Factors Which Influence Owners When Deciding to Use Chemotherapy in Terminally Ill Pets

Cat and dog owners' expectations and attitudes towards advanced veterinary care (AVC) in the UK, Austria and Denmark

Modern veterinary medicine offers a level of care to cats and dogs similar to that available to their owners, including blood transfusions, chemotherapy and MRI scans. The potential benefits to the animals of owners who can afford such care are obvious, but there can also be negative consequences if owners with strong emotional attachments to their pets pursue treatments that significantly reduce the quality of the animal's life while attempting to prolong it. Moreover, caring for a chronically or seriously ill animal can lead to emotional distress and financial and practical challenges for the pet owner. A questionnaire was used to survey cat and dog owners from representative samples of citizens in the UK, Austria and Denmark, to investigate owners' expectations and attitudes towards advanced veterinary care, and the factors that might influence those views. Overall, 58.4% of the pet owners surveyed believed that their pets should have access to the same treatment options as humans, while 51.5% believed that they should have access to the same diagnostic tests as humans. Owners were most likely to be neutral on the question of whether advanced veterinary care has 'gone too far' (45.3%), and to disagree with the statement that advanced care is 'unnecessary' (40.1%). In all three countries, the level of attachment owners had to their pets was most strongly associated with attitudes towards advanced care, with owners scoring higher on Lexington Attachment to Pets Scale (LAPS) being more likely to expect advanced care to be available. Other factors such as owner age, living situation (alone or not), income or possession of pet insurance were less consistently with owner attitudes. Our findings will help inform veterinarians and other health care providers about pet owner expectations and attitudes towards advanced veterinary care, and contribute to the debate on increasing specialisation within the profession.

Effects of a high-protein, increased-fibre, dry diet supplemented with omega-3 fatty acids on quality of life in dogs undergoing chemotherapy

Quality of life (QOL) in dogs with cancer is a key consideration in the assessment of cancer treatment options. Despite interest in dietary strategies to improve management of oncology patients, there have been very few clinical studies showing the impact of diet on adverse effects of chemotherapy in dogs. This study was a randomised, controlled, double-blinded, multicenter clinical trial to investigate a high-protein, increased-fibre diet supplemented with omega-3 fatty acids, for dogs with cancer undergoing standard-of-care chemotherapy. Client-owned dogs with newly diagnosed grade 2 or higher mast cell tumours (or non-resectable/incompletely resected tumours) or multicentric lymphoma were randomised to receive the test diet (n = 24) or control diet (n = 21) for 8 weeks. Primary outcomes were QOL assessments, faecal scores, and blood concentrations of C-reactive protein and monocyte chemoattractant protein-1. Of 12 QOL parameters, 10 significantly improved from baseline to Week 8 in the test group compared with one in the control group. However, differences between the two groups were only statistically significant for 'frequency of signs of illness' (P = .009). There were no significant differences in the incidence of any adverse events, including gastrointestinal adverse events or clinically significant differences in laboratory parameters or faecal scores between the two groups. The absence of an observed negative impact of the test diet, combined with the magnitude of QOL improvements associated with the diet, suggest that a larger trial is warranted.

Viscum album (mistletoe) extract for dogs with cancer?

Compared with the options available to human patients with cancer, treatment choices for dogs are often more limited. Chemotherapy is frequently the first-line treatment for many cancers. However, its efficacy can be limited, and its side effects can affect the quality of the remaining life. This paper briefly summarizes the experience with Viscum album L. (mistletoe) extract in human patients as a stipulation to consider treatment with mistletoe extract for canines with cancer. The mistletoe extract contains -among others - lectins and viscotoxins that have documented anti-proliferative effect on cancer cells as well as immune-stimulatory function. Importantly, it also improves the well-being of patients with cancer due to its lectin ML-1 content, which can trigger the release of endorphins. Being cross-reactive with canine cells and having a relatively low side effect profile, it raises the question of whether mistletoe preparations might be considered as part of the treatment approach for dogs with cancer.

