New perspectives on the development of extrahepatic portosystemic shunts

In this essay we use clinical evidence and knowledge of anatomy to examine the relationship between blood flow and formation of congenital extrahepatic portosystemic shunts in dogs and cats. First we report on the clinical findings in a series of 50 dogs and 10 cats and then systematically review peer‐reviewed data on the detailed anatomy of shunts in dogs and cats. In dogs four types of shunt: spleno‐caval, left gastro‐phrenic, left gastro‐azygos and those involving the right gastric vein account for 94% of extrahepatic shunts. Cats also exhibit four types of shunt: spleno‐caval, left gastrophrenic, left gastro‐caval and left gastro‐azygos, and the first three of these account for 92% shunts in this species. Our findings lead us to propose that preferential blood flow influences the subsequent formation of one of a number of defined and consistent congenital extrahepatic portosystemic shunts in dogs and cats.     

ACVIM consensus statement on the diagnosis of immune‐mediated hemolytic anemia in dogs and cats

Immune‐mediated hemolytic anemia (IMHA) is an important cause of morbidity and mortality in dogs. IMHA also occurs in cats, although less commonly. IMHA is considered secondary when it can be attributed to an underlying disease, and as primary (idiopathic) if no cause is found. Eliminating diseases that cause IMHA may attenuate or stop immune‐mediated erythrocyte destruction, and adverse consequences of long‐term immunosuppressive treatment can be avoided. Infections, cancer, drugs, vaccines, and inflammatory processes may be underlying causes of IMHA. Evidence for these comorbidities has not been systematically evaluated, rendering evidence‐based decisions difficult. We identified and extracted data from studies published in the veterinary literature and developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria for IMHA, comorbidities, and causality. Succinct evidence summary statements were written, along with screening recommendations. Statements were refined by conducting 3 iterations of Delphi review with panel and task force members. Commentary was solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted. The resulting document is intended to provide clinical guidelines for diagnosis of, and underlying disease screening for, IMHA in dogs and cats. These should be implemented with consideration of animal, owner, and geographical factors.     

Antithrombotic Therapy

Thrombosis or thromboembolism are significant concerns in companion animals and can be associated with cardiac, metabolic, neoplastic disease processes or can be one manifestation of inflammatory, infectious, and neoplastic disease conditions. Options for thromboprophylaxis available for clinical use in small animal patients are very limited, with heparin (primarily unfractionated, but more recently low-molecular-weight forms) and aspirin predominating. Controlled studies evaluating the use of these drugs are few, but there is some limited evidence for efficacy in prevention of formation of thrombi. Use of the vitamin K antagonist warfarin has been described, but the narrow therapeutic window has resulted in a high rate of serious adverse events. In human patients, the efficacy of aspirin, heparins, and vitamin K antagonists is well documented in a variety of thrombotic conditions, but there are significant limitations to each of these options. These limitations have prompted the search for new alternatives, some of which are now in wide clinical use in humans. Although the use of some of the drugs discussed here has not yet been described in veterinary patients at risk for thrombosis, many of these agents have been evaluated experimentally in dogs, cats, or both. These new thromboprophylactic agents may soon be beneficial in management of small animal patients at risk for thrombosis.     

Use of dopamine in acute renal failure

Objective: To review the current understanding of dopamine and its use in the prevention and treatment of acute renal failure (ARF). Data sources: Original research articles and scientific reviews. Human data synthesis: Low‐dose dopamine administration has been shown to increase natriuresis and urinary output in both healthy individuals and in a few small studies in human patients with renal insufficiency. However, in several large meta‐analyses, dopamine treatment did not change mortality or the need for dialysis. Due to the potential side effects, the use of dopamine for prevention and treatment of ARF is no longer recommended in human medicine. Veterinary data synthesis: Low‐dose dopamine increases urinary output in healthy animals and animal models of ARF if given before the insult. There are no available studies looking at the effect of low‐dose dopamine therapy in naturally occurring ARF in dogs or cats. Conclusion: Due to the potential side effects of low‐dose dopamine therapy, the results from large human trials, and the lack of information in veterinary medicine, the use of dopamine for treatment of ARF in veterinary patients should be further evaluated.     

Challenges of Cardiopulmonary Bypass—A Review of the Veterinary Literature

Cardiopulmonary bypass (CPB) has been used in veterinary medicine in experimental surgery and to address congenital and acquired diseases. We review the veterinary literature and expose common challenges of CPB in dogs and cats. Specifically, we describe the most specific elements of this technique in veterinary patients. The variety in animal size has made it difficult to standardize cannulation techniques, oxygenators, and priming volumes and solutions. The fact that one of the most common cardiovascular disorders, mitral valve disease, occurs predominantly in small dogs has limited the use of bypass in these patients because of the need for small, low prime oxygenators and pumps that have been unavailable until recently. Coagulation, hemostasis, and blood product availability have also represented important factors in the way CPB has developed over the years. The cost and the challenges in operating the bypass machine have represented substantial limitations in its broader use.     

