The effects of aging on hydromorphone-induced thermal antinociception in healthy female cats

Characterization of pain behaviors in kittens following ovariohysterectomy using video assessment

This study aimed to characterize the duration and/or frequency of pain behaviors in kittens following ovariohysterectomy using video assessment. A total of 229 videos comprising 18 h of recordings were obtained during a prospective, randomized, clinical trial using an opioid-free protocol with (multimodal group, MMG) or without (control group, CG) multimodal analgesia. Videos included behaviors of 36 kittens (≤ 6 months) before and after surgery, as well as pre/post rescue analgesia. A veterinary behaviorist blinded to treatments and timepoints performed the behavioral assessment using an ethogram. Statistical analyses were performed using linear models (P < 0.05). Duration (%) of 'no attention to surroundings' (5 ± 16 and 0.0 ± 0.7, P = 0.02), 'lowered head position' (4 ± 12 and 0.3 ± 2, P = 0.009) and 'eyes partially closed' (15 ± 29 and 5 ± 17, P < 0.02) was longer in kittens before than after analgesia, respectively. When compared with baseline, kittens in MMG had longer duration of playing (i.e. 'pawing', %) (35 ± 34) than CG (7 ± 12, P = 0.001) at 1 h postoperatively. This study identified behavioral differences between painful and non-painful kittens following ovariohysterectomy contributing to feline acute pain assessment.

Effects of multimodal pain management strategies on acute physiological and behavioral response to cautery disbudding in neonatal goat kids

Dairy goat kids are commonly disbudded in the United States without pain relief. Our objective was to identify an efficient pain management strategy by monitoring changes in plasma biomarkers and behavior of disbudded goat kids. A total of 42 kids (5-18 d old at the time of disbudding) were randomly allocated to 1 of 7 treatments (n = 6/treatment): sham treatment; 0.05 mg/kg i.m. xylazine (X); 4 mg/kg subcutaneous buffered lidocaine (L); 1 mg/kg oral meloxicam (M); xylazine and lidocaine (XL); xylazine and meloxicam (XM); and xylazine, meloxicam, and lidocaine together (XML). Treatments were administered 20 min before disbudding. One trained individual, blinded to treatment, disbudded all kids; sham-treated kids were handled similarly except the iron was cold. Jugular blood samples (3 mL) were obtained before (-20, -10, and -1 min) and after (1, 15, and 30 min, and 1, 2, 4, 6, 12, 24, 36, 48 h) disbudding and analyzed for cortisol and prostaglandin E₂ (PGE₂). Mechanical nociceptive threshold (MNT) testing was performed at 4, 12, 24, and 48 h after disbudding, and kids were weighed daily until 2 d post-disbudding. Vocalizations, tail flicks, and struggle behavior during disbudding were recorded. Cameras were mounted over home pens; continuous and scan observations over 12 periods of 10 min each, in the 48 h after disbudding, captured frequency of locomotion and pain-specific behaviors. Repeated measures and linear mixed models assessed treatment effects on outcome measures during and after disbudding. Models accounted for sex, breed, and age as random effects, and Bonferroni adjustments accounted for multiple comparisons. At 15 min after disbudding, XML kids had lower plasma cortisol concentrations compared with L (50.0 ± 13.2 vs. 132.8 ± 13.6 mmol/L) and M kids (50.0 ± 13.2 vs. 145.4 ± 15.7 mmol/L). Cortisol was also lower in XML kids over the first hour after disbudding compared with L kids (43.4 ± 9 vs. 80.2 ± 9 mmol/L). Change from baseline PGE₂ was not affected by treatment. Behaviors observed during disbudding did not differ by treatment group. Treatment affected MNT such that M kids were more sensitive overall compared with sham kids (0.93 ± 0.11 kgf vs. 1.35 ± 0.12 kgf). None of the recorded post-disbudding behaviors were affected by treatment, but study activities did influence behavior over time, with kid activity levels declining in the first day after disbudding but largely recovering thereafter. We conclude that none of the drug combinations investigated here appeared to fully attenuate pain indicators during or after disbudding, but triple modality seems to have offered partial relief compared with some of the single-modality treatments.