Acceptance of a Novel, Highly Palatable, Calorically Dense, and Nutritionally Complete Diet in Dogs with Benign and Malignant Tumors

Diminished appetite and poor eating behavior accompanied by weight loss or cachexia are often reported in dogs living with cancer. This study was conducted to determine the acceptance and eating enthusiasm in dogs with cancer for a new therapeutic, nutritionally balanced, and calorically dense food designed for dogs with cancer. Adult dogs with diagnosis of cancer were recruited from general and oncology practices and were fed the study food for 28 days. Evaluations included physical examination, body weight, food intake, caloric intake, hematology and serum biochemistry, and owner assessments, namely food evaluation, quality of life, and stool scores. The dogs transitioned smoothly and tolerated the food very well. The results showed high food acceptance within the first day, with continued eating enthusiasm over the 28 days. Significant increases in food and caloric intake were observed, with the study food having a positive impact on body weight in dogs that were losing weight and helping to maintain a high quality of life. Blood laboratory parameters remained within reference ranges. Thus, the therapeutic study food was well accepted and efficacious in supporting continued eating and required caloric intake, promoting a healthy weight gain and maintaining a high quality of life in dogs with cancer.

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.

Canine Gastric Cancer: Current Treatment Approaches

Simple Summary

Human gastric cancer is a prevalent cancer worldwide with a high mortality rate. Although sharing many other features, the incidence of gastric cancer is lower in dogs than in humans. Surgery is the first-line treatment; however, it is associated with several complications. Nevertheless, chemotherapy to treat canine gastric cancer has not received much attention, probably due to its late diagnosis, fast progression, low median survival time, and very high mortality rate, along with the lack of publications with concrete scientific results. In this review, we explore the pharmacological approach used in treatment of this often-fatal disease.

Abstract

Human gastric cancer (GC) ranks as the fifth most prevalent cancer worldwide, and is the third leading cause of cancer-related death. The incidence of GC is lower in dogs than in humans, accounting for less than 1% of all canine malignancies. In recent years, efforts have been made to understand the pathogenesis of GC and in find an appropriate therapy to maximize curative results, such as adjuvant chemotherapy treatments in addition to surgery. Although surgery is the first-line treatment, it is associated with several complications. In terms of chemotherapeutic intervention, canine gastric cancer has not received much attention, probably due to its late diagnosis, fast progression, low median survival time, and very high mortality rate, along with the lack of publications with concrete scientific results. In this review, we explore canine GC and the pharmacological approach used in the treatment of this often-fatal disease.

Field safety experience with an autologous cancer vaccine in tumor-bearing cats: a retrospective study of 117 cases (2015-2020)

OBJECTIVES

The aim of this study was to determine the frequency and severity of adverse events (AEs) reported from use of an adjuvanted whole-cell autologous cancer vaccine in cats with solid tumors under field conditions.

METHODS

The case accession database at Torigen Pharmaceuticals was searched to identify client-owned cats that underwent biopsy or surgical resection of their primary tumor, had histologic confirmation of neoplasia and received at least one subcutaneous dose of an adjuvanted whole-cell autologous cancer vaccine. Records were reviewed for any reported AEs.

RESULTS

In total, 117 cats met the inclusion criteria and received 422 doses of autologous cancer vaccine. Six (5.1%) cats had seven reported AEs, with the majority of these (85.7%) being characterized as grade 1 or 2 (mild) and resolving without medical intervention.

CONCLUSIONS AND RELEVANCE

AEs were infrequent in cats treated with an adjuvanted whole-cell autologous cancer vaccine under typical field use conditions. This form of active cancer immunotherapy appears to be well tolerated by cats and may represent a treatment option for owners who are concerned about AEs associated with chemotherapy or radiotherapy. Additional studies are warranted to determine the efficacy of this form of individualized immunotherapy in cats with solid tumors.

Dying like a dog: the convergence of concepts of a good death in human and veterinary medicine

Standard views of good death in human and veterinary medicine considerably differ from one another. Whereas the good death ideal in palliative medicine emphasizes the positive aspects of non-induced dying, veterinarians typically promote a quick and painless killing with the aim to end suffering. Recent developments suggest a convergence of both professions and professional attitudes, however. Palliative physicians are confronted with patients wishing to be 'put to sleep', while veterinarians have begun to integrate principles and practices from hospice care. We will argue that the discourses on good human and animal deaths are not distinct, but that they interact and influence each other. On the one hand, veterinary medicine adapts techniques like chemotherapy or sedation from palliative end-of-life care. On the other hand, philosophers, veterinarians, pet owners, patients and the general public alike make certain assumptions about the (dis)analogy of human and animal dying or killing. Unfortunately, these interactions have only scarcely been reflected normatively, especially on the part of human medicine. Conflicts and misattributions with potential serious negative consequences for the (animal and human) patients' wellbeing are provoked. For these reasons, palliative physicians and veterinarians are invited to engage in the debate around human and animal end-of-life care.

