Equine Programs Research
Our primary research occurs in four main areas:
- Endotoxemia and Systemic Inflammation
- Foal Pneumonia, and
We chose these areas because they are critical diseases of the horse.
Laminitis is a debilitating disease that occurs in horses with severe cases of colic and in horses that have to bear an excessive amount of weight on one limb; the most common example of the latter is a horse recovering from repair of a fracture it its leg.
Presently, the mechanisms responsible for the development of laminitis are unknown. As a result, treatments are directed towards relieving the symptoms rather than the cause.
We recently have determined that the small veins in the horse’s foot function abnormally in the earliest stages of laminitis, at the same time there is local evidence of inflammation.
Our goals are to identify the underlying reason for this functional abnormality in the laminar veins, to identify the link, if any, with the inflammatory response, and to test the ability of well-targeted therapies to prevent these changes from happening.
Endotoxemia and Systemic Inflammation
While the inflammatory response is a normal component of tissue healing and repair, it can also be deleterious. Inflammatory white blood cells entering the tissue can release damaging enzymes, and result in the tissue destruction.
The effects of inflammation are particularly evident in horses in which bacterial endotoxins move from the intestine into the blood stream. These endotoxins stimulate a variety of responses involving white blood cells, endothelial cells that line blood vessels, and circulating proteins. Many of these responses are due to changes in the activity of the genes involved in the inflammatory response.
Because horses are exquisitely sensitive to the ill effects of endotoxins, our goals are to identify the specific ways endotoxins stimulate horse cells and test new treatments designed to interfere with these inflammatory responses.
Pneumonia is the leading cause of sickness and death in foals in the U.S., and many of these animals are infected with Rhodococcus equi, a pathogen that lives and replicates inside macrophages in the foal’s lungs.
We have performed in vitro studies with macrophages obtained from normal, healthy foals, and have determined that the foal’s macrophages respond differently to the Rhodococcus equi organisms than do macrophages from adult horses.
We currently are studying the effects of inflammatory proteins secreted by macrophages from adult horses on the response of the foal macrophages to the organisms. We hope that the results of these studies will move us closer to development of a vaccine against this devastating disease.
Coagulation, or blood clotting, is a normal process that prevents excessive blood loss after blood vessels are damaged. However, coagulation also can be detrimental, especially if it occurs in the absence of direct trauma to a vessel.
Sick horses, especially those with colitis (inflammation of the colon), often develop blood clots that impair organ function or prevent the intravenous administration of fluids needed to restore their circulating blood volume.
To address these problems, we are using new techniques to evaluate blood coagulation in horses and are evaluating new drugs that are designed to regulate coagulation.
Endowed Research Chair
Meet UGA CVM’s first Marguerite Thomas Hodgson Chair of Equine Studies
by Sue Myers Smith
Dr. Steeve Giguère’s interest in equine medicine arose from growing up around horses. However, his interest in research really took off after seeing some unusual cases of partial paralysis in foals. As an intern, Dr. Giguère encountered several foals infected with Rhodococcus equi that presented with abscesses compressing their spinal cords. R. equi typically manifests as pneumonia with abscesses in the lungs, but in these cases, the compression caused by the abscesses paralyzed the foals’ hind limbs. Dr. Giguère became fascinated with the pathogen and, as a result, published a series of case studies; he also made it the topic of his doctoral research.
Dr. Giguère, the first recipient of the Marguerite Thomas Hodgson Chair of Equine Studies at the University of Georgia College of Veterinary Medicine, has since become an award-winning researcher and teacher, most recently receiving the Intervet/Schering-Plough Animal Health Applied Equine Research Award at the World Equine Veterinary Association Congress held in Guarujá-SP, Brazil in September. He comes to the College from the University of Florida’s College of Veterinary Medicine, where he was a professor of large animal medicine and head of the neonatal unit.
“The main reason (I was interested in working at UGA) was that many people work in similar areas of research — inflammation, immunity and infectious diseases — so there will be more opportunities for team work and collaborations,” said Dr. Giguère.
His education has taken him from the University of Montreal, where he completed his doctorate in veterinary medicine and internship in equine medicine and surgery, to the University of Pennsylvania’s New Bolton Center for a residency, then back to Canada to complete a Ph.D. in veterinary microbiology and immunology at the Ontario Veterinary College at the University of Guelph.
With more than 70 refereed papers to his credit — more than half of those on various diseases and conditions affecting foals — as well as numerous book chapters and a book on antimicrobial therapies, Dr. Giguère has researched everything from vaccines to diagnosis and treatment of infections such as R. equi, a treatable pathogen that seldom affects adult horses. He recently has focused on how to treat foals infected with antimicrobial-resistant strains of the disease, and also trying to better understand why it is that foals are susceptible to the pathogen while adults are resistant. His other research areas have included the use of antimicrobials in horses and the study of cardiovascular monitoring in neonatal foals.
