Background: Antibiotic treatment of horses with strangles is reported to impair the development of immunity to subsequent exposure to Streptococcus equi ssp equi (S. equi). However, apart from a single clinical report, evidence-based studies for this hypothesis are lacking.
Full Answer
Why should equine veterinarians be vigilant for strangles outbreaks?
Equine veterinarians and horse owners should be vigilant for outbreaks of strangles due to the disease’s high prevalence, potentially fatal complications, and the difficulty and cost of recovery, site clean-up, and eradication.
What is strangles and how is it treated?
Strangles is an infection caused by bacteria called Streptococcus equi. The bacteria that cause strangles can be killed by certain antibiotics including penicillin but there is considerable disagreement as to, if or when antibiotic treatment should be given.
What are the risks of strangles in horses?
Risks for strangles exposure include high stocking density, frequency of travel, comingling with horses from other locations, and susceptibility due to lack of prior vaccination or natural exposure to S. equi sspequi.
Is systemic anti-infective treatment an effective treatment for acute-phase strangles in horses?
Systemic anti-infective (AIF) treatment of uncomplicated, acute-phase strangles is somewhat controversial because it can conceivably limit the affected horse’s post- infection immune response, leaving it at risk for re-infection. It should be noted that this is not an evidence-based contraindication supported by experimental or clinical data.
Can you treat strangles with antibiotics?
Can it be treated? The bacteria that cause strangles can be killed by certain antibiotics including penicillin but there is considerable disagreement as to, if or when antibiotic treatment should be given.
Can you cure a strangles carrier?
Carrier status Carriers can be treated (in isolation) by guttural pouch medication (involving repeated flushing with sterile saline and appropriate antibiotics) Some cases form infected hard lumps of pus in the guttural pouches.
Can antibiotics make a horse sick?
A horse's body is host to lots of beneficial bacteria, particularly in the gut and on the skin. Giving unnecessary antibiotics can disrupt that delicate ecosystem, leading to problems such as colitis.
What to do if your horse is a strangles carrier?
Steps to follow if you suspect strangles: Isolate the horse that is showing signs of strangles and any other horses that have had direct contact with that horse. Also isolate those which have/may have had indirect contact with the horse. Call your vet out for advice and to examine the horse showing signs.
Can horses get strangles twice?
Can A Horse Get Strangles More Than Once? Yes, but this is uncommon. About 75% of horses that get strangles will also develop a very strong immune response against S. equi, making them immune to reinfection for a long time, if not for the rest of their lives.
How long do strangles antibodies last?
Antibody production takes around two weeks and once produced antibodies to strangles will remain in the blood for up to six months, even after the horse has fully recovered from strangles.
How much penicillin do you give a horse with strangles?
The daily dose of penicillin is 3,000 units per pound of body weight (1 mL per 100 lbs body weight).
How long is a horse contagious with strangles?
Horses who have had strangles may be contagious to other horses for a minimum of 3 weeks after all signs have resolved. Some horses are contagious for much longer (months).
How effective is the strangles vaccine for horses?
The intranasal vaccine is more effective and probably safer with regard to risk of purpura. The intramuscular vaccine only reduces disease outbreaks by about 50%, while the intranasal one seems to perform much better (due to the fact that it stimulates immunity right where the bacteria enter the horse- the nostrils!).
How do you stop strangles from spreading?
Protecting Your Horse Biosecurity protocols such as observation and screening of newly arriving horses help to prevent the spread of disease. However, vaccination is the best way to combat strangles. Pinnacle® I.N. is the only two-dose, modified-live bacterial vaccine developed to help prevent strangles.
How do you clean an abscess from strangles?
Veterinarians usually recommend applying hot packs to the lower jaw. This will help the abscesses mature so they can be safely opened. Once opened, flush the inside of the abscess with dilute povidone-iodine solutions until they heal. Horses usually recover fully after the abscesses open.
Can a horse be asymptomatic with strangles?
Up to 10% of horses in a strangles outbreak can become chronic, asymptomatic carriers. Chronic shedders are often the culprit in new outbreaks when horses suddenly develop signs of strangles with no known exposure; a chronic shedder also can make it difficult to end an outbreak once it begins.
How to treat strangles in horses?
In most cases, strangles is treated with rest and supportive care. Horses are monitored closely to ensure pain management and adequate consumption of food and water. If not treated with antibiotics, 75% of horses mount a sufficient immune response to develop long-term immunity to strangles.
