Despite being well described clinically, the exact etiology of swimmer syndrome remains unclear. Several theories suggest a multifactorial origin involving genetic predisposition-such as altered neuromuscular synaptic function-as well as environmental and management-related factors, including slippery flooring conditions.

Nutritional imbalances, particularly excessive protein intake during pregnancy or lactation, obesity, maternal metabolic disorders, and low litter size have also been proposed as contributing factors. In addition, developmental abnormalities of the musculoskeletal system and neurological disorders, such as lower motor neuron disease or anterior horn neuropathy, have been implicated in the pathogenesis of the condition^2-10.

Swimmer syndrome may be associated with a range of concurrent abnormalities, including pectus excavatum, medial patellar luxation, joint deformities such as genu recurvatum, and physiological cardiac murmurs^{1,2,5,7-9,11-13}. Diagnosis is primarily based on clinical history and physical examination findings, while radiographic evaluation is useful for identifying concurrent skeletal malformations and excluding other orthopedic conditions^2,5,6.

Although no standardized treatment protocol has been established for swimmer syndrome^3, conservative management strategies-including bandaging techniques, physiotherapy, and limb immobilization-have been reported to result in favorable outcomes, particularly when initiated early in life^2,3,6. Historically, euthanasia has been considered in severe cases due to concerns regarding prognosis¹; however, increasing evidence suggests that early intervention can lead to substantial functional recovery.

The aim of the present study is to describe the clinical characteristics, management, and outcomes of cats diagnosed with swimmer syndrome and to evaluate the effectiveness of early treatment using a flexible-hobble bandage technique, which is simple to apply and may significantly improve functional recovery and quality of life in affected kittens.

Study Population and Case Selection: This retrospective study included 21 client-owned cats presented to the Istanbul University-Cerrahpasa Faculty of Veterinary Medicine, Department of Surgery, between 2019 and 2024. According to owner-reported histories, none of the other littermates of the included cats exhibited clinical signs consistent with swimmer syndrome. Cats were enrolled in the study based on a clinical diagnosis of swimmer syndrome, defined by an inability to rise from the ground, marked lateral abduction of the hind limbs, and failure to develop a normal gait pattern. The onset of clinical signs during the neonatal or early juvenile period was considered a prerequisite for inclusion. Only cats with normal findings on general physical, orthopedic, and neurological examinations were included in the study. Cats showing evidence of primary neurological disease, traumatic injury, or systemic disorders that could account for the observed gait abnormalities were excluded.

Clinical and Radiographic Examination: All cats underwent a standardized clinical examination, with particular emphasis on limb posture, ability to stand, and gait characteristics. Excessive abduction of the hind limbs and absence of a normal gait pattern were consistently observed in all cases (Figure 1).

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Figure 1: The pelvic limbs diverted laterally (excessive abduction)

Radiographic examinations were performed to evaluate the presence of concurrent musculoskeletal abnormalities, including hip dysplasia and thoracic deformities such as pectus excavatum. Hip joints were evaluated on ventrodorsal pelvic radiographs with emphasis on femoral head-acetabular congruity, presence of subluxation, and acetabular depth. Due to the very young age and small body size of the kittens, perfect symmetry in ventrodorsal positioning could not be achieved in all cases; however, the radiographic assessment was considered sufficient for the identification of morphological features consistent with hip dysplasia.

Treatment
Flexible-Hobble Bandage: All of the cases were treated using elastic adhesive bandages (Petflex, Kruuse, Denmark) and elastic fixation bandages (Hypafix, BSN Medical, Germany), applied in an "8" shape. The bandages were positioned over the tarsal joint and distal tibia, and/or metatarsal region, with the legs kept parallel to each other, considering the width of the hips (Figure 3). In Case 6, where there was significant outward rotational pressure at the metatarsal region, an additional hobble bandage was applied to the metatarsal area. This bandaging method was adapted from Verhoeven et al. ² and Gomes et al. ¹¹. The purpose of this bandaging technique was to address the abduction (sideward movement) of the hind limbs observed during each step and while attempting to stand, and to help the patient adapt to a normal stance position. After the initial bandage application, follow-up examinations and bandage changes were routinely performed on days 5 and 10. Subsequent follow-up intervals were individualized according to clinical progression. The duration of bandage application was not fixed and was determined individually for each case. Treatment success was defined as the achievement of normal weight-bearing, characterized by the ability to stand and ambulate with appropriate limb positioning and without lateral abduction of the hind limbs. Accordingly, the duration of bandaging varied among cases depending on the clinical improvement period. During the treatment period, regular bandage checks were performed; in one case the bandage was renewed due to loosening, and in another case due to contamination. No bandage-related complications were observed during the bandaging period.

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Figure 2: Radiographic appearance of right hip dysplasia, characterized by a shallow acetabulum

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Figure 3: Kitten diagnosed with swimmer syndrome treated using a flexible hobble bandage. The bandage was applied in a figure-eight configuration at the tarsal level to prevent excessive abduction of the hind limbs

The owners were instructed to encourage the patients to walk during the day. To simulate the natural muscle movements that occur during stepping, light pressure was applied to the hind limbs to facilitate the flexion movement, and the owners helped the patient extend its legs using its own strength. Additionally, the patients? living environments were altered by replacing slippery surfaces with hard, non-slip flooring.

