Back to the West Nile Virus listserv archive.
WNV & DOGS - follow up to Sept'01 news
Date: Tue, 15 Jan 2002
The following two ProMED postings, both mailed Jan 15 (today), are follow-up to an intriguing (but apparently incorrect) article in the Bainbridge, GA Post-Searchlight, Sept 29 '01, reporting what they thought to be the first case of a dog sickened from WNV. The Ducks Unlimited Magazine article (#1 below) 'confirming' this case of WNV must be read in conjunction with the Georgia Department of Agriculture communication refuting it (#2 below)! For context, the initial story (in an Oct 1'01 WESTNILEVIRUS-L posting forwarded in part from ProMED) is also pasted in (#3 below).
SUMMARY: Although WNV sera has been detected in healthy dogs (5-11% seroconversion in dogs near the WNV epicenter in 1999), it is now thought that WNV neither sickened nor even infected the 2-year-old male Labrador retriever in Georgia--who 'fully recovered days after receiving antibiotics.' Thus there are still no confirmed clinical cases of WNV in dogs in the United States, though a single clinical canine case was reported in Botswana, Africa in 1982. All indications are that dogs and cats are not at risk of developing clinical disease from natural infections of WNV.--LCL
--------------------------------------------------------------------------------------------------
ProMED-Id: 20020115.3257
[see also:
Date: Thu 10 Jan 2002
West Nile Virus Infected Labrador Retriever
In September 2001, veterinarian Dr. David Bryan of Bainbridge,
Georgia, examined a 2-year-old male Labrador retriever with "classical
symptoms of nervous system problems," including drooling, facial tics
around the muzzle, impaired vision, and a fever. "West Nile Virus
(WNV) wasn't even in my thoughts," he said, suspecting either Eastern
or Western Equine Encephalitis. But blood tests conducted by the
University of Georgia's Serology Department confirmed WNV, the first
time, Bryan says, an infected dog had shown ill effects from the disease.
The Labrador retriever fully recovered days after receiving antibiotics.
Bryan points out, however, that antibiotics have limited effects on
viruses [none on viruses -- only on secondary bacterial infection -
Mod.CP], so the dog may have improved on its own. This would
provide further evidence that dogs have a natural resistance to WNV.
Nevertheless, dog owners who live in areas where the virus is
prevalent may want to keep a watchful eye for any strange behavior in
their pets.
[Byline: Brian McCombie]
--
[Labradors are hunting/birding dogs, often around water where
mosquitoes may be more likely. Likewise, Labs are very short-haired,
and more succeptible to mosquitoes. It is an entirely new clinical entity
that veterinarians should be aware of when examining dogs and
potentially cats, with neurological conditions. - Mod.TG]
[The response to antibiotic treatment suggests that the West Nile virus
infection may not have been the cause of the dog's illness. Apart from
those in horses, there have been very few confirmed reports of West
Nile virus-associated disease in wild or domestic mammals. - Mod.CP]
-----------------------------------------------------------------------------------------
A ProMED-mail post http://promedmail.org
Date: Tue, 15 Jan 2002 07:56:40 -0600
This dog was found NOT to be infected with WNV.
[Communication from]:
November 1, 2001
Canine Exposure to West Nile Virus
On August 30, 2001, the Veterinary Diagnostic and Investigational
Laboratory in Tifton, Georgia received blood and serum samples for a
CBC and arbovirus profile from a 2.5 year old male Labrador Retriever
residing in southwestern Georgia. The submitting veterinarian reported
the dog had unexplained central neurological signs.
The serologic arbovirus profile was negative for EEE and WEE.
Serum neutralization for WNV indicated a titer of 1:16.
The CBC revealed the following:
The WBC differential displayed the following:
All other CBC values were within normal reference ranges.
Treatment included broad spectrum antibiotics and supportive care.
The dog appeared to completely recover within a few days and
continues to be clinically normal.
