inflammatory and neoplastic processes are the most common diagnostic findings when evaluating canine nasal diseases , these carry very different prognoses . endoscopy is a common diagnostic tool used to evaluate the nasal cavity and to target samples [ 2,4,5,10 - 16 ] . in a study in 1990 , mccarthy and mcdermaid   stated that the use of the rhinoscopic technique as part of a complete and well - conducted diagnostic investigation can achieve a correct diagnosis in more than 90% of cases without the help of surgical inspection . such a high percentage of success , in the opinion of the authors , can only be reached by correlating rhinoscopy with all of the clinical and anamnestic information previously gained , and with the radiographic images in the correct projections . to our knowledge , no study in the literature has looked at the correlation between endoscopic and histopathologic findings in a group of dogs with a final histopathologic diagnosis of either neoplastic or primary inflammatory nasal disease . in order to evaluate the degree of concordance between endoscopic findings and histological diagnosis , a retrospective study was performed to analyze medical records of 54 dogs which presented with symptoms of chronic nasopharyngeal disease later diagnosed as neoplasia or chronic nasal inflammation , after exclusion of mycosis , protozoal diseases ( e.g. ehrlichiosis and leishmaniasis ) or foreign body inhalation . we reviewed medical records of 54 dogs which presented at the department of veterinary clinical sciences , university of bologna , between january 1 , 2005 and october 1 , 2008 . each dog had undergone nasal endoscopy and received a final diagnosis of either chronic inflammatory rhinitis or nasal neoplasia . chronic symptoms were defined as lasting for more than two months and included nasal discharge ( mucoid , mucopurulent , hemorrhagic ) , sneezing , epistaxis or stertor . other inclusion criteria were normal findings for complete blood count , serum chemistries , clotting examination ( aptt , pt , d - dimer ) , urinalysis , regional lymph nodes examination , liver echography , and thoracic radiographs . information obtained from the medical records included in the study consisted of signalment , history , clinical signs , results of rhinopharyngeal endoscopy and results of histologic examination of nasal biopsy specimens . an initial diagnosis was recorded by the endoscopist on the basis of rhinoscopy and the results of another test ( e.g. x - ray ) . cases of ehrlichiosis and leishmaniasis ( diagnosed by serology ) , fungal disease and foreign body inhalation were excluded . the study included 33 sexually intact males and 21 females ( 13 sexually intact , eight spayed ) aged from 1 to 15 years and of 21 different breeds . rhinoscopy was performed in all patients with a double endoscopic technique : a rigid endoscope , for the inspection of the rostral part until the ethmoidal volutes of the nasal cavity ( anterograde approach ) , and a flexible endoscope was inserted orally into the nasopharynx ( retrograde approach ) . patients underwent general anaesthesia after intubation and insufflation of the endotracheal cuff . in case of unilateral symptoms , both nostrils were examined and rhinoscopy was first performed in the healthy nostril . generally , after orotracheal intubation , the first operative phase to be performed was the retrograde approach with the flexible endoscope , because of frequent bleeding during the anterograde approach when using the rigid endoscope or maneuvering instruments . for the retrograde approach , a 6 mm in diameter and 1,050 mm in length flexible bronchoscope ( pentax eg-1840 ; pentax , usa ) was used , equipped with an instrumental portal to insert forceps for tissue sampling . during this phase , the animal was positioned in dorsal recumbence to facilitate the insertion and manipulation of the flexible endoscope . to further facilitate the insertion of the endoscope into the rhinopharynx , curve grasping forceps were used to hold and pull forward the soft palate . the flexible endoscope was " j - flexed " and pulled cranially to visualize the choanae . a sample tissue was always performed in presence of masses or mucosal abnormalities . however , because biopsy forceps could n't be inserted in working channel with the endoscope tip flexed , after endoscopic examination , the scope had to be withdrawn from the rhino - pharynx and the biopsy forceps was inserted prior endoscope