How much does strangles kill horses?
When complications occur (which happens in 10% of cases overall), the disease can have a mortality rate of up to 40%. Some horses become carriers that appear healthy but harbor S. equi bacteria in the guttural pouches. These carriers can intermittently shed the bacteria, creating a reservoir of chronically infected animals that perpetuate the disease in the population.
What is a strangle?
What is strangles? Strangles is a highly contagious disease of the equine upper respiratory tract caused by the bacterium Streptococcus equi subspecies equi (S. equi). The bacteria cross mucous membranes in the nose and mouth to infect lymph nodes where they cause abscesses that can eventually rupture.
How long does it take for a horse to recover from strangles?
The prognosis for full recovery of uncomplicated cases of strangles is good, but usually takes 3 to 6 weeks. Approximately 70-75% of infected horses go on to develop an immunity to S. equi that can last for at least five years.
How long should you rest a horse after strangles?
Handlers should wash and sanitize hands before contact with individual horses and should work with sick horses after work with healthy horses has been completed for the day. Pastures and stables that contained infected horses should be rested for 4 to 6 weeks.
What antibiotics are used for fever in horses?
Antibiotic treatment may include penicillin, ceftiofur, or ampicillin. The appropriate use of antibiotics may shorten the course of the disease and prevent complications.
Do horses have strangles?
Horses that are older and previously exposed generally have a milder form of strangles limited to upper respiratory signs, minimal to no lymph node abscesses, and a relatively fast recovery.
What is the most dramatic non-respiratory complication of strangles?
sspequiabscesses that develop in lymphoid tissue at sites other than the respiratory tract (Figure 3), can cause gastrointestinal pain and complications when the mesenteric lymph nodes are affected. Purpura hemorrhagica is perhaps the most dramatic non-respiratory complication of strangles. This immune- mediated sequela is a necrotizing vasculitis characterized by edema and localized hemorrhage caused by deposition of S. equi sspequiM-protein immune complexes in blood vessel walls. A retrospective case analysis of 53 horses with purpura hemorrhagica determined that 17 were infected with or exposed to S. equi sspequi.16
What are the effects of a horse strangle?
Among the assortment of profound clinical and pathological effects were subcutaneous edema of all four limbs, reluctance to move, hemorrhages on visible mucous membranes, anorexia, fever, tachycardia, colic, lymph node drainage, hematologic and biochemical abnormalities, and 13.6% mortality in S. equi- associated cases.10,16The horses involved in this study were aged <1 to 19 years of age. Although horses >5 years old tend to be more resistant to strangles,4the age range in this study indicates that prior exposure or immune status is not protective once S. equi sspequi
What is the status of a guttural pouch infection?
equi sspequiinfection, with the sinuses also involved in some cases.7,11,19The guttural pouch becomes infected soon after oronasal infection when the retropharyngeal lymph nodes rupture. Transient empyema in the guttural pouch then occurs. When the purulent exudate persists, as in chronic cases of strangles, chondroids (inspissated or solidified exudate) develop in the guttural pouch. Chondroids harbor and continuously shed large numbers of S. equi sspequiand serve as the source of transmission via sporadic coughing or intermittent nasal discharge by carrier horses that are otherwise clinically normal. Diagnostic evaluation of the guttural pouches of convalescent and recovered horses is critical for identifying asymptomatic carriers. Repeat culturing or PCR analysis of nasopharyngeal or guttural pouch lavage samples is a reliable method for detecting acute S. equi sspequiinfection from 24 hours to 3 weeks after onset, and is also the diagnostic gold standard for identifying asymptomatic long-term carrier horses. The ACVIM Consensus Statement recommends analysis of 3 nasopharyngeal swabs or lavages obtained at weekly intervals after clinical recovery.10However, European investigators found that repeated testing over 2 to 3 months was useful in identifying persistent infection in asymptomatic carrier horses.7
What is strangles in horses?
equiinfections, or strangles. Strangles is not only one of the most frequently diagnosed infectious diseases of horses worldwide,1-3but it also has a number of potentially fatal complications and the capability of persistent infection in populations of asymptomatic carrier horses.4-10In fact, it is estimated that half of all strangles outbreaks produce at least one carrier horse, creating a reservoir of chronically infected animals that perpetuate the disease in the highly mobile equine population.6,11When complications occur, strangles changes from a self-resolving upper respiratory infection to a disseminated disease with a mortality rate as high as 40%.10As one expert has noted, strangles is “a highly dangerous disease” and detection of S. equi sspequiin any horse is significant.6
Which anti-infective agent to use S. equi sspequiis consistently sensitive to pen?
