Standing flank laparotomy for the treatment of small colon impactions in 15 ponies and one horse

Impactions are the most common problem affecting the small colon in horses and are much more prevalent in ponies and miniature horses. Ventral midline laparotomy under general anaesthesia is the standard of care for this condition when medical management fails to resolve the impaction or when the impaction causes complete intraluminal obstruction and tympany. This case series reports the use of standing flank laparotomy (SFL) in 15 ponies with focal small colon impactions and one large breed horse with an elongated small colon impaction. All cases presented with signs of colic of 1–4 days' duration. The horses were initially vigorously treated with both enteral and parental fluids but failed to pass faeces, with no resolution of abdominal distention or pain. In all cases, a definitive diagnosis was made during SFL and the small colon appeared to be viable. The impaction was resolved by extraluminal massage. In the horse and in one pony, in addition to extraluminal massage, high enema was administered during surgery. Routine perioperative treatment with fluids, analgesics, antimicrobials and wound care was provided. All animals survived to discharge. The time from surgical resolution of the impaction to passing faeces was less than 2 h in all but one case. Median duration of hospitalisation was 2 days and all animals returned to their original use by 2 months. The encouraging results of this case series suggest that SFL is a viable alternative to ventral laparotomy for ponies and horses with either focal SCI or extensive SCI.     

Right flank laparotomy and abomasotomy for removal of a phytobezoar in a standing cow

A 4.5-year-old Holstein-Friesian cow underwent surgery because of left abomasal displacement. Intra-operative palpation of the pyloric region revealed a phytobezoar. The abomasum containing the phytobezoar was exteriorized, and an incision was made directly over the mass in the region of the greater curvature of the pyloric part of the abomasum.     

Nerve stimulator-guided paravertebral lumbar plexus anaesthesia in dogs

Veterinary Research Communications -     

Combined paravertebral plexus block and parasacral sciatic block in healthy dogs

ObjectiveTo evaluate the effectiveness of paravertebral lumbar plexus block combined with parasacral sciatic block to anesthetize one hind limb in awake dogs.Study designRandomized, controlled, blinded experimental study.AnimalsEight healthy mongrel dogs weighing 12.4 ± 4.5 kg and aged 7 ± 2.33 years.MethodsAfter sedation with medetomidine, dogs received B1: bupivacaine 0.25%, 0.2 mL kg^?1, B2: bupivacaine 0.5%, 0.2 mL kg^?1, B3: bupivacaine 0.25% 0.4 mL kg^?1, P1: NaCl 0.2 mL kg^?1, P2: NaCl 0.4 mL kg^?1. The lumbosacral plexus was blocked through a paravertebral block of the fourth, fifth and sixth lumbar nerves combined with a parasacral block. The relevant nerves were located using a nerve stimulator and injections of each treatment were administered. Degree and durations of sensory blockade were determined through the response to a Halsted clamp pressure on the skin innervated by the saphenous/femoral and lateral cutaneous femoral nerves (lumbar dermatomes) and by the peroneal and tibial nerves. The degree and duration of motor blockade was assessed evaluating the ability to walk normally and proprioception.ResultsP1 and P2 treatments did not show any grade of sensory or motor blockade. The B2 treatment produced a higher degree of sensory blockade compared to B1 and B3 for both lumbar and sciatic dermatomes. There was no significant difference in the degree of sensory blockade comparing B1 to B3. The B2 treatment had greater motor blockade compared to B1 and B3. The duration of sensory and motor blockade was longer in B2 compared to B1 and B3.Conclusion and clinical relevanceWhen the nerve stimulator is used to perform the lumbosacral plexus block, the concentration of the bupivacaine has a more important role than the volume to produce a more solid and longer block.     

Mediastinal lymphoma with complete atrioventricular block in a horse

A 15-year-old, neutered-male pony presented with a history of weight loss during 4 months. Clinical evaluation revealed severe bradycardia and complete atrioventricular block. At necropsy, a lobulated mass in the anterior mediastinum and moderate enlargement of the superficial cervical lymph nodes were observed. The vagus nerve and the brachiocephalic trunk were embedded in this anterior mediastinal tumor. Histologically, the mass was composed of sheets of neoplastic lymphoid cells expressing CD3, with a low mitotic rate. To the best of our knowledge, this is the first reported case of mediastinal lymphoma associated with complete atrioventricular block in horses.     

Successful small intestinal resection and anastomosis in a late term broodmare with colic via a standing left flank laparotomy

A late term broodmare presented with low‐grade intestinal colic. Clinical findings were consistent with a small intestinal lesion requiring surgical intervention. The risks of general anaesthesia to the fetus, combined with clinical findings in an otherwise quiet natured horse influenced the decision to choose an alternative standing left flank approach first. A small intestinal resection and anastomosis was performed successfully and the mare delivered a healthy foal without complications a month later. Standing colic surgery might be a preferred alternative to general anaesthesia in certain circumstances as discussed in this case report.     

Comparison of lidocaine, lidocaine/epinephrine or bupivacaine for thoracolumbar paravertebral anaesthesia in fat-tailed sheep

ObjectiveTo evaluate the speed of onset and duration of loss of sensation in the flank following paravertebral administration of lidocaine (with or without epinephrine) or bupivacaine.Study designBlinded, randomized experimental study.AnimalsNine healthy fat-tailed male lambs (mean weight ± SD, 22.9 ± 3 kg). Each animal was used twice.MethodsAnimals were allocated randomly to receive two of three treatments: lidocaine 2% (LID, n = 6), lidocaine with epinephrine 5 μg mL^?1 (LIDEP, n = 6) or bupivacaine 0.5% (BUP, n = 6). The sheep received a total volume of 9 mL (3 mL for each paravertebral nerve) of anaesthetic. Onset and duration of loss of sensation on the flank were evaluated using nociceptive stimuli (superficial and deep pin-prick and clamping with a haemostat). Values for heart (HR) and respiratory (f_R) rates, rectal and skin temperatures were recorded before and at predetermined intervals after paravertebral injection. Parameters were compared using anova followed by Duncan’s test where relevant.ResultsMean ± SD times to onset of loss of flank sensation following paravertebral administration of LID, LIDEP or BUP were 1.8 ± 1.2, 2.0 ± 0.9 and 3.6 ± 1.3 minutes, respectively. Durations of action in minutes were 65 ± 18, 95 ± 46 and 303 ± 98, respectively. Onset and duration of effects after BUP treatment were significantly longer than after LID or LIDEP (p < 0.05), but did not differ significantly between LID and LIDEP. No clinical signs of local anaesthetic toxicity were noticed and HR and f_R remained stable with all protocols.Conclusions and clinical relevanceParavertebral administration of bupivacaine produces a longer duration of anaesthesia when compared to lidocaine with or without epinephrine and is indicated when prolonged flank surgery is to be performed.