Clinical features of muscle cramp in 14 dogs.

BACKGROUND: Muscle cramps (MCs) are prolonged, involuntary, painful muscle contractions characterized by an acute onset and short duration, caused by peripheral nerve hyperactivity. OBJECTIVES: To provide a detailed description of the clinical features and diagnostic findings in dogs affected by MCs. ANIMALS: Fourteen dogs. METHODS: Multicenter retrospective case series. Cases were recruited by a call to veterinary neurologists working in referral practices. Medical records and videotapes were searched for dogs showing MCs. The follow-up was obtained by telephone communication with the owner and the referring veterinarian. RESULTS: Three patterns of presentation were identified depending on the number of affected limbs and presence/absence of migration of MCs to other limbs. In 9/14 (64%) of dogs, MCs were triggered by prompting the dogs to move. 8/14 (58%) dogs were overtly painful with 6/14 (42%) showing mild discomfort. The cause of MCs was hypocalcemia in 11/14 (79%) dogs: 9 dogs were affected by primary hypoparathyrodism, 1 dog by intestinal lymphoma and 1 dog by protein losing enteropathy. In 3/14 cases (21%) the cause was not identified, and all 3 dogs were German Shepherds. CONCLUSIONS AND CLINICAL IMPORTANCE: Muscle cramps can manifest in 1 of 3 clinical patterns. Muscle cramps are elicited when dogs are encouraged to move and do not always appear as painful events, showing in some cases only discomfort. The main cause of MCs in this study was hypocalcemia consequent to primary hypoparathyroidism. In dogs having MCs of unknown etiology, idiopathic disease or paroxysmal dyskinesia could not be ruled out.

Clinical characteristics of Scottie Cramp in 31 cases.

OBJECTIVE: To report the clinical features, with response to therapy and long-term outcome of Scottie Cramp as described by owners. METHODS: Owners of affected dogs provided a description of clinical signs, age of onset and disease progression. Medical records, pedigrees and videotapes of cramp episodes were evaluated. RESULTS: Thirty-one dogs were recruited; 19 showed generalised spasticity and 12 exhibited only hind limb spasticity and skipping. Episodes were noted in the first year of life in 76% of dogs and were triggered by excitement, stress and exercise. Episode frequency and severity decreased over time with behaviour modification and decreased exposure to triggers playing a role in their development. One dog was euthanased because of severe refractory signs. Fluoxetine reduced the frequency and duration of episodes in seven dogs, but not in one severely affected dog. Female dogs were over-represented with only eight affected males in the study cohort, and the presence of dogs with cerebellar degeneration in the same pedigrees may suggest a more complex mode of inheritance than previously reported. CLINICAL SIGNIFICANCE: The disorder recognised as Scottie Cramp by dog owners includes dogs with hind limb spasticity in addition to generalised cramping. Signs usually improve over time without specific treatment.

Phenotypic characterisation of canine epileptoid cramping syndrome in the Border terrier.

OBJECTIVES: To characterise the phenotype of Border terriers suspected to be affected by canine epileptoid cramping syndrome and to identify possible contributing factors. METHODS: Owners of Border terriers with suspected canine epileptoid cramping syndrome were invited to complete an online questionnaire. The results of these responses were collated and analysed. RESULTS: Twenty-nine Border terriers were included. Most affected dogs had their first episode before 3 years of age (range: 0·2 to 7·0 years). The majority of episodes lasted between 2 and 30 minutes (range: 0·5 to 150 minutes). The most frequent observations during the episodes were difficulty in walking (27 of 29), mild tremor (21 of 29) and dystonia (22 of 29). Episodes most frequently affected all four limbs (25 of 29) and the head and neck (21 of 29). Borborygmi were reported during episodes in 11 of 29 dogs. Episodes of vomiting and diarrhoea occurred in 14 of 29, with 50% of these being immediately before or after episodes of canine epileptoid cramping syndrome (7 of 14). Most owners (26 of 29) had changed their dog's diet, with approximately 50% (14 of 26) reporting a subsequent reduction in the frequency of episodes. CLINICAL SIGNIFICANCE: This study demonstrates similarities in the phenotype of canine epileptoid cramping syndrome to paroxysmal dystonic choreoathetosis, a paroxysmal dyskinesia reported in humans. This disorder appears to be associated with gastrointestinal signs in some dogs and appears at least partially responsive to dietary adjustments.

Muscle cramps in two standard poodles with hypoadrenocorticism.

Two standard poodles were evaluated for painful, episodic muscle cramps affecting their thoracic and pelvic limbs. Both dogs had been diagnosed with hypoadrenocorticism and were being treated with fludrocortisone acetate and prednisone when evaluated for muscle cramps. However, the muscle cramping started approximately 1 month prior to the diagnosis of hypoadrenocorticism. Findings on general physical examination included lethargy and dehydration. Neurological examination was normal between episodes. Serum biochemical abnormalities included hyperalbuminemia, azotemia, hyponatremia, hypochloremia, and hyperkalemia. Altering treatment to desoxycorticosterone pivalate resolved the electrolyte abnormalities and the episodes of muscle cramping in both dogs. The authors conclude that hypoadrenocorticism can be associated with episodes of painful muscle cramping in standard poodles.

Muscle spasms associated with ear tick (Otobius megnini) infestations in five horses.

Severe muscle cramping not associated with exercise was observed in 5 horses. Focal muscle groups in various regions underwent intermittent visible contraction. Intermittent prolapse of the third eyelid, sweating, pawing, muscle tremors, and muscle fasciculations also were observed. Clinical signs often were misconstrued as signs of colic. Percussion of muscle induced contraction of muscle groups. Concentrations of serum electrolytes and the acid-base balance were within reference limits, but activities of creatine kinase and aspartate transaminase were moderately high. Muscle biopsy revealed no abnormalities except for a few necrotic muscle fibers undergoing phagocytosis. Electromyography of 1 horse was suggestive of increased motor unit activity. All horses had Otobius megnini (ear tick) infestations and had recurrence of signs until treatment was initiated for ear ticks.

Spastic syndrome in a Holstein bull: a histologic study.

A 4-year-old Canadian holstein bull developed the spastic syndrome, an episodic but progressive disorder causing pelvic limb muscular spasms. A post-mortem study, including morphometry of skeletal muscles and teased peripheral nerve fibers of the pelvic limb, revealed mild type II skeletal muscle fiber atrophy and minimal, focal segmental demyelination with remyelination, and axonal degeneration in peripheral nerves. Such alterations are probably incidental or age-associated. Idiopathic muscular cramps is the most probable explanation of the clinical disease and is consistent with the absence of significant morphologic pathologic lesions.