On the morning of Day 4, the dog was bright, alert, and responsive and was eating dry Purina Pro Plan (Nestlé Purina). The dog's rectal temperature was 102.4 F. A follow-up abdominal radiographic examination revealed improved serosal detail, a large bladder, formed stool in the colon, and no obvious pattern of gastrointestinal obstruction. We discharged the patient with instructions to continue the metronidazole for 10 days and the enrofloxacin for nine days. We also instructed the owners to continue feeding the dry Pro-Plan diet and to return for a recheck in one week.

SECOND PRESENTATION

The following afternoon, the dog was presented to our hospital acutely stiff and in pain. Earlier in the day, the dog had been running with other dogs in the yard. In addition, the dog had produced a normal stool and had been eating and drinking normally. No vomiting or diarrhea had been noted. The owner had not given the metronidazole in the morning. On examination, the patient had a rectal temperature of 103.4 F (39.7 C). The dog's mucous membranes were pink, and its hydration was normal. The abdomen appeared slightly tense, and the dog walked with a slightly stiff gait.

The next morning (Day 6 since initial presentation), the dog was again bright, alert, and responsive and was walking well with no evidence of pain. The dog's rectal temperature was 100.6 F (38.1 C). We discharged the dog and continued the oral metronidazole and enrofloxacin therapy. In addition, we advised the owner to give half of a 325-mg buffered aspirin tablet once or twice a day as needed for pain.

Table 1 Patient Findings Throughout Treatment*

The dog became clinically normal after Day 25 with an improving white blood cell count beginning on Day 25, but a mild anemia was present for about one month before the dog relapsed on Day 43 (Table 1).

THIRD PRESENTATION

Forty-three days after the initial presentation, the dog was presented to our hospital for evaluation of an intense acute exacerbation of clinical signs. The owner stated that the dog seemed stiff without anti-inflammatory medication and that the dog's discomfort seemed to wax and wane over several days' time. The owner had given one 325-mg buffered aspirin tablet once a day for two consecutive days before presentation.

On physical examination, the patient had a rectal temperature of 103.2 F (39.6 C), moderate paraspinal pain, and mild ocular inflammation. The patient's weight was normal at 42.7 lb (19.4 kg). An in-clinic CBC showed marked leukocytosis with neutrophilia (Table 1).

We revised our differential diagnoses to include autoimmune, rickettsial, protozoal, and fungal diseases. We submitted blood samples to a diagnostic laboratory for a canine autoimmune profile, a CBC, and tick serology and initiated treatment with doxycycline hyclate (100 mg orally b.i.d.) for 14 days.