Clinical outcome in dogs with nasal tumors treated with intensity-modulated radiation therapy

Intensity-modulated radiation therapy (IMRT) is a valuable tool in human radiation oncology, but information on its use in veterinary medicine is lacking. In this study, 12 dogs with nasal tumors were treated with IMRT at a median radiation dose of 54 Gy. Patient survival times and frequency and severity of side effects on ocular structures, oral mucosa, and skin were recorded. Eight dogs (67%) had resolution of clinical signs during radiation therapy. Median overall survival time was 446 d with a 50% 1-year and a 25% 2-year survival rate. Minimal grade 2 or 3 acute skin toxicity, no grade 2 or 3 late skin toxicity, and no grade 2 or 3 toxicity to oral mucosa or the eye opposite the tumor were identified in the dogs treated with IMRT in this study. The ipsilateral eye could not be routinely spared due to its proximity to the tumor.     

Long-term outcome of eight cats with non-lymphoproliferative nasal tumours treated by megavoltage radiotherapy

A retrospective study was undertaken to evaluate the long term survival of eight cats with non-lymphoproliferative nasal tumours treated by megavoltage radiotherapy alone. Adenocarcinoma was the most commonly diagnosed tumour. Megavoltage radiotherapy was given to eight cats in 4-6 fractions of 4-8 Gys over a 16 to 28 day period. Seven cats completed the radiotherapy schedule and only two cases developed mild acute radiotherapy side effects. Median survival time after the completion of the radiotherapy course as calculated by Kaplan-Meier survival analysis was 382 days. The 1 year survival rate was 63%. All cats were euthanased because of either a poor response to radiotherapy or recurrence of the nasal tumour. This study demonstrates that a coarse fractionation regime of megavoltage radiotherapy can provide effective long-term palliative treatment for feline nasal tumours. The coarse fractionation schedule has the advantages of requiring only four to six treatments.     

Long-term survival of four dogs with disseminated Aspergillus terreus infection treated with itraconazole

SUMMARY Four dogs with disseminated aspergillosis caused by Aspergillus terreus were treated with oral itraconazole for 190 to 1095 days. Infection was eliminated in 1 dog. Two dogs were treated for 1000 and 1095 days but were eventually euthanased 572 and 485 days after treatment was stopped. At necropsy both dogs had widespread aspergillosis. The fourth dog was euthanased for other reasons after 190 days of treatment when it was showing a good clinical response although there was radiographic evidence that the disease was progressing.     

Treatment of eight dogs with nasal tumours with alternating doses of doxorubicin and carboplatin in conjunction with oral piroxicam

OBJECTIVE: To determine the efficacy and toxicity of chemotherapy in the treatment of canine nasal tumours. DESIGN: Retrospective clinical study PROCEDURE: Eight dogs with histologically confirmed nasal tumours were staged by means of complete blood count, serum biochemical analysis, cytological analysis of fine needle aspirate of the regional lymph nodes, thoracic radiographs and computed tomography scan of the nasal cavity. All dogs were treated with alternating doses of doxorubicin, carboplatin and oral piroxicam. All dogs were monitored for side effects of chemotherapy and evaluated for response to treatment by computed tomography scan of the nasal cavity after the first four treatments. RESULTS: Complete remission was achieved in four dogs, partial remission occurred in two dogs and two had stable disease on the basis of computed tomography evaluation. There was resolution of clinical signs after one to two doses of chemotherapy in all dogs. CONCLUSIONS: This chemotherapy protocol was efficacious and well tolerated in this series of eight cases of canine nasal tumours.     

Palliation of clinical signs in 48 dogs with nasal carcinomas treated with coarse-fraction radiation therapy

Data from 48 dogs with nasal carcinomas treated with palliative radiation therapy (PRT) were retrospectively reviewed. Factors potentially influencing resolution of clinical signs and survival after PRT were evaluated. Clinical signs completely resolved in 66% of dogs for a median of 120 days. The overall median survival time was 146 days. Duration of response to PRT was shorter in dogs that had clinical signs for <90 days before PRT. Survival times were shorter in dogs that had partial or no resolution of clinical signs after PRT than in dogs that had complete resolution of clinical signs.     

