respiratory | Horse Racing Free Tips

Can I Contract Coronavirus From My Horse? A Vet Responds

Just weeks before the COVID-19 pandemic became a reality for people in the United States, the equine version of the coronavirus was making its way through show facilities and racetracks across the nation. Thankfully, the equine coronavirus is not transmissible to humans and is not the cause of the worldwide pandemic.

Dr. James Williams of Novato, CA, reports that the only way a human could contract COVID-19 from a horse would be for an infected human to cough onto a horse's coat and then for another human to touch the horse (and the droplets), then touch his nose or mouth. This is the same way a non-infected human might contract COVID-19 from a countertop an infected person coughed on.

Thankfully, both scenarios seem highly unlikely: Most viruses are species specific. When horses are infected with the equine corona, they typically run a fever, have no appetite, are lethargic and have diarrhea. Rarely is their respiratory tract affected. Equine coronavirus typically lasts four to five days and recovery is generally uneventful. Supportive therapies may be used, including administering fluids and non-steroidal anti-inflammatories.

Equine coronavirus is spread between horses through the fecal-oral route: a horse must have direct contact with infected feces to contract the disease. Clinical signs typically begin between 48 and 72 hours after exposure; the horse will shed the virus in his feces three to four days after exposure. This may cause horse's feces to test negative for the disease in its early stages. The horse sheds the most amount of disease three to four days after clinic signs begin.

Infected horses generally shed the disease for about three weeks. Asymptomatic shedders can also spread the disease. How long the disease can last in the environment is not known, similar to human coronaviruses. Equine coronavirus is often seen in cold weather, though transmission in warmer months is possible.

Stall-Side Test Can Help Determine If A Cough Is Contagious

A coughing horse isn't always an immediate concern, but sometimes his cough can be caused by more than just inhaled dust. A new stall-side blood test can help determine if his cough is caused by a chronic inflammatory condition or infectious disease. If the cough is caused by an infectious disease, it's important to take immediate steps to protect other horses on the farm.

Drs. Molly Vinera, Melissa Mazan, Daniela Bedenice, Samantha Mapes and Nicola Pusterla created a study to test for the significance of the protein serum amyloid (SAA) in the blood of horse's with various respiratory conditions. The presence of SAA is indicative of inflammation; it has been used to evaluate and monitor colic and joint disease treatment.

The research team reviewed records of 167 horses that were sent to clinics for respiratory issues; they then analyzed stored serum samples related to each case. The scientists divided the horses into four groups: horses with equine influenza virus (EIV), horses with equine herpesvirus-4 (EHV-4), horses with strangles and horses with heaves. Serum samples from an additional 40 healthy horses served as controls.

They then used an available stall-side test to determine SAA levels in the stored samples. The results of the test showed that all horses with respiratory issues had higher SAA levels then the control horses. Horses that had equine influenza or other infectious respiratory diseases had significantly higher SAA levels than the horses that had heaves or other noninfectious inflammatory conditions.

The team concludes that these findings suggest that stall-side SAA tests can be a useful first step in diagnosing the cause of equine coughs: It allows for the differentiation between infectious and non-infectious respiratory problems, which can help veterinarians make better treatment and management recommendations.

Read the full study here.

Study: Mare Size Affects Birth Process

Drs. Christina Nagel, Maria Melchert, Christine Aurich and Jörg Aurich created a study to determine if the size of the mare affected the birthing process. The team used 23 pregnant mares and studied hormone and heart-related changes that occur in the mare and the fetus around birth. The groups consisted of six Shetland Pony (small); eight Haflinger (medium) and nine warmblood (large) mares.

They discovered that foal weight was approximately 10 percent of mare weight, no matter the size of the mare. Placenta weight was highest in Warmbloods; it did not differ between the small- and medium-sized mares. Progestins and cortisol were also highest in the larger mares. Progestin concentrations decreased as foaling got closer and cortisol increased as parturition was imminent in all sizes of horse studied.

Heart rates in all mares increased before foaling, but the most pronounced increase was in the small mares. Overall, the small mares foaled earlier than the larger mares.

Missed heartbeats during foaling occurred regularly in the larger mares, but only occasionally in the small- and medium-sized mares. The scientists report that this is most likely because of differences in heart efficiency. Small- and medium-sized mares occasionally had missed beats during the expulsive phase of foaling and the first two hours after delivery. The researchers suggest that this is an effect of breed, not size.

The team concludes that fit, athletic horses have highly efficient respiratory and cardiovascular systems; while at rest, these horses have reduced heart rates. Fetal heart rate also went down toward birth, with the most prominent reduction in full-sized horses.

The authors determined that mare of different sizes show both similarities and differences in cardiac and endocrine changes as the time for them to give birth nears. They note that late pregnancy puts substantial strain on the mare's cardiovascular system, but that mares are well adapted to these demands, no matter their size.

Read the full article here.