Menu
From the 6th to the 12th of May is Strangles Awareness Week - a week that focuses on strangles. The aim is to raise awareness of the disease and spread knowledge about how to prevent an outbreak. We spoke to veterinarian and internal medicine specialist Lynette Ramsay about what to do if you have strangles at your stables and how to prevent the disease from spreading.
Lynette graduated as a veterinarian from the University of Munich, Germany, and has been working as an equine veterinarian since then. In 2017, Lynette took up a position at the University of Zurich, where she specialised in equine internal medicine. Since then, Lynette has been working as an independent veterinarian with a mobile specialist service in equine internal medicine and sports medicine.
Strangles is a respiratory infection of the horse's upper respiratory tract, primarily the head region. It is one of the most common infectious diseases in horses. It has an infection rate of almost 100%. The disease is caused by a bacterium called Streptococcus equi. It can take up to two weeks from the time a horse is infected until it starts showing symptoms.
Symptoms begin one to two and a half days before the horse starts shedding. That's why temperature measurement is an essential tool to prevent a strangles outbreak.
"Know your horse's temperature and know what its normal temperature is, because it actually varies slightly from horse to horse."
Therefore, Lynette Ramsay's most important advice is that if your horse seems a little dull or hasn't eaten all its creep feed, take its temperature.
You can easily take your horse's temperature yourself. You'll just need an ordinary thermometer. However, it's important to insert the thermometer quite far into the rectum to get an accurate temperature. Most horses are quite relaxed about having their temperature taken but do the process slowly so the horse isn't surprised or frightened.
Usually, a strangles outbreak begins with a single horse being infected. Lynette Ramsay explains: "In this case, the damage has already been done because that horse has had time to excrete the infection before the lab results come back and strangles has been diagnosed."
In the situation where a horse has contracted strangles, you need to implement what Lynette calls the Traffic Light System. Here, all horses are divided into zones directed by color. The color is a code for how likely a horse is to have been infected with strangles. The division can either be done by using other stable compartments or by using safety tapes.
Red: Horses with symptoms of fever, runny nose, and/or swollen lymph nodes in the head region. These horses should be isolated in a stable or a separate area.
Yellow: Horses that have been in contact with horses in the red group. These horses should also be isolated and temperatures should be taken twice daily. If the temperature is above 38.2 degrees, the horse should be moved to the red group.
Green: Horses that have not been in contact with horses in the yellow or red group. Check the temperature of these horses twice daily and if the temperature is above 38.2 degrees, the horse should be moved to the red group. This is because horses can become infected via equipment or people who have had contact with horses in the yellow or red group.
When feeding and handling horses, the green group should always be handled first, followed by the yellow group and finally the red group.
If a stable is found to be infected with strangles, in addition to the implementation of the traffic light, a quarantine must also be implemented. This means that the stable is shut down completely and no horses are allowed to leave or enter the stable. Quarantine often ends up lasting for a long time, as the quarantine must last for at least three weeks after the last horse has shown symptoms. In a large stable, if many horses are affected, it can take a few months before the quarantine can be lifted. This can have financial, sporting and mental consequences for both grooms and stable owners.
Humans cannot be infected by strangles but can carry the disease on clothing and other objects. There have been a few cases where a person with a weakened immune system has been infected with strangles. This could be people with cancer or HIV.
"It's really important that you completely separate things out."
explains veterinarian Lynette Ramsay
So, it's essential to change clothes, shoes, gloves and wash hands when moving between the different groupings of horses. The experienced vet suggests using protective clothing such as lab coats, overalls, changing shoes, and so on.
Strangles bacteria can be found on the surface of objects and on our hands and clothes. This can easily spread the infection.
There is no cure for strangles, which is why prevention is so important. However, there are some ways to help the horse through the course of the disease. Depending on how sick the horse is, the vet will have different approaches.
If the horse has a high fever, it should be given anti-inflammatory medication, which is similar to Ibuprofen for humans. It will reduce fever and pain and the horse will feel more comfortable.
For most bacterial infections, antibiotics will be used, but Lynette Ramsay points out that recent studies show, that antibiotics such as penicillin are not a good treatment option if the horse is suffering from strangles. This is because the horse subsequently develops a lower immunity to strangles. Studies have also shown that horses that have been treated with penicillin in connection with a course of strangles are at greater risk of developing various complications such as 'traveling strangles', where the infection spreads around the body.
If the horse is severely affected by strangles, it may be necessary to split the large abscesses in the lymph nodes. The abscesses can become so large that they can press inside the horse's throat and air sacs. This can make it difficult for the horse to eat and drink. Here, the abscess was opened and flushed out by the vet. In these cases, the horse will typically be given penicillin to prevent further infection in the surgical wounds. It is important to keep the wound clean afterward to avoid infection.
One particular reason why we need to be so careful to prevent strangles and minimize the risk of infection is that there is no cure or direct treatment. But prevention is always better than cure, and there is a relatively new and highly effective vaccine against strangles.
"It's like vaccinating your horse against the flu virus and tetanus, and some people also vaccinate against the herpes virus, so now there is also this vaccine against strangles."
explains the experienced veterinarian.
Lynette Ramsay says that prevention is key when it comes to strangles. Therefore, it's important to incorporate some considerations into your daily behavior with your horses.
Avoid the horse having direct contact with other horses, even though it can be difficult.
Avoid sharing equipment and tools with other horses as much as possible, especially at competitions or when you're out and about, but it's also a good consideration to make at home in the stable.
By cleaning it thoroughly, you can prevent any infection from spreading, especially if others borrow your trailer.
This can be especially important when you return home from a competition - and preferably for up to 14 days afterward, as it can take up to two weeks for the horse to show symptoms after being infected. It's also a good idea to get into the habit of taking your horse's temperature regularly at home.
Regular cleaning is effective and removes up to 90% of bacteria.
Strangles bacteria thrive in watery environments, so keeping these areas clean is important, and avoiding sharing them between horses as much as possible. Both, in the stable and the paddock.
In the international consensus on incorporating new horses into a herd, new horses should be isolated for three weeks, have daily temperature measurements, and have no contact with other horses on-site.
The best prevention against strangles is to vaccinate your horse. However, it is still important to take other precautions, as the vaccine does not have 100% protection. Vaccination significantly reduces the risk of infection, and the horse will have a milder disease course if it is unfortunate enough to become infected. Likewise, a vaccinated horse will shed less infection than other horses.
They are both contagious infectious diseases. Covid19 is caused by a virus (coronavirus), while strangles is caused by a bacterium (streptococcus equi). Although they are two very different diseases, the principles of prevention and mitigation are very similar. Therefore, we may be able to use all the knowledge we gained from the Covid epidemic to reduce the spread of strangles among our horses. We may not be able to put masks on them, but we can maintain good hygiene, distance, disinfect and vaccinate our horses.
