SUMMER 2013
Location: Pine Mountain
Resort in the Sitzmark,
Iron Mountain, MI
RSVP: Lyn Schuh at
(920) 450-7903 or
[email protected]
upper motor neuron bladder paralysis).
Bromethalin is rapidly absorbed, with concentra-
The LD50 for bromethalin rat baits in dogs is
tions peaking in as little as four hours. The
about 2.38-5.6 mg/kg. However, ASPCA has
half-life is approximately 6 days (in rats) and the
deaths reported at doses as low at 0.95 mg/kg.
of the length of clinical signs. This affects
recommendations for decontamination and
activated charcoal.
Clinically signs are categorized into two
syndromes – paralytic or convulsant. Dogs
Rodenticides:
a shift in the previous trend
By Samantha VandeHey, DVM
Recently, there have been some changes
Cholecalciferol is another type of roden-
to the rodenticides available to the public
tacide that is not as available, but may
which will shift the toxicities we see in the
become more popular. Cholecalciferol
veterinary profession. The EPA has placed
causes hypercalcemia. This article is
restrictions on the second generation
going to review the common toxic doses,
anticoagulants (including brodifacoum,
signs and treatments of bromethalin;
bromadiolone, difenacoum, difethialone).
the non-anticoagulant rodenticide
These are now only available commer-
which is now one of the most common
cially – not residentially (i.e. the general
rodenticides available.
public can not find these products at local
n
sensitive to cellular edema.
recirculation is suspected and is a component
DATE:
Thursday
June 27, 2013 at 5pm
SPEAKERS:
Lisa Peters, DVM, ACVECC
Bruce VanEnkevort, DVM,
ACVS
and an inability to urinate (secondary to
majority of excretion is in the bile. Enterohepatic
NEXT GRAND ROUNDS
TOPIC:
“GDV: Emergency
Management, Surgery,
and Post-operative
Care” and “New
CPR Guidelines.”
seen as the central nervous system is the most
stores and only pet control experts can
Bromethalin is very different from other
get them). The rodenticides that are avail-
rodenticides. It uncouples oxidative
able residentially include bromethalin,
phosphorylation which results in a
diphacinone and chlorophacinone and
decrease of ATP which inhibits the
have an EPA approved tamper resistant
sodium/potassium pump and ultimately
bait station. Both diphacinone and
results in cells loosing osmotic control.
chlorophacinone are 1,3-indandione
This causes the cells to swell due to
anticoagulant rodentacides and are
sodium retention. Clinically, neurological
treated with decontamination and
signs are most commonly
vitamin K supplementation.
that ingest less than the LD50 dose but more
than minimal toxic dose tend to have a paralytic
Cats are more sensitive, with toxic doses of 0.54
syndrome. This includes ataxia, weakness
mg/kg and the ASPCA has reports of clinical
that can progress to depression, tremors,
signs at doses as low as 0.24 mg/kg.
hyper-reflexive hindlimb paralysis over one to
four days after ingestion. Other signs can include
A key point with bromethalin toxicity is that there
vomiting, anorexia, nystagmus, Schiff-Sherrington
is no antidote. Early intervention with aggressive
syndrome, seizures, and coma. Signs can
decontamination and active charcoal administra-
progress over one to two weeks and signs
tion is important. Once symptomatic, supportive
can take several weeks to resolve.
care may be needed for days to weeks.
Dogs that ingest the lethal dose have the
In the referenced article by Dunayer, there is
convulsant syndrome. In this situation, the
a table available that has decontamination
A 1 oz block
of .01%
bromethalin
contains
2.84 mg of
bromethalin.
signs generally start
recommendations based on dosages ingested
within 36 hours and
and time frame in which they were ingested.
include hyperexcitability,
This article has more in depth information if
hyperthermia, tremors,
desired about bromethalin toxicity.
seizures that can be
sound or light induced,
References:
and death.
Dunayer, E. (n.d.). Bromethalin: The other rodenticide. (2003).
Veterinary Medicine, (September), 732-736.
Cats seem to always
Safer rodenticide products. (2013, March). Retrieved from
http://www.epa.gov/pesticides/mice-and-rats/
have the paralytic syndrome, no matter how
much is ingested. Some cats have also shown
signs of abdominal distention (due to ileus)
Welcome Our New Doctor
Shandy Chapin, DVM
Department: Emergency
Education: DVM from Colorado State University 2009
Internship: Animal Emergency Center/Lakeshore
Veterinary Specialists in Glendale, WI
To read more about Shandy Chapin click here.
FVARC has a redesigned website!
Please visit us at www.FVARC.com.
There’s An App for That!
We now have an app for both
Droid and Apple systems.
Just follow the links below.
• iTunes store: goo.gl/nbjjM
• Android store: goo.gl/Y2asR
Fox Valley Humane Society - “Bark in the Park”
pet walk is June 1, 2013. Go to http://www.foxvalleypets.org/Events/Bark_in_the_Park_2013.aspx
for more information.
