Quality of Life Measurement in Prospective Studies of Cancer Treatments in Dogs and Cats

Background

Quality of life (QOL) is an important consideration in healthcare decision‐making for pets with cancer. To determine the effect of disease and treatment on pet QOL, this important variable should be objectively measured as an outcome in veterinary cancer studies.

Objectives

To determine the prevalence and methodology of QOL measurement in a sample of recently published reports of prospective studies evaluating cancer treatments in client‐owned dogs and cats; to characterize reporting of QOL outcomes and to identify article characteristics associated with QOL measurement.

Methods

English‐language reports of prospective studies of cancer treatments in dogs and cats published from 2008 to 2013 were identified using medical research databases combined with a hand‐searching strategy. Data pertaining to general article characteristics and QOL measurement were abstracted and summarized.

Results

Reports of 144 eligible studies were identified. QOL was measured in 16 (11.1%) studies, with 8 (5.6%) reporting the results. All studies that measured QOL reported using unvalidated instruments, or did not report how QOL was assessed. Only 1 study provided sufficient information for QOL measurements to be replicated. Recently published articles (2011–2013) were significantly more likely to report measuring QOL, compared with earlier articles.

Conclusions

Quality of life of pets undergoing cancer treatment is largely unreported and cannot be meaningfully compared across treatments or disease states using the existing literature. Reliable, validated instruments are needed to facilitate the measurement and comparison of pet QOL in veterinary cancer research. Consistent reporting practices could improve transparency and interpretation of QOL results.     

Pancreatitis in Cats

Pancreatitis was considered a rare disease in the cat until a couple of decades ago when several retrospective studies of severe acute pancreatitis were published. It was apparent that few of the diagnostic tests of value in the dog were helpful in cats. With increasing clinical suspicion, availability of abdominal ultrasonography, and introduction of pancreas-specific blood tests of increasing utility, it is now accepted that acute pancreatitis is probably almost as common in cats as it is in dogs, although the etiology(s) remain more obscure. Pancreatitis in cats often co-exists with inflammatory bowel disease, less commonly with cholangitis, and sometimes with both. Additionally, pancreatitis may trigger hepatic lipidosis, while other diseases, such as diabetes mellitus, may be complicated by pancreatitis. Therapy is similar to that used in dogs, with added emphasis on early nutritional support to prevent hepatic lipidosis. Less is known about chronic pancreatitis than the acute form, but chronic pancreatitis is more common in cats than it is in dogs and may respond positively to treatment with corticosteroids.     

Evaluation of an Electrolyte Analyser for Measurement of Concentrations of Ionized Calcium and Magnesium in Cats

The goal of this study was to evaluate the Nova CRT 8 electrolyte analyser for determination of concentrations of ionized calcium (Ca_i) and magnesium (Mg_i) in cats, todetermine the effects of sample handling and storage and to establish reference ranges. The precision and analytical accuracy of the Nova CRT 8 analyser were good. The concentrations of Ca_i and Mg_i were significantly lower in aerobically handled serum samples than in those handled anaerobically. The concentrations of Ca_i and Mg_i differed significantly among whole blood, plasma and serum. In anaerobically handled serum, the concentration of Ca_i was stable for 8 h at 22°C, for 5 days at 4°C and for 1 week at −20°C. The concentration of Mg_i was stable for 4 h at 22°C but for less than 24 h at 4°C and for less than 1 week at −20°C. In serum from 36 cats, the reference ranges were 1.20–1.35 mmol/L for Ca_i and 0.47–0.59 mmol/L for Mg_i. The Nova CRT 8 electrolyte analyser is suitable for determination of Ca_i and Mg_i concentrations in cats. Anaerobically handled serum samples are recommended and, stored at room temperature, they yield accurate results when analysed within 4 h.     

Cisplatin Toxicity in Cats

Cisplatin (cis-diamminedichloroplatinum; Platinol, Bristol, Syracuse, NY) was administered to 11 cats, divided into three groups of experimental and clinical patients. In group 1, cisplatin was administered at a dose of 60 mg/m2 to four cats. In an attempt to avoid renal toxicity, saline diuresis was induced by administering 0.9% saline solution intravenously at a rate of 20 ml/kg/hr for 4 hours before and 2 hours after cisplatin administration. All four cats became dyspneic and died 48-96 hours after cisplatin administration. Postmortem findings included severe hydrothorax, pulmonary edema, and mediastinal edema. In group 2, four experimental cats entered a trial comparing the effects of saline diuresis and cisplatin (60 mg/m2) with the effects of saline diuresis and placebo (0.9% saline solution). The cats in the saline control group remained completely normal, while the cats that received cisplatin developed clinical signs and gross postmortem pulmonary changes identical to those in the first group of cats. Histopathologic examination showed that the alveolar septa were thickened and congested, and contained macrophages, occasional neutrophils, thrombi, and small foci of necrosis and fibrin. Microangiopathic changes were seen in the alveolar capillaries. In the third group, three additional cats were treated with a lower dose of cisplatin. Two cats that received 40 mg/m2 of cisplatin developed pulmonary changes similar to, but less severe than, those seen in the cats that received the higher dose of cisplatin. One cat treated with 20 mg/m2 of cisplatin showed no pulmonary changes ante mortem or post mortem. This series of 11 clinical and experimental cases identifies an apparent species-specific, dose-related, primary pulmonary toxicity of cisplatin in cats.     

