present study has the purpose to evaluate the renal excretion and serum profile of calcium, phosphorus, sodium and potassium in healthy dogs and in dogs with naturally acquired CKD. Three groups of adult male and female dogs of varied breeds were evaluated. Normal dogs were in the control group (G1) and the CKD dogs were distributed into two groups in accordance with the stage of renal function impairment (G2 e G3, respectively, stages 1-2 and stages 3-4, proposed by IRIS 2006 staging CKD). The G3 dogs showed increased serum levels of ionized calcium and phosphorus, in addition to the reduction of sodium levels. Regarding the renal excretion of the analyzed electrolytes, the G1 and G2 groups showed a decrease of filtered load and increase of fractional excretion, yet there were no significant variations on the urinary excretions. The results suggest that the kidneys of the CKD dogs can maintain similar values of electrolytes urinary excretion as the kidneys of normal dogs. The mechanism involves an increase of fractional excretion while glomerular filtration decreases. This compensation process, however, can lose its efficiency in the later stages of the disease, in relation to the maintenance of phosphorus and sodium serum levels.

• Renal disease electrolytes doença renal eletrólitos

Abstract in Portuguese:

RESUMO.- Martínez P.P. & Carvalho M.B. 2010. [Participation of renal excretion of calcium, phosphorus, sodium and potassium on the homeostasis in healthy dogs and in dogs with chronic kidney disease.] Participação da excreção renal de cálcio, fósforo, sódio e potássio na homeostase em cães sadios e cães com doença renal crônica. Pesquisa Veterinária Brasileira 30(10):868-876. Departamento de Medicina Veterinária, Área de Clínica Médica de Pequenos Animais, Faculdade de Ciências Agrárias e Veterinárias, Universidade Estadual Paulista, Jaboticabal, SP 14870-000, Brazil. E-mail: pedromartinezpadua@hotmail.com Na doença renal crônica (DRC) a manutenção da homeostase de água e sódio é o primeiro problema a ser contornado pelo organismo e com o agravamento das lesões renais surgem outros problemas graves relacionados à homeostase de cálcio e fósforo. O presente estudo tem por escopo avaliar a excreção renal de cálcio, fósforo, sódio e potássio, e o perfil sérico destes eletrólitos em cães normais e em cães com DRC naturalmente adquirida. Foram avaliados três grupos de cães adultos, machos ou fêmeas, de raças variadas. Animais normais compuseram o grupo controle (G1) e os cães com DRC foram distribuídos em dois grupos de acordo com os estágios de comprometimento da função renal (G2 e G3, respectivamente, estágios 1-2 e estágios 3-4, descritos pela IRIS 2006 staging CKD). Os cães do G3 apresentaram aumento das concentrações séricas de cálcio ionizado e fósforo, além de diminuição da concentração sérica de sódio. Quanto à excreção renal dos eletrólitos analisados, os animais dos grupos G1 e G2 apresentaram diminuição de carga filtrada e aumento de excreção fracionada, mas as excreções urinárias não variaram significativamente. Os resultados são indicativos de que os rins de cães com DRC podem manter a excreção urinária dos eletrólitos em valores semelhantes aos dos normais. O mecanismo envolve aumento da excreção fracionada na medida em que haja diminuição da filtração glomerular. Esse processo de compensação, entretanto, pode perder a eficiência nos estágios mais avançados da enfermidade no que se refere à manutenção das concentrações séricas de fósforo e sódio.

Abstract in English:

ABSTRACT.- Riet-Correa F., Simões S.D.V. & Vasconcelos J.S. 2008. [Urolithiasis in sheep and goats.] Urolitíase em ovinos e caprinos. Pesquisa Veterinária Brasileira 28(6):319-322. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Urolithiasis is a common disease in the Brazilian semiarid in rams and bucks fed with grains, mainly with low C:P ratio. From 28 rams with urolithiasis sent to the Veterinary Hospital of the Federal University of Campina Grande, Paraíba, 19 died and 9 survived, and from the bucks, 13 died and 3 survived At necropsy the main lesions were presence of calculi in the urethra and urinary bladder, diffuse purulent urethritis, hemorrhagic necrotizing urethritis, rupture of the urethra with presence of urine in the subcutaneous tissue, hydronephrosis, urinary bladder rupture, necrotizing diffuse nephritis, pyelonephritis, renal hemorrhage, and renal rupture. The severity of the lesions is responsible for the high case fatality rate despite medical and chirurgic treatment. The most important preventive measure is the correction of the Ca:P ratio to at least 2:1. The administration of good quality roughage in the food is also necessary. In cases in which the amount of concentrate food is higher than 1.5% live weight, the addition of 1% ammonium chloride and 0.5-4% of sodium chloride in the diet could be also necessary. Water had to be offered ad libitum. It is necessary to abolish the use of ad libitum mineral supplementation in sheep and goats fed grains or their byproducts.

