Page 284 - Problem-Based Feline Medicine

276 PART 5 CAT WITH ACUTE ILLNESS

Hypoglycemia. Severe sepsis without an externally obvious source
● Cats with acute pancreatitis may be hypoglycemic, of infection.
but it is not known if this contributes to depression. ● Septic cats may not have a fever. Meticulous phys-
Clinical hypoglycemia usually results from insulin ical examination, serum, chemistries, diagnostic
overdose. This is confirmed by measuring blood imaging and fine-needle aspiration will help local-
glucose levels and by prompt resolution of clinical ize the infection (e.g. deep subcutaneous abscess,
signs following intravenous dextrose or intramus- pyometra, pyelonephritis, peritonitis, pyothorax,
cular glucagon. Portable glucose meters have a ten- pneumonia).
dency to measure falsely low values, so a diagnosis
Toxoplasmosis.
of hypoglycemia should be reconsidered if the cat
● Acute systemic toxoplasmosis typically affects kit-
does not respond to intravenous glucose or
tens or immunosuppressed cats, causes a fever,
glucagon. Lack of response to sugar solutions
and uveitis is a common finding. Confirmation is by
rubbed on the gums or given by stomach tube does
measuring serum IgM antibodies or demonstrating
not rule out hypoglycemia, because most absorp-
rising serum IgG antibodies.
tion of glucose occurs in the small intestine.
Ethylene glycol poisoning.
Acute gastritis/gastroenteritis.
● The diagnosis of acute poisoning relies on history
● This is a differential diagnosis for cats with pancre-
of ingestion or a high index of suspicion. Both cats
atitis that are vomiting. Indeed, some cases diag-
with pancreatitis and cats with acute ethylene gly-
nosed with acute gastritis probably have acute
col poisoning may have acute depression without
pancreatitis. If signs are mild, then distinguishing
other signs, but cats with acute ethylene glycol
the two diseases is not important, because both are
poisoning should be isosthenuric, while cats with
similarly treated (short-term withholding of food
pancreatitis should have well-concentrated urine,
and fluid therapy). The most useful test for distin-
unless there is a concurrent disorder causing dilute
guishing the two is abdominal ultrasound examina-
urine, such as chronic renal failure. Metabolic aci-
tion. Abdominal radiography will help rule out
dosis, increased anion gap and increased osmolal
foreign material and obstruction as a cause of acute
gap will be more severe than in pancreatitis.
vomiting.
Definitive diagnosis relies on measuring ethylene
Acute heart failure. glycol in serum or urine or seeing oxalate crystals
● Potential overlapping signs of acute heart failure in urine or in a kidney biopsy.
and pancreatitis include pale mucus membranes, ● In the later stage of poisoning (renal failure), kid-
hypothermia, weak pulses, tachycardia, bradycar- neys may be firm and painful on palpation, and the
dia, dyspnea and vomiting. Clinical findings of a bladder is usually small because of anuria. The ele-
heart murmur, irregular heart rate, and pulmonary vations in urea and creatinine will be marked.
crackles, and radiographic findings of pulmonary
Lily poisoning.
edema and cardiomegaly help establish the diagno-
● The diagnosis of acute poisoning relies on history
sis of heart failure. (Note that both heart failure and
of ingestion or a high index of suspicion. Cats in the
pancreatitis may be associated with pleural effu-
acute stage of lily poisoning should have poorly
sion.) Definitive diagnosis of cardiomyopathy
concentrated urine, while cats with pancreatitis
requires echocardiography.
should have well-concentrated urine, unless there is
Panleukopenia. a concurrent disorder causing dilute urine, such as
● Severe panleukopenia usually affects immature chronic renal failure.
cats while pancreatitis usually affects mature cats. ● In the later stage of poisoning (renal failure), kid-
A complete blood count will usually reveal severe neys may be firm and painful on palpation, and
neutropenia. Depression and vomiting are early the bladder is usually small because of anuria.
signs. Marked diarrhea typically develops later, The elevations in urea and creatinine will be
but may not be evident at the time of presentation. marked.