Izvorni znanstveni članak

Otitis externa in dogs – microbial pathogens and antimicrobial susceptibility

Tomislav Sukalić ; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Križevci, Hrvatska;
Ivica Pavljak ; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Križevci, Hrvatska;
Ana Končurat ; Hrvatski veterinarski institut – Veterinarski zavod Križevci, Križevci, Hrvatska;
Berislav Sivončik ; Veterinarska ambulanta Simba, Varaždin, Hrvatska

Sažetak

Inflammation of the external ear canal or otitis externa (OE) is common in dogs. Disease is of a multifactorial aetiology, and the most common primary causes are allergies, glandular disorders, epithelial disorders, tumours or polyps of the auditory canal, foreign bodies in the auditory canal and autoimmune diseases. Bacterial and yeast infections are secondary causes of inflammation in the OE, which occur due to the action of primary causes and factors that alter the microenvironment of the auditory canal. Predisposing factors may be obstruction of the auditory canal, excessive humidity, endocrinopathies or trauma. Inflammation will always be the result of a combination of the above-mentioned factors. The most common pathogens that complicate inflammation in dogs are staphylococci and streptococci among the Gram positive bacteria, and the genera Pseudomonas, Proteus and Escherichia among the Gram negative bacteria. In addition to the above-mentioned bacterial pathogens, Malassezia pachydermatis is frequest, and settles on the skin of the dog as an opportunist. In this study, we examined 44 swabs of the external ear canal of dogs with a pronounced clinical picture of inflammation. Of these samples, pathogenic bacteria and yeasts were identified in 25 cases or 56.81%. The most common pathogens
were Staphylococcus pseudintermedius (n=8 or 32%) and Malassezia pachydermatis (n=5, 20%), followed by coagulase-negative staphylococci (16%), streptococci (12%), Pseudomonas aeruginosa (8%), Bacillus spp. (8%) and Proteus mirabilis (4%). The susceptibility of isolates to antimicrobial drugs was determined by the disc diffusion method, and 14 commercially available antimicrobial drugs were tested. Bacterial isolates showed the highest susceptibility to amoxicillin with clavulanic acid (88.9%), gentamicin, enrofloxacin and cephalexin. The highest resistance of isolates was observed against ceftiofur (100%), cefovecin, neomycin and sulfamethoxazole with trimethoprim. Staphylococcus pseudintermedius strains showed 100% susceptibility to amoxicillin with clavulanic acid, unlike isolates of Gram negative bacteria which showed complete resistance to amoxicillin with clavulanic acid. In cases of infection with Pseudomonas aeruginosa and Proteus mirabilis, isolates showed full sensitivity only to gentamicin and complete resistance to other tested antimicrobials. The high percentage of negative results (43.18%) is likely the result of sampling after commenced or completed antimicrobial therapy.

Ključne riječi

dog; otitis externa; pathogens; antimicrobial susceptibility

Hrčak ID:

222678

URI

https://hrcak.srce.hr/222678

Datum izdavanja:

4.12.2017.

Podaci na drugim jezicima: hrvatski

Posjeta: 2.186 *