Statistical Analysis: Cases were analyzed using descriptive and non-parametric statistical methods. This study was designed as a retrospective descriptive case series; therefore, no a priori power analysis or sample size calculation was performed. Case inclusion was based on the availability of eligible clinical and follow-up data during the study period rather than predefined sample size targets. The effective sample size was reduced from 21 to 17 cases due to loss to follow-up, which limits the feasibility of robust statistical inference and reduces the generalizability of the findings.

The sex distribution of the included cats was 61.9% (n = 13) male and 38.1% (n = 8) female. Breed distribution consisted of British Shorthair (47.62%, n = 10), Scottish Fold (33.33%, n = 7), and Persian cats (19.05%, n = 4). The mean duration from symptom onset to initiation of treatment was 47.38 ± 31.16 days.

To evaluate factors associated with clinical recovery, correlation and group comparison analyses were performed in an exploratory manner. The relationship between age at treatment initiation (days) and time to treatment completion (days) was assessed using Spearman?s rank correlation analysis (Spearman?s rho), as the limited sample size and the potential violation of normal distribution assumptions precluded the use of parametric correlation tests.

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Table 1: Clinical findings of cats diagnosed with swimmer syndrome

Among the cats that completed the treatment protocol, the time required to achieve normal weight-bearing ranged from 14 to 45 days. Treatment was discontinued when stable normal weight-bearing was observed. The age at treatment initiation ranged from 20 to 120 days, and treatment duration varied according to individual clinical response. Detailed case-specific information regarding age at treatment initiation and treatment completion is presented in Table 2.

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Table 2: Ages at the start and completion of treatment

All cats that achieved normal weight-bearing were followed clinically after treatment completion. When evaluating the duration until treatment completion, four cases for which follow-up could not be ensured were excluded from the analysis. For the 17 cases, the mean duration to complete treatment was found to be 24.94±13.51 days. No recurrence of clinical signs associated with swimmer syndrome was observed in any of the successfully treated cases during the follow-up period. Correlation analysis showed that age at treatment initiation was significantly associated with recovery time. A moderate, positive, and statistically significant correlation between age at treatment initiation and time to recovery (Spearman's rho=0.555, p=0.021) was found, indicating that recovery time tended to increase in cases in which treatment was initiated at an older age. Statistical significance was set at p<0.05.

Although a genetic predisposition has been proposed-particularly in brachycephalic dog breeds-definitive evidence remains limited. In cats, breed predisposition has not been clearly established due to the small number of reported cases. In our study, most affected cats belonged to brachycephalic breeds (Scottish Fold, Persian, and British Shorthair), which may suggest a comparable predisposition. However, the absence of affected littermates contrasts with previous reports describing multiple affected kittens within the same litter^11, indicating that genetic factors require further investigation.

Historically, swimmer syndrome has been associated with thoracic deformities such as pectus excavatum, and severe cases were often considered untreatable, with euthanasia recommended^1,16,18,19. Swimmer syndrome and pectus excavatum can occur independently or together²⁰. Such deformities may worsen prognosis due to secondary complications, including respiratory distress and feeding difficulties⁶. In the present study, despite thoracic flattening in one case and pectus excavatum in another, no life-threatening complications occurred, and euthanasia was not required. These favorable outcomes likely reflect early diagnosis, appropriate owner education, and close clinical follow-up.

Environmental management and supportive care were essential components of successful treatment. Consistent with previous reports, the use of soft, non-slip surfaces was strongly recommended, as slippery flooring has been identified as a contributing factor to disease severity^2,11. Passive range-of-motion exercises and massage were advised, while dietary modification and complete limb immobilization were avoided to preserve controlled movement and muscle activity.

The flexible hobble bandage technique applied in this study differed from previously described methods that restrict hind limb and lumbar movement^3,17. Our approach aimed to provide stabilization without completely limiting limb motion, allowing functional muscle activation while minimizing the risk of bandage-related complications. This technique was well tolerated and contributed to favorable outcomes when combined with early intervention.

As a retrospective case series, this study has inherent limitations. The absence of a control group limits causal inference regarding treatment efficacy, and owner compliance with home-care recommendations could not be objectively verified. Nevertheless, ethical considerations precluded withholding treatment in juvenile animals, and the rarity of swimmer syndrome in cats limits the feasibility of controlled studies. Despite these limitations, the consistent clinical improvement observed in most cases provides valuable practical insight into the management of feline swimmer syndrome.

Finally, owner compliance emerged as a critical factor influencing treatment success. Cases that discontinued treatment or follow-up failed to show improvement, whereas consistent owner involvement and regular monitoring were associated with recovery, even in older kittens. These findings highlight that successful management of swimmer syndrome depends not only on early diagnosis and appropriate treatment but also on effective communication and cooperation between veterinarians and pet owners.

In conclusion, swimmer?s syndrome is a condition that can occur in both cats and dogs. In our study, it was most frequently observed in Scottish Fold breed cats. The earlier the syndrome is detected and the earlier intervention is applied, the better the prognosis for the patients. The material and method used for bandaging must be purpose-specific and sufficient. Bandaging and physical therapy protocols can be developed based on the severity of the syndrome, and swimmer?s syndrome can be treated effectively.

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