Which anti-infective agent to use S. equi sspequiis consistently sensitive to penicillin. Although penicillin is generally acknowledged to be the drug of choice for systemic AIF treatment of strangles, ceftiofur’s activity against a broad range of S. equi sspequistrains has also been confirmed.22Most S. equi sspequiisolates are also sensitive to TMS, although exceptions have been noted.4,18,19One report noted that initial TMS treatment of guttural pouch carriers of S. equi sspequiwas unsuccessful in 33% (5/15) of cases.19When these horses were then treated with penicillin and ceftiofur, guttural pouch infection and inflammation were eliminated. Antimicrobial sensitivity data for North American equine S. equi sspequi
How much contact attack rate is equi?
equiinfections.11S. equi ssp equi has an estimated 80% contact attack rate in susceptible horses.6In addition, morbidity of >90% and mortality of 10% of clinical cases have been reported.4,13
What is the determinant of susceptibility in horses?
equistrain, rather than the horse’s age, are the determinants of susceptibility. Despite experiencing an attenuated disease, infected horses with some residual immunity will still shed S. equi sspequi, contaminating the environment or infecting susceptible contact horses.10An estimated 70-75% of horses develop a durable, post-convalescent
What are the signs of a horse having a strangle?
Any horse that shows suspicious signs of illness (high temperature, nasal discharge, difficulty in swallowing, swollen throat or glands) should be isolated until strangles is confirmed or ruled out by veterinary examinations and laboratory investigations. Any horse that has strangles should be immediately isolated from all other horses.
How often should I give S. equi?
More recently an attenuated live strain of S. equi has been used in an intranasal vaccine. Initially two doses at 2-3 week intervals are administered then annual boosters are recommended. This vaccine should not be administered during an outbreak except to horses with no known contact.
How to treat a swollen gland?
Recommended treatments include application of hot towels to the swollen glands to encourage abscesses to burst or to grow to a size and maturity that allows them to be safely and successfully lanced. Once open, the abscess cavities should be flushed with dilute povidone-iodine solutions and allowed to heal naturally.
Can a horse die from a strangle?
This is something else that should be discussed with your veterinarian. Strangles is rarely fatal but deaths can occur.
Can penicillin kill strangles?
The bacteria that cause strangles can be killed by certain antibiotics including penicillin but there is considerable disagreement as to, if or when antibiotic treatment should be given.
Can horses recover from abscesses?
Horses usually recover fully after natural rupture of the abscesses. You should seek veterinary help without delay. The veterinarian will help confirm the diagnosis by clinical examination and the collection of swab samples for laboratory investigation and will help you with appropriate treatment and management.
Can you take blood samples from a horse for strangles?
A compromise is to take temperatures and blood samples daily from in-contact horses and to treat horses with a course of antibiotics from the very first sign ...
What is strangles?
Strangles is a highly contagious bacterial infection of the upper airway in horses. Strangles can cause the lymph nodes to block the upper airway. Veterinarians can diagnose strangles by taking a swab.
How to keep horses from strangling?
Thoroughly disinfect equipment, stables, fences, trailers, etc. Use a phenolic disinfectant. Change your clothes and wash your hands before coming in contact with healthy horses. Ideally, isolate new horses for two to three weeks. Check their temperatures regularly and watch for any signs of strangles. If signs occur, have a veterinarian take ...
How to heal abscesses on horses?
This will help the abscesses mature so they can be safely opened. Once opened, flush the inside of the abscess with dilute povidone-iodine solutions until they heal. Horses usually recover fully after the abscesses open.
Can horses get strangles?
Horses that haven’t been exposed to the bacteria in recent years are more prone to strangles. Intramuscular and intranasal vaccines are available for horses. These vaccines decrease the severity of strangles symptoms but don’t completely prevent the disease.
Can hot packs help with abscesses?
Hot packs can help the abscesses mature before opening and flushing them out.
Can horses recover from abscesses?
Horses usually recover fully after the abscesses open. Many veterinarians refrain from using antibiotics for uncomplicated cases. Antibiotics can delay the abscesses from maturing. Horses that have trouble breathing need a more aggressive treatment. They’ll likely need anti-inflammatories and antibiotics.