Acromegaly in 14 Cats

Acromegaly was diagnosed in 14 middle-aged to old cats of mixed breeding. Thirteen (93%) of the cats were male and one was female. The earliest clinical signs in the 14 cats included polyuria, polydipsia, polyphagia, all of which were associated with untreated diabetes mellitus. All developed severe insulin resistance within a few months; peak insulin dosages required to control severe hyperglycemia ranged from 20 to 130 U per day. Other clinical findings weeks to months after diagnosis included enlargement of one or more organs (e.g., liver, heart, kidneys, and tongue) (n = 14), cardiomyopathy (n = 13), increase in body size and weight gain (n = 8), nephropathy associated with azotemia and clinical signs of renal failure (n = 7), degenerative arthropathy (n = 6), and central nervous system signs (i.e., circling and seizures) caused by enlargement of the pituitary tumor (n = 2). The diagnosis of acromegaly was confirmed by demonstration of extremely high basal serum growth hormone concentrations (22 to 131 micrograms/l) in all cats. Computerized tomography disclosed a mass in the region of the pituitary gland and hypothalamus in five of the six cats in which it was performed. Two cats were treated by cobalt radiotherapy followed by administration of a somatostatin analogue (octreotide), whereas two cats were treated with octreotide alone. Treatment had little to no effect in decreasing serum GH concentrations in any of the cats. Eleven of the 14 cats were euthanized or died four to 42 months (median survival time, 20.5 months) after the onset of acromegaly because of renal failure (n = 2), congestive heart failure (n = 1), concomitant renal failure and congestive heart failure (n = 3), progressive neurologic signs (n = 2), persistent anorexia and lethargy of unknown cause (n = 1), the owner's unwillingness to treat the diabetes mellitus (n = 1), or unknown causes (n = 1). Results of necropsy examination in ten cats revealed a large pituitary acidophil adenoma (n = 10), marked left ventricular and septal hypertrophy (n = 7), dilated cardiomyopathy (n = 1), arthropathy affecting the shoulder, elbow, or stifle (n = 5), and glomerulopathy characterized by expansion of the mesangial matrix and variable periglomerular fibrosis (n = 10).     

Propofol Anaesthesia in Cats

Propofol was administered to forty nine cats to induce anaesthesia. The mean dose required was 6.8 mg/kg and this was not affected by prior administration of acepromazine maleate. In 27 cases, propofol was also used as the principal maintenance agent (mean dose rate 0.51 mg/kg/minute). Inductions were very smooth and problem free. Intubation was easily achieved in 15 cats with the aid of local desensitization by lignocaine spray or neuromuscular relaxation by suxamethonium. Heart rate did not vary significantly during induction or maintenance of anaesthesia but respiratory rates did fall significantly.     

Measurement of Faecal Cortisol Metabolites in Cats and Dogs: A Non-invasive Method for Evaluating Adrenocortical Function