His teaching credentials are equally impressive, and he has received numerous teaching awards stretching from his days as a resident at New Bolton all the way to the highest veterinary teaching honor bestowed each year: the Carl Norden-Pfizer Distinguished Teacher Award, which he received from the veterinary college at the University of Florida in 2006.
“Dr. Giguère is a talented researcher, teacher, and clinician — a genuine triple threat,” said Dr. Andrew Parks, head of the College’s department of large animal medicine.
For Dr. Giguère, teaching was not his original intent, but rather a manifestation of a self-discovery.
“I always intended to work in an equine practice after veterinary school. However, during my internship I really enjoyed teaching students and I decided to pursue advanced training in order to remain in an academic environment,” he said, adding: “There is nothing more gratifying than seeing the evolution of a veterinary student from their first day on clinics, when they have much theoretical knowledge that they do not know how to apply, to their last rotation, when they have evolved into astute young clinicians.”
UPDATE: June 14, 2017
- As of June 14, 2017, we are aware of fourteen confirmed cases of Canine influenza from
five Georgia counties. These numbers include samples tested in our Veterinary Diagnostic Laboratories lab as well as two other labs which tested samples from Georgia. The locations of these confirmed cases are in the following counties: Brantley (1), Burke (1), Cherokee (1), Jasper (10), Toombs (1).
What is the current situation of canine influenza in Georgia?
- As of May 31, 2017, the Athens Veterinary Diagnostic Laboratory and at least two out-of-state laboratories have confirmed about 10 recent cases of canine influenza in dogs from Georgia. Some of these cases have been typed and determined to be caused by the H3N2 subtype. All positive Georgia cases came either from dogs that just returned from the May 19-21 Perry, Ga., dog show or had been in contact with such dogs. Recent cases of H3N2 canine influenza have also been reported in FL, IL, KY, MI, MO, and NC.
- Canine influenza, H3N2, was initially documented in the US in 2015 when it was associated with an outbreak of canine respiratory disease in the Chicago area. Between May-August 2015, hundreds of dogs in Georgia were also confirmed to be affected by H3N2. Other subtypes of canine influenza include H3N8, which was first documented in dogs in North America in 1999, and H5N2, which is currently limited to China.
Can these viruses be transmitted to other animals or to people?
- All influenza viruses are prone to changing over time (termed “antigenic shift”) and adapting to new hosts or becoming more pathogenic in their current hosts. This is likely the mechanism by which the H3N8, H3N2, and H5N2 strains became adapted to dogs. It is conceivable that in the future other strains may emerge in dogs.
- Currently, there is no documentation of dog-to-human spread of H3N8, H3N2 or H5N2. The H3N8 type of influenza has been endemic in horses in the United States since at least 1963 and horses are the suspected source of the type of H3N8 influenza we now see in dogs. There are no documented cases of H3N8 transmission from horses to humans. The H3N2 subtype of canine influenza has been shown to infect cats in shelter settings, but it is not yet clear how likely this is under normal household circumstances. H3N2 has been documented in cats in a shelter in Indiana. Influenza H7N2 was documented in a large outbreak in 2016 in cats, but not in dogs, in a shelter in New York City. We encourage pet owners with sick animals to be diligent about washing their hands, as well as their pet’s bedding, bowls, toys, etc.
What dogs are at risk of contracting canine influenza?
- All dogs are at risk of contracting canine influenza, but those that have not been vaccinated against the virus are at a higher risk. Current evidence suggests that at least 80% of healthy dogs of all ages exposed will contract the flu. The incubation period for the onset of clinical signs is 2 to 4 days after exposure. However, dogs can shed the virus during this incubation period, thus contaminating in-contact dogs before the first signs of disease appear. About 25% of dogs exposed to the virus do not show any clinical signs, but they may still shed the virus and infect other dogs who may become sick. Dogs infected with H3N2 can shed the virus for up to 26 days and should be isolated from unexposed dogs for a minimum of 21 days.
- The dogs most at risk of serious illness and/or other complications from the infection are the very old, the very young, or those that have been previously unhealthy or have a chronic condition (e.g., dogs undergoing treatment for cancer, or that have diseases that suppress the immune system, or that require immune-suppressive medications such as prednisone for chronic conditions, those with chronic lung or airway diseases, etc.).
How does canine influenza spread?
- Like other respiratory illnesses, canine influenza spreads through respiratory secretions — droplets of mucus, from sneezing or coughing, that aerosolize in the air and settle on surfaces. The virus does not remain alive for long in the environment, and it can be easily killed by common disinfectants. Canine influenza lives up to 48 hours on surfaces in a climate‐controlled environment, a shorter time outside in the sun and heat, and it may survive up to 12 hours on unwashed skin and up to 24 hours on clothing.