A second blood sample obtained two weeks later revealed a
convalescent WNV SN titer of <=1:4. According to Dr. Sandy
Baldwin, Veterinary Diagnostic Laboratory Director, this second,
negative titer suggests the original titer was due to a non-specific
inhibitor in the original serum and not due to WNV infection.
Although it has been shown that dogs may produce antibodies against
West Nile Virus, there have been no confirmed clinical cases of WNV
in dogs in the United States (in 1982 a clinical canine case was reported
in Botswana, Africa). A serosurvey of dogs near the epicenter of WNV
activity in New York in 1999 revealed 5-11% seroconversion.
However, present studies indicate dogs and cats are not at risk of
developing clinical disease from natural infections of WNV.
The Georgia Department of Agriculture is currently tracking
arboviruses in all species. Please report all laboratory findings and
suspicious clinical disease of WNV, EEE, WEE, or SLE by contacting
Drs. Jeff Mahany or Carter Black with the Georgia State Veterinarian's
Office at (404) 656-3667.
--
[Many thanks to Bill Johnston for passing this on. It appears that
ProMED's Mod.CP was right, in his comment on the original report, in
suspecting that as the infection responded to antibiotics, it was not due
to WNV. The original report was erroneous in claiming confirmation
based on a single serum specimen. - Mod.JW]
-----------------------------------------------------------------------------------------
...snip...
DOGS: A newspaper report was posted to ProMED-mail this weekend re: a dog showing clinical symptoms of WNV and testing WNV-positive. We have not been able to find independent confirmation of this case on the Georgia WNV webpages nor on the USDA APHIS site. The Pro-MED posting with the newspaper article is pasted below. If confirmed, this will apparently be the first domestic case of a dog showing WNV symptoms. However, in 1999 CDC tests found 3 positive sera from healthy dogs in a preliminary screen of 84 dog serum samples from New York City.--LCL
-----
Date: Sun, 30 Sep 2001 07:08:16 -0400
First Case Of WNV In Dogs Found In Georgia
The focus to date on West Nile Virus has been on birds, horses and
humans, but now dogs are added to the list. A local veterinarian, Dr.
David Bryan of Bryan and Hight Veterinary Clinic, received results
this week that a blood sample of a dog he treated earlier in the month
had come back positive for the mosquito-borne West Nile Virus. The
virus is spread by migrating birds, which are in turn bitten by
mosquitoes, and those in turn transmit the virus to horses, humans,
and [other animals such as] dogs.
Several cases of WNV in horses have been diagnosed in the North
Florida/South Georgia area since the virus headed south earlier this
year, and a dead osprey collected in the Lake Douglas area tested
positive. But this is the first case of WNV in a dog.
Dr. Bryan said he had just attended a seminar on WNV in Tifton where
the Serology Department at the UGA diagnostic lab in Tifton presented
a list of 8 clinical signs of WNV in horses. The dog he treated showed
6 of the 8. Dr. Bryan said the dog was an otherwise-healthy two and
one-half-year-old male Labrador whose owners live just across Lake
Seminole near Sneads, Fla. When he was brought in, the dog was
drooling, appeared to feel bad, had facial tics in the muzzle-area
muscles, and his left ear was drawn up toward the top of his head. His
vision appeared to be impaired, his appetite was poor and his
temperature was up. All in all, Bryan said, he showed signs of a
central nervous system problem.
In-house lab work was reasonably unremarkable, so blood samples were
sent to Tifton for screening, including Eastern and Western equine
encephalitis and West Nile virus. The encephalitis screenings were
negative, but the WNV was positive. Dr. Bryan said veterinarians had
thought that dogs would not be affected by WNV.
Bryan had begun treating the dog with chloramphenicol, an old
broad-spectrum antibiotic which the doctor says he has used for years.
He explained that this medicine will cross the blood-brain barrier and
might have some anti-viral properties as well. The human version,
chloromycetin, had been off the market for some time. The great news
is that the dog was well enough to go home in 3 or 4 days and reached
full recovery about 5 days after that.
