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Case 31
Two Months Later
 | Heartworm Disease |
| Respiratory arrest last night @ the referring
veterinarian's clinic |
| Boris presented to the VMTH two months ago and was
diagnosed with heartworm disease. At that time his
PCV was 25% and hemoglobinuria was present. He was placed on prednisone
@ 5 mg BID for 7 days, then 5 mg SID x 14 days, then 5 mg
every other day for 14 more days with a recheck in 4 to 6 weeks. The
referring veterinarian also placed him on a monthly
heartworm preventative (ivermectin). |
| 2/3/98: Yesterday at 4:30 pm, Boris was noted to have fallen over and
then defecated. He then became limp and
unconscious but could still be seen to be breathing. He was taken to the
referring veterinarian's facility with sudden onset
of weakness and dyspnea (open mouth breathing). The cat was put on an oxygen
mask and went into respiratory arrest. He was intubated and provided with
positive pressure ventilation until he was able to breath on his own. He was
treated with 5 mg of dexamethasone IV, 2 cc aminophylline, & 0.5 cc of Lasix
IV. Chest films were taken at this time and revealed severe pulmonary
infiltrates. Dexamethasone injections were repeated IV q 3 hrs and the cat
spent the evening in their oxygen chamber. |
| Grade V/VI right sided holosystolic murmur, HR=170 (regular), R=57 with
increased effort. Presumptive hemoglobinuria (urine was red).
Urine from pad was not saved.
Urinalysis could not be obtained as the bladder was
too small to obtain a cystocentesis. Pale pink MM that were later slightly
lavender after venipuncture Temperature was not taken due to desire to not stress the cat. Body condition score=3/9. Jugular veins were
distended with pulses visible at least 1.5 inches dorsal to the thoracic
inlet. Strong femoral pulses were present with pulse deficits which
corresponded on auscultation in timing to what sounded like
premature beats. Expiratory crackles palpable on sternum when carried
from Radiology. Extremities were cool and the cat was very quiet for all medical
procedures though he was alert. He was also
approximately 8% dehydrated and drank thirstily when offered water. Bladder
was very small. |
| Heartworm disease |
| Presumptive hemoglobinuria/
hematuria |
| Mixed interstitial alveolar infiltrates, severe on referral films;
greatly improved on VMTH films 24 hours later |
| Respiratory arrest episode, historical |
| Abnormalities on CBC (see details in the Comments section) |
| Abnormalities on Chemistry panel (please see Comments) |
| CBC: Thrombocytopenia (35,000), moderate hyperproteinemia (9.0), mild
neutrophilia (12,150), and moderate lymphopenia (675). The marked
thrombocytopenia is of concern as it may be due to shearing secondary to caval
syndrome or consumption at the site of the probable pulmonary worm embolism. A
platelet count will need to be rechecked tomorrow and followed closely to see
if he is continuing to lose platelets or if prednisone is aiding his
thrombocytopenia. The neutrophilia, though mild,
is notably increased above his previous values and so for Boris this likely
represents a moderate amount of inflammation (compare: 6/97: 4836, 12/97:
3750). He also had a mildly low Hct
(27%), Hgb (8.4) and RBC count (6.21
M/ul). His Hct, however, has remained reasonably stable (6/97: 29%,
12/97: 25%). |
| Chemistry panel: Elevated ALT (552 IU/L), AST (455 IU/L), and BR (0.9).
Cats with right sided CHF may have increased serum liver enzyme levels but
usually not to this degree. Moderate hyperproteinemia (TP=8.9, globulins=5.8,
albumin=3.1). Mild azotemia (BUN=52, Cr=2.8). In light of Boris' dehydrated
state his azotemia is likely prerenal and hyperproteinemia secondary to this
as well. Hyperglobulinemia is often seen in cats with heartworm disease and
presumed to be secondary to chronic antigen stimulation. Hyperglycemia=294
(probably stress related). Very mild decreases in Na (149), K (3.3), Cl (112),
PO4 (3.0). |
| ECG: R waves seemed decreased at 0.25 mV with a bifid component.
Arrhythmia is ventricular in origin (occasional PVCs
were present). |
| Radiographs: A referral lateral thoracic radiograph taken last night
after Boris' respiratory arrest revealed marked pulmonary infiltrates in the
caudal lung fields. Today's films (VMTH) showed a marked improvement with
respect to pulmonary infiltrates but the caudal vena cava remains dilated. The
radiologists felt that the cardiac silhouette was also notably decreased in
size compared to yesterday. |
| Echocardiogram: The RV was very dilated as was the RA. Diastolic septal
flattening was again observed. One heartworm was visualized entwined within
the tricuspid valve apparatus, extending into the right atrium. More worms
were seen in the pulmonary artery. |
| Today we have found evidence of caval syndrome in Boris. One heartworm
was visualized entangled in the tricuspid valve of his heart. However the
remainder of the worms visualized were present in his pulmonary artery. When
worms are present in this location they can cause tricuspid regurgitation with
resultant shearing of his red blood cells and the hemoglobin from the red
cells can then be passed out in the urine. The finding that his urine was red
today is supportive evidence that this is most likely happening. |
| Another finding today was that Boris has a decreased number of
platelets (35,000) which could increase his tendency to bleed. He should have
his blood parameters checked tomorrow and Saturday to see if he is continuing
to lose platelets (CBC). |
| Boris is also showing some elevation in his BUN and creatinine which
measure kidney function. These should also be checked at the same time.
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| If Boris is noticed to have increased respiratory effort or respiratory
distress you should call your veterinarian and/or return to a veterinary
hospital as a new worm may have lodged in his lungs. |
| Please refer to your drug label for instructions on
prednisone. |
Quiz
Correct Quiz
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