- Just like when people contract the flu, pet owners with sick dogs should be diligent about washing their pet’s bedding, toys, food and water bowls, and other surfaces that may come into contact with your animal. You can disinfect bedding and other items by washing them in common disinfectants, including bleach and quaternary ammonium compounds (QACs or Quats). Most Lysol products have benzalkonium chloride as an active ingredient, which is a QAC. There are also commercial or hospital versions of these products, which contain higher concentrations of these compounds.
What are the typical symptoms of canine influenza?
- As noted above, the majority of dogs will show clinical signs of the disease within 2 to 4 days after exposure to it, and these dogs will shed virus during the incubation phase of the illness. About 25% of exposed dogs will not show clinical signs, but they can shed the virus, meaning they can infect other dogs.
- The typical clinical signs are fever, coughing, sneezing and lethargy, which are indistinguishable from more classic causes of canine infectious tracheobronchitis, also known as “kennel cough” or ITB. Things to watch for that may point to canine influenza include a rapid spread of infection through a population of otherwise healthy and/or vaccinated adult dogs, and potentially higher rates of fever.
If my dog contracts canine influenza, how is the disease likely to progress?
- Most dogs will recover within 2 to 3 weeks after the onset of clinical signs of the illness. In most cases, the illness will resolve without treatment, though some dogs will need supportive care (e.g., fluids or therapeutics as prescribed by a veterinarian). Very old dogs, very young dogs, and dogs that have been recently unhealthy or that are under treatment for chronic disease are the dogs at greatest risk of complications from canine influenza. The most dangerous complication would be pneumonia.
Can my dog die from canine influenza?
- The majority of dogs that contract the disease will recover from it, but a small percentage will die from canine influenza. Current available data suggests that 1 to 5% of dogs that contract H3N8 will die from the disease or from complications that arise from the disease. While the recent Chicago outbreak garnered a lot of media attention, there is no evidence that the H3N2 strain responsible for this outbreak is more severe than the H3N8 strain that has circulated in North America since 1999. If popular press reports about the 2015 Chicago outbreak are accurate, more than 1500 dogs were diagnosed with H3N2, and 6 deaths were reported, which would equal a survival rate of approximately 99.6%.
Should my dog be vaccinated for canine influenza, and if it is, will the vaccination protect against H3N8 and H3N2?
- Individual vaccines are available for canine influenza H3N2 and H3N8 and a bivalent vaccine, containing both of these subtypes, has recently come on the market. Canine influenza vaccination is considered a “non-core” vaccine and is recommended for socially active dogs, such as those that travel, are boarded with other dogs, or are exposed to dog shows or dog parks. The risk factors for Bordetella infection and canine influenza are the same and it only takes a single infected dog to bring the virus into a new area. Consult a veterinarian for more information about the vaccination and to decide if your dog has a lifestyle that would support administration of the vaccine.
Are the other animals in my house at risk?
- The H3N2 strain of canine influenza has been shown to infect cats in shelter settings, but it is not yet clear how likely this is under normal household circumstances. We do encourage pet owners with sick animals to be diligent about washing their hands, as well as their pet’s bedding, bowls, toys, etc. to prevent contamination of objects and inadvertent spread among animals.
- Various species of wild birds are permissive hosts of many strains of influenza, meaning that they can harbor more than one strain of the virus and allow antigenic shift to occur. Oftentimes, the birds themselves do not exhibit signs of the flu that they are carrying. H3N8 has not been known to infect poultry or other birds and it is also unknown if the canine-adapted strain H3N2 can infect pet birds.
Where can more information about canine influenza in Georgia be obtained?
- The UGA Veterinary Diagnostic Laboratories in Athens and Tifton are the official veterinary diagnostic labs for the state of Georgia and are closely following the current cluster of canine influenza cases in Georgia and other states. As of this writing, there have been three confirmed cases of canine influenza at the Athens Veterinary Diagnostic Laboratory for samples submitted during the last week of May 2017 from dogs that had just returned from the Perry, Ga., dog show. In order to rule in or out canine influenza as well as the many other pathogens that can cause respiratory disease in dogs, the recommended laboratory test is the Canine Respiratory PCR Panel. For information on cost, turn-around time, and samples to submit, veterinarians can refer to https://adlab.vet.uga.edu/LabPortal/catalog/show/403 or call 706-542-5568.
- For more information about canine influenza virus, vaccination, or whether your dog should be vaccinated, contact your veterinarian. If you believe you have a dog that may have become infected with canine influenza virus, contact your veterinarian. You may also find information on the American Veterinary Medical Association’s website at https://www.avma.org/Search/results.aspx?k=canine%20influenza
*This article is an updated version of the information sheet that was created by Kate Creevy, DVM, MS, DACVIM and Jeremiah Saliki, DVM, PhD, DACVM on 5/21/201.