Treatment of nasal tumours in dogs: a review

Nasal tumours are common neoplasms in dogs and often represent a diagnostic and therapeutic challenge due to their confined location within the nasal cavities. The main goal of this review is to extract the most relevant information from a wide and often confusing evidence-based medicine on the treatment of canine nasal tumours and conclude with current recommendations. This report highlights the different therapeutic modalities available and describes their technical aspects, interests and limitations. Megavoltage radiotherapy, as the most recent treatment and standard of care, is particularly examined, especially the different types of radiotherapy units, the main protocols used and their advantages and limits. Newer and non-conventional treatments are also discussed.     

Diagnosis and outcome of nasal polyposis in 23 dogs treated medically or by endoscopic debridement

This study describes the clinical, diagnostic, and pathological characteristics of canine nasal polyps and how they responded to medical, endoscopic, and surgical treatments. The database of a multi-center veterinary endoscopy group was searched from 2010 to 2018. All dogs with a histological diagnosis of nasal polyposis that were undergoing endoscopic investigation (N = 23), were included. Clinical signs at presentation were sneezing (91%), nasal discharge (83%), stertor (74%), and frontonasal deformation (17%). Skull radiography on 13 dogs had alterations in 77% of cases, including turbinate lysis (6/13), increased radiopacity of one (4/13) or both (6/13) nasal cavities, and lysis of the nasal vomer bone (3/13). Nasal polyposis had a characteristic endoscopic appearance. There were clinical and diagnostic similarities between this cohort of dogs and dogs with nasal neoplasia, although dogs with nasal polyps were often younger and polypoid tissue was external to the nose. Steroid therapy alone was not effective in treating polyposis in dogs; however, endoscopic debulking with a laser and forceps was more effective.     

Long-term outcome of myotonia associated with hyperadrenocorticism in 2 dogs

Two dogs were diagnosed with myotonia associated with hyperadrenocorticism and treated with trilostane. One dog showed temporary improvement, but the other dog showed no improvement. The dogs survived 2383 and 1902 days, respectively. Findings suggest that myotonia persists despite treatment, but this condition is not associated with a poor prognosis for survival.     

Intranasal melanoma treated with radiation therapy in three dogs

Three dogs were investigated for chronic unilateral nasal discharge. In all cases CT imaging showed an intranasal mass causing turbinate lysis and no evidence of metastasis. Cytology in cases 1 (a 14-year-old neutered male crossbreed dog) and 2 (a five-year-old neutered male German Shepherd dog) demonstrated a pleomorphic cell population with variable intracellular pigment suspicious of melanocytic neoplasia. Histopathology with immunohistochemistry (Melan-A and vimentin, plus PNL-2 in one case) confirmed the diagnosis of melanoma in all dogs. All dogs were treated with megavoltage radiotherapy using linear accelerators. Cases 1 and 3 (a nine-year-old neutered female beagle dog) received a hypofractionated (4 × 8 Gy) protocol and case 2 received a definitive (12 × 4 Gy) protocol. Complete remission was demonstrated on repeat CT scan five months after diagnosis in case 1 and seven months in case 2. Stable disease was documented on CT at four months for case 3; however, clinical signs in this dog remained controlled for 10 months in total. Case 1 died of unrelated causes five months after diagnosis, case 2 was euthanased due to the development of seizures 13 months after diagnosis, and case 3 was lost to follow-up 12 months after diagnosis. Melanoma should be considered as a rare differential diagnosis for primary nasal neoplasia in the dog and radiation therapy can be used as effective local therapy.     

Histological evaluation of the adrenal glands of seven dogs with hyperadrenocorticism treated with trilostane

The lesions in the adrenal glands of seven dogs with hyperadrenocorticism that had been treated with trilostane were studied histologically. The glands of the six dogs with pituitary-dependent hyperadrenocorticism had moderate to severe cortical hyperplasia that was either diffuse or nodular. The lesions were more pronounced in the zona fasciculata than in the zona reticularis, and the zona glomerulosa was normal. In the dog with a functional adrenal tumour the non-tumour bearing adrenal gland showed mild nodular hyperplasia. Five of the seven dogs had variable degrees of adrenal necrosis, which was severe in two of them. The terminal deoxynucleotidyl transferase-mediated DUTP nick-end labelling (TUNEL) reaction specified areas of cell death as apoptosis in three of the dogs, and was positive in one of the dogs without visible areas of cell death. There were variable degrees of cortical haemorrhage in three of the dogs. In some of the dogs the lesions were severe enough to lead to hypoadrenocorticism.     

