Swimmers syndrome, also known as swimming-puppy syndrome, flat-puppy syndrome, swimmer puppy syndrome, flat-pup syndrome, twisted legs, or turtle pup, is an uncommon developmental deformity of newborn dogs and cats whereby the limbs, primarily the hind limbs, are splayed laterally resulting in an inability to stand or walk. Forward movement with this affliction is only accomplished by lateral pedaling motions (1–6). Swimmers syndrome has generally been considered to be untreatable; therefore, animals that present with symptoms of the syndrome have tended to be euthanized (5,6). However, there have been several notable cases in which clinicians successfully treated animals — (1 kitten and 3 puppies) suffering from the syndrome with a combination of intensive physiotherapy, bandaging, external splinting, and hospitalization (2,4). In the present case, this miniature puppy with swimmers syndrome demonstrates that owners can provide satisfactory home-care and physiotherapy. Also, this case has been followed for over 10 y, and the dog is still alive, thus providng information about the prognosis.
This study presents the case of a dog that was born with swimmers syndrome; the original veterinarian had advised euthanization, but the owner chose to donate the dog to a teaching hospital. One of the authors adopted the dog and has been caring for it for the past 10 y. As a result of the home-care treatment, the dog recovered from the syndrome and continues to live a healthy life.
Case description
A 50-day-old, female miniature schnauzer was presented with astasia, dorsoventral flattening of the thorax, stiffness of hind-limb joints, hypoplasia of hind-limb muscles, paddling leg motion, and panting (). A severe exorotation of both hind paws and a pronounced hyperextension of both tarsal joints were present. In addition, there was an inability to adduct the hind limbs and zero range of motion in the hind-limb joints was observed. Neither of the hind legs could be placed in a normal standing position even with manual support. At rest, the dog remained in sternal recumbency; if positioned in dorsal recumbency the dog was unable to right herself.
Swimmer puppy. A — Before treatment — note the outward projection of the hind limbs, the flat thorax, and the rough hair coat. B — After treatment — note the resemblance to a normal puppy.
The owner brought the dog to the hospital and described its situation and signs. The owner explained that the dog was smaller than its littermates and that this, combined with its immobility, meant it had difficulty feeding. Moreover, the owner noted that the dog regurgitated its food after every feed. The regurgitation contributed to the dog’s low weight (the puppy weighed only 850 g when she arrived at the hospital).
In addition, the dog’s ventrum was covered with erosive lesions from urine and fecal scalding. A neurological examination identified no abnormalities. Thoracic radiographs revealed dorsoventral thoracic compression and displacement of the heart and lungs (). A complete blood (cell) count (CBC) was normal. The level of blood urea nitrogen (BUN) (0.83 mmol/L, reference range: 2.14 to 7.83 mmol/L) was low and other serum chemistry panels (including albumin, alkaline phosphatase, aspartate aminotransferase, calcium, creatine phosphokinase, creatinine, glucose, lactic dehydrogenase, magnesium, and total protein) were within the reference ranges.
Survey thoracic radiographs of the dog before treatment. Dorsal deviation of the sternum and left deviation of the cardiac silhouette were found. A — Right lateral view, B — Ventrodorsal view.
Environmental modification, nutritional support, and physiotherapy were recommended as treatment. As an environmental modification, a non-slippery floor was constructed with a cotton carpet, and an absorbent pad, which was frequently changed, was placed on the bed. In addition, the ventrum was wiped regularly with a wet cloth, and baby powder was applied regularly to prevent further erosions. A mixture of 2 pet foods — Science Diet Prescription p/d canned (Hill’s Pet Nutrition, Topeka, Kansas, USA) and Science Diet Prescription a/d canned (Hill’s Pet Nutrition), 10 g each — was fed to the dog every 2 h, 9 times a day. The dog consumed 15 to 20 g at each feeding. The total calorie intake for the dog was 173.2 to 230.94 kcal per day, an appropriate amount for a young dog weighing 850 g. After feeding, the dog was lifted upward and massaged gently from head to tail for 5 min to prevent regurgitation.
