A 1-year-old 58.3-lb (26.5-kg) castrated male English bulldog presented to the Mathew J. Ryan Veterinary Hospital at the University
of Pennsylvania for evaluation of progressive pain that was difficult to localize. The dog's vaccination status was current
for rabies, canine distemper, and parvovirus. The dog had not traveled outside of Pennsylvania, and there was no history of
Ten days before admission to the University of Pennsylvania, the dog had been evaluated by a local veterinarian for continuous
crying out, shaking, and panting. The complete blood count, serum chemistry profile, and urinalysis results had been normal.
Empiric treatment had been initiated with prednisolone acetate (1 mg/kg subcutaneously once), diazepam (0.25 mg/kg orally
every 8 hours), and carprofen (2.2 mg/kg orally every 12 hours). Over the next 10 days, the dog had progressively exhibited
more pain, had been unable to lower its head and neck to eat, and had developed progressive pelvic limb lameness. Consequently,
the dog was reevaluated by the local veterinarian, given another injection of prednisolone (1 mg/kg subcutaneously), and referred
to the University of Pennsylvania.
PHYSICAL AND NEUROLOGIC EXAMINATIONS
On admission to the University of Pennsylvania, physical examination revealed mild upper airway stridor. The dog had normal
heart and respiratory rates and a normal rectal temperature. The dog's sensorium was quiet and responsive. The patient had
a normal gait in its thoracic limbs but a stiff and short-strided gait in both pelvic limbs. The dog had difficulty rising
from a recumbent position and was reluctant to walk and unwilling or unable to run.
Postural reactions were normal in all limbs. During the postural reaction tests, the dog would cry out. Muscle tone was normal
in all limbs. No muscle atrophy was detected. The dog's spinal reflexes and the results of a cranial nerve examination were
normal. The dog appeared to be in extreme pain when the spinous processes were palpated and when the vertebral column was
manipulated, especially the caudal lumbar vertebrae and sacrum.
Given the patient's abnormal pelvic gait and sensitivity to palpation in the lumbar region, we presumed that the lesion's
neuroanatomic location was between L4 and S2. Conditions that may cause this presentation of generalized pain or pain that
is difficult to localize to a specific area include degenerative, neoplastic, infectious, inflammatory, immune-mediated, or
traumatic diseases that affect the intervertebral disks, facet joint capsules, dorsal root ganglia and sensory nerves, vertebral
ligaments, musculature, periosteum, or meninges.1
DIAGNOSTIC TESTING AND DIFFERENTIAL DIAGNOSES
The results of a serum chemistry profile, complete blood count, and urinalysis were within reference ranges. Serologic testing
for neutralizing antibodies to canine distemper virus revealed a titer of 1:192, which was likely a result of the previous
vaccinations for canine distemper virus. In addition, the serum concentrations of IgG directed against Neospora caninum and IgM and IgG directed against Toxoplasma gondii were normal. A serum latex agglutination test for Cryptococcus neoformans was negative. Serum creatine kinase activity was normal. Radiographic examination of the thorax revealed no abnormalities.