Appetite Stimulant and Anti-Emetic Effect of Mirtazapine Transdermal Ointment in Cats Affected by Lymphoma Following Chemotherapy Administration: A Multi-Centre Retrospective Study

Simple Summary

Feline cancer patients’ owners are increasingly willing to undertake oncologic treatment, such as chemotherapy. Concerns regarding worsening quality of life are common since chemotherapy could cause toxicities, such as vomiting, nausea, anorexia, and consequently weight loss. In humans, mirtazapine effectively prevents chemotherapy-induced nausea and vomiting, improving the quality of life in people receiving chemotherapy. Recently, the use of mirtazapine transdermal ointment has been evaluated in cats with non-cancer diseases. This study describes the use of transdermal mirtazapine administration in cats diagnosed with lymphoma and receiving chemotherapy. Patients included in the study did not receive any prophylactic anti-emetics other than transdermal mirtazapine. Data regarding patients, type of chemotherapy, and incidence of weight loss and gastrointestinal toxicities were retrospectively evaluated. Transdermal mirtazapine was well tolerated, and substantial weight loss was not observed in the 14 days following chemotherapy administration. These results support further studies assessing the impact of mirtazapine in preventing chemotherapy-induced gastrointestinal toxicity in cats.

Abstract

In humans, mirtazapine can prevent chemotherapy-induced nausea and vomiting (CINV) and improve cancer patients’ quality of life (QoL). This drug is being increasingly used as an appetite stimulant in cats. The hypothesis of this retrospective study was that mirtazapine could reduce the incidence of CINV and weight loss in feline patients affected by lymphoma. The objectives were to report the use of mirtazapine transdermal ointment and assess the incidence of gastrointestinal (GI) toxicity and weight loss in cats diagnosed with lymphoma and receiving chemotherapy. Transdermal mirtazapine was topically administered to the inner surface of the pinna (2 mg/cat/daily) for 14 days following chemotherapy administration. Data recorded from 20 patients were collected. Different grades of GI toxicity were shown in 8/20 (40%) patients. Body weight (BW), body condition score (BCS), and muscle condition score (MCS) improved in 12/20 (60%), 6/20 (30%), and 2/20 (10%) cats, respectively. Mirtazapine-induced adverse events (AEs) occurred in 4/20 (20%) cats and did not require mirtazapine discontinuation. Substantial weight loss was not encountered, suggesting that patients had an adequate food intake after chemotherapy administration. Transdermal mirtazapine ointment was considered safe and well tolerated.

The Use of Oligo Fucoidan in Cancer Bearing Dogs Undergoing Chemotherapy: A Double-Blinded Study

We evaluated the effect of oligo fucoidan (Laminina Japonica) derived from oceanic brown seaweed on the quality of life in dogs with cancer undergoing chemotherapy in a double-blinded case control study. Included in this prospective study were 100 dogs with a confirmed diagnosis of cancer that were being treated with chemotherapy. Dogs were randomly assigned to be treated with oligo fucoidan (treated group; n = 68) or placebo (placebo group; n = 32). Dogs were evaluated every 2-3 weeks for 3 months with a complete blood count (CBC) and serum biochemistry profile, and a complete history and physical examination by blinded clinicians at The Veterinary Cancer Center. The owners of the dogs enrolled in the study were required at each visit to complete a Quality-of-Life Questionnaire specifically designed for cancer-bearing veterinary patients. The owners were also blinded as to whether their dog was receiving oligo fucoidan or placebo. There were no significant differences between the CBC parameters or the serum biochemical parameters of the dogs in the treated and placebo-controlled groups. There was no significant difference in the median quality of life scores between the 2 cohorts, however, when evaluating the individual quality of life metrics, 5 out of the 23 metrics showed statistically significant improvement, and none of the quality-of-life metrics declined in the oligo fucoidan group as compared to the placebo group. All of the dogs that had a positive change in overall quality of life scores were dogs that received oligo fucoidan. There were minimal adverse side effects of giving the oligo fucoidan to dogs. Treatment with oligo fucoidan was safe and improved some of the quality-of-life metrics in dogs who were being treated with chemotherapy for cancer.

Survival time for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone: the Canine Lymphoma Steroid Only trial

OBJECTIVE

To evaluate survival times for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone.