tip flexion . after removal of the flexible endoscope , the patient was positioned in sternal recumbency with the head lifted slightly by a soft support . to facilitate the outflow of the fluids used to irrigate the nasal cavities , the patient was put in the trendelenburg position . the pharynx was packed with cotton swabs to prevent aspiration of nasal exudates or irrigation fluid . for the anterograde approach , a rigid endoscope ( karl storz , germany ) with a diameter of 2.7 mm with a 30 angle and a length of 19 cm was used . the endoscope was inserted inside a cannula of 4 mm diameter with a luer - lock tap for irrigation with fluids and aspiration of secretions . a 2.5 mm endoscopic forceps was used for biopsy . after the systematic examination of nasal cavities , bilateral biopsy specimens were collected in both endoscopic phases , even when nasal disease was recognized as unilateral , in order to obtain a histopathological confirmation of unaffected nasal mucosa . abnormalities recorded during examination included mucosal hyperemia or edema , mucus or blood accumulation , presence of a mass , turbinate atrophy and ulceration . biopsy specimens were gently extracted from the forceps and properly oriented on cellulose acetate supports ( endofilters bioptica , italy ) , fixed in 10% buffered formalin , embedded in paraffin , sectioned at 4 m and stained with haematoxylin and eosin . inflammation was diagnosed when all biopsies showed stromal infiltration of inflammatory cells ; in particular , cases were diagnosed as chronic lymphoplasmacytic rhinitis when lymphocytes and plasma cells were the predominant inflammatory cell components , active lymphoplasmacytic rhinitis when a significant proportion of neutrophils was also evident , and eosinophilic chronic rhinitis if eosinophils were readily evident together with lymphocytes and plasma cells . cases matching the diagnosis of tumour were classified according to the world health organization criteria . a comparison was made between the endoscopic report and the histological diagnosis , which was seen as the gold standard . the agreement between endoscopy and histology regarding the diagnosis of chronic inflammation or neoplasia was tested by application of cohen 's kappa coefficient . a poor agreement was defined as a k value 0.20 , a fair agreement as 0.21~0.40 , a moderate agreement as 0.41~0.60 , a substantial agreement as 0.61~0.80 and a good agreement as > 0.80 . the influence of gender on the two classes ( inflammatory process vs. neoplastic process ) was compared using the chi - squared test with the data arranged in a 2  2 table . the influence of age on the two classes was compared by applying a non - parametric distribution test ( wald wolfowitz run test ) , in relation to the non - normal distribution of the variables as analyzed by the shapiro wilk 's w test . the dichotomous parameters obtained from anamnesis , clinical examination and endoscopy ( presence / absence of nasal discharge , unilateral / bilateral nasal discharge , presence / absence of cough , presence / absence of sneezing , patency / obstruction of nasal cavity , unilateral / bilateral involvement of the nasal cavity , involvement / non - involvement of the rhinopharynx , presence / absence of exudate in the nasal cavity , presence / absence of haemorrhage in the nasal cavity , presence / absence of masses , presence / absence of ulcerate masses ) were compared using a logistic regression analysis . we reviewed medical records of 54 dogs which presented at the department of veterinary clinical sciences , university of bologna , between january 1 , 2005 and october 1 , 2008 . each dog had undergone nasal endoscopy and received a final diagnosis of either chronic inflammatory rhinitis or nasal neoplasia . chronic symptoms were defined as lasting for more than two months and included nasal discharge ( mucoid , mucopurulent , hemorrhagic ) , sneezing , epistaxis or stertor . other inclusion criteria were normal findings for complete blood count , serum chemistries , clotting examination ( aptt , pt , d - dimer ) , urinalysis , regional lymph nodes examination , liver echography , and thoracic radiographs . information obtained from the medical records included in the study consisted of signalment , history , clinical signs , results of rhinopharyngeal endoscopy and results of histologic examination of nasal biopsy specimens . an initial diagnosis was recorded by the endoscopist on the basis of