Canine Infuenza Virus
Dec 29, 2018 19:18:05 GMT 10
Post by Tom Meulman on Dec 29, 2018 19:18:05 GMT 10
University of Florida researchers report outbreaks of canine influenza virus (CIV), which causes an acute respiratory infection.
WHAT This highly contagious virus is a newly emerging respiratory pathogen in dogs and causes a clinical syndrome that mimics "kennel cough." Canine influenza virus infections are frequently mistaken for infections due to the Bordetella bronchiseptica/parainfluenza virus complex
WHERE The virus has been identified in dogs in shelters, humane societies, boarding facilities and veterinary clinics in Florida (predominantly in Broward, Dade, Palm Beach and Duval counties), New York, Massachusetts, New Jersey, Washington DC, California and Oregon.
WHO Because this is a newly emerging pathogen, all dogs, regardless of breed or age, are susceptible to infection and have no naturally acquired or vaccine-induced immunity.
Virtually 100 percent of exposed dogs become infected. Nearly 80 percent have clinical signs.
TRANSMISSION Primarily by aerosolized respiratory secretions, but also known to be transmitted by inanimate surfaces and people in contact with both infected and uninfected dogs.
CIV can be killed by quaternary ammonia products or 10% bleach. It is not thought to survive in the environment for longer than a few hours. The virus is highly contagious, however, and is spread through respiratory secretions. People can carry it on their clothing between infected and uninfected dogs, so hygiene is critical when working with affected patients.
CLINICAL SIGNS There are two general clinical syndromes - the milder syndrome and a more severe pneumonia syndrome. The milder disease syndrome occurs in most dogs.
Milder disease
In the milder disease, the most common clinical sign is a cough that persists for 10 to 28 days despite therapy with antibiotics and cough suppressants.
Most dogs have a soft, moist cough, while others have a dry cough similar to that induced by Bordetella bronchiseptica/parainfluenza virus infection.
Many dogs have purulent nasal discharge and a low-grade fever. The nasal discharge likely represents a secondary bacterial infection that quickly resolves with treatment with a broad-spectrum, bactericidal antibiotic.
More severe disease
Some dogs develop a more severe disease with clinical signs of pneumonia, such as a high fever (104°F to 106°F) and increased respiratory rate and effort.
Thoracic radiographs may show consolidation of lung lobes.
Dogs with pneumonia often have a secondary bacterial infection and have responded best to a combination of broad-spectrum, bactericidal antibiotics and maintenance of hydration with intravenous fluid therapy.
1 MORTALITY Fatal cases of pneumonia have been documented, but the fatality rate so far is low, at 1 percent to 5 percent.
INCUBATION/SHEDDING PERIOD The incubation period is two to five days after exposure before clinical signs appear.
Infected dogs may shed virus for seven to ten days from the initial day of clinical signs.
Nearly twenty percent of infected dogs will not display clinical signs and become the silent shedders and spreaders of the infection.
DIAGNOSIS There is no rapid, real-time test for diagnosis of dogs with an acute influenza virus infection. Current diagnostic tests rely on detection of antibodies to canine influenza virus, which are detected as early as seven days after onset of clinical signs.
Paired acute and convalescent serum samples are necessary for diagnosis of recent infection.
The convalescent sample is collected at least two weeks after the acute sample. There are many situations in which collection of an acute sample is not feasible. In this case, testing of a convalescent sample will indicate whether the dog was infected at some time in the past.
Serology tests not only indicate if a dog was infected, but also serve to alert veterinarians that the virus is present in their community so they can take precautions with dogs presenting for "kennel cough."
In addition to serology, the lungs and distal trachea from dogs that died of pneumonia can be tested for influenza virus by PCR analysis and virus culture (ship overnight on cold packs). PCR testing from an oropharyngeal swab can be performed, but it is considered to have low clinical yield.
PREVENTION There is no vaccine for canine influenza virus at this time.
This virus is spread by aerosolized respiratory secretions, contaminated inanimate objects and even by people moving back and forth between infected and uninfected dogs.
This is an enveloped virus that is most likely killed by routine disinfectants, such as quaternary ammoniums and 10 percent bleach.
Because the virus is highly contagious and all dogs are susceptible to infection, veterinarians, boarding facilities, shelters and pet stores should use isolation protocols for dogs that have a "kennel cough."
WHAT VETERINARIANS CAN DO Veterinarians can submit serum samples for canine influenza antibody titers.
Paired acute and convalescent samples are preferable for confirmation of infection, while single samples collected after seven days of clinical disease are also useful.
