Digital archive of theses discussed at the University of Pisa


Thesis etd-10012012-181700

Thesis type
Tesi di laurea specialistica LC5
Thesis title
Parasitic otitis and dermatitis in dogs in Tuscany Otiti e dermatiti parassitarie nei cani della Toscana
Course of study
relatore Prof. Perrucci, Stefania
correlatore Prof. Corazza, Michele
  • Dermatitis
  • Otitis externa (OE)
  • parasites
  • dogs
Graduation session start date
Otitis externa (OE) and dermatitis are very common diseases in dogs. In a population of affected dogs we focused on parasitic dermatitis and OE with the aim to evaluate their frequency and the parasitic species more frequently involved. The main symptoms associated with each isolated parasite and the frequency of some predisposing factors (sex, age, breed and living situation), were also evaluated. In the period between March 2011 and September 2012, skin and wax samples were collected from 87 dogs including owned animals living in Pisa municipality or animals hosted in kennels located in Pisa and Florence districts. For sampling collection, skin scraping, scotch test, trichogram and ear swab methods were used. In order to find parasitic arthropods, skin scrapings were digested by NaOH 10% or just mixed with few drops of paraffin oil and then checked under the microscope (100 X- 400 X ), ear wax samples were mixed with paraffin oil or directly observed , while the scotch test and trichogram samples were directly observed under the microscope. To find Malassezia, smears of ear wax samples were stained with Diff-Quick and microscopically observed at 400 X and 1000X magnifications. All data was statistically analyzed. Overall, 54% of the dogs had dermatitis, 43% had otitis and 3% had both. Out of the cases of dermatitis 44% were diagnosed with Demodicosis and 38% with Sarcoptic mange. Out of the cases of OE 67.5% were diagnosed with Malassezia, 7.5% with Malassezia and Otodectes cynotis, 2.5% with Malassezia and Trombicula autumnalis, 2.5% with O. cynotis and 20% were negative for parasites. From statistical analysis, parasitic OE was more frequent in kenneled and crossbreed dogs (P<0.01), while purebred dogs were more likely to have a parasitic dermatitis (P<0.01). Age resulted an important predisposing factor in parasitic dermatitis (mainly demodicosis and sarcoptic mange), with a significant higher prevalence in the 0-2 years age group (P<0.05). However, age was not found to be a predisposing factor in parasitic otitis (P>0.05). Sex was correlated neither with parasitic dermatitis nor with parasitic OE. Pruritus (100%) and erythema (89%) resulted the main clinical signs of sarcoptic mange, while pruritus (82%), alopecia (68%) and erythema (68%) were the main clinical signs of demodicosis. The main symptoms of parasitic OE (Malassezia and O. cynotis) were abundant (77%, 100%) and dark (68%, 100%) wax.