rhinoscopy and the results of another test ( e.g. x - ray ) . cases of ehrlichiosis and leishmaniasis ( diagnosed by serology ) , fungal disease and foreign body inhalation were excluded . the study included 33 sexually intact males and 21 females ( 13 sexually intact , eight spayed ) aged from 1 to 15 years and of 21 different breeds . rhinoscopy was performed in all patients with a double endoscopic technique : a rigid endoscope , for the inspection of the rostral part until the ethmoidal volutes of the nasal cavity ( anterograde approach ) , and a flexible endoscope was inserted orally into the nasopharynx ( retrograde approach ) . patients underwent general anaesthesia after intubation and insufflation of the endotracheal cuff . in case of unilateral symptoms , both nostrils were examined and rhinoscopy was first performed in the healthy nostril . generally , after orotracheal intubation , the first operative phase to be performed was the retrograde approach with the flexible endoscope , because of frequent bleeding during the anterograde approach when using the rigid endoscope or maneuvering instruments . for the retrograde approach , a 6 mm in diameter and 1,050 mm in length flexible bronchoscope ( pentax eg-1840 ; pentax , usa ) was used , equipped with an instrumental portal to insert forceps for tissue sampling . during this phase , the animal was positioned in dorsal recumbence to facilitate the insertion and manipulation of the flexible endoscope . to further facilitate the insertion of the endoscope into the rhinopharynx , curve grasping forceps were used to hold and pull forward the soft palate . the flexible endoscope was " j - flexed " and pulled cranially to visualize the choanae . a sample tissue was always performed in presence of masses or mucosal abnormalities . however , because biopsy forceps could n't be inserted in working channel with the endoscope tip flexed , after endoscopic examination , the scope had to be withdrawn from the rhino - pharynx and the biopsy forceps was inserted prior endoscope tip flexion . after removal of the flexible endoscope , the patient was positioned in sternal recumbency with the head lifted slightly by a soft support . to facilitate the outflow of the fluids used to irrigate the nasal cavities , the patient was put in the trendelenburg position . the pharynx was packed with cotton swabs to prevent aspiration of nasal exudates or irrigation fluid . for the anterograde approach , a rigid endoscope ( karl storz , germany ) with a diameter of 2.7 mm with a 30 angle and a length of 19 cm was used . the endoscope was inserted inside a cannula of 4 mm diameter with a luer - lock tap for irrigation with fluids and aspiration of secretions . a 2.5 mm endoscopic forceps was used for biopsy . after the systematic examination of nasal cavities , bilateral biopsy specimens were collected in both endoscopic phases , even when nasal disease was recognized as unilateral , in order to obtain a histopathological confirmation of unaffected nasal mucosa . abnormalities recorded during examination included mucosal hyperemia or edema , mucus or blood accumulation , presence of a mass , turbinate atrophy and ulceration . biopsy specimens were gently extracted from the forceps and properly oriented on cellulose acetate supports ( endofilters bioptica , italy ) , fixed in 10% buffered formalin , embedded in paraffin , sectioned at 4 m and stained with haematoxylin and eosin . inflammation was diagnosed when all biopsies showed stromal infiltration of inflammatory cells ; in particular , cases were diagnosed as chronic lymphoplasmacytic rhinitis when lymphocytes and plasma cells were the predominant inflammatory cell components , active lymphoplasmacytic rhinitis when a significant proportion of neutrophils was also evident , and eosinophilic chronic rhinitis if eosinophils were readily evident together with lymphocytes and plasma cells . cases matching the diagnosis of tumour were classified according to the world health organization criteria . a comparison was made between the endoscopic report and the histological diagnosis , which was seen as the gold standard . the agreement between endoscopy and histology regarding the diagnosis of chronic inflammation or neoplasia was tested by application of cohen 's kappa coefficient . a poor agreement was defined as a k value 0.20 , a fair agreement as 0.21~0.40 , a moderate agreement as 0.41~0.60 , a substantial agreement as 0.61~0.80 and a good agreement