A RELATED TOXICOSIS—BENZOCAINE
"The cat ate my Orajel!"
Benzocaine is an over-the-counter topical anesthetic that, if ingested or absorbed through the skin, can also result in a
toxicosis characterized by methemoglobinemia and a Heinz body anemia in cats. Methemoglobinemia can develop in cats in just
20 to 30 minutes after a single topical application (spray). Treatment is the same as that for acetaminophen toxicosis. If
the benzocaine was applied topically, bathing with a mild soap is also indicated. If the benzocaine was ingested, attempts
to decontaminate the gastrointestinal tract may be necessary.
"Wait, plants can be poisonous?"
True lilies are highly nephrotoxic, producing acute tubular necrosis. In some studies of Easter lily intoxication, pancreatitis
and pancreatic fibrosis were also identified.1-3 However, not all plants called lilies are true lilies. Easter lilies, tiger lilies, Asiatic hybrid lilies, and daylilies
are deadly to cats. But calla lilies and peace lilies are not true lilies, and ingestion only results in mild gastrointestinal
upset. Lily of the valley plants contain cardiac glycosides and produce toxicosis similar to digitalis. Because of this confusion,
it is important to identify the type of lily that has been ingested.
- Acute (within one to three hours)—highly dose-dependent: salivation, pain on abdominal palpation, vomiting, and anorexia
- 12 to 36 hours after ingestion (may appear clinically normal between acute signs and this period): polyuria and polydipsia,
dehydration, and anuric renal failure
- Clinical signs and history
- Serum chemistry profile results consistent with acute renal failure
- Urinalysis: casts, glucose, protein (suggestive of tubular damage)
Within six hours of ingestion (do not assume the cat is OK if it is not showing clinical signs at this time):
- Induce vomiting.
- Administer activated charcoal.
- Initiate fluid therapy with normal saline solution at two to three times maintenance rates and then continue it for at least
48 to 72 hours. Aggressive fluid therapy is crucial to prevent anuric renal failure.
- Perform daily urinalysis and evaluation of renal parameters during therapy to gauge the progression of renal failure and adjust
fluid and electrolyte therapy.
- Begin standard protocol for acute renal failure.
Beyond six hours of ingestion (most presentations; most cats are already experiencing renal failure, so the prognosis is poor):
- Gastrointestinal decontamination is not useful.
- Initiate fluid therapy.
- Consider dialysis.
Inform owners that therapy will take days to weeks of hospitalization and that long-term renal disease is likely when treatment
is initiated beyond six to eight hours after ingestion.