Microclima do canal auditivo de cães e efeito do Rosmarinus officinalis L. e do Triticum vulgare no tratamento da otite externa experimental

• Ano de defesa: 2011
• Autor(a) principal: Mueller, Eduardo Negri
• Orientador(a): Nobre, Márcia de Oliveira
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Pelotas
• Programa de Pós-Graduação: Programa de Pós-Graduação em Veterinária
• Departamento: Veterinária
• País: BR
• Palavras-chave em Português: Óleo essencial; pH auditivo; Cães; Termometria; Extrato aquoso
• Palavras-chave em Inglês: Essential oil; Auditory pH; Dogs; Thermometry; Aqueous extract
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA
• Link de acesso: https://guaiaca.ufpel.edu.br/handle/123456789/2578

The aim of this study was to evaluate the microenvironment of the ear canal of dogs and determine the effect of Rosmarinus officinalis L. (rosemary) and Triticum vulgare (wheat) in healthy ears and in the treatment of experimental noninfectious external otitis of Wistar rats. For analysis of the microenvironment of the ear canal 141 healthy dogs were used, 30 to evaluate the ear canal pH and 111 to measure the ear temperature. Dog ears with absent to mild, moderate or intense cerumen were studied, and the auditory canal was washed for pH measurements. The rectal temperature (TR) was measured with a mercury thermometer and the ear temperature with an infrared thermometer. The difference between TR and TAM (average ear temperature), was classified in the following scores: A=TAM<TR until 1.2°C and B=TAM<TR more than 1.2°C, and these results were related to ear type. For the evaluation of the effects of plant extracts in the experimental external otitis in Wistar rats an inoculation of 80μL of croton oil 5% in acetone was performed and in 24 hours the clinical score of the ears was evaluated. The animals were divided in 5 groups and the topic treatment was realized for up to seven days with rosemary aqueous extract 25% in propylene glycol (Group I), rosemary essential oil 25% (Group II), wheat aqueous extract 0.2% in propylene glycol (Group III), propylene glycol (Group IV) and NaCl 0.9% (Group V). At days four (4d), six (6d) and ten (10d), the ears of four animals were clinically evaluated and the animals were euthanized for hystopathological evaluation. For the evaluation of the effects of plant extracts on the healthy ear 48 Wistar rats were distributed in five groups according previously described and classified for clinical score. In the analysis of the microenvironment of the ear canal the pH values ranged from 5.0 to 8.0 and there was a negative correlation between cerumen quantity and pH (p=0.0271). The ear type did not affect the TAM and predominated ears score B regardless of the type. In the evaluation of the treatment for experimental otitis groups I, II and V had an increase in clinical score until the fourth day then decreased gradually. Groups III and IV had the scores lower tha day 0 for almost all experimental period. Group III showed a progressive decrease; group II showed the highest score at days four and six and the group V at day ten. There was hyperplasia in all groups at the end of the experiment, and in groups II and IV it was more frequent. All groups had otitis with predominantly histiocytic infiltrate at the beginning, although at 10 days with a suppurative infiltration in groups II, III and V. In healthy ears at four days, all groups showed an increase of clinical scores, which was higher in groups I (2.6), II (3.6) and III (2.4), but only the essential oil of rosemary 25% in propylene glycol was topically irritant. There was a progressive decrease of the scores in groups I, II and III starting at day four and at day 10 the highest score was observed in groups I (2.0) and II (2.0). It is concluded that the pH of the ear canal of dogs is neutral and can acidify with increased amount of cerumen; the average ear temperature is lower than the rectal temperature by 1.53°C±0.75 and the conformation of the ear does not influence the average ear temperature; aqueous extract of Rosmarinus officinalis L. 25% and aqueous extract of Triticum vulgare 0.2% reduced the clinical scores, while the essential oil of Rosmarinus officinalis L. 25% is not effective in noninfectious otitis externa in Wistar rats and the aqueous extract of Rosmarinus officinalis L. 25% and the aqueous extract of Triticum vulgare 0.2% are non-irritating topics, while the essential oil of Rosmarinus officinalis L. 25% irritates the auditory epithelium.