A retrospective study of more than 400 feline nasal biopsy samples in the UK (2006-2013)

Investigation of Ki-67 and Clinical Outcome in Feline Nasal Adenocarcinoma Treated Using Hypofractionated Radiotherapy

Ki-67 has been reported as a prognostic marker in human cancers treated using RT. The current study investigated the prognostic significance of Ki-67 expression and its association with clinicopathological characteristics in 19 cats diagnosed with nasal adenocarcinoma and treated using hypofractionated RT. Data collected encompassed signalment, clinical signs, clinicopathological variables, treatment outcomes, and survival times. Median survival times (MST) were estimated using Kaplan-Meier curves and analyzed based on the log-rank test. Based on the results, white blood cell counts were significantly (p < 0.001) higher before treatment than after, although this was not associated with survival time. The overall MST was 550 days (range: 56-1118 days). Cats achieving a favorable response (complete or partial response) had significantly (p = 0.006) longer survival times (1055 days) than those with a poor response (stable or progressive disease; 369 days). Cats with high Ki-67 expression had significantly (p = 0.028) longer survival times (1055 days) than those with low Ki-67 expression (256 days). These results suggested that Ki-67 may be a potential prognostic factor for feline nasal adenocarcinoma.

Nasal telangiectatic osteosarcoma with direct extension to the brain in a domestic shorthair cat

Case summary

This case report describes the clinical and pathological features of telangiectatic osteosarcoma (TOS) with brain invasion in a 4-year-old female domestic shorthair cat. The cat presented with respiratory distress, epistaxis, anorexia and significant nasal obstruction. A rhinoscopy revealed an amorphous white neoformation in the left nasal cavity. Despite treatment, the cat's condition deteriorated and it succumbed to the disease. Necropsy and histopathologic examination revealed an infiltrative malignant neoplasm with osteoid matrix and sarcomatous cells surrounding blood-filled non-vascular spaces. Immunohistochemistry showed positive staining for bone cell markers and vimentin, while endothelial markers were negative, confirming TOS.

Relevance and novel information

Nasal diseases in cats present significant diagnostic challenges due to similar clinical signs, such as respiratory distress and nasal discharge. Nasal osteosarcomas are rare, and TOS is the rarest subtype, characterized by blood-filled spaces within an aggressive osteolytic lesion. This case highlights the diagnostic complexities and poor prognosis associated with TOS in cats, emphasizing the need for advanced imaging and immunohistochemical tests for accurate diagnosis. Given the aggressive nature and rapid progression of TOS, it should be considered in differential diagnoses of feline nasal obstructive lesions.

Retrospective study of 540 cats with respiratory diseases in Japan (2003-2020)

BACKGROUND

Few epidemiological studies on respiratory medicine and the relationship between clinical signs and various respiratory diseases in cats have been reported.

OBJECTIVES

This retrospective study aimed to investigate the prevalence and breed predisposition to feline respiratory diseases in Japan and determine the association between clinical signs, duration and type of respiratory diseases.

METHODS

The medical records of cats with feline respiratory diseases were examined to obtain information on age, sex, breed, final diagnosis, clinical signs and duration. The odds ratios (ORs) and 95% confidence intervals were calculated to evaluate breed predispositions. Mann-Whitney U, Kruskal-Wallis and Dunn's tests were used to assess the duration of clinical signs.

RESULTS

This study included 540 cats with 615 respiratory diagnoses. The American Shorthair breed was predisposed to bronchopneumonia (BP; OR: 5.0) and pulmonary tumour (PT; OR: 3.6), while the Russian Blue breed exhibited a predisposition to inflammatory lower airway diseases (OR: 3.4), BP (OR: 6.1) and interstitial lung diseases (OR: 11.1). Similarly, the Scottish Fold breed displayed predisposition to PTs (OR: 5.8). The duration of clinical signs among nasal diseases, nasopharyngeal diseases and lower tracheal/bronchial and pulmonary diseases differed significantly (p = 0.001, p = 0.012, p < 0.0001, respectively).

CONCLUSIONS

The results suggest that some popular breeds in Japan are predisposed to feline respiratory diseases, especially the American Shorthair, Russian Blue and Scottish Fold breeds. The characteristics of occurrence, clinical signs and duration of each disease will aid in diagnosing, treating, preventing and elucidating the pathophysiology of feline respiratory disease.

The Expression Levels of CD20 as a Prognostic Value in Feline B-Cell Nasal Lymphoma: A Pilot Study

The effect of the semi-quantitative expression of CD20 in the prognosis of feline nasal lymphoma has not been described. This study investigated the prognostic significance of CD20 expression, clinicopathological characterization, and treatment outcomes in cats with nasal lymphoma. Clinical data from cats diagnosed with nasal lymphoma were retrospectively collected, including signalment, clinical signs, clinicopathological variables, treatment outcomes, and survival times. Using ImageJ software, CD20 expression was semi-quantitatively measured based on the proportion of CD20-positive areas. Correlations between laboratory findings, immunohistochemical expressions, and survival outcomes were investigated. All cats included in the study exhibited the B-cell immunophenotype. During treatment, a reduction in PCV was noted in the cats at the second and sixth weeks (p = 0.01 and p = 0.01, respectively). The cats with low CD20 expression exhibited a significantly shorter MST (91 days; 95% CI, 41-141) than those with high CD20 expression (MST, 214 days; 95% CI, 76-351) (p = 0.01). Stage T1 cats displayed a higher MST (143 days; 95% CI, 144-172) than those in other stages > T1 (120 days, 95% CI, 71-169 days) (p = 0.04). Anemia, a common adverse effect in feline nasal lymphoma, did not impact MST. T1 clinical staging and high CD20 expression showed a trend for better MST.

