If you had a chance to do the Strangles quiz in the Summer DVEP newsletter then you have come to the right place to check your answers!
If you didn't receive a newsletter and would like to have a go at the quiz, download it below:
Check below to see how you did.
1. A - Strangles is caused by the bacterium Streptococcus equi.
2. B - Strangles causes inflammation of the upper respiratory tract resulting in swollen, painful abscessed lymph nodes in the throat.
3. C - New outbreaks of strangles occur by the movement of healthy horses that have become carriers and intermittent shedders of the strangles bacteria following recovery from infection. Despite being healthy themselves, these horses can shed bacteria in their nasal secretions causing infection in other susceptible horses.
4. A - Fever causing dullness and inappetance is usually the first sign of infection. This is why the temperature of all horses should be taken twice daily during an outbreak to monitor for new cases.
5. C - Strict isolation of suspected strangles cases is required in order to limit possible spread of disease. Isolate the horse and any other horses which have had nose-to-nose contact with the suspect horse away from other horses in the yard. If possible, create three groups: infected horses; horses who have had close contact with the infected horses; and “clean” horses. Do not allow other animals to enter the stable where the horse was kept or have access to its feed or water container.
6. B - A nasopharyngeal swab would be taken from a suspected strangles case and sent for culture and PCR. The back of the throat is brushed with a cotton swab on a long handle which is introduced up the nose. Combining PCR and culture increasing the likelihood of positively diagnosing a case of strangles.
7. C - Endoscopy of the guttural pouch would be performed if a carrier was suspected. Carriers can intermittently shed strangles bacteria from their guttural pouch and therefore endoscopy is performed to look for chondroids and to wash the guttural pouch with saline. This guttural pouch washing is then sent for culture and PCR.
8. A - A blood test is available that identifies if your horse has antibodies to the strangles bacteria (Strep equi). Antibodies are produced approximately 2 weeks following exposure to the bacteria and last for about 6 months. Therefore, horses that have been exposed to the bacteria within the last 6 months will show up positive to this test. It is important to realise that antibodies indicate prior exposure to strangles bacteria and not active carrier / shedder status. A horse that is positive on the blood test may or may not be a chronic shedder of strangles bacteria - scoping and culture of guttural pouch washings is the ONLY way to determine shedder status.
9. C - The strangles bacteria can live for many months in pus in the environment and therefore contamination of equipment and people with respiratory secretions from infected horses is an important source of disease transmission. This is why strict isolation of infected horses is so important and why using separate people and equipment to monitor and care for these horses is recommended.
10. B - Lymph nodes at the back of the throat become very large and painful and can make swallowing very difficult.
11. B - One of the lymph nodes in the throat lies just below the guttural pouch (an outpouching of the middle ear unique to horses). Rupture of an abscess of this lymph node into the guttural pouch commonly occurs in strangles.
12. C - In most horses, treatment of strangles consists of anti-inflammatories (such as bute) to reduce fever and hot packing of abscesses to encourage drainage. Abscesses may also be lanced to encourage drainage. Despite strangles being caused by bacteria, use of antibiotics in strangles is controversial as many vets believe it delays resolution of infection and therefore most vets do not use them in routine strangles cases. In our practice, we tend to reserve the use antibiotics for horses that are so sick that they have difficulty swallowing, eating or drinking, treatment of carrier cases or for prophylactic use for in-contact horses if they can be removed to an isolation area.
13. B - A horse may get over strangles and not become a carrier but in some horses a carrier status is established in which bacteria are intermittently shed from the guttural pouch. It is essential to perform endoscopy and guttural pouch washings to identify carriers following an outbreak to prevent these carrier horses causing new outbreaks.
14. A - Chondroids are hard stones of dried out pus that occur in a small proportion of horses following strangles infection. Horses with chondroids will act as chronic shedders of strangles bacteria. Abscesses in other body cavities e.g. the abdomen (bastard strangles) and inflamed, leaky blood vessels (purpura haemorrhagica) can also occur following strangles infection but these are less common than chondroids.
15. C - A vaccine for twice yearly administration into the upper lip that produced good immunity to strangles was licensed several years ago but problems with the vaccine shelf life caused it’s withdrawal shortly afterwards. It is supposed to be re-launched at the end of this year so watch this space!
HOW DID YOU DO?
1-5 = Some reading required.
6-10 = You know your stuff!
11-15 = Are you a vet?
If you have any queries regarding strangles, call the practice on 0131 445 4468 and ask to speak to one of the vets.
This article was published on Mar 4, 2013