as > 0.80 . the influence of gender on the two classes ( inflammatory process vs. neoplastic process ) was compared using the chi - squared test with the data arranged in a 2  2 table . the influence of age on the two classes was compared by applying a non - parametric distribution test ( wald wolfowitz run test ) , in relation to the non - normal distribution of the variables as analyzed by the shapiro wilk 's w test . the dichotomous parameters obtained from anamnesis , clinical examination and endoscopy ( presence / absence of nasal discharge , unilateral / bilateral nasal discharge , presence / absence of cough , presence / absence of sneezing , patency / obstruction of nasal cavity , unilateral / bilateral involvement of the nasal cavity , involvement / non - involvement of the rhinopharynx , presence / absence of exudate in the nasal cavity , presence / absence of haemorrhage in the nasal cavity , presence / absence of masses , presence / absence of ulcerate masses ) were compared using a logistic regression analysis . the endoscopic examination allowed diagnosis of 29 subjects with suspected inflammation of the nasal cavity and 25 subjects with suspected presence of a neoplastic process ; the histological examination provided a diagnosis of inflammation in 36 cases ( table 1 ) and a diagnosis of neoplasia in 18 cases ( table 2 ) . in particular , all cases diagnosed as cancer by histology were also diagnosed as neoplasia by endoscopy , while seven cases histologically diagnosed as inflammation were misdiagnosed as cancer by endoscopy ( fig . no macroscopic metastases were visualized in regional lymph nodes , lung or liver by x - ray and ultrasound examinations . in the inflammation group , histology demonstrated a chronic lymphoplasmacytic rhinitis in 23 of 36 cases ( figs . 2 and 3 ) , active lymphoplasmacytic rhinitis in 11 of 36 cases , and eosinophilic chronic rhinitis in two cases . accessory findings in chronic lymphoplasmacytic rhinitis were hyperplasia of the epithelium with areas of squamous metaplasia , excessive mucus secretion and stromal fibrosis . in active lymphoplasmacytic rhinitis there were areas of hyperplastic epithelium with intraepithelial neutrophils admixed with areas where the epithelium was eroded , active fibroplasia of the lamina propria and vasculitis . in eosinophilic chronic rhinitis the epithelium was markedly hyperplastic and infiltrated by eosinophils , and the lamina propria showed vascular proliferation , fibroplasias and accumulation of lymphocytes and plasma cells . as for tumor masses ( 18 cases ) , most dogs had epithelial tumors ( 11 adenocarcinoma and three papilloma ) ( fig . 4 ) and two had malignant mesenchymal tumors ( one chondrosarcoma and one liposarcoma ) ( fig . the seven cases diagnosed as cancer by endoscopy and inflammation by histology were five cases of chronic lymphoplasmacytic rhinitis , one of active lymphoplasmacytic rhinitis and one of eosinophilic chronic rhinitis . in all cases there was marked hyperplasia of subepithelial and epithelial layers which endoscopically matched a tumor - like pattern . in particular , of these seven cases , four were characterized at clinical examination by unilateral nasal discharge , one by bilateral nasal discharge and in two cases by no nasal discharge . evaluation of the histological and endoscopic agreement by cohen 's kappa coefficient gave a value of 0.73 , indicating a " substantial agreement " . no statistical analysis on the breed was effected in relation with the high dispersion of the sample represented by 21 different breeds . no significant differences were found when comparing the two groups ( inflammation vs. neoplasia ) for the variables of gender and age . based on the histological diagnosis , the analysis of anamnestic and clinical findings between the two groups showed significantly more frequent unilateral nasal discharge in the neoplasia group than the inflammation group ( p<0.01 ) . meanwhile , no difference was detected between the two groups in terms of presence / absence of nasal discharge , presence / absence of cough and presence / absence of sneezing . based on the endoscopic diagnosis , several parameters were significantly more associated with the neoplasia group : the obstruction of the nasal cavity ( p<0.001 ) , the unilateral involvement of the nasal cavity ( p<0.01 ) , the involvement of the rhinopharynx ( p<0.001 ) , the presence of blood in the nasal cavity ( p<0.05 ) , and the presence