ANIMALS

109 client-owned dogs recruited from 15 institutions in the United States.

PROCEDURES

Dogs were treated with prednisone at a dosage of 40 mg/m², PO, once daily for 7 days and at a dosage of 20 mg/m², PO, once daily thereafter. Quality of life (QOL) was assessed by owners with a visual analog scale when treatment was started (day 0), 1 and 2 weeks after treatment was started, and every 4 weeks thereafter. The primary outcome of interest was survival time as determined by the Kaplan-Meier method. Factors potentially associated with survival time were examined.

RESULTS

Median overall survival time was 50 days (95% CI, 41 to 59 days). Factors associated with survival time included substage (a vs b) and immunophenotype (B cell vs T cell). Owner-assigned QOL scores on days 0 and 14 were significantly positively correlated with survival time. When QOL score was dichotomized, dogs with day 0 or day 14 QOL scores ≥ 50 had significantly longer survival times, compared with dogs with day 0 or day 14 QOL scores < 50. No variables were predictive of long-term (> 120 days) survival.

CONCLUSIONS AND CLINICAL RELEVANCE

Results suggested that survival times were short for dogs with previously untreated, peripheral nodal, intermediate- or large-cell lymphoma treated with prednisone alone. Owner-perceived QOL and clinician-assigned substage were both associated with survival time. Findings provide potentially important information for clinicians to discuss with owners of dogs with lymphoma at the time treatment decisions are made.

"What Would You Do?": How Cat Owners Make End-of-Life Decisions and Implications for Veterinary-Client Interactions

Cats are the most common companion animals in New Zealand. Advances in veterinary care means that cats are living longer and there are many older cats. End-of-life decisions about cats are complicated by owner-cat relationships and other psychosocial factors. Our study explored the ways in which end-of-life decisions were being made by owners of older and chronically ill cats in New Zealand and the role of their veterinarian in the process. Qualitative data were gathered via retrospective semi-structured interviews with 14 cat owners using open-ended questions. Transcripts of these interviews were explored for themes using template analysis and nine themes were identified. Four were animal-centered themes: cat behavior change, pain was a bad sign, signs of ageing are not good, and the benefits of having other people see what owners often could not. Five were human-centered themes: veterinarians understanding owners' relationships with their cat, normalizing death, the need for a good veterinarian to manage end of life, veterinary validation that owners were doing the right thing, and a strong desire to predict the time course and outcome for their cat. End-of-life decision making is complex, and the veterinarian's role is often poorly defined. Our owners appreciated the expertise and validation that their veterinarian provided but continuity of care was important. Future research aimed at exploring the veterinarian's perspective during end-of-life decision making for cats would be a valuable addition to the topic.

A systematic review of the quality of life assessment tools for cats in the published literature

Quality of life (QoL) is an important parameter to assess in cats, as it can be pivotal to important decision-making. Research reports that owners of cats with heart disease would trade longevity for QoL, and treatment associated improvement in QoL is very important for cats with chronic kidney disease. This systematic review aimed to explore the published literature to identify the number and range of QoL assessment tools available to researchers and veterinary professionals, by discovering tools which have already been used in published studies. Medline and CAB Abstracts were searched in March 2018, using terms relevant to cats and QoL or well-being. Inclusion and exclusion criteria were applied and information on uniqueness, validation and a short description of each tool extracted. A total of 1138 manuscripts were identified, of which 96 met all criteria. Forty of 96 manuscripts contained an assessment of QoL, using one of 32 unique tools identified. Sixteen of the tools identified were structured, making detailed patient assessments. Only eight of the structured tools were validated, and of these, three could be applied to healthy cats; the remainder being specific to a disease or being hospitalised. Some validated tools appeared in more than one manuscript. Overall, 12 manuscripts used a validated tool. In the 16 unstructured tools, five tools assessed QoL by assigning a single word (e.g. 'poor'). Eight tools assessed QoL on a single Likert scale (e.g. a number between 1 and 5). This work identifies the tools that are currently available for the assessment of QoL by researchers and veterinary professionals. Additionally, it demonstrates that many are not validated or lack detailed animal assessment, highlighting that further work in this important area is needed.