Normal variation of clinical mobility of the mandibular symphysis in cats

Introduction

The primary objective of this retrospective study was to document the normal variation of clinical mobility of the mandibular symphysis in cats and possible associations with bodyweight, age, sex, sexual status, breed and skull morphology. Secondarily, the radiographic appearance of the mandibular symphysis and possible associations with the analyzed data were evaluated.

Materials and methods

Two hundred and sixteen cats of 15 different breeds that underwent maxillofacial, oral and dental procedures from April 2015 to December 2021 were included. Clinical mobility was evaluated under general anesthesia using a 0 to 3 scale in lateromedial (LM) and dorsoventral (DV) directions. The symphysis was radiographically classified on the occlusal radiographic view of the rostral mandibles as fused or open, and with parallel or divergent margins.

Results

Bodyweight ranged from 2.2 to 12.5 kg (median 4.0 kg), age from 4 months to 17 years and 4 months (median 6 years and 4 months). At the first evaluation DV symphyseal mobility was 0 in 177 cases (82%), 1 in 32 cases (14.8%) and 2 in 7 cases (3.2%), LM mobility was 0 in 61 cases (28.3%), 1 in 110 cases (50.9%) and 2 in 45 cases (20.8%). 81.1% of the radiographs were included in the statistical analysis. Three symphyses (1.6%) were classified as fused and 190 (98.4%) as open, 129 (68.8%) having divergent margins and 61 (31.6%) parallel. One hundred and forty-eight cases (76.7%) did not show the presence of odontoclastic replacement resorption on the canine teeth (TR subgroup 1), 23 (11.9%) showed stage ≤3 lesions (TR subgroup 2) and 22 (11.4%) stage 4 lesions (TR subgroup 3). Logistic regression models exploring factors that affected DV and LM mobility were statistically significant (p < 0.0001; p < 0.0001) with an increase in LM mobility predicting an increase in DV mobility, and vice versa. An increase in DV mobility was associated with an increase in age and in having resorptive lesions. A decrease in LM symphyseal mobility was associated with being brachycephalic.

Conclusion

The great majority of cases showed some degree of LM symphyseal mobility, and 18% showed DV mobility. Symphyseal bony fusion is rare but possible.

Use of a cyclical hypofractionated radiotherapy regime ('QUAD shot') for the treatment of feline sinonasal carcinomas

OBJECTIVES

Radiation therapy is the treatment of choice for cats with sinonasal carcinomas. Different protocols have been described in the literature, though a clear consensus regarding the optimal protocol is lacking. The aim of the study was to describe the tolerability, efficacy and outcome of cats treated with a cyclical hypofractionated protocol.

METHODS

Cats with histologically diagnosed sinonasal carcinomas in a single institution were retrospectively included. All patients were treated with a cyclical hypofractionated protocol ('QUAD shot' regime). Cats were treated with 4 Gray (Gy) delivered in four fractions within 48 h, with a minimum of 6 h between two treatments, and repeated every 3-4 weeks for a total dose of 48 Gy in three cycles.

RESULTS

Seven cats met the inclusion criteria. Nasal discharge and sneezing were the most common presenting complaints. All cats presented with advanced stage of disease with CT examination (three with modified Adams stage 3 and four with stage 4). Clinical improvement was seen in six cats. Five cats had a follow-up CT; one had a complete response, two had partial responses, one had stable disease and one had progressive disease. Two cats were still alive at the time of writing while four were euthanased owing to tumour-related causes. The median overall survival time was 460 days. The 1-year survival time was 80% and the 2-year survival time was 0%. Severe acute or late toxicity was not reported.

CONCLUSIONS AND RELEVANCE

This is the first report of a cyclical hypofractionated protocol in the veterinary literature that can provide prolonged survival in cats with advanced stage sinonasal carcinoma. Its use should be considered in patients when prolonged hospitalisation can be detrimental to quality of life, while still delivering a therapeutic total dose of radiation therapy.

Nasal Lymphoma with Low Mitotic Index in Three Cats Treated with Chlorambucil and Prednisolone

Lymphoma is the most common tumor of the nasal cavity in cats. Commonly used treatment modalities are radiotherapy and chemotherapy, or both. Typical chemotherapy protocols used in cats with nasal lymphoma are COP (cyclophosphamide, vincristine prednisolone) and CHOP (cyclophosphamide, doxorubicin, vincristine and prednisolone). Thus far, the use of single-agent chlorambucil in nasal lymphoma has been evaluated in a single case report. We report a case series of three cats with B cell nasal lymphoma, two cats with intermediate cell, and one large cell, all with a low mitotic index (MI) of less than 5 mitotic figures per ×400 field, treated with chlorambucil and prednisolone. Two of the cases achieved a long disease-free interval, while the one with the highest MI did not. Protocols using chlorambucil and prednisolone may have potential as a first-line therapy for feline nasal lymphoma cases with a very low mitotic index.