2022 ISFM Consensus Guidelines on the Management of Acute Pain in Cats

PRACTICAL RELEVANCE

Increases in cat ownership worldwide mean more cats are requiring veterinary care. Illness, trauma and surgery can result in acute pain, and effective management of pain is required for optimal feline welfare (ie, physical health and mental wellbeing). Validated pain assessment tools are available and pain management plans for the individual patient should incorporate pharmacological and non-pharmacological therapy. Preventive and multimodal analgesia, including local anaesthesia, are important principles of pain management, and the choice of analgesic drugs should take into account the type, severity and duration of pain, presence of comorbidities and avoidance of adverse effects. Nursing care, environmental modifications and cat friendly handling are likewise pivotal to the pain management plan, as is a team approach, involving the cat carer.

CLINICAL CHALLENGES

Pain has traditionally been under-recognised in cats. Pain assessment tools are not widely implemented, and signs of pain in this species may be subtle. The unique challenges of feline metabolism and comorbidities may lead to undertreatment of pain and the development of peripheral and central sensitisation. Lack of availability or experience with various analgesic drugs may compromise effective pain management.

EVIDENCE BASE

These Guidelines have been created by a panel of experts and the International Society of Feline Medicine (ISFM) based on the available literature and the authors' experience. They are aimed at general practitioners to assist in the assessment, prevention and management of acute pain in feline patients, and to provide a practical guide to selection and dosing of effective analgesic agents.

Endogenous opiates and behavior: 2019

This paper is the forty-second consecutive installment of the annual anthological review of research concerning the endogenous opioid system, summarizing articles published during 2019 that studied the behavioral effects of molecular, pharmacological and genetic manipulation of opioid peptides and receptors as well as effects of opioid/opiate agonists and antagonists. The review is subdivided into the following specific topics: molecular-biochemical effects and neurochemical localization studies of endogenous opioids and their receptors (1), the roles of these opioid peptides and receptors in pain and analgesia in animals (2) and humans (3), opioid-sensitive and opioid-insensitive effects of nonopioid analgesics (4), opioid peptide and receptor involvement in tolerance and dependence (5), stress and social status (6), learning and memory (7), eating and drinking (8), drug abuse and alcohol (9), sexual activity and hormones, pregnancy, development and endocrinology (10), mental illness and mood (11), seizures and neurologic disorders (12), electrical-related activity and neurophysiology (13), general activity and locomotion (14), gastrointestinal, renal and hepatic functions (15), cardiovascular responses (16), respiration and thermoregulation (17), and immunological responses (18).

Anesthetic and analgesic effects of an opioid-free, injectable protocol in cats undergoing ovariohysterectomy: A prospective, blinded, randomized clinical trial

This study evaluated the effects of ketamine-dexmedetomidine-midazolam as part of an opioid-free, multimodal protocol in cats undergoing ovariohysterectomy. In a prospective, blinded, randomized clinical trial, cats received either 1 of 2 doses of ketamine [5 mg/kg body weight (BW), n = 10, K5 or 7 mg/kg BW, n = 13, K7] with midazolam (0.25 mg/kg BW) and dexmedetomidine (40 μg/kg BW) intramuscularly, intraperitoneal bupivacaine (2 mg/kg BW) and subcutaneous meloxicam (0.2 mg/kg BW) after surgery. Buprenorphine (0.02 mg/kg BW, intravenously) was administered if pain scores exceeded intervention scores with 2 pain scoring systems. Similar prevalence of rescue analgesia was observed (K5 = 6/10; K7 = 7/13) with significantly lower requirements in kittens (2/8) than adults (11/15). Tachypnea (K5 = 7/10 and K7 = 9/13) and desaturation (K5 = 3/10 and K7 = 4/13) were the 2 most common complications. Age influenced the prevalence of rescue analgesia. Most adult cats required opioids for postoperative pain relief.

Analgesia: What Makes Cats Different/Challenging and What Is Critical for Cats?

Cats have unique anatomic, physiologic, and behavioral considerations that may influence analgesia and pain management. They present specific challenges that require an individualized, feline-specific approach. This article presents an overview of recent advances in feline pain management and their differences in relation to other species and evolves on its future challenges. The main specific anatomy and physiology of the cat and how it may affect analgesia is discussed. Validated pain assessment tools including the UNESP-Botucatu Multidimensional Composite Pain Scale, Glasgow Feline Composite Measure Pain Scale, and the Feline Grimace Scale are summarized.