Splenic torsion, though extremely rare in cats, is a condition that requires immediate medical attention due to the potential for severe complications such as splenic infarction, rupture, and haemorrhage. To the authors’ knowledge, there is only one case report describing a cat with splenic torsion with concurrent splenitis and chronic anaemia [1]. This case report details the ultrasonographic findings of splenic torsion in a cat, with one key distinction from previously published cases: in our case, a color Doppler signal was detected in the splenic vasculature. In dogs, splenic torsion commonly appears secondary to gastric dilatation and volvulus [2]. Primary splenic torsion, an isolated rotation of the spleen around the gastrosplenic and phrenicosplenic ligaments, is also well-described in canines [3]. Primary splenic torsion is most common in large and giant deep-chested breeds for example German shepherd and Great Danes [3], although it is also described in smaller dog breeds [4]. Splenic torsion can be partial or complete, and in canine patients, this condition is readily diagnosed using B-mode ultrasound [5]. The ultrasonographic findings of splenic torsion include splenomegaly, a diffuse, mottled, or lacy pattern of the spleen, hypoechoic parenchyma, and absence or reduction of the colour Doppler signal in the splenic vein [5][6]. Furthermore, the surrounding fat tissue may become hyperechoic, and a hyperechoic, triangular perihilar finding may be supportive of the diagnosis of acute splenic torsion in dogs [5][7].

Splenic torsion is an extremely rare condition in cats, with previously only one other documented case [1]. The clinical presentation and ultrasonographic findings in this case were consistent with those reported in splenic torsion cases in other species, such as dogs, where the condition is more commonly recognized. This report adds valuable information to the scant literature on feline splenic torsion, particularly in terms of ultrasonographic characteristics and postoperative outcomes.

Ultrasound is a key diagnostic tool in the identification of splenic torsion. In dogs, splenomegaly with a diffuse, mottled, or lacy splenic pattern, hypoechoic parenchyma, and an absence or reduction of the color Doppler signal are typical findings [5][6]. Splenomegaly is a relatively rare finding in cats and most of the time is secondary to neoplastic transformation of the splenic tissue such as lymphoma or mast cell tumor [8][9]. Splenomegaly is often reported secondary due to anaesthesia and sedation in dogs but given the difference in sinusoid splenic tissue in cats, there is only a small significant response of the splenic parenchyma to general anaesthesia [8][10]. Fine needle aspiration (FNA) is commonly used to determine the underlying cause of the splenomegaly, and it is considered a safe procedure [5]. In our case, authors decided against the FNA of the enlarged spleen because the suspicion of a possible splenic torsion was made and explorative laparotomy was planned. A regional lymphadenomegaly was reported in a previous case of splenic torsion and splenitis might be a possible cause of that. It is unclear why regional lymphadenomegaly was visible in our case, given that no histopathological changes were reported. However, our case demonstrated a marked difference compared to previously reported splenic torsion in a cat. Despite the complete torsion of the splenic pedicle, a clear color Doppler signal was observed throughout the splenic tissue. This finding is unexpected and contrasts with the usual presentation of splenic torsion in dogs, where Doppler flow is typically absent due to compromised blood supply. One potential explanation for the presence of Doppler flow could be a partial torsion at the time of the ultrasound examination, which later progressed to complete torsion. However, this is considered unlikely given the short amount of time between the ultrasound examination and surgery. Another hypothesis is that arterial flow was retained despite venous occlusion, a phenomenon not commonly described but theoretically possible. The degree of pedicle rotation may have contributed to the observed Doppler signal, as extensive torsion can disproportionately compromise venous drainage while permitting low-grade arterial inflow, due to the higher intraluminal pressure of arteries. This imbalance could result in splenic congestion and splenomegaly while still allowing detectable intraparenchymal blood motion on colour Doppler examination. Importantly, colour Doppler ultrasound detects blood motion rather than effective tissue perfusion, therefore, persistent arterial inflow or congested intravascular flow within the spleen may generate a Doppler signal despite functionally compromised venous drainage. Further investigation into the vascular dynamics of splenic torsion in cats could provide insight into this anomaly.