A survey of anaesthesia in small animal practice: AVA/BSAVA report

Over 150 veterinary surgeons from 53 small animal practices collaborated in a prospective survey of anaesthetic accidents and emergencies by recording all anaesthetics administered and detailing the problems they encountered. From these records it is estimated that 1 in 679 of the healthy dogs and cats died primarily as a result of anaesthesia; many of these deaths apparently occurred at a time when the animal was not under close observation. Anaesthetics involving the use of xylazine seemed to result in an exceptionally high mortality rate. Complications following endotracheal intubation appeared to be associated with several deaths in cats. The death rate in cats and dogs with pathological but not immediately life-threatening conditions was estimated to be 1 in 31. There was no evidence to suggest that some breeds (with the possible exception of the Pekingese) were more likely than others to die under anaesthesia.     

Quality of life assessment in dogs and cats receiving chemotherapy – a review of current methods

This study aimed to review currently reported methods of assessing the effects of chemotherapy on the quality of life (QoL) of canine and feline patients and to explore novel ways to assess QoL in such patients in the light of the experience to date in human pediatric oncology. A qualitative comparative analysis of published papers on the effects of chemotherapy on QoL in dogs and cats were conducted. This was supplemented with a comparison of the parameters and domains used in veterinary QoL‐assessments with those used in the Pediatric Quality of Life Inventory (PedsQL^?) questionnaire designed to assess QoL in toddlers. Each of the identified publications including QoL‐assessment in dogs and cats receiving chemotherapy applied a different method of QoL‐assessment. In addition, the veterinary QoL‐assessments were mainly focused on physical clinical parameters, whereas the emotional (6/11), social (4/11) and role (4/11) domains were less represented. QoL‐assessment of cats and dogs receiving chemotherapy is in its infancy. The most commonly reported method to assess QoL was questionnaire based and mostly included physical and clinical parameters. Standardizing and including a complete range of potentially relevant parameters in future QoL assessments may benefit owner decision making.     

ACVIM consensus statement on the treatment of immune‐mediated hemolytic anemia in dogs

Immune‐mediated hemolytic anemia (IMHA) causes severe anemia in dogs and is associated with considerable morbidity and mortality. Treatment with various immunosuppressive and antithrombotic drugs has been described anecdotally and in previous studies, but little consensus exists among veterinarians as to the optimal regimen to employ and maintain after diagnosis of the disease. To address this inconsistency and provide evidence‐based guidelines for treatment of IMHA in dogs, we identified and extracted data from studies published in the veterinary literature. We developed a novel tool for evaluation of evidence quality, using it to assess study design, diagnostic criteria, explanation of treatment regimens, and validity of statistical methods. In combination with our clinical experience and comparable guidelines for humans afflicted with autoimmune hemolytic anemia, we used the conclusions of this process to make a set of clinical recommendations regarding treatment of IMHA in dogs, which we refined subsequently by conducting several iterations of Delphi review. Additionally, we considered emerging treatments for IMHA in dogs and highlighted areas deserving of future research. Comments were solicited from several professional bodies to maximize clinical applicability before the recommendations were submitted for publication. The resulting document is intended to provide clinical guidelines for management of IMHA in dogs. These guidelines should be implemented pragmatically, with consideration of animal, owner, and veterinary factors that may vary among cases.     

The cardiopulmonary effects and quality of anesthesia after induction with alfaxalone in 2‐hydroxypropyl‐β‐cyclodextrin in dogs and cats: a systematic review

To systematically review the quality of evidence comparing the cardiopulmonary effects and quality of anesthesia after induction with alfaxalone vs. other anesthetic agents in dogs and cats. Studies published from 2001 until 20th May 2013 were identified with the terms ‘alfaxan’ OR ‘alfaxalone’ OR ‘alphaxalone’ in electronic databases: Discovery, PubMed, ScienceDirect, and Wiley Interscience. The study design and risk of bias of all included studies were assessed. Twenty‐two studies from 408 (22 of 408, 5.39%) satisfied the inclusion criteria. Fourteen studies (14 of 22, 64%) focused on dogs and nine (9 of 22, 40%) on cats. One study had both dogs and cats as subjects. (Hunt et al., 2013) Twelve studies were rated an LOE1, and six of these as ROB1. One, seven, and two studies were rated as LOE2, LOE3, and LOE5, respectively. In dogs, strong evidence shows that induction quality with either alfaxalone‐HPCD or propofol is smooth. Moderate evidence supports this finding in cats. In dogs, moderate evidence shows that there is no significant change in heart rate after induction with either alfaxalone‐HPCD or propofol. In cats, moderate evidence shows no significant difference in postinduction respiratory rate and heart rate between alfaxalone‐HPCD and propofol induction. Strong evidence shows dogs and cats have smooth recoveries after induction using either alfaxalone‐HPCD or propofol, before reaching sternal recumbency.     

