PALLIATIVE RADIATION THERAPY OUTCOMES FOR CATS WITH ORAL SQUAMOUS CELL CARCINOMA (1999–2005)

Squamous cell carcinoma (SCC) accounts for approximately 10% of all feline tumors. The purpose of this retrospective study was to describe outcomes for a group of cats with oral SCC that were treated with palliative radiation therapy. Fifty‐four cats met the inclusion criteria of nonresectable, oral SCC treated with coarse fractionated megavoltage (MeV) radiation therapy. Radiation therapy for all cats was delivered with a 6 MeV linear accelerator. Total radiation doses of 24 Gray to 40 Gray were administered in three to four fractions, once‐per‐week over 4 to 5 weeks. Concurrent chemotherapy protocols varied and were administered at the discretion of the clinician and client. Forty‐nine patients completed the planned treatment protocols. Overall mean and median survival times for cats completing the planned treatment protocols were 127 and 92 days (n = 49). Mean and median survival times of cats receiving palliative radiation therapy alone were 157 and 113 days (n = 12). Mean and median survival times of patients receiving both radiation therapy and chemotherapy were 116 and 80 days (n = 37). Patients with sublingual tumors had a median survival time of 135 days (n = 15), compared to mandibular tumors that had a median survival time of 80 days (n = 26). For the majority of patients that completed the planned treatment protocol (65%), owners reported a subjectively improved quality of life. Findings from this uncontrolled study supported the use of palliative radiation therapy for cats with nonresectable oral squamous cell carcinoma.     

The neurophysiology of dyspnea

Objective – To review the human and veterinary literature regarding the neurophysiology of dyspnea and to provide evidence for the beneficial effects of several novel therapies aimed at the alleviation of dyspneic sensations. Data Sources – Data sources included scientific reviews, case reports, original research publications, and recent research conference proceedings. Human Data Synthesis – The use of blood oxygenation level‐dependent functional magnetic resonance imaging technology has revealed that the brain regions activated by air hunger in humans are also those activated by fear, pain, and thirst perception. In human subjects, it has been found that agents known to enhance the firing of pulmonary slowly adapting receptors (SARs) can alleviate the sensation of dyspnea without altering central respiratory drive. Several small studies have also shown that nebulized opioids can reduce the sensation of dyspnea apparently via activation of peripheral opioid receptors in the lung. Veterinary Data Synthesis – There are several animal models relevant to both small and large animal clinical patient populations. Treatment of rats with a nebulized SAR sensitizing agent (furosemide) enhances SAR firing in response to lung inflation. Behavioral escape responses to airway occlusion are reduced in lightly anesthetized cats when treated with nebulized furosemide. Opioid agonists have been shown to inhibit the release of acetylcholine and other mediators from the airways of dogs and guinea pigs. Studies using a goat model with bilateral destruction of the pre‐Bötzinger Complex do not support current paradigms of air hunger origination. Conclusions – Veterinary patients may benefit from an approach to dyspnea that incorporates an understanding of the origins of the unpleasant sensations associated with the condition. Several novel therapies have shown promise in alleviating dyspneic sensations without altering respiratory drive. Further study is needed to determine the safety and efficacy of these therapies in veterinary patients.     

PALLIATIVE RADIOTHERAPY FOR CANINE APPENDICULAR OSTEOSARCOMA

Fifteen dogs with appendicular osteosarcoma (presumptive diagnosis, n = 6 dogs; biopsy confirmed, n = 9 dogs) were treated with palliative radiotherapy. Treatment entailed a total of three 10 Gy fractions of ⁶⁰Co radiation delivered over a three week period on days 0, 7 and 21, for a total dose of 30 Gy. Twelve dogs experienced improvement in limb function 7–22 days after the start of treatment. Long term followup was available for nine of the twelve responders. The duration of response was 17–288 days (n = 9 dogs; median = 130 days; mean = 116 days). Response duration did not appear to be related to initial tumor size. Palliative radiotherapy can result in improved limb function in dogs with appendicular osteosarcoma.     