• Urolithiasis grain feeding phosphorous phosphorus:calcium rate

Abstract in Portuguese:

ABSTRACT.- Riet-Correa F., Simões S.D.V. & Vasconcelos J.S. 2008. [Urolithiasis in sheep and goats.] Urolitíase em ovinos e caprinos. Pesquisa Veterinária Brasileira 28(6):319-322. Hospital Veterinário, CSTR, Universidade Federal de Campina Grande, Patos, PB 58700-000, Brazil. E-mail: franklin.riet@pq.cnpq.br Urolithiasis is a common disease in the Brazilian semiarid in rams and bucks fed with grains, mainly with low C:P ratio. From 28 rams with urolithiasis sent to the Veterinary Hospital of the Federal University of Campina Grande, Paraíba, 19 died and 9 survived, and from the bucks, 13 died and 3 survived At necropsy the main lesions were presence of calculi in the urethra and urinary bladder, diffuse purulent urethritis, hemorrhagic necrotizing urethritis, rupture of the urethra with presence of urine in the subcutaneous tissue, hydronephrosis, urinary bladder rupture, necrotizing diffuse nephritis, pyelonephritis, renal hemorrhage, and renal rupture. The severity of the lesions is responsible for the high case fatality rate despite medical and chirurgic treatment. The most important preventive measure is the correction of the Ca:P ratio to at least 2:1. The administration of good quality roughage in the food is also necessary. In cases in which the amount of concentrate food is higher than 1.5% live weight, the addition of 1% ammonium chloride and 0.5-4% of sodium chloride in the diet could be also necessary. Water had to be offered ad libitum. It is necessary to abolish the use of ad libitum mineral supplementation in sheep and goats fed grains or their byproducts.

Abstract in English:

ABSTRACT.- Domingues-F. L.M. & Gioso M.A. 2007. [Comparison of the application of temporary endodontic dressing in teeth of dogs: histopathological and microbiological aspects.] Comparação entre sessão única e a utilização do “curativo de demora” no tratamento endodôntico em cães: aspectos histopatológicos e microbiológicos. Pesquisa Veterinária Brasileira 27(5):191-193. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Bloco 8, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br During a root canal therapy the microbiota is the major concern. Bacteria present in dentinal tubules, apical foramens and apical delta is related to failure of this procedure. Some studies reveal that during endodontic treatment in one session bacteria still remain in dental structures. The aim of the present study was to evaluate the endodontic treatment in one or two sessions, using calcium hydroxide plus camphorated paramonochlorophenol (CMCP) with temporary endodontic medicaments. Four dogs were used, and two animals were submitted the treatment in one session only and the others in two sessions. Premolar teeth were used in this study: second and third upper premolar teeth and second, third and fourth lower premolar teeth were divided into two groups. Opening of the pulp chamber was performed with burns, and the pulp was exposed for 60 days. After this period the group treated in only session was obtured with gutta-percha and zinc oxide and eugenol, and the group treated in two sessions received the CMCP that remained in the canal per 30 days and was afterwards obtured with the material of the other group. Clinical and radiographical control was performed twice a week, and after 60 days a small block containing the teeth, surrounding periapical tissues and the periodontium was removed for histological and microbiological study. Histological analysis revealed intense inflammatory response in both groups. Microbiological analysis showed a more severe microbial reduction in the group treated in one session. However, bacteria were still observed in the two groups, indicating that none of the treatments presented total efficiency.