Current attitudes to,and use of,peri-operative analgesia in dogs and cats by veterinarians in New Zealand

AIM: To investigate the attitudes of veterinary practitioners in New Zealand to pain and analgesia, and their use of analgesic drugs, in dogs and cats.

METHODS: A questionnaire posted to 1,200 practising veterinarians was used to gather information about the use of analgesia in dogs and cats, assessment of pain, attitudes to pain relief, analgesic drugs and procedures used, factors affecting choice of analgesic agent, and veterinary demographics, continuing education and staffing.

RESULTS: Three hundred and twenty questionnaires with useable data were returned, a response rate of 28%. Male and female veterinarians were evenly represented. The analgesic agents most commonly used were morphine (opioids) and carprofen (a non-steroidal anti-inflammatory drug; NSAID). Use of peri-operative pain relief ranged from 50% for castration of cats to 91% for fracture repair in dogs. For most procedures, female veterinarians scored pain at a significantly higher level than their male colleagues. Fifty-eight percent of respondents considered their knowledge in the area of assessment and treatment of pain was adequate.

CONCLUSIONS: This survey was considered representative of veterinarians working in companion animal practice in New Zealand. Results indicated a relatively high use of peri-operative analgesia, including both pre-emptive and multi-modal analge- sia, in cats and dogs, although there was still some disparity between the perception of how painful a procedure was and the consequent use of pain relief.

CLINICAL RELEVANCE: The establishment of current attitudes and practices indicates to practising veterinarians how their own use of analgesics compares with that of their colleagues. It also provides information to educators on potential areas of focus, given that 42% of respondents felt their knowledge in the area of assessment and treatment of pain was inadequate.     

Current attitudes to, and use of, peri-operative analgesia in dogs and cats by veterinarians in New Zealand

AIM: To investigate the attitudes of veterinary practitioners in New Zealand to pain and analgesia, and their use of analgesic drugs, in dogs and cats. METHODS: A questionnaire posted to 1,200 practising veterinarians was used to gather information about the use of analgesia in dogs and cats, assessment of pain, attitudes to pain relief, analgesic drugs and procedures used, factors affecting choice of analgesic agent, and veterinary demographics, continuing education and staffing. RESULTS: Three hundred and twenty questionnaires with useable data were returned, a response rate of 28%. Male and female veterinarians were evenly represented. The analgesic agents most commonly used were morphine (opioids) and carprofen (a non-steroidal anti-inflammatory drug; NSAID). Use of peri-operative pain relief ranged from 50% for castration of cats to 91% for fracture repair in dogs. For most procedures, female veterinarians scored pain at a significantly higher level than their male colleagues. Fifty-eight percent of respondents considered their knowledge in the area of assessment and treatment of pain was adequate. CONCLUSIONS: This survey was considered representative of veterinarians working in companion animal practice in New Zealand. Results indicated a relatively high use of peri-operative analgesia, including both pre-emptive and multi-modal analgesia, in cats and dogs, although there was still some disparity between the perception of how painful a procedure was and the consequent use of pain relief. CLINICAL RELEVANCE: The establishment of current attitudes and practices indicates to practising veterinarians how their own use of analgesics compares with that of their colleagues. It also provides information to educators on potential areas of focus, given that 42% of respondents felt their knowledge in the area of assessment and treatment of pain was inadequate.     