A standardized physiotherapy routine was performed every 2 h for 40 d following admission. The dog was placed in dorsal recumbency, and the physiotherapy session began with a gentle stroking massage from the head to the hind limbs for 20 s. Then, for the flat thorax, both lateral sides of the thorax were gently pressed and released using the palms of the hands, every 5 s for 1 min. For the hind limbs, an effleurage massage was applied from the hip to the digits for 20 s, followed by a kneading massage that was applied from the digits to the hip for 20 s.
After the massage session, each of the hind-limb joints was put through a series of passive range of motion exercises in the sequence outlined. First, to improve digit flexion and extension, the practitioner gently flexed and extended the dog’s digits for 10 s, while supporting the carpus with 1 hand and the digits with the other. Second, to improve the stifle flexion and extension, the practitioner gently flexed and extended the dog’s stifle for 10 s, while supporting the distal femur with 1 hand and the tibia with the other. Third, to improve hip flexion and extension, the practitioner gently flexed and extended the dog’s hip for 10 s, while supporting the proximal femur in 1 hand and the pelvis in the other. Fourth, to improve movement in the hip joints, the practitioner applied a gentle stroking massage with the fingers to both the dog’s hip joints for 20 s. To improve rotation in the joints, gentle pressure was applied medially, and excessive pressure was avoided during all massages and passive range of movements. In future cases, it is recommended that, as in this case, the passive range of motion on each joint be performed separately to prevent applying excessive stress on the joints. Finally, the dog was held in a normal standing position with all 4 limbs touching the ground for 1 min. After 40 d of treatment, the puppy was able to ambulate normally but experienced bilateral grade I medial patella luxation up to 1 y of age, after which the condition spontaneously resolved. Survey thoracic radiographs of the dog after treatment are shown in .
Survey thoracic radiographs of the dog after treatment. A — Right lateral view, B — Ventrodorsal view.
The dog, now 10 y old, has not suffered from any health issues, other than those seen in the first year of treatment; the dog has regular heartworm prevention medication and vaccinations.
Discussion
Swimmers syndrome is similar to myofibrillar hypoplasia syndrome, which is seen in piglets (1); the cause of each syndrome is unknown (1,6,7). However, it has been suggested that genetic and environmental factors may be responsible, including hard or slippery floors, weight gain exceeding skeletal development, dysfunction of synaptic or ventral horn cells, abnormal myelinization, delayed neuromuscular development, and obesity (2,4,6). In addition, it has been proposed that in-utero viral or fungal infections may cause muscular dystrophy in the developing fetus of piglets (1). In the disease of piglets, the histological appearance of affected muscles resembles that of experimentally induced glucocorticoid myopathy, suggesting that the condition could result from stress during pregnancy (7).
Pectus excavatum is a malformation of the sternum and costocartilages that results in dorsoventral flattening and narrowing of the thorax (1,8,9). Swimmers syndrome and pectus excavatum can occur independently or concurrently. Pectus excavatum is a congenital thoracic skeletal deformity, while the main symptoms of swimmers syndrome are the inability to stand or walk by the normal age of 3 wk, the limbs being splayed laterally; the inability to stand or ambulate; and forward movement being accomplished only by lateral pedaling motions (1–6). In this case, the dog was unable to stand or walk, and it was diagnosed with swimmers syndrome.
Environmental modifications can help improve the health and hygiene of dogs suffering from swimmers syndrome. To help swimmer dogs in their efforts to stand, it is necessary to provide a non-slippery floor to prevent slippage and further injury. In addition, because swimmer puppies urinate and defecate where they rest, it is suggested that an absorbent pad be placed on or near the bed, baby powder be applied after each movement of the bowels or bladder, and that they be wiped regularly to prevent urine and fecal scalding.