PALLIATIVE RADIOTHERAPY OF APPENDICULAR OSTEOSARCOMA IN 95 DOGS

Ninety-five dogs with either a presumptive (n = 24) or biopsy confirmed diagnosis (n = 71) of osteosarcoma received palliative radiotherapy using 60Co photons. Parallel opposed beams were used with each dog receiving either 10 Gy on days 0, 7 and 21 (n = 58) or 8 Gy on days 0 and 7 (n = 37). The 8 Gy fractionation scheme was given with the intent of retreating upon relapse from pain relief. Only 9 of 37 (24%) dogs in the 8 Gy group returned for retreatment. Forty-seven of the 95 dogs (49%) received concurrent or sequential chemotherapy. Seventy of the 95 dogs (74%) experienced pain relief following treatment. In dogs experiencing pain relief the median duration of response was 73 days. Numerous clinical variables were evaluated as predictors of response. The only variable significantly related to achieving a response was the use of chemotherapy. The following variables were significantly related to the duration of response: extent of bone lysis, chemotherapy use, length of bone involved and tumor site (humerus). In a multivariate analysis (n = 73 dogs), after adjusting for chemotherapy use, extent of bone involvement (p = 0.01) and tumor site (p = 0.02) retained statistical significance, while degree of bone lysis did not (p = 0.11). No difference in response incidence or duration was found between 3 fractions of 10 Gy vs. 2 fractions of 8 Gy. Administration of a low initial dose with the intent of retreatment was not a successful strategy.     

RESPONSE OF FELINE ORAL SQUAMOUS CELL CARCINOMA TO PALLIATIVE RADIATION THERAPY

Seven cats with advanced oral squamous cell carcinoma were treated with palliative radiotherapy. Megavoltage radiation in 8 Gray (Gy) fractions was delivered on days 0, 7, and 21 for a total dose of 24 Gy. Treatment field included the mandible, oropharynx, retropharyngeal lymph nodes, and tonsils. Adjuvant treatment with chemotherapy was variable. Age ranged from 13 to 18 years old with a median age of 15 years. Three of the seven cats (43%) did not complete treatment. Six cats were euthanized due to tumor growth and/or radiation side effects with a median survival time of 60 days (range = 42 to 97 days, mean = 63 +/- 8.4 days). Radiotherapy complications or progression of disease occurred in 6 of 7 (85.7 %) cats and included adverse clinical signs, such as mucositis, serosanguinous oral discharge, pain, and dysphagia. These data suggest that coarse fractionation radiotherapy did not result in palliation in cats with inoperable oral squamous cell carcinoma.     

PALLIATIVE IRRADIATION OF SCOTTISH FOLD OSTEOCHONDRODYSPLASIA

This report describes palliative irradiation as treatment for Scottish Fold osteochondrodysplasia. A 3-year-old female spayed Scottish Fold cat suffering from osteochondrodysplasia was referred to the Veterinary Teaching Hospital, University of Zurich. Based on the breed, history, clinical signs, radiographic findings, and the histologic diagnosis of a biopsy specimen, Scottish Fold osteochondrodysplasia was confirmed. To control the exostoses leading to inflammatory processes and pain, radiotherapy was initiated as palliative treatment. This was successful in relieving the clinical signs within a few weeks. The short- and long-term results after radiotherapy are presented and discussed with a comparable human disease, the plantar heel spur, which also responds well to radiotherapy.     

Hypofractionated radiation therapy for the treatment of microscopic canine soft tissue sarcoma

Soft tissue sarcomas (STSs) are locally invasive and surgery with or without radiation therapy is the current standard of care in dogs. Typical protocols for treating incompletely excised STSs involve curative intent radiation with total dose in excess of 50 Gy. Forty‐eight dogs with histologically confirmed incomplete or closely excised STSs were treated with a hypofractionated protocol that is typically reserved for palliative radiation therapy (RT) (6–8 Gy/weekly fractions to a total dose of 24–32 Gy). Ten dogs (21%) developed local recurrence, 11 dogs (23%) developed metastasis, and 3 dogs developed both (included in each group). The median progression free survival was 698 days. The local failure‐free probability at 1 and 3 years was 81 and 73%. The 1 and 3 years tumour‐specific overall survival was 81 and 61%. Long‐term local tumour control was achieved in the majority of dogs. This protocol is reasonable to prescribe in older patients or when financial limitations exist.     