Long-term outcome of surgery for dogs with cranial cruciate ligament deficiency

Fifty-eight dogs with cranial cruciate ligament deficiency were assessed and treated surgically. At an average of 50 months postoperatively, the functional outcome was assessed by means of an owner-based clinical assessment and a clinical examination. Client-based data were available for 26 dogs and 20 dogs were reassessed after 50 months. The results were compared with the initial values and with data from an assessment 13 months postoperatively. The level of disability at 50 months was judged to be significantly less than initially. However, there were no differences between the initial assessments and those made after 50 months for the perceived 'effect of cold weather' and the dogs' 'ability to jump', despite both measures having improved after 13 months. Age and meniscal injury were identified as poor prognostic indicators for the long-term outcome. The equivalent joint on the contralateral limb deteriorated significantly during the study.     

Long-term outcome of gonadectomy performed at an early age or traditional age in dogs

OBJECTIVE: To determine long-term results and complications of gonadectomy performed at an early age (prepubertal) or at the traditional age in dogs. DESIGN: Cohort study. ANIMALS: 269 dogs from animal shelters. PROCEDURE: Dogs that underwent gonadectomy were allotted to 2 groups on the basis of estimated age at surgery (traditional age, > or =24 weeks old; prepubertal, < 24 weeks old). Adoptive owner information was obtained from shelter records, and telephone interviews were conducted with owners to determine physical or behavioral problems observed in the dogs since adoption. Follow-up information was obtained from attending veterinarians for dogs with complex problems or when owners were uncertain regarding the exact nature of their dog's problem. RESULTS: Prepubertal gonadectomy did not result in an increased incidence of behavioral problems or problems associated with any body system, compared with traditional-age gonadectomy, during a median follow-up period of 48 months after gonadectomy. Rate of retention in the original adoptive household was the same for dogs that underwent prepubertal gonadectomy as those that underwent traditional-age gonadectomy. Infectious diseases, however, were more common in dogs that underwent prepubertal gonadectomy. CONCLUSIONS AND CLINICAL IMPLICATIONS: With the exception of infectious diseases, prepubertal gonadectomy may be safely performed in dogs without concern for increased incidence of physical or behavioral problems during at least a 4-year period after gonadectomy.     

Long-term outcome of therapy for 59 cats and 11 dogs with cryptococcosis

OBJECTIVE: To determine the outcome of therapy in cats and dogs with naturally occurring cryptococcosis. Design Retrospective study of 59 cats and 11 dogs at the University Veterinary Centre Sydney from 1986 to 2004. METHOD: Following detailed analysis of case notes potential associations between patient characteristics, cryptococcal species, retroviral status (cats), disease severity and type of therapy were examined in relation to duration and success of therapy. Treatment protocols based on amphotericin B, fluconazole and itraconazole were compared. RESULTS: Seventy-six percent of feline patients were successfully treated. For cats, the presence of central nervous system disease was the only factor found to influence outcome. Cats with neurological involvement, disseminated disease or refractory disease treated with amphotericin B containing protocols did as well, on average, as cats with less severe disease treated with azole monotherapy. Amphotericin B was thus an effective agent for treating severe cases of cryptococcosis. The median cumulative dose of amphotericin B for cats cured at the first attempt was 16 mg/kg (range 7 to 23 mg/kg). The median duration of treatment required to effect a cure at first attempt was significantly shorter for fluconazole (4 months; range 1 to 8 months) than for itraconazole (9 months; range 3 to 24 months; P = 0. 0191; Mann Whitney U test). The success rate for treatment of canine cases was 55%. No factor appeared to influence disease outcome in dogs. Large cumulative doses of amphotericin B could be administered via the subcutaneous route in both species and generally with minimal nephrotoxicity. Recrudescence occurred in a significant proportion of animals, in some cases despite a reduction of serum latex cryptococcal antigen agglutination test to zero. CONCLUSION: Although the prognosis of cryptococcosis should be described as guarded, a majority of the canine and especially feline patients can be expected to be cured, although treatment is protracted and expensive.     