In addition to determining infection, these samples will contribute toward virus surveillance nationwide. The turnaround time for results is less than two weeks.
Veterinarians may also submit fresh (no formalin or freezing) lung and tracheal tissues from dogs that die from pneumonia. Canine influenza virus culture and PCR analysis will be performed on these tissues. Virus recovered from these samples will greatly contribute toward development of vaccines and diagnostic tests.
ZOONOSIS Equine influenza (H3N8) has been found in horses for over 40 years with no suspected transmission to human. At this time, there is no evidence that the canine influenza virus transmits to humans.
ISOLATION Clients calling with symptomatic dogs should be advised of the risk of contamination and steps taken to limit exposure to other patients:
Escort patient through back of Hospital to avoid contact with other dogs.
Once one dog with clinical signs is seen in an exam room, designate that room to be used only for cats or other dogs with clinical signs for the remainder of the day.
2 DIAGNOSTICS
-Complete Blood Cell Count/Chemistry panel/Urinalysis
-Paired serology for CIV testing; ideally 14 days apart
-Chest radiographs; repeat q48-72 hours
-Pulse oximetry or arterial blood gas upon presentation
-If SpO 2 < 94% or PaO < 75 mmHg: O 2 cage or nasal oxygen if over 40 pounds
-Transtracheal wash, culture and suseptiblity (aerobic, cytology, +/-mycoplasma) if patient is stable
TREATMENT Mild Form Dogs with no sign of pneumonia, respiratory distress, or dehydration can be treated as outpatients.
-Broad spectrum antibiotics should be administered for 14-21 days or 7 days after resolution of clinical signs.
-Cough suppressants can be tried but they are reported to be ineffective.
Severe Form
Dogs with signs of pneumonia, respiratory distress, or dehydration should be treated as in-patients. Treatments may include:
-IV fluids to maintain hydration
-Parenteral bacteriocidal antibiotics in combination:
-O2 supplementation
-Nebulization and coupage
-Bronchodialators
CONTACT INFORMATION
Dr. Cynda Crawford UF/DVM Department of Small Animal Clinical Sciences
(352) 392-4700 ext. 5731
(352) 392-6215 crawfordc@mail.vetmed.ufl.edu
Dr. Nancy Halpern, state veterinarian New Jersey Department of Agriculture Animal Health Diagnostic Laboratory PO Box 330 Trenton, NJ 08625
WHAT This highly contagious virus is a newly emerging respiratory pathogen in dogs and causes a clinical syndrome that mimics "kennel cough." Canine influenza virus infections are frequently mistaken for infections due to the Bordetella bronchiseptica/parainfluenza virus complex
WHERE The virus has been identified in dogs in shelters, humane societies, boarding facilities and veterinary clinics in Florida (predominantly in Broward, Dade, Palm Beach and Duval counties), New York, Massachusetts, New Jersey, Washington DC, California and Oregon.
WHO Because this is a newly emerging pathogen, all dogs, regardless of breed or age, are susceptible to infection and have no naturally acquired or vaccine-induced immunity.
Virtually 100 percent of exposed dogs become infected. Nearly 80 percent have clinical signs.
TRANSMISSION Primarily by aerosolized respiratory secretions, but also known to be transmitted by inanimate surfaces and people in contact with both infected and uninfected dogs.
CIV can be killed by quaternary ammonia products or 10% bleach. It is not thought to survive in the environment for longer than a few hours. The virus is highly contagious, however, and is spread through respiratory secretions. People can carry it on their clothing between infected and uninfected dogs, so hygiene is critical when working with affected patients.
CLINICAL SIGNS There are two general clinical syndromes - the milder syndrome and a more severe pneumonia syndrome. The milder disease syndrome occurs in most dogs.
Milder disease
In the milder disease, the most common clinical sign is a cough that persists for 10 to 28 days despite therapy with antibiotics and cough suppressants.
Most dogs have a soft, moist cough, while others have a dry cough similar to that induced by Bordetella bronchiseptica/parainfluenza virus infection.
Many dogs have purulent nasal discharge and a low-grade fever. The nasal discharge likely represents a secondary bacterial infection that quickly resolves with treatment with a broad-spectrum, bactericidal antibiotic.
More severe disease
Some dogs develop a more severe disease with clinical signs of pneumonia, such as a high fever (104°F to 106°F) and increased respiratory rate and effort.
Thoracic radiographs may show consolidation of lung lobes.