of a mass in the nasal cavity ( p<0.001 ) . no differences were detected between the two groups for the presence / absence of an ulcerated mass in nasal cavity or for the presence / absence of an exudate in the nasal cavities . the inspection of the nasal cavities by the anterograde approach with a rigid endoscope ( diameter of 2.7 mm ) allowed a complete visualization of the ventral meatus only in patients heavier than 10 kg . the inspection in dogs of a smaller size was comparatively difficult and often incomplete due to the instruments and the impossibility of performing some movements mandatory for the visualization of the meatus . in addition , a further factor able to influence the degree of visualization of the nasal cavities seemed to be the morphology of the head . in particular , in brachycephalic dogs the forward endoscopic visualization was more difficult independent of body weight . nevertheless , the use of the two different endoscopic approaches ( retrograde and anterograde ) and the specific endoscopes used in this review decreased the range of unexaminable areas . as previously reported in the literature , an examination with rigid endoscopes precludes visualization of nearly 50% of the caudal portion of the nasal cavity , while a combined approach of anterograde visualization with a rigid endoscope and retrograde visualization with a flexible endoscope provides a broader view of the nasal cavity . in the retrograde approach , the flexible endoscope had to be positioned for the acquisition of only one image , thus the inspection was not hindered no matter how small the dog was . the only limitation with the flexible endoscope was the anatomy of each dog , and depending on the dimensions of the pharynx , it was sometimes more difficult to bend the endoscope backwards to visualize the nasopharynx in smaller subjects . it should be stressed that other imaging techniques such as ct and mri are able to examine the nasal cavity and border structures with greater sensitivity than endoscopy . however , the current costs of these modalities limit their routine use . also , chronic rhinopathy symptoms tend to be mild for a prolonged period of time , so anatomical changes are often very evident by the time of clinical presentation . a further inherent strength of the endoscopic approach is that in addition to being an imaging technique it also allows for precise tissue sampling , and thus histological examination , the gold standard for nasal disease diagnosis . this represents an advantage over ct or mri , for which sampling is only possible in the presence of osteolysis . however , an important and unique advantage of mri is its ability to differentiate between tumor types ( e.g. sarcoma vs. carcinoma ) on account of their intensity on t1-weighted and t2-weighted images . the comparison of endoscopic diagnoses with histological results has elicited a substantial agreement ( cohen 's kappa coefficient : 0.73 ) . this value was reached with the acquisition of several biopsy samples ( at least four ) during the endoscopic examination and with the continued cooperation and interchange of information between the clinicians and the pathologist . chronic idiopathic inflammatory rhinitis is generally characterized by a primarily lymphoplasmacytic infiltrate or , less frequently , by a concurrent neutrophilic and eosinophilic infiltrate . this condition was present in our study with 23 of 36 cases characterized by an infiltrate of lymphocyte and plasma cells , 11 of 36 cases with prevalent neutrophilic and plasma cell infiltrate , and 2 of 36 with prevalent infiltrate represented by eosinophils and plasma cells . it is difficult to affirm if the neutrophilic / eosinophilic infiltrate represents an evolution of the process started with lymphocyte and plasma cell reaction or a response to a different inflammatory stimulus . the prevalence of nasal tumor in the literature ranges between 0.3% and 2.4% of all neoplasia surveyed in the dog , with a high incidence of carcinomas ( particularly adenocarcinomas and squamous cell carcinomas ) which metastasize , rarely , to the brain , lymph node , lung and liver . lower incidence is represented by sarcomas ( fibrosarcoma , chondrosarcoma , osteosarcoma and undifferenciate sarcoma ) . the incidence of the various tumors observed in our study does not differ from what was previously reported in the literature . indeed , 67% of cancer was represented by carcinomas ( adenocarcinoma and