Effects of radiotherapy alone and surgery and radiotherapy on survival of dogs with nasal tumours

The case records of 26 dogs with nasal tumours, treated either with radiation alone or surgery and radiation, were compared. One- and two-year actuarial survival rates for 12 dogs treated with radiotherapy were 58 and 13 per cent, respectively, compared to 71 and 38 per cent, respectively, for 14 dogs which were treated with surgery before radiotherapy. Sixty-seven per cent of the dogs treated with radiotherapy had recurrent clinical signs by 52 weeks compared to 36 per cent of the dogs treated with surgery and radiotherapy. The longer disease-free interval of the dogs treated with surgery and radiotherapy was statistically significant. When dogs with sarcomas were compared to those with carcinomas, there was no significant difference in disease-free interval or survival time.     

Long-term outcomes in dogs with sinonasal aspergillosis treated with intranasal infusions of enilconazole

Long-term outcomes (mean 38+/-17 months) were evaluated in 27 dogs with sinonasal aspergillosis after successful medical treatment using intranasal infusions of 1% or 2% enilconazole (1%, n=15; 2%, n=12). Long-term outcomes with both treatment protocols were good, with half of the dogs being asymptomatic throughout the follow-up period. The remaining dogs showed mild clinical signs compatible with chronic rhinitis/sinusitis. These clinical signs were interpreted as chronic lymphoplasmacytic rhinitis/sinusitis and episodes of bacterial rather than fungal infection. Three dogs had confirmed reinfection or relapse 2 to 36 months after clinical resolution.     

Severe carpal and tarsal shearing injuries treated with an immediate arthrodesis in seven dogs

The medical records of seven dogs with severe, grade 3, open shearing wounds of the carpus or tarsus that were treated with an immediate arthrodesis were reviewed. Six dogs were managed with a transarticular external skeletal fixator (ESF), and one dog was treated with plate fixation. The soft tissues were managed simultaneously along with the definitive joint stabilization in all cases. Minor complications occurred in four dogs: one dog that required a skin graft, one dog in which a skin graft was recommended but not performed, one dog in which a secondary skin closure was performed, and one dog in which a delayed cancellous bone graft was placed. Major complications occurred in three dogs: two dogs that required restabilization of the arthrodesis and one dog that required implant (i.e., plate) removal due to infection. All dogs healed with acceptable functional and cosmetic results. Further long-term evaluation of five dogs revealed that all but one dog had either excellent or good functional outcomes, and the remaining dog had a fair outcome. Similarly, five dogs had either excellent or good cosmetic outcomes, with the remaining dog having a fair outcome. All owners were very satisfied with the overall results. This clinical study demonstrated that an immediate, definitive management technique, in which bone fusion and wound management are undertaken as simultaneous objectives, is a viable technique of managing severe periarticular shearing injuries. Transarticular stabilization with an ESF is the technique recommended.     

Outcomes of 35 dogs with craniomaxillofacial osteosarcoma treated with stereotactic body radiation therapy

Canine craniomaxillofacial osteosarcoma (OSA) is most commonly treated surgically; however, in cases where surgery is not feasible or non-invasive treatment is desired, stereotactic body radiation therapy (SBRT) may be elected for local tumour control. In this study, we evaluated 35 dogs treated with SBRT. Nine dogs (26%) had calvarial, seven (20%) had mandibular and 19 (54%) had maxillary OSA. Median time to first event (TFE) was 171 days, and overall median survival time (MST) was 232 days. Site-specific MSTs were 144 days for mandible, 236 days for calvarium and 232 days for maxilla (p = .49). Pulmonary metastatic disease was observed in 12/35 (34%) patients and was detected pre-SBRT in six dogs (17%) and post-SBRT in the remaining six dogs (17%). Eighteen adverse events post-SBRT were documented. Per veterinary radiation therapy oncology group criteria, five were acute (14%) and three were late (9%) grade 3 events. Neurological signs in two dogs were suspected to be early-delayed effects. Cause of death was local progression for 22/35 (63%) patients, metastasis for 9/35 (26%) patients and unknown for four. On univariate analysis, administration of chemotherapy was associated with a longer TFE (p = .0163), whereas volume of gross tumour volume was associated with a shorter TFE (p = .023). Administration of chemotherapy and five fractions versus single fraction of SBRT was associated with increased survival time (p = .0021 and .049). Based on these findings, a treatment protocol incorporating chemotherapy and five fractions of SBRT could be considered for dogs with craniomaxillofacial OSA electing SBRT with careful consideration of normal tissues in the field.