• Apical delta endodontics gutta-percha calcium hydroxide dog camphorate paramonochlorophenol

Abstract in Portuguese:

ABSTRACT.- Domingues-F. L.M. & Gioso M.A. 2007. [Comparison of the application of temporary endodontic dressing in teeth of dogs: histopathological and microbiological aspects.] Comparação entre sessão única e a utilização do “curativo de demora” no tratamento endodôntico em cães: aspectos histopatológicos e microbiológicos. Pesquisa Veterinária Brasileira 27(5):191-193. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando Marques de Paiva 87, Bloco 8, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br During a root canal therapy the microbiota is the major concern. Bacteria present in dentinal tubules, apical foramens and apical delta is related to failure of this procedure. Some studies reveal that during endodontic treatment in one session bacteria still remain in dental structures. The aim of the present study was to evaluate the endodontic treatment in one or two sessions, using calcium hydroxide plus camphorated paramonochlorophenol (CMCP) with temporary endodontic medicaments. Four dogs were used, and two animals were submitted the treatment in one session only and the others in two sessions. Premolar teeth were used in this study: second and third upper premolar teeth and second, third and fourth lower premolar teeth were divided into two groups. Opening of the pulp chamber was performed with burns, and the pulp was exposed for 60 days. After this period the group treated in only session was obtured with gutta-percha and zinc oxide and eugenol, and the group treated in two sessions received the CMCP that remained in the canal per 30 days and was afterwards obtured with the material of the other group. Clinical and radiographical control was performed twice a week, and after 60 days a small block containing the teeth, surrounding periapical tissues and the periodontium was removed for histological and microbiological study. Histological analysis revealed intense inflammatory response in both groups. Microbiological analysis showed a more severe microbial reduction in the group treated in one session. However, bacteria were still observed in the two groups, indicating that none of the treatments presented total efficiency.

Abstract in English:

ABSTRACT.- Domingues-F. L.M., Gioso M.A. & Padilha Filho J.G. 2007. Histopathological and histomicrobiological study of root canal therapy medication, comparison of calcium hydroxide versus gutta-percha with zinc oxide/eugenol in the teeth of dogs. Pesquisa Veterinária Brasileira 27(2):71-74. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br The presence of microorganisms in dental structures with experimentally induced necrosis was evaluated. The materials were tested to evaluate their antimicrobial activity and tissue repair efficacy. Four dogs were used in this experiment, with a total of 64 roots of premolar teeth, divided into three groups. The root canals of Group I were filled with gutta-percha and zinc oxide/eugenol cement; Group II were filled with calcium hydroxide, and Group III were not filled. All animals were clinically and radiographically examined 15 days after surgery and then again every subsequent 15 days until 120 days, when the teeth were extracted en bloc. Histopathological analysis showed inflammatory infiltration, cement and bone resorption and necrotic tissue in the apical delta in different proportions. Histomicrobiological analysis showed the presence of microorganisms inside the teeth structures, with different concentrations according to the treatment used. There was statistical significance between the groups (p>0.05). Gutta-percha with zinc oxide/eugenol demonstrated good antimicrobial activity; calcium hydroxide was not efficient. The conclusion of this study is that gutta-percha with zinc oxide/eugenol is the better protocol for filling root canals in dogs.

• Apical delta endodontic gutta-percha calcium hidroxide microorganisms dogs

Abstract in Portuguese:

ABSTRACT.- Domingues-F. L.M., Gioso M.A. & Padilha Filho J.G. 2007. Histopathological and histomicrobiological study of root canal therapy medication, comparison of calcium hydroxide versus gutta-percha with zinc oxide/eugenol in the teeth of dogs. Pesquisa Veterinária Brasileira 27(2):71-74. Departamento de Cirurgia da Faculdade de Medicina Veterinária e Zootecnia, Universidade de São Paulo, Av. Prof. Dr. Orlando de Marques de Paiva 87, Bloco 8-superior, Cidade Universitária, São Paulo, SP 05508-000, Brazil. E-mail: lesliedf@usp.br The presence of microorganisms in dental structures with experimentally induced necrosis was evaluated. The materials were tested to evaluate their antimicrobial activity and tissue repair efficacy. Four dogs were used in this experiment, with a total of 64 roots of premolar teeth, divided into three groups. The root canals of Group I were filled with gutta-percha and zinc oxide/eugenol cement; Group II were filled with calcium hydroxide, and Group III were not filled. All animals were clinically and radiographically examined 15 days after surgery and then again every subsequent 15 days until 120 days, when the teeth were extracted en bloc. Histopathological analysis showed inflammatory infiltration, cement and bone resorption and necrotic tissue in the apical delta in different proportions. Histomicrobiological analysis showed the presence of microorganisms inside the teeth structures, with different concentrations according to the treatment used. There was statistical significance between the groups (p>0.05). Gutta-percha with zinc oxide/eugenol demonstrated good antimicrobial activity; calcium hydroxide was not efficient. The conclusion of this study is that gutta-percha with zinc oxide/eugenol is the better protocol for filling root canals in dogs.