Investigation of Bacterial Isolations and Antimicrobial Susceptibility of Chronic Rhinitis in Cats

Chronic rhinitis is a quite common upper respiratory tract (URT) disease in cats. As a result of unclear etiology, frequently, multidrug-resistant bacteria are identified. This study investigated bacterial isolations and an antimicrobial susceptibility test (AST) in chronic rhinitis in cats. The medical records of 395 cats with chronic URT signs were reviewed at the Kasetsart University Veterinary Teaching Hospital (KUVTH) between 2016 and 2021 to survey the underlying causes of URT. Then, apart from rhinitis, other causes were excluded to identify the bacterial species and antimicrobial susceptibility. The results indicated that the most frequent finding was neoplasia, followed by rhinitis and anatomical defects. Furthermore, the only significant association was between the age range and disease group, with gender, FIV, or FeLV infection not being significant. Rhinitis was 4.7 times more likely to occur than neoplasia in younger and young adult cats in the age range < 1−3 years compared to the group > 10 years. The main bacterial species was the Pseudomonas species. Antimicrobials with a susceptibility rate of more than 90% were amikacin, gentamicin, ciprofloxacin, norfloxacin, marbofloxacin, imipenem, and meropenem. In conclusion, rhinitis was the second most common chronic URT disease in cats and was more common in younger and young adult cats. The predominant bacteria with AST in this study reflect the antimicrobial resistance situation. Thus, antimicrobial usage should follow antimicrobial use guidelines first.

Long-term management of a cat with nasopharyngeal lymphoma by chlorambucil

Background:

Lymphoma in the nasal cavity is the most common tumor of cats' upper respiratory tract. However, the effect of single-agent chlorambucil on nasal or nasopharyngeal lymphoma has not been evaluated in cats.

Case Description:

An 8-year-old, castrated male Scottish Fold weighing 3.5 kg presented with an 8-month history of nasal discharge, sneezing, and mild epistaxis. CT and rhinoscopy revealed nasal discharge and slight swelling of the nasopharyngeal mucosa, but no masses and local invasions were detected. Histopathological and immunohistochemical analyses of the nasopharyngeal mucosa demonstrated B-cell lymphoma in the cat. The treatment with chlorambucil led to long-term management of the cat without any side effects. No recurrences of clinical signs have been observed for 754 days.

Conclusion:

The present case report suggests that chlorambucil can be a therapeutic option for feline localized nasopharyngeal B-cell lymphoma without masses and local invasions.

Facial distortion due to chronic inflammation of unknown cause in a cat

Case summary

An 8-year-old neutered male indoor cat was presented for evaluation of a year-long history of swelling over the bridge of the nose that extended from the subcutaneous tissue of the right upper eyelid to the dorsum of the skull. Intermittent regression of the mass lesion was reported with antibiotic or corticosteroid therapy; however, progressive swelling, malaise and hiding behavior persisted. CT revealed an aggressive osteolytic mass lesion in the right and left nasal cavities and extending into the frontal sinuses. Rhinoscopy using a 2.8 mm rigid telescope revealed somewhat normal-appearing turbinates rostrally and ventrally on the left side, with turbinate destruction on the right. After obtaining a biopsy from the right side of the nasal cavity, thick material filling the entire nasal cavity was visible caudally and was extracted endoscopically from a rostral approach. Surgical biopsy of the dorsal nasal bridge resulted in protrusion of inspissated material from the incision site. Rhinoscopic exploration revealed that the material extended into both frontal sinuses. Following extensive debridement and medical therapy, marked resolution of facial asymmetry was achieved.

Relevance and novel information

Facial distortion is often considered suggestive of a neoplastic process; however, it can also be seen with fungal and mycobacterial infections, and, in this case, an inflammatory condition of unknown etiology. In this cat, aggressive intervention and debridement of necrotic debris resulted in substantial bony remodeling of the skull and return to normal activity levels.

Presumed Primary Bacterial Rhinosinusitis-Associated Optic Neuritis in a Cat

Acute bacterial rhinosinusitis is a common illness in children and can lead to complications such as preseptal/orbital cellulitis, orbital/subdural/cerebral abscessation, osteomyelitis, meningitis, and optic neuritis with blindness. Primary bacterial infections leading to rhinosinusitis in cats is rare and descriptive reports are lacking. The current report describes a cat with Escherichia coli and Actinomyces spp. infections causing severe chronic rhinosinusitis and subsequent loss of vision. Treatment with antibiotics and prednisolone coincided with a complete resolution of nasal disease-related clinical signs and substantial improvement in vision. This is the first description of a cat with presumed severe primary bacterial rhinosinusitis resulting in optic neuritis and loss of vision.