Strangles vs Pigeon Fever in Horses - What is the Difference?
By Jack Root, DVM
Both "strangles" and "pigeon fever" are terms used to describe primary bacterial infections in horses, and are sometimes confused because they both very often cause abcesses. Pigeon fever and strangles can both be serious infections in horses but with different characteristics, potential outcomes, and are caused by distinct bacteria. Here is a general comparison of the two:
- Strangles: Strangles is a highly contagious bacterial infection caused by Streptococcus equi subspecies equi. It primarily affects the lymph nodes in the head and neck of horses, but occasionally may cause abscess in the thoracic inlet, chest, or abdomen. Symptoms include fever, nasal discharge, difficulty swallowing, and swollen lymph nodes most often in the submandibualr and throat latch. The name "strangles" comes from the fact that affected horses can sometimes have difficulty breathing due to the swelling of the lymph nodes in the throat area.
Key features of strangles:
- Caused by Streptococcus equi subspecies equi bacteria.
- Most often ffects the lymph nodes in the head and neck.
- Symptoms can include fever, nasal discharge, swollen lymph nodes, coughing, and possible difficulty breathing.
- Highly contagious among horses and can spread through drinking water, direct contact, shared equipment, or contaminated environment.
Horses with strangles require supportive care, isolation, careful management, and sometimes antibiotics.
- Pigeon Fever: Pigeon fever, also known as dryland distemper or Colorado strangles, is caused by the bacterium Corynebacterium pseudotuberculosis. This condition leads to abscesses primarily in the pectoral region (chest) of horses, giving the appearance of a "pigeon breast", thus the given name of the disease. The abscesses can also occur in the ventral abdomen or other areas of the body, and rarely in the chest or abdominal cavities. Pigeons have absolutely nothing to do with the disease, which unfortunately for the poor little birds, has resulted in people believing they should be eliminated to control the spread of the disease. which I repeat, has absolutely nothing t0 do with pigeons. They neither cause nor trasmit it in any way.
Management involves isolating the infected horses, maintaining hygiene, and addressing abscesses as they develop.
Key features of pigeon fever:
- Caused by Corynebacterium pseudotuberculosis bacteria.
- Characterized by abscesses, often in the pectoral region, resembling a "pigeon breast."
- Abscesses may occur in the ventral abdomen or other areas as well. Other common symptoms can also include fever, decreased appetite, weight loss, respiratory issues or abdominal pain.
- Transmitted by biting insects, contact with contaminated soil, fomites, or other infected horses.
In summary, while both strangles and pigeon fever are bacterial infections that affect horses, they are caused by different bacteria and result in distinct clinical signs and symptoms. Strangles primarily affects the lymph nodes in the head and neck, causing respiratory symptoms, while pigeon fever leads to abscesses, often in the chest area. It's important for horse owners and caretakers to be familiar with these conditions and their respective symptoms to ensure proper diagnosis and management.
Most horses affected with pigeon fever or strangles recover uneventfully with proper care and treatment. Treatment of these diseases can be tricky and frustrating thus it is strongly advised that you work closely with your veterinarian.
There is an effective and safe vaccine availiable from your veterinarian to help prevent strangles. To date there is not a commercially available vaccine for pigeon fever.
If you suspect your horse has been exposed or is developing symptoms, contact your veterinarian for accurate diagnosis and treatment. Early intervention and proper management are the keys that can help reduce the severity of these cases and minimize the impact on your horse or other equids in the area.