Dr. Bryan said while there are WNV vaccines for horses, there are none
yet for dogs, and he has contacted a pharmaceutical company which
produces horse vaccine to see if a dog vaccine is forthcoming.
[Pet owners should not panic. As ProMED posted in 1999:
Pets: No [clinical] cases of encephalitis linked to WNV have been documented in pets in this [1999] outbreak, nor does it appear from other WNV outbreaks overseas that this will be likely. However, CDC has found 3 positive sera from healthy dogs in a preliminary screen of 84 dog serum samples from New York City. Pets will probably be similar
to most species of mammals and birds in that they are susceptible to a
transient WNV infection if bitten by an infected mosquito, but are
unlikely to become clinically ill. Ref: West Nile-like virus - USA
(New York): UPDATE 19991023.1908. There were no reports of clinically
WNV-positive dogs in 2000. - Mod.JW]
------------------------------------------------------------------------------------
--
-------------------------------------------------------------------------------------------
Posted by: Lois Levitan (lcl3@cornell.edu)
1.DUCKS UNLIMITED MAGAZINE JAN/FEB'02: WNV INFECTED LAB RETRIEVER
A ProMED-mail post
ProMED-mail is a program of the International Society for Infectious Diseases
West Nile virus surveillance - USA 2000 final report 20010423.0792
West Nile virus surveillance 2001: New World update 20011212.3003]
From: Jeffery Jordan (jjordan@vetmed.wsu.edu)
Source: Ducks Unlimited Magazine, Jan/Feb 2002 [edited]
------------------------------------------
Jeffrey M. Jordan
Research Associate
Washington State University
jjordan@vetmed.wsu.edu
2. GEORGIA DEPARTMENT OF AGRICULTURE, Nov 1'01
From: wjohnston@adph.state.al.us
Georgia Department of Agriculture
Tommy Irvin, Commissioner
19 Martin Luther King Jr. Dr. SW
Atlanta, GA 30334
WBC at 19.1x10(3)/ul (ref. 6.00-12.00x10(3)/ul)
RBC of 5.18x10(6)/ul (ref. 5.50-8.50x10(3)/ul)
MCH of 27.2 pg (ref. 10.50-24.50 pg)
MCHC 36.2% (ref. 32.00-36.00%)
Segmented neutrophils - 18.0x10(3)cell/ul (ref. 3.00-11.50x10(3)
cells/ul)
Lymphocytes - 0.7x10(3)cells/ul (ref. 1.00-4.80x10(3) cells/ul)
Bill Johnston, DVM, DACVPM
State Public Health Veterinarian
Alabama Dept. of Public Health
P.O. Box 303017
Montgomery, AL 36130-3017
(334)206-5969 FAX (334)206-5967
wjohnston@adph.state.al.us
3. WESTNILEVIRUS-L POSTING, Oct 1'01
ProMED-mail post http://promedmail.org
From: "Patricia Doyle, PhD" dr_p_doyle@hotmail.com
Source: The Post-Searchlight, Bainbridge, GA 29 Sep 2001 [edited]
-------------------------------------------
Lois Levitan, PhD Program Leader
Environmental Risk Analysis Program
Center for the Environment
213 Rice Hall, Cornell University
Ithaca, New York USA 14853-5601
Phone: (607) 255-4765 Fax: (607) 255-0238
Email: LCL3@cornell.edu
Program Email: envrisk@cornell.edu
Web:http://www.cfe.cornell.edu/ERAP
WESTNILEVIRUS-L is an email discussion group for communication
and discussion about West Nile Virus, particularly regarding policy,
risk reduction and public education issues. It is moderated by
Dr. Lois Levitan at Cornell University's Center for the Environment.
To subscribe (or unsubscribe), send an email request to (envrisk@cornell.edu).
Subscribers can post to the group by sending an email to: WESTNILEVIRUS-L@cornell.edu. Archives are posted at: http://www.cfe.cornell.edu/erap/WNV/WNV-LArchiveIndex.cfm
-------------------------------------------------------------------------------------------