Evaluation of an autologous cancer vaccine for the treatment of metastatic canine hemangiosarcoma: a preliminary study

Background

Canine hemangiosarcoma (HSA) is an aggressive cancer arising from multipotential bone marrow-derived stem cells. Anthracycline chemotherapy drugs have been the mainstay adjuvant chemotherapy following surgery with only modest improvement in survival and an attendant risk for adverse events. Immunotherapy, using a whole cell autologous cancer vaccine adjuvanted with MIM-SIS, may improve outcomes for dogs with HSA with a lower risk for adverse events compared with chemotherapy.

Results

In cultured DH82 canine monocyte-like cells, autologous cancer vaccines prepared from 13 dogs with HSA increased MHC-II surface expression ranging from 20.0-60.4% on single-stained cells, CD80 surface expression ranging from 23.7–45.9% on single-stained cells, and MHC-II/CD80 surface expression ranging from 7.2–20.1% on double-stained cells. Autologous cancer vaccines were able to, on average, stimulate an up-regulation of MHC-II and CD80 by 48-fold as compared to media only (MHC-II + CD80 + cells: 12.19 ± 3.70% vs. 0.25 ± 0.06%; p < 0.001). The overall median survival time for dogs treated with the autologous cancer vaccine was 142 days (range, 61 to 373 days). Dogs treated with the autologous cancer vaccine or maximum tolerated dose (MTD) chemotherapy had significantly (P < 0.001) longer survival than dogs treated with surgery alone. The 1-year survival rate was 12.5% for dogs treated with the autologous cancer vaccine, and 0% for dogs treated with surgery alone or MTD chemotherapy. No adverse events were observed in the dogs treated with the autologous cancer vaccine.

Conclusions

The adjuvanted autologous cancer vaccine is capable of up-regulating MHC-II and CD80 in cultured canine monocyte-derived cells, which are important stimulatory molecules in generating an immune response and improves survival time in dogs with metastatic (stage III) HSA when compared to surgical treatment alone. Autologous cancer vaccine-treated dogs had survival similar to those dogs treated with MTD chemotherapy without any observed adverse events. This autologous cancer vaccine represents an effective form of individualized immunotherapy that is an appealing option for dog owners not wanting to pursue adjuvant chemotherapy for HSA.

Complex Disease Management: Managing a Cat with Comorbidities

Many older cats often suffer concurrently from multiple conditions. By focusing on the common concerns, rather than conflicting requirements, a management program can be devised. Optimize hydration, nutrition, and ensure comfort though providing analgesia and a low-stress environment in which the patient's feline-specific nature is respected both in the clinic and at home. Additional requirements, such as hyperphosphatemia or hypokalemia, can be met using treatments outside of diet, if necessary.

The Use of Chemotherapy to Prolong the Life of Dogs Suffering from Cancer: The Ethical Dilemma

Despite the emergence some years ago of oncology as a veterinary specialty, there has been very little in the way of ethical debate on the use of chemotherapy in dogs. The purpose of this article is to undertake an ethical analysis to critically examine the use of chemotherapy to prolong the life of dogs suffering from cancer. If dogs have no concept of the future and are likely to suffer at least some adverse effects with such treatments, consideration should be given as to whether it is ethical and in the animal's best interests to use chemotherapy. Chemotherapeutic drugs are mutagenic, carcinogenic, teratogenic and may be irritant. Furthermore, chemotherapy may involve multiple trips to the veterinarian, multiple procedures and periods in isolation. Cancer-associated pain has been shown to be under-diagnosed and pet owners overestimate the effects of chemotherapy on treatment survival time. Of additional concern is the public health risks associated with chemotherapeutic drugs. As chemotherapy is not generally considered curative, it is in effect palliative care. However, palliative care may not be in the best interests of a terminally ill animal. As the specialty of veterinary oncology continues to grow and as the use of chemotherapy becomes more commonplace in the treatment of animals with cancer, it is imperative that there is an ongoing ethical debate on the use of chemotherapy in animals.

Anorexia and the Cancer Patient

Appetite influences perceived quality of life for a dog or cat with cancer. Inappetence often is multifactorial, complicating treatment. Cancer-related anorexia/cachexia syndrome is a metabolic, paraneoplastic syndrome characterized by decreased food intake, involuntary weight loss, and loss of fat and muscle. If weight loss/cachexia has an impact on canine and feline cancer patients as in humans, management may improve survival times and quality of life. The challenge is having effective, proved therapies available for clinical use. Recent Food and Drug Administration approvals for appetite stimulation have renewed interest and discussion and has the potential to alter the course of case management.