Splenic torsion can be classified as either acute or chronic, depending on the location of vascular compromise. In chronic splenic torsion, the spleen rotates distal to the splenic hilus. If collateral veins, such as the splenogonadal or left gastroepiploic vein remain uninvolved, alternative venous pathways may develop, facilitating drainage from the spleen into the systemic circulation [11]. This adaptation can reduce venous congestion, resulting in more subtle clinical signs. In contrast, acute splenic torsion typically occurs near the splenic hilus, without the possibility of collateral compensation. This leads to rapid-onset, severe splenic venous congestion, marked splenomegaly, and potential capsular distension or rupture. In our case, the combination of acute clinical deterioration, severe splenomegaly, absence of identifiable collateral circulation, and evidence of splenic rupture is consistent with an acute splenic torsion.

The findings in this case are in some ways similar to those reported in the previous case of feline splenic torsion, particularly the presence of splenomegaly, hemoperitoneum, and regional lymphadenopathy. However, the previous case did not report the unusual Doppler findings seen here, suggesting variability in the ultrasonographic appearance of this condition. The presence of haemoperitoneum in both cases suggests that haemorrhage may be a common complication of splenic torsion in cats, possibly more so than in dogs, where the incidence of haemoperitoneum is also noted but may be less frequent. Further studies and case reports are necessary to draw this conclusion.

The underlying cause of splenic torsion in our patient remains unclear. In dogs, the condition is often secondary to gastric dilatation-volvulus [2], which is extremely rare in felines. One of the reasons for this might be the barrel shaped chest anatomy in felines, compared with over presented deep chested canines. The absence of neoplastic or significant inflammatory changes in the spleen suggests that primary splenic torsion, where the spleen rotates independently of other structures, might have occurred. However, the anatomical and physiological factors that predispose cats to this rare condition are not well understood. The role of immune response, splenic sinusoid architecture, and vascular differences in felines might be considered in future studies. A potential contributing factor to splenic torsion in this case is the patient’s history of chronic pancreatitis. In cats, the left pancreatic lobe lies in close proximity to the splenic hilus and is most commonly affected in inflammatory pancreatic disease. Chronic pancreatitis could theoretically lead to local inflammation, fibrosis, or adhesions involving adjacent structures, potentially altering splenic mobility and predisposing to torsion. However, this association is considered unlikely in the present case. Chronic inflammatory changes would be expected to result in a more gradual or chronic alteration of splenic position, potentially allowing the development of collateral circulation. In contrast, the absence of collateral vessels and the presence of an acute haemoperitoneum support an acute torsion event, making a direct causal relationship with chronic pancreatitis less probable, although it cannot be completely excluded.

The prognosis following splenectomy for splenic torsion in dogs is generally good [11], and this seems to be true for cats as well, based on the limited data available. Despite the eventual euthanasia in this case, the initial perioperative recovery was successful. This suggests that, when diagnosed early and treated appropriately, splenic torsion in cats can be managed effectively with surgical intervention. Possible complications as postoperative infections, vascular damage to left pancreatic lobe and gastric fundus which could lead to abscess formations or gossypiboma are possible and described in literature [12][13] and underscore the importance of careful postoperative monitoring. The presence of a short-term mild neutropenia perioperatively may have contributed to the suspected postoperative abscess formation in this case.

This case report contributes to the understanding of splenic torsion in cats, particularly in terms of its ultrasonographic appearance. While the condition remains rare, it should be considered for the differential list in cats presented with acute abdominal pain, splenomegaly, or hemoperitoneum. The findings in this case also suggest that splenic torsion in cats may have a different pathophysiology compared to other species, warranting further investigation. Despite the unfavorable outcome in this instance, the good perioperative response indicates that splenectomy should be strongly considered as a treatment option in similar cases.

The authors received no financial support for the research, authorship, and/or publication of this article.

The data supporting the findings of this study are available from the corresponding author upon reasonable request.

The work described in this manuscript involved the use of non-experimental (owned or unowned) animals. Established internationally recognised high standards (“best practice”) of veterinary clinical care for the individual patient were always followed and/or this work involved the use of cadavers. Ethical approval from a committee was therefore not specifically required for publication in JFMS Open Reports. Although not required, where ethical approval was still obtained it is stated in the manuscript.

Informed consent (verbal or written) was obtained from the owner of the animal described in this work. No animals or people are identifiable within this publication, and therefore additional informed consent for publication was not required.

No animals or people are identifiable within this publication, and therefore additional informed consent for publication was not required.