A Lunch ‘n Learn for your team can be scheduled
have recently moved into the Northeastern Wisconsin
area to practice.
If you would like your new associate or colleague to
receive their 2013 Welcome Package, please e-mail
the DVM/VMD graduate’s name, year of graduation,
school of graduation, and work mailing address to
[email protected].
Future Grand Rounds
Date: Thursday June 27th at 5pm
Place: Pine Mountain Resort in the Sitzmark,
Iron Mountain, MI
by contacting Lyn Schuh at [email protected] or
920-882-4304. The CPCR talk available is now race approved.
Topics: “GDV - Emergency Management,
Surgery, and Post-operative Care”
and “New CPR Guidelines”
NEWVMA Invitation to New Grads
Speakers: Lisa Peters, DVM, ACVECC
Bruce VanEnkevort, DVM, ACVS
For a limited time, NEWVMA is offering a New Graduate
Welcome Package that includes a free NEWVMA
membership and a welcome gift to 2013 veterinary
medicine graduates who will be working in the following
Northeastern Wisconsin counties: Brown, Calumet,
Door, Fond du Lac, Green Lake, Kewaunee, Manitowoc,
Marinette, Oconto, Outagamie, Shawano, Sheboygan,
Waupaca, and Winnebago.
NEWVMA is also extending the free six
month membership to veterinarians who
RSVP: Lyn Schuh at 920-450-7903 or
[email protected]
Don’t forget to visit us on Facebook for
breaking news and pictures. A link can be found on our website at www.fvarc.com
along with links to Twitter and Linked In.
Potential Risks of Hydrogen Peroxide Treatment
By Jim Graham, DVM
Recently, Elsa, a 2 year old FS Doberman Pincher,
presented for acute collapse after the owners had
administered hydrogen peroxide. The owners were
suspicious that she had eaten a hearing aid battery.
Both Elsa and her housemate had eaten inappropriate
objects in the past and had responded appropriately
to hydrogen peroxide administered by the owners.
This time Elsa vomited twice, without producing the
battery, and than collapsed.
At presentation, Elsa was non-ambulatory without any
neck or back pain appreciated. She appeared mentally
appropriate with normal cranial nerves except for a
lack of menace OU and an inability to swallow water.
Conscious proprioception was slow, withdrawal reflexes
were absent, but she had voluntary motor and sensation
in all four legs. Blood pressure was normal. Blood work
(cbc, chemistry, electolytes, pt/ptt) and urinalysis were
unremarkable except for hyperglycemia and
increased lactate.
Differentials for her collapse included a vasovagal
response to vomiting, cardiac disease, air emboli from
hydrogen peroxide, or a CVA.
Elsa was also tachypneic at presentation and had a pulse
oximetry reading of 91%. Cardiac disease was unlikely
with a normal ECG, BP, and no evidence of pericardial,
pleural, or abdominal effusion by ultrasound. Radiographs did not show any signs of a metallic foreign body
and showed a mild increased interstitial pattern in the
caudal lung fields. Aspiration pneumonia was suspected.
Other differentials included pulmonary air emboli.
With the unusual neurologic findings, a search was done
on VIN for similar cases. There was a case found of a
cat that had developed CNS
air emboli after treatment with
hydrogen peroxide. A follow
up literature search on PubMed
found numerous cases and
one review article on CNS
air emboli in humans after ingestion of hydrogen peroxide.
Although unproven, the
working diagnosis at this point
was multiple CNS air emboli
from hydrogen peroxide ingestion and possibly one or more
pulmonary air emboli. Diagnosis
would require an MRI which was not
available at the time. Alternatively, a
prolonged vagal reflex from vomiting
could cause transient hypoxia and
neurologic damage resulting in
similar symptoms.
Treatment in people for air
emboli includes hyperbaric oxygen
therapy which was also not
readily available. Consultation
with the neurology department
at UW Veterinary Teaching
Hospital suggested than many
of these cases improve with
supportive care.
Elsa was treated for potential aspiration pneumonia
with antibiotics and nebulization. She was provided
supportive care with iv fluids, famotidine, and
physical therapy with passive range of motion
exercises and regular rotation.
Elsa quickly began to improve and was able to swallow
within 48 hours. She was developing increased muscle
tone when standing and was developing voluntary
motor activity in her thoracic limbs. She was
discharged after 3 days.
Over the course of the next two weeks, Elsa’s progress
improved to the point at which she could rise, walk,
and run, except on slippery surfaces.
Hydrogen peroxide therapy for emesis induction is
usually safe and effective in dogs. If Elsa developed CNS
emboli, it is not clear whether they entered her blood
stream through her stomach or lungs. Gastric mucosal
disease may predispose to emboli formation, but
there was no evidence for this in Elsa’s case.
We recommend using hydrogen peroxide to induce
vomiting in dogs almost every day. Although
hydrogen peroxide is generally safe, there are
potential complications. Owners should be advised
of these possible issues, and informed that
emesis induction with apomorphine in a
veterinary setting may be a safer choice.