neuroendocrine carcinoma ) while the remainder consisted of sarcomas , mastocytoma and papillomas . the incidence of breed , sex and age in the development of inflammatory rhinitis compared to nasal neoplasia has been studied by various authors . a higher predilection in the development of nasal neoplasia has been observed in males , while no gender influence has been proved in dogs with lymphoplasmacytic rhinitis . similarly the mean age in dogs with nasal neoplasia is ten years   and eight years in those with lymphoplasmacytic rhinitis . accurate statistical analysis regarding the influence of breed on the development of inflammation or nasal neoplasia is limited by the relatively low number of cases involved ( n = 54 ) and the high distribution of breeds . additionally , almost half the population ( n = 25 ) was represented by mixed breeds . it should be stressed that no difference was seen between groups in terms of gender and age . additionally , the comparison of anamnestic elements and clinical and endoscopic findings in dogs with histological diagnoses of inflammatory rhinitis and nasal neoplasia showed a higher prevalence of unilateral nasal discharge in the neoplastic group , associated with unilateral nasal cavity involvement , the obstruction of the nasal cavity , the evidence of a mass in the nasal cavity , the involvement of the rhinopharynx and the presence of blood in the nasal cavity . our results contrast with those of a study on canine nasal and paranasal tumors by ogilvie and larue   evidencing a bilateral dissemination of nasal neoplasia in almost half of the analyzed cases . windsor et al .   reported that in course of lymphoplasmocytic rhinitis , nasal discharge was unilateral in 42% and bilateral in 58% . however , there was no agreement between clinical and endoscopic examination , with the latter evidencing a unilateral involvement in 11% and bilateral involvement in 89% . similarly , in our study , while the clinical examination evidenced unilateral nasal discharge in the course of chronic inflammatory rhinitis in 39% of cases and bilateral discharge in 61% , less variability was seen on endoscopic examination , with 32% unilateral involvement and 68% bilateral involvement . other clinical symptoms , namely nasal discharge ( unilateral or bilateral ) , cough or sneezing and the presence of exudate inside the nasal cavity , seemed to be equally associated with inflammatory and neoplastic nasal disease , in agreement with the literature . no lymph nodes or pulmonary metastases were seen at the time of neoplasia diagnosis , in agreement with ogilvie and larue   who only found metastasis ( commonly in the brain , lymph nodes , lung and liver ) later in the course of the disease . in conclusion , rhinoscopy , while superficial in nature , combines good quality diagnostic investigation with the possibility of operative procedures , reducing invasiveness and the time under anaesthesia , and consequently improving the safety of the patient . moreover , the combined rhinoscopic technique allows a complete exploration of the nasal cavity , the observation of macroscopic images useful for the pathologist , and the advantage of being able to perform several biopsies . it is important to note the advantage of imaging magnification which , like other endoscopic techniques , allows greater inspection of the nasal internal surface , even if it is sometimes not enough to visualize microscopic lesions . finally , it is our opinion that different sites have to be always sampled , to avoid the error of withdrawing inadequately or achieving bad processing samples .
nasal diseases are very common in dogs and rhinoscopy is often required for a definitive diagnosis . 
 rhinoscopy , while superficial in nature , can guide the clinician to the final diagnosis . in this study , 
 rhinoscopy was performed on 54 dogs with symptoms of chronic nasopharyngeal disease . 
 the endoscopic diagnosis of neoplasia or chronic nasal inflammation was validated with histological examination of pathological samples , in order to evaluate the degree of concordance between endoscopic findings and histological diagnosis . the agreement between endoscopy and histology 
 was tested by application of cohen 's kappa coefficient . 
 we conclude that correlation between endoscopic results and histological diagnosis , expressed by a cohen 's kappa coefficient of 0.73 , is only possible with a constant cooperation between the clinician and the pathologist .