Case 10
The radiographic lesions coupled with Max's age make you most suspicious of a neoplastic process. The diffuse nature of the lesions makes a transthoracic aspirate a viable diagnostic step. Infectious causes of pneumonia are still a possibility as well, and pulmonary fine-needle aspiration is a relatively safe procedure that may provide a quick diagnosis. Parasitic infections may be a consideration, but you think this is less likely given Max's history and environment.
You discuss obtaining an aspirate with the owners, noting the risk of hemorrhage or pneumothorax. But with a 1.5-in, 25-ga needle, the risk should be minimal. The owners agree to the procedure as well as baseline laboratory tests to look for any other systemic problems (you draw a little extra blood in case you decide to add other tests later). With Max lightly sedated and by using the radiographs as a guide, you aseptically prepare an area likely to provide the best access to lung lesions and perform the aspirate.
Max does well and is hospitalized overnight to be monitored closely for worsening respiratory signs. In case Max has a protozoal infection such as toxoplasmosis, you start clindamycin at 25 mg/kg given orally divided b.i.d.
The following day you receive the results of his laboratory tests:
CBC
Patient values
Reference range
WBC (/µl)
28,000
3,500-16,000
-Neutrophils (/µl)
24,000
2,500-8,500
-Monocytes (/µl)
1,975
0-600
-Lymphocytes (/µl)
1,100
1,200-8,000
-Eosinophils (/µl)
925
0-1,000
Hct (%)
31
29-48
Hgb (g/dl)
10.2
9.3-15.9
RBC morphology
Normal
Platelets (/µl)
203,000
200,000-500,000
Serum chemistry profile
Patient values
Reference range
BUN (mg/dl)
45
14-36
Creatinine (mg/dl)
2.6
0.6-2.4
Phosphorus (mg/dl)
5.3
2.4-8.2
ALP (IU/L)
89
6-102
ALT (IU/L)
73
10-100
Total bilirubin (mg/dl)
0.2
0.1-0.4
Albumin (g/dl)
3.4
2.5-3.9
Globulin (g/dl)
4.8
2.3-5.3
Glucose (mg/dl)
193
64-170
Calcium (mg/dl)
9.4
8.2-10.8
Sodium (mEq/L)
149
145-158
Potassium (mEq/L)
3.6
3.4-5.6
T4 (µg/dl)
1.3
0.8-4
FeLV antigen
Negative
Negative
FIV antibody
Negative
Negative
Urinalysis
Patient values
Reference range
Urine specific gravity
1.057
1.015-1.060
pH
7.1
5.5-7
Protein
Negative
Negative
WBC (/hpf)
0-3
0-3
Bacteria
None seen
Negative
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