Description and efficacy of a response-based “QUAD” cyclical hypofractionated palliative-intent radiation protocol in dogs with macroscopic solid tumours: 108 cases

Palliative-intent radiation therapy can alleviate pain and clinical signs in dogs with cancer, but optimal fractionation scheme is unknown. The objective of this retrospective case series is to evaluate clinical benefit, objective response, adverse effects, and outcomes in 108 dogs with macroscopic solid tumours treated with a cyclical “QUAD” hypofractionated palliative-intent radiation therapy protocol. Median QUAD dose was 14 Gy (14–16 Gy). Median total dose was 28 Gy (14–48 Gy). Clinical benefit rate was 93%, with median onset of subjective palliation 21 days after the first QUAD, lasting a median of 134 days. Tumour volumetric objective response was assessed with CT prior to the third QUAD in 36 dogs, with stable disease in 24 dogs (67%) and partial response in 9 dogs (25%). Sinonasal and oral were the most common tumour locations in 32 and 30 dogs, respectively. Median progression-free survival was 153 days (95% CI 114–200). Median overall survival was 212 days (95% CI 152–259). Number of QUAD cycles completed, clinical benefit achieved, anti-inflammatory received, total radiation dose, time to maximum clinical benefit, and response duration were positively associated with progression-free and overall survival. Acute toxicities were observed in 15 dogs (14%) with 3 high-grade (grade 3) toxicities (3%). Low-grade (grade 1 and 2) late skin and ocular toxicities were observed in 31 dogs (29%), predominantly leukotrichia, alopecia, keratoconjunctivitis sicca, and cataracts. This report demonstrates that QUAD radiation is an alternative protocol to be considered for palliation of dogs with inoperable or advanced stage solid tumours.     

USE OF FORCE PLATE ANALYSIS TO EVALUATE THE EFFICACY OF EXTERNAL BEAM RADIATION TO ALLEVIATE OSTEOSARCOMA PAIN

A standard of therapy for osteosarcoma includes amputation with or without adjuvant chemotherapy. There is a subset of dogs with osteosarcoma that are unsuitable for amputation. We evaluated kinetic variables in dogs with appendicular osteosarcoma treated with a single 8 Gy dose of radiation. Eighteen pet dogs with appendicular osteosarcoma received one 8 Gy fraction of palliative radiation on day 0. Force plate measurements and clinical assessments were made on days 0, 7, 14, and 21. Peak vertical forces ( F _z) were recorded for each limb and a symmetric index (SI) was calculated. There were no significant changes in kinetic parameters after one 8 Gy dose of radiation therapy. Nine of these 18 dogs exhibited increased limb function at day 21 based on force plate analysis. Significant factors affecting F _z included gender and tumor location. There was a significant correlation between F _z and response to therapy based on SI at day 21. SI seems to be useful to objectively assess response in this mixed population of dogs. One 8 Gy fraction of radiation therapy alone did not reduce lameness associated with appendicular osteosarcoma, but a subset of dogs did have improved limb function after a single dose.     

Palliative radiotherapy as treatment for non-resectable soft tissue sarcomas in the dog – a report of 15 cases

Fifteen dogs with various non‐resectable soft tissue sarcomas were treated with a palliative protocol of Cobalt⁶⁰ radiation. Twelve (80%) of the 15 tumours were fibrosarcomas and haemangiopericytomas. Total tumour radiation dose was 24 Gy, given in three 8 Gy fractions, on days 0, 7, 21 or weekly. Thirteen tumours (87%) responded with stable disease; median time to progression and median survival time were 263 and 332 days, respectively. Radiation toxicity was negligible. The survival and local control with this palliative protocol are almost comparable with curative intent primary radiotherapy.     

Assessment of a point-of-care lactate monitor in emergency admissions of adult horses to a referral hospital

BACKGROUND: Blood lactate concentration [LAC] is considered a useful indicator of disease severity in horses. Agreement of point-of-care (POC) lactate monitors with laboratory standards has not been established for clinically abnormal horses. Hypothesis: It was hypothesized that results from a POC lactate monitor would be in agreement with a laboratory-based measurement of [LAC]. ANIMALS: The study included adult horses presented for emergency evaluation. METHODS: A prospective observational study was performed. [LAC] was measured with whole blood (AWB) and plasma (APL) by means of a POC monitor (Accutrend) and compared with results from whole blood measured by a laboratory blood gas analyzer (NOVA). RESULTS: Samples from 221 horses were used to compare the 2 lactate measurement techniques. Agreement (p +/- SE) was closest between APL and NOVA (0.97 +/- 0.01); an average observed difference of 0.15 +/- 0.89 (mean +/- SD) and 95% limits of agreement (LOA) -1.89, 1.59 also were found. Agreement was preserved and 95% LOA further decreased in horses with NOVA [LAC] of <5 mM and PCV <40%. Agreement was modest when testing whole blood samples on the POC monitor with increased 95% LOA. CONCLUSIONS AND CLINICAL IMPORTANCE: Results indicate close agreement between NOVA and the POC monitor when [LAC] was measured with plasma. Results were less consistent at higher [LAC] but sufficiently reliable to follow trends. Although whole blood may be used with the POC monitor to identify clinically important hyperlactatemia, results may be insufficiently reliable to monitor trends.     

