Based on the results of the present study, cats that underwent limb amputation tolerated the procedure well with only minor complications including mild balance difficulty, mild incisional pain, and mildly depressed mentation. Approximately 1 in 20 cats that underwent limb amputation were reported to have major complications, which were reported as severe balance difficulty, and major decrease in appetite. The results of the owner survey were consistent with previous studies of owner satisfaction following limb amputation in cats in a UK population [10]. Previous data in canine studies indicating 91–100% of owners satisfied and 86%-100% of owners would elect the procedure again parallels the results of our study in cats [3, 4, 5, 7]. This study supported our hypothesis that, within this US-based population, cat owner satisfaction would be positive when complications, recovery outcome, and expectation were considered. This study also indicated that there was no statistical difference in postoperative complications detected by owners between thoracic and pelvic limb amputation in cats, which is similar to that of the results of the previous study in cats in a UK population.
The prevalence and types of postoperative complications after limb amputation in cats have not been extensively described in the literature. In our study, the most common postoperative complication was mild balance difficulty. Although cat and dog owners have reported concerns related to anticipated problems with mobility and adaptation before limb amputation [7], postoperative complication of balance difficulty has not been previously reported in cats. Adaptation to thoracic limb amputation has revealed greater changes in ground reaction forces, impulses, and contact times of the remaining limbs and location of center of gravity compared to pelvic limb amputation in dogs [6]. In dogs, those with thoracic amputations tend to have more difficulty maintaining their balance, whereas those with pelvic limb amputation tend to have more difficulty with acceleration [12, 13]. In normal cats, gait symmetry at a walk reveals peak vertical force and vertical impulse being statistically greater in the thoracic limbs than in the pelvic limbs, which is similar to that of healthy dogs [14]. Furthermore, healthy cats have a thoracic to pelvic limb asymmetry similar to the one in healthy dogs [15]. According to our study there was no difference in recovery outcome for cats after either thoracic limb or pelvic limb amputation as perceived by owner satisfaction. Although not evaluated in this study, kinetic and kinematic analyses would have been valuable objective data in evaluating the new locomotion pattern and adaptation in cats before and after limb amputation.
The second most prevalent postoperative complication of limb amputation reported by the owner was mild pain, which has been reported in two studies [4, 10]. In our study, all cats were discharged with analgesics; however, mild pain was reported as a postoperative complication in approximately 1 in 4 cats. In a UK study in cats with limb amputation, 35% of owners observed signs of pain during recovery although 89% of all cats received analgesics after discharge [10]. In the same UK study, a significant difference existed in the time taken to return to normal quality of life where the owner perceived postoperative pain. Approximately 10% of the cats did not return to normal quality of life as defined by the owner, and approximately one third were reported to be in pain after discharge [10]. Similarly, our current study reported that 10.2% (6/59) of cats did not return to normal quality of life (Fig. 1). Although only 23.7% (14/59) cat owners observed minor signs of incisional pain, 96.6% reported either excellent (59.3%) or good (37.3%) pain management with the analgesic medication. Because there were no reported issues when administering postoperative pain-relief medications, the results may be a reflection of increased owner recognition of pain in their pet. In contrast, the reports of overall good to excellent pain management scores may reflect the evolution of analgesia protocols perioperatively. Previous historical data has indicated a lack of perioperative analgesic practices. A UK study in 1999 reported that only 74% of veterinarians dispensed analgesics beyond the immediate postoperative period in orthopedic cases [16], while perioperative use of analgesics in dogs and cats following common surgeries by Canadian veterinarians in 2001 revealed up to 12% of veterinarians did not use any analgesics [17]. Furthermore, a New Zealand study in 2005 reported only 68% of cats and 79% of dogs were dispensed additional analgesia at discharge after fracture repair [18]. More recently in 2014, attitudes regarding the use of perioperative analgesics in dogs and cats by Brazilian veterinarians revealed that cats received lower pain scores than dogs for common surgeries [19]. Recognizing pain not only requires palpation to the painful area but an appropriate understanding of the cat’s normal behavior, which should involve information from the owner [19]. In a previous canine study, 91% of owners perceived no change in their dog’s attitude after amputation,3 whereas in our study 6.8% of cat owners reported depressed mentation in their pet. Owner observation (i.e., depressed mentation), is an important resource when assessing and managing pain in the patient [19]. Although many studies have raised concern for perioperative pain management in cats, it is clear that the current attitudes of veterinarians regarding pain management are moving toward multimodal analgesia, which may address an owner’s concern for their pet’s pain management.
Limitations of this current study are primarily related to its retrospective design and the use of questionnaire-based surveys. These limitations included the potential for incomplete medical records and the subjectivity of surveys with having to rely on one’s memory. These questionnaires introduce owner bias by the level of knowledge, emotional involvement with the cat, and ability to interpret behavioral changes. However, the satisfaction of an owner represents useful information combined with the recommendations of the veterinary surgeon in the ultimate decision to treat the pet.
Although the mode of research conducted was primarily following a hypothesis-generating paradigm, the descriptive statistics have identified areas of additional research including a pet’s mobility and perceived pain. Future studies should be considered to objectively validate these findings. A prospective study including statistically significant case number and objective data, via kinetics and kinematic analyses, would be beneficial in identifying and quantifying orthopedic changes arising from amputation.
Results presented by this study suggest that limb amputation in the cat is well tolerated. The majority of owners were satisfied with the outcome post-amputation and they did not regret pursuing the procedure for their cat. However, owners should be educated on the potential for postoperative complications including balance difficulty, pain, and change in mentation, with the majority of these complications being classified as minor.