The aim of this comparative study was to gain more information about the metabolism and excretion of glucocorticoids in cats and dogs in order to establish non-invasive methods for evaluating stressful conditions. Therefore, in a first experiment, [¹⁴C]cortisol was administered intravenously to 8 animals (two of each sex and species). Over a period of 6 days, faeces and urine were collected immediately after spontaneous defecation and urination. Marked species differences were found, as cats mainly excreted cortisol in the faeces (82%±4% of the total recovered radioactivity), whereas in dogs only a small portion was found there (23%±4%). The highest urinary radioactivity was observed after 9±3 h in cats and 3±1 h in dogs. Peak concentrations in the faeces occurred after 22±6 h in cats and after 24±4 h in dogs. Most of the radioactivity was not extractable with diethyl ether, indicating that the metabolites excreted in urine and faeces were mainly of the conjugated or polar unconjugated types. This was confirmed by RP-HPLC, which also revealed marked differences between cats and dogs concerning the metabolites formed. In addition, the immunoreactivity of the metabolites was tested in cortisol, corticosterone and 11-oxoaetiocholanolone EIAs. The latter, measuring 11,17-dioxoandrostanes (11,17-DOA) detected the highest quantities of immunoreactive metabolites in cats, but not in dogs. In a second experiment, the adrenal cortex of both species was stimulated by ACTH and, three weeks later, suppressed by dexamethasone. In this study, only faeces were collected over a period of 7 days. In both species, inter-animal variability in the basal and maximal/minimal faecal cortisol metabolite concentrations and the time course was observed. The 11-oxoaetiocholanolone EIA in cats and the cortisol EIA in dogs proved best suited for monitoring changes in adrenocortical activity. ACTH injections resulted in an increase above baseline values of 355% (median) in 11,17-DOA concentrations in cats and of 702% in the concentrations of cortisol equivalents in dogs by about 25 h and 22 h (median) after injection, respectively. Minimal concentrations after dexamethasone administration were about 17% in cats and 31% in dogs (in relation to baseline values) and were reached in 66 h and 72 h, respectively. It was concluded that measuring cortisol metabolites in faeces should be a useful non-invasive tool for monitoring stress in carnivores.     

Primary Hypoadrenocorticism in Ten Cats

Primary hypoadrenocorticism was diagnosed in ten young to middle-aged cats of mixed breeding. Five of the cats were male, and five were female. Historic signs included lethargy (n = 10), anorexia (n = 10), weight loss (n = 9), vomiting (n = 4), and polyuria (n = 3). Dehydration (n = 9), hypothermia (n = 8), prolonged capillary refill time (n = 5), weak pulse (n = 5), collapse (n = 3), and sinus bradycardia (n = 2) were found on physical examination. Results of initial laboratory tests revealed anemia (n = 3), absolute lymphocytosis (n = 2), absolute eosinophilia (n = 1), and azotemia and hyperphosphatemia (n = 10). Serum electrolyte changes included hyponatremia (n = 10), hyperkalemia (n = 9), hypochloremia (n = 9), and hypercalcemia (n = 1). The diagnosis of primary adrenocortical insufficiency was established on the basis of results of adrenocorticotropic hormone (ACTH) stimulation tests (n = 10) and endogenous plasma ACTH determinations (n = 7). Initial therapy for hypoadrenocorticism included intravenous administration of 0.9% saline and dexamethasone and intramuscular administration of desoxycorticosterone acetate in oil. Three cats were euthanatized shortly after diagnosis because of poor clinical response. Results of necropsy examination were unremarkable except for complete destruction of both adrenal cortices. Seven cats were treated chronically with oral prednisone or intramuscular methylprednisolone acetate for glucocorticoid supplementation and with oral fludrocortisone acetate or intramuscular injections of repository desoxycorticosterone pivalate for mineralocorticoid replacement. One cat died after 47 days of therapy from unknown causes; the other six cats are still alive and well after 3 to 70 months of treatment.     

Doppler Ultrasonographic, Oscillometric Sphygmomanometric, and Photoplethysmographic Techniques for Noninvasive Blood Pressure Measurement in Anesthetized Cats

Blood pressure (BP) measurements obtained using 3 indirect BP measuring instruments, a Doppler ultrasonic flowmeter, an oscillometric device, and a photoplethysmograph, were compared with direct arterial pressure measurements in 11 anesthetized cats. The standard deviation of the differences (SOD) between direct and indirect pressure measurements were not significantly different from each other ( P <.01), and ranged from 10.82 to 24.32 mm Hg. The high SDD values indicate that indirect BP estimates obtained with all these devices must be interpreted cautiously in individual patients. The mean errors (calculated as the sum of the differences between direct and indirect pressure measurements divided by the number of observations) of the 3 indirect devices were significantly different for systolic (SAP), diastolic (DAP), and mean (MAP) arterial pressures ( P <.05). The Doppler and photoplethysmographic devices had the highest overall accuracy, as indicated by mean error values of less than 10 mm Hg. Correlation coefficients varied from .88 to .96 for the Doppler flowmeter, and from .85 to .94 for the photoplethysmograph; for both devices, the regression line slopes were close to unity. The Doppler flowmeter detected a pulse under all experimental conditions. The photoplethysmograph was also efficient in obtaining BP measurements, obtaining over 90% of SAP, DAP, and MAP readings attempted. The oscillometric device was the least accurate, with mean error values varying from 10 to 22 mm Hg. Correlation coefficients were high (.90 to .94) for this device, but the slopes of the regression lines were 0.7 to 0.8, indicating a trend for increased error at higher BP. The oscillometric device tended to underestimate BP by increasing amounts as the BP increased. The oscillometric device was the least efficient device for obtaining BP measurements ( P <.01).