While the symptoms may sometimes be a bit similar, there is a very important difference between strangles and influenza. Strangles is caused by a bacterium and influenza by a virus. So, they are actually two very different conditions. However, strangles sometimes gets a chance when a horse's immune system is already weakened after infection with a virus, such as influenza or a cold virus. In such cases, your horse can have both of these diseases at the same time!

What is strangles?

Strangles is caused by the bacterium Streptococcus equi equi. This bacterium is highly contagious and causes an infection of the upper respiratory tract. This infection can lead to high fever and abscesses (inflammatory spots) forming at the lymph nodes under and behind the jaw. These abscesses, from which yellow pus emerges when they burst, are the most well-known symptom of strangles. However, research by the Animal Health Service (GD) has shown that many horses go through strangles without ever having these types of inflammation. Coughing almost always occurs with strangles. Therefore, strangles is sometimes mistaken for a common cold. A swab from the nose may be useful in making a diagnosis.

Immunity against strangles

Horses often get strangles once at a young age and then build up some immunity. Unfortunately, this does not mean that they can never get sick from the strangles bacterium again. Vaccines also do not provide 100 percent protection. However, animals with some immunity are usually much less sick if they later become infected again. In some cases, strangles can get out of hand completely, and horses can die from it. More often than not, the horse will recover on its own, often supported by antipyretics. Antibiotics are not always used against strangles because the abscesses are best left to ripen and burst as soon as possible. Moreover, not all strains of bacteria are equally pathogenic. Vaccination against strangles is possible from the age of four months. Some breeding stables even make strangles vaccination mandatory for foals. Once your horse has completed the basic series of two vaccinations, you can quickly boost immunity in the event of an outbreak with a booster shot. If all horses on a farm are vaccinated, the strangles bacterium cannot spread and a large outbreak is unlikely to occur.

What is influenza?

Equine influenza, also known as 'horse flu,' is caused by a virus. There are many different flu viruses, which change a little each year. Therefore, flu vaccinations need to be adjusted to the dominant virus at the time. The symptoms of influenza include fever, a runny nose (often clear mucus), coughing, and decreased appetite. Influenza viruses also attack the immune system. Therefore, it can take a long time for a horse to fully recover from the flu. Additionally, the animal is more sensitive to dust, bacteria, and other viruses in the meantime. Antibiotics do not help against a virus infection. The veterinarian can treat fever with antipyretics, and any (secondary) infections, such as pneumonia, can be treated with antibiotics. The most important thing is rest, good care, and proper nutrition. Your horse needs time to recover, otherwise, you risk other problems like pneumonia or bacterial infections. Expect a week of recovery for every day your horse had a fever. A respiratory infection due to influenza can become chronic if your horse does not have enough time to recover completely, especially if there is a lot of dust or mold present in the stable. The horse can then develop COPD.

Immunity against influenza

Most horses in the Netherlands are vaccinated annually against influenza. For example, this is mandatory to compete in competitions. Because the influenza virus mutates so quickly, vaccines must be adjusted continuously, and protection is not always 100 percent. Well-vaccinated horses usually have (much) fewer symptoms and also shed fewer virus particles than unvaccinated horses. This means that the disease is less likely to spread. When horses do not receive a vaccine and then get sick, they are much more contagious and can easily spread the virus.

Good hygiene is important

Besides vaccinating, hygiene measures are essential to prevent strangles and influenza. Especially when you go to competitions or are on unfamiliar terrain for other reasons. Do not let your horse nuzzle with strange horses and do not use water buckets from other horses. Wash your hands regularly and try to avoid contact with horses that cough or have a runny nose. Both the strangles bacterium and the influenza virus are highly contagious and easily spread through the air, our hands, or items like brushes and halters.

Supporting the immune system

Unfortunately, we cannot always prevent our horses from coming into contact with pathogens. That is why it is so important to feed them well, provide enough exercise, minimize stress, and maintain their immune system. In addition to a good balanced diet with the right vitamins and minerals, there are several supplements that can support your horse's immune system. Consider, for example, cannabinoids from cloves or the Indian herbal mixture Triphala. A supplement that is very good for the immune system and can help reduce symptoms if your horse has contracted a bacterial or viral infection is black cumin.

Black cumin against strangles and influenza

Black cumin is a powerful plant extract that works both antibacterially and antivirally. The antiviral effect occurs because the thymoquinone molecules in black cumin block the 'spike proteins' of viruses, preventing them from attaching. Black cumin also increases the activity of lymphocytes and macrophages, which are cells that act as soldiers attacking and consuming viruses and other invaders. The antiviral properties of thymoquinone have been shown for several viruses, including the virus that causes infectious mononucleosis, influenza viruses, and multiple coronaviruses. Additionally, black cumin is anti-inflammatory and boosts the immune system. Research in humans has shown that symptoms of COVID-19 and other viral infections decrease more rapidly when black cumin is used.

Sources:

Animal Health Service. "Strangles in horses." https://www.gddiergezondheid.nl/nl/Diergezondheid/Dierziekten/Droes

Shad, Kaneez Fatima, et al. "The role of thymoquinone, a major constituent of Nigella sativa, in the treatment of inflammatory and infectious diseases." CEPP. 2021. https://onlinelibrary.wiley.com/doi/abs/10.1111/1440-1681.13553

Khader M, Eckl PM. "Thymoquinone: an emerging natural drug with a wide range of medical applications." Iran J Basic Med Sci. 2014;17(12):950-957. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387230/

Ali, Yousuf, et al. "Thymoquinone in autoimmune diseases: Therapeutic potential and molecular mechanisms." Biomedicine & Pharmacotherapy. Volume 134, February 2021, 111157 https://www.sciencedirect.com/science/article/pii/S0753332220313500

Ahmad A, Husain A, Mujeeb M et al. "A review on therapeutic potential of Nigella sativa: A miracle herb." Asian Pac J Trop Biomed. 2013;3(5):337-352. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3642442/