Dogs with pneumonia often have a secondary bacterial infection and have responded best to a combination of broad-spectrum, bactericidal antibiotics and maintenance of hydration with intravenous fluid therapy.
1 MORTALITY Fatal cases of pneumonia have been documented, but the fatality rate so far is low, at 1 percent to 5 percent.
INCUBATION/SHEDDING PERIOD The incubation period is two to five days after exposure before clinical signs appear.
Infected dogs may shed virus for seven to ten days from the initial day of clinical signs.
Nearly twenty percent of infected dogs will not display clinical signs and become the silent shedders and spreaders of the infection.
DIAGNOSIS There is no rapid, real-time test for diagnosis of dogs with an acute influenza virus infection. Current diagnostic tests rely on detection of antibodies to canine influenza virus, which are detected as early as seven days after onset of clinical signs.
Paired acute and convalescent serum samples are necessary for diagnosis of recent infection.
The convalescent sample is collected at least two weeks after the acute sample. There are many situations in which collection of an acute sample is not feasible. In this case, testing of a convalescent sample will indicate whether the dog was infected at some time in the past.
Serology tests not only indicate if a dog was infected, but also serve to alert veterinarians that the virus is present in their community so they can take precautions with dogs presenting for "kennel cough."
In addition to serology, the lungs and distal trachea from dogs that died of pneumonia can be tested for influenza virus by PCR analysis and virus culture (ship overnight on cold packs). PCR testing from an oropharyngeal swab can be performed, but it is considered to have low clinical yield.
PREVENTION There is no vaccine for canine influenza virus at this time.
This virus is spread by aerosolized respiratory secretions, contaminated inanimate objects and even by people moving back and forth between infected and uninfected dogs.
This is an enveloped virus that is most likely killed by routine disinfectants, such as quaternary ammoniums and 10 percent bleach.
Because the virus is highly contagious and all dogs are susceptible to infection, veterinarians, boarding facilities, shelters and pet stores should use isolation protocols for dogs that have a "kennel cough."
WHAT VETERINARIANS CAN DO Veterinarians can submit serum samples for canine influenza antibody titers.
Paired acute and convalescent samples are preferable for confirmation of infection, while single samples collected after seven days of clinical disease are also useful.
In addition to determining infection, these samples will contribute toward virus surveillance nationwide. The turnaround time for results is less than two weeks.
Veterinarians may also submit fresh (no formalin or freezing) lung and tracheal tissues from dogs that die from pneumonia. Canine influenza virus culture and PCR analysis will be performed on these tissues. Virus recovered from these samples will greatly contribute toward development of vaccines and diagnostic tests.
ZOONOSIS Equine influenza (H3N8) has been found in horses for over 40 years with no suspected transmission to human. At this time, there is no evidence that the canine influenza virus transmits to humans.
ISOLATION Clients calling with symptomatic dogs should be advised of the risk of contamination and steps taken to limit exposure to other patients:
Escort patient through back of Hospital to avoid contact with other dogs.
Once one dog with clinical signs is seen in an exam room, designate that room to be used only for cats or other dogs with clinical signs for the remainder of the day.
2 DIAGNOSTICS
-Complete Blood Cell Count/Chemistry panel/Urinalysis
-Paired serology for CIV testing; ideally 14 days apart
-Chest radiographs; repeat q48-72 hours
-Pulse oximetry or arterial blood gas upon presentation
-If SpO 2 < 94% or PaO < 75 mmHg: O 2 cage or nasal oxygen if over 40 pounds
-Transtracheal wash, culture and suseptiblity (aerobic, cytology, +/-mycoplasma) if patient is stable
TREATMENT Mild Form Dogs with no sign of pneumonia, respiratory distress, or dehydration can be treated as outpatients.
-Broad spectrum antibiotics should be administered for 14-21 days or 7 days after resolution of clinical signs.
-Cough suppressants can be tried but they are reported to be ineffective.
Severe Form
Dogs with signs of pneumonia, respiratory distress, or dehydration should be treated as in-patients. Treatments may include:
-IV fluids to maintain hydration
-Parenteral bacteriocidal antibiotics in combination:
-O2 supplementation
-Nebulization and coupage
-Bronchodialators
CONTACT INFORMATION
Dr. Cynda Crawford UF/DVM Department of Small Animal Clinical Sciences
(352) 392-4700 ext. 5731
(352) 392-6215 crawfordc@mail.vetmed.ufl.edu
Dr. Nancy Halpern, state veterinarian New Jersey Department of Agriculture Animal Health Diagnostic Laboratory PO Box 330 Trenton, NJ 08625