The palliative efficacy of modified Mohs paste for controlling canine and feline malignant skin wounds

In veterinary medicine, the management of malignant skin wounds is highly challenging. We conducted a study on seven case animals (four dogs and three cats) which presented with malignant skin wounds. All seven animals had signs and symptoms which were controlled following treatment with a modified Mohs paste. Upon obtaining informed consent from their owners, the animals requiring management of malignant wounds were enrolled in this study. The modified Mohs paste was prepared by mixing zinc chloride, zinc oxide starch powder, glycerin, and distilled water. The modified Mohs paste was topically applied to and left to remain on the malignant wounds for one hour, under controlled conditions. Once the paste was removed, the wounds were irrigated with a solution of sterile saline. At the first examination, the wounds of each animal were observed for signs of exudate, malodor, and bleeding. In every case, visible improvement was observed immediately after the modified Mohs paste treatment. Specifically, the size of the malignant wounds, and the number of times the dressing gauze required changing, significantly decreased (p < 0.05 and p < 0.01, respectively). The open malignant skin wounds caused by mammary gland tumors disappeared in two cases. The Mohs paste has been shown to be a viable option for the palliative treatment in canine and feline malignant skin wound management.     

A possible role of coarse fractionated radiotherapy in the management of gingival squamous cell carcinoma in dogs: A retrospective study of 21 cases from two referral centers in the UK

Surgery with or without the addition of radiotherapy is the treatment of choice for canine oral squamous cell carcinoma (SCC). Fractionated radiotherapy alone is also effective in the long-term control of the disease, however coarse fractionated radiotherapy (CF-RT) for gingival SCC has not been extensively reported. The aim of this study was to describe side effects, clinical response, and median survival time (MST) of dogs with gingival SCC treated with CF-RT in the palliative and adjuvant setting. Twenty-one cases from two referral centres in the UK treated with CF-RT for gingival SCC between July 2013 and June 2019 were retrospectively evaluated. Of the 21 dogs, 11 developed mild acute adverse effects. Oral mucositis was the most common radiation induced toxicity. Three dogs developed chronic severe adverse effects (oro-nasal fistula, bone necrosis and gum recession). Overall clinical response rate was 77% in dogs receiving palliative treatment with MST of 365 days (60–1,095 days). MST was not reached for dogs treated in the adjuvant setting with a mean of 466 days (121–730 days). In cases of advanced gross disease CF-RT might have a role in short term palliation of clinical signs. However, it carries a significant risk of late toxicity for cases with unexpectedly long survival times and further investigations are required to identify an optimal CF-RT protocol. Randomized controlled trials are needed to confirm the role of CF-RT as adjuvant treatment of incompletely resected gingival SCC.     

Successful use of short‐term mechanical ventilation to manage respiratory failure secondary to profound hypokalemia in a cat with hyperaldosteronism

Objective – To report successful management of respiratory failure due to severe hypokalemia in a cat with hyperaldosteronism, including short‐term mechanical ventilation strategies and aspects of medical and surgical treatment. Case Summary – A cat presented with bilateral pelvic limb weakness that rapidly progressed to tetraparesis and respiratory muscle failure. Point‐of‐care testing revealed severe hypokalemia (1.9 mmol/L) and mild azotemia. Initial management included endotracheal intubation, mechanical ventilation, and aggressive potassium supplementation. Spironolactone was started due to a high index of suspicion for hyperaldosteronism. A right adrenal mass visualized during abdominal ultrasonographic examination and a serum aldosterone level greater than 3329 pmol/L confirmed the diagnosis. The cat made a full recovery following surgical removal of a right adrenal adenoma. New or Unique Information Provided – We report successful management of respiratory failure in a cat with hyperaldosteronism using short‐term mechanical ventilation. Respiratory failure due to severe hypokalemia should be considered a complication of hyperaldosteronism in cats and may require mechanical ventilation. However, full recovery is possible.     

如何做好猪群的保健

猪群保健不只是平常所说的保健用药，而是一个系统的工程，它包括猪场的选址，猪群营养，猪群的管理，养殖人员工作落实情况等几个关键点，文章对这几个方面谈谈自己的看法和体会，供大家参考。