The dog in this study had a low BUN. Possible causes for decreased BUN in a dog are malnutrition, liver dysfunction due to infectious diseases, toxins, and portosystemic shunts (10). However, the latter factors were excluded because the liver enzyme and CBC values were within the reference ranges; thus, malnutrition due to competition among the littermates was regarded as most likely. To treat the malnutrition, we selected a canned diet rich in calories and protein and with a desirable texture, and fed small, frequent amounts to improve the dog’s nutritional status (11).
These dogs may be at greater risk of inhalation pneumonia from regurgitation after feeding, as shown in a previous report of a German shepherd dog afflicted with swimmers syndrome (6).The dog herein was therefore lifted regularly and massaged from head to tail to prevent regurgitation.
In a previous case, in which a 6-month-old swimmer dog was euthanized, the dog never gained weight, was undersized (18 kg), walked unsteadily, and tired easily after moderate exercise (6). In the present case, while the dog was smaller than its littermates, weighing only 3.5 kg at 6 mo and 4.5 kg at 1 y, being undersized did not lead to any further health issues once the dog had recovered from swimmers syndrome. This indicates that, while swimming puppies may remain underweight, they can function normally, as long as the nutritional support is appropriate.
It has been suggested that hobbling, or tying the hind limbs of piglets suffering from myofibrillar hypoplasia syndrome together below the hocks with adhesive tape may accelerate recovery and help affected piglets to stand and move around more freely (7). Some veterinarians have suggested hobbling the hind limbs together to prevent the splay-legged stance in dogs. However, while hobbling reduced the permanent dorsoventral flattening in swimming puppies, there was no effect on the speed of functional improvement (1). In addition, care must be taken not to cause swelling, edema, or ischemia by hobbling (2).
Physiotherapy is beneficial in increasing muscle tone and strength, activating limb coordination, and stimulating circulation of the tissues (2,12–14). Stroking, effleurage, and kneading massage techniques were applied. The stroking technique exerts a calming and soothing effect that helps animals become accustomed to being touched, reduces tension and anxiety, lowers muscle tone, and thus serves as a useful way to start and to finish massage sessions. The effleurage technique reduces swelling and edema, removes chemical by-products of inflammation, maintains mobility of soft tissues, and stretches the muscles. Kneading increases circulation and lymphatic flow, mobilizes soft tissues, removes chemical by-products of inflammation, increases sensory stimulation and invigoration, relaxes the animal, and lowers muscle tension (13,14).
Passive movement is the movement of a joint by external forces and is generally used when a patient is incapable of moving the joint on its own or when active motion may be injurious to the patient (13,15). The ability to maintain or increase muscle length and flexibility is one benefit of passive movements. Other benefits include the prevention of adhesions in articular capsules and joints that helps maintain joint range; improvement of articular nutrition by increasing synovial fluid production and diffusion; and maintaining mobility between different tissues. Furthermore, producing or maintaining normal patterns of movement and stimulating mechanoreceptors in joints, muscles, skin, and other soft tissues help to improve proprioceptive awareness and increase circulatory and lymphatic return (12,13,15). Thus, physiotherapy includes massages and passive range of motion exercises to develop and strengthen muscles and joint flexibility.
As muscles develop and are strengthened through therapy, animals will begin to self-correct their own walking. Therapy that commences before 3 to 4 wk of age has a better prognosis (1,3). In a previous report, an English bulldog puppy was treated by splinting and hospitalization for 14 d (2). However, the present case shows that home care with intensive physiotherapy is an effective alternative to bandaging or external splinting. Home care reduces stress to patients and provides better protection from infectious diseases compared with hospitalization.
As our case shows, swimmers syndrome is treatable with appropriate home-care treatment that involves environmental and nutritional management along with intensive, diligent physiotherapy. This case has been followed for over 10 y, and is, therefore, an invaluable resource for information about the prognosis. Owner education for treatment is important, with emphasis on the importance of maintaining regular physiotherapy.