INTER‐ AND INTRAFRACTION MOTION FOR STEREOTACTIC RADIOSURGERY IN DOGS AND CATS USING A MODIFIED BRAINLAB FRAMELESS STEREOTACTIC MASK SYSTEM

Precise and accurate patient positioning is necessary when doing stereotactic radiosurgery (SRS) to ensure adequate dosing to the tumor and sparing of normal tissues. This prospective cross‐sectional study aimed to assess feasibility of a commercially available modified frameless SRS positioning system for use in veterinary radiotherapy patients with brain tumors. Fifty‐one dogs and 12 cats were enrolled. Baseline and verification CT images were acquired. The verification CT images from 32 dogs and five cats had sufficient images for fusion to baseline CT images. A rigid box‐based fusion was performed to determine interfraction motion. Forty‐eight dogs and 11 cats were assessed for intrafraction motion by cine CT. Seventy percent of dogs and 60% of cats had interfraction 3D vector translational shifts >1 mm, with mean values of 1.9 mm in dogs, and 1.8 mm in cats. In dogs muscle wasting was weakly correlated with translational shifts. The maximum angular interfraction motion observed was 6.3° (roll), 3.5° (pitch), and 3.3° (yaw). There was no correlation between angular interfraction motion and weight, brachycephaly, or muscle wasting. Fifty‐seven percent of dogs and 50% of cats had respiration‐related intrafraction motion. Of these, 4.5% of dogs and 10% of cats had intrafraction motion >1 mm. This study demonstrates the modified Brainlab system is feasible for SRS in dogs and cats. The smaller cranial size and difference in anatomy increases setup uncertainty in some animals beyond limits usually accepted in SRS. Image‐guided positioning is recommended to achieve clinically acceptable setup accuracy (<1 mm) for SRS.     

The ACVD task force on canine atopic dermatitis (XXII): nonsteroidal anti-inflammatory pharmacotherapy.

The pharmacotherapy of canine atopic dermatitis has relied primarily on the use of glucocorticoids and anti-histamines. During the last decade, other anti-inflammatory drugs have been investigated in clinical trials. This paper will review the studies using misoprostol, cyclosporine, tacrolimus, phosphodiesterase inhibitors, capsaicin, leukotriene inhibitors and serotonin-reuptake inhibitors for treatment of dogs with atopic dermatitis. For each drug the mechanism of action, the rationale for use in atopic dermatitis, the clinical efficacy, reported adverse effects and strength of recommendation for treatment of canine atopic dermatitis are described. At the time of this writing, there is fair evidence to support the recommendation for using cyclosporine, misoprostol and pentoxifylline for treatment of canine atopic dermatitis. This recommendation can be strengthened by the performance of additional blinded randomized controlled trials with larger number of dogs. In contrast, there is insufficient evidence to recommend for or against treatment with tacrolimus, leukotriene inhibitors, serotonin-reuptake antagonists and capsaicin.     

Current British veterinary attitudes to perioperative analgesia for dogs.

In March 1996, a questionnaire was sent to 2000 veterinary surgeons, primarily involved in small animal practice, to assess their attitudes to perioperative analgesic therapy in dogs, cats and other small mammals. This paper is concerned only with the data relating to dogs. The veterinary surgeons considered that pain was a consequence of all the surgical procedures specified, but there were differences in their treatment of pain. Some veterinarians considered that a degree of pain was necessary postoperatively to prevent excessive activity. In general, women and more recent graduates assigned higher pain scores to the procedures and were more likely to treat the pain with analgesics. A significant number of veterinarians consider the use of opiates or non-steroidal anti-inflammatory drugs before surgical procedures, but relatively few appear to use combinations of different classes of analgesics either before or after operations.     

Glucocorticoids in the cat

Glucocorticoids are one of the two main classes of hormones, along with mineralocorticoids, which are secreted from the adrenal cortex. Since the discovery of the anti‐inflammatory properties of the natural glucocorticoid hydrocortisone, a large number of artificial glucocorticoids have been synthesized to attempt to increase efficacy and decrease side effects. These drugs are now considered one of the most commonly prescribed agents in veterinary practice. The effect of these drugs has been shown to vary significantly between species. Cats appear to tolerate glucocorticoids well, resulting in these drugs being recommended for a wide variety of conditions; however, there are few studies on the effects of glucocorticoids in cats. In this paper we review some of the available literature on glucocorticoid use in the cat.     

Oral medications for treating diabetes mellitus in dogs and cats

Five classes of oral hypoglycaemic drugs and two trace minerals used to treat diabetes mellitus in humans are reviewed and current knowledge on the use of these drugs in diabetic dogs and cats is presented. Oral sulphonylurea drugs stimulate insulin secretion and have been used successfully to treat diabetes in cats but not dogs. Preliminary studies evaluating the efficacy of the biguanide, metformin, in diabetic cats have not been promising. Pharmacokinetic studies have been performed in healthy cats, but clinical studies evaluating the efficacy of the insulin-sensitising drugs, thiazolidinediones, have not been reported. Treatment with the alpha-glucosidase inhibitor, acarbose, improved control of glycaemia in diabetic dogs; similar studies have not been reported in cats. Although chromium picolinate did not improve control of glycaemia in diabetic dogs, vanadium has improved control of the abnormality in diabetic cats.