Transient skin and fur color change after trichotomy of the sacrococcygeal region for epidural anesthesia in a domestic cat (Felis catus)

Abstract

A clinical case in which skin and hair color change occurred after sacrococcygeal epidural anesthesia in a nine-month-old Siamese cross queen undergoing ovariohysterectomy (OHE) is described. Six weeks after surgery, during a re-check, it was noted that in the sacrococcygeal region the color of the skin and new hair growth was dark with a color comparable to the color present on the body extremities (muzzle, pinnae, legs, and tail). The skin and new hair growth of the shaved abdomen presented a standard color. The key enzyme of the melanogenic pathway in mammals is tyrosinase (TYR), and the Siamese temperature-sensitive phenotype is the result of genetic mutations that makes TYR function thermolabile. The activity of TYR in these cats is limited to the extremities where the temperature is lower while pigment production is impaired in the other body areas. The trichotomy of the sacrococcygeal region performed during wintertime in an outdoor cat was probably the trigger for increased activity of TYR in this area promoting pigment production. The absence of the same alterations in the abdominal area may be justified by less exposure of that region to the external environment, as well as to the feline habits of sedentarism, that avoid significant cooling in these regions. This report highlights the importance of taking this type of occurrence into account when performing an epidural in the Siamese cat breed. Also, to avoid skin color change in this breed, the authors recommend a midline abdominal instead of a flank approach to perform OHE.

Comparison between Bilateral Ultrasound-Guided Quadratus Lumborum Block and Sacrococcygeal Epidural in Cats Undergoing Ovariectomy

“…Conversely, employing a sacrococcygeal approach for epidural anaesthesia is widely acknowledged as the suitable choice for perioperative analgesia in cats [ 14 ], and it is characterised by its minimal complication rate [ 8 , 15 , 16 ]. In addition, studies have reported the analgesic effects of epidural anaesthesia in cats undergoing perineal or hind limb surgeries [ 5 ] and ovariectomies [ 8 ].…”