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Emergency Tale - #2, August 2005
Oreo, a 3 year old male, neutered, indoor and outdoor domestic short hair cat
presented to Gwynedd Veterinary Hospital Emergency Service for twitching. The
patient was acting normally for the previous 2 hours, until his owners had
applied an over-the-counter flea product containing Permethrin as the active
ingredient. Later, his owners found Oreo collapsed in the garden, twitching,
unable to stand and salivating. They rushed Oreo to GVH Emergency Service;
he had a seizure during the 20 minute car-ride.
On arriving at the hospital, Oreo was immediately taken into the treatment
area and triaged. His body temperature was elevated at 104.5 ° F. He was
unable to stand, and was shaking and salivating. His face, whiskers and ears
were twitching. His heart rate was elevated at 200 beats per minute, as were
his respirations at 48 breaths per minute. The nursing staff started to place
an IV catheter into Oreo’s foreleg but he had a grand mal seizure while
the fur was being clipped from his leg. He was treated with an injection of
valium to stop the seizure.
After a review of his history and discussing the case with his owners, Oreo
was admitted to the hospital to be treated for Permethrin Toxicity. Immediate
treatments included a thorough bathing to wash off any of the residual over-the-counter
flea product, an IV injection of robaxin/methocarbimal to treat the tremors,
and valium as needed for the seizures. Fluids and prophylactic antibiotics
were also started to maintain hydration. Oreo’s body temperature, respiratory
rate and heart rate all normalized within hours of admission to the hospital.
Initial routine blood work was normal.
Oreo was hospitalized for three days to treat his tremors. He did not seizure
again after the first night and he started eating on his own the following
morning. His nursing care included monitoring for tremors and IV robaxin to
keep the tremors low. He was also housed in a darkened cage with minimal stimulation
to help decrease the tremors. By the 2 nd evening in the hospital, Oreo was
able to stand and use the litter pan on his own. By the 3 rd day of hospitalization,
he was walking well and was no longer twitching. He was later discharged to
his owners.
A diagnosis of Permethrin Toxicity is made from exposure or change in exposure
to permethrins, an absence of other toxic exposure and eliminating the likelihood
of other diseases such as liver failure, brain damage or trauma.
Permethrin is a synthetic pyrethroid insecticide used in many common household
bug sprays and flea treatments. Toxicity for mammals is generally thought to
be low, but Permethrins can affect sodium channels and cause toxicity to the
nervous system in dogs, cats, rabbits, cows, horses and goats. Permethrin Toxicity
is seen more frequently in cats than dogs, and is also weight dependent: a
smaller cat is more likely to be affected than a larger cat. Toxicity is manifested
as seizures, twitching, tremors, hyperesthesia (increased sensitivity to stimulation)
and hyperthermia (increased body temperature). If twitching and tremors are
prolonged and uncontrolled, muscle damage can result. If seizures are constant
and uncontrolled, brain edema (swelling) and irreversible brain damage can
result. Permethrin Toxicity can be fatal.
There are multiple “over the counter” spot-on type flea and tick
products available in grocery stores, pet stores and discount stores which
contain permethrins. Many of these products are labeled for use in cats as
well as dogs. Cases of toxicity in cats have been reported with one time dosage
of a product marketed for cats, a repeat dosing of a product previously used
without problems, and more rarely from cats interacting with dogs treated with
the product.
The individual sensitivity to these products is unpredictable and exposure
in some cases has been fatal.
Be sure to purchase appropriate flea and tick products from your Veterinarian
to ensure the safety of your pets. If you have questions about new products
or products you have seen advertised, please discuss the ingredients with your
Veterinarian before you purchase or administer them.
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