What are the myths and misconceptions surrounding strangles?
The myths and misconceptions surrounding strangles tend to overplay the current gaps in scientific knowledge about the disease. Given recent genetic advances in characterizing the strangles organism, truly effective prevention is no longer a pipe dream.
What is the treatment for strangles in horses?
Treatment for more seriously affected strangles victims varies case by case, but it typically includes penicillin. If the sick horse has difficulty breathing or swallowing or has large accumulations of pus in the guttural pouches, he will probably receive injectable penicillin along with drainage of affected lymph nodes and lavage or surgical drainage of pus from the guttural pouches. Anti-inflammatory drugs, such as phenylbutazone and flunixin meglumine (Banamine), are indicated to reduce fever and swelling.
How does S. equi bacterium spread from horse to horse?
equi bacterium without visible signs of sickness, is introduced into a herd. The organisms spread from horse to horse through direct contact, such as touching muzzles, environmental contamination and shared equipment, such as feed buckets and bridles.
Why do horses die from bastard strangles?
So-called because the infection doesn't follow the normal disease pattern, bastard strangles affects lymph nodes in the chest and abdomen. As these internal abscesses progress, they can't be drained or effectively treated, and their rupture within the body cavity usually results in the horse's death.
How long does it take for a horse to get strangles?
Also called equine distemper, the infection typically begins 10 to 12 days after exposure to S. equi.
Is strangles a bad name for horses?
Certainly, no one who's had to nurse a horse through to recovery wants a repeat experience, and anyone who's read John Steinbeck's The Red Pony about a young boy's first exposure to death and loss can't help but expect the worst of the disease. Yes, strangles has a terrible name and a worse reputation. Horses who come down with a Streptococcus equi infection get an ugly kind of sick, and they seem to be knocked out of training forever.
Is strangles a big deal?
In textbook terms, then, strangles isn't really a big deal. It hardly ever kills or causes lasting damage to horses, and it's easily controlled by physical separation, the most basic of medical precautions. Yet the fact that strangles isn't effectively prevented or treated by the same means applied to other common equine diseases gives it a rather sinister cast. It must be some sort of super infection, right, if treatment is iffy and vaccines aren't reliable? Well, not exactly. The myths and misconceptions surrounding strangles tend to overplay the current gaps in scientific knowledge about the disease. Given recent genetic advances in characterizing the strangles organism, truly effective prevention is no longer a pipe dream.
How do you know if you have strangles on horses?
Historically, strangles got its name because affected horses were sometimes suffocated from large, infected lymph nodes that obstructed their upper airway or trachea. The hallmark clinical signs of infection are fever (temperature >101.5ºF), nasal discharge, and enlarged submandibular lymph nodes (in the space between the lower jaw bones) which ultimately abscess. Purulent nasal discharge is typically present, although it may initially be clear. The retropharyngeal lymph nodes, which are behind the throatlatch, may also become enlarged and abscess. These will sometimes drain into the guttural pouches, which are air-filled spaces within the head that are an expansion of the Eustachian tubes. Guttural pouch infection and pus accumulation (empyema) are often the result of retrophayngeal lymph nodes that abscess and rupture into the guttural pouches. Guttural pouch infection may also occur from bacterial entrance through the pharynx (throat). Anorexia, depression, and difficulty swallowing may also accompany signs of infection.
Can strangles kill horses?
Fortunately, although strangles is highly contagious and can affect many horses on a farm, most horses with infection recover without complication. The occurrence of complications will increase the likelihood of death from the infection (from 8% to 40% of cases). Complications from
Do antibiotics help with strangles?
Antibiotic therapy for the treatment of strangles remains controversial. Uncomplicated cases of submandibular lymph node abscessation do not require antibiotic therapy in this author's opinion. Complicated cases and those requiring tracheostomy for management of respiratory distress generally do require antibiotic and other supportive therapies. There is some evidence that treatment with antibiotics (such as penicillin) at the first sign of fever and in horses with no lymph node enlargement may prevent infection. However, early antibiotic treatment will also prevent these cases from developing immunity to the infection, and subsequently makes them susceptible to reinfection earlier.
Clinical Disease
- S. equi can affect any age of horse but will often be more severe in those that are young due to a lack of innate immunity (although foals can have maternally derived antibodies inferring a degree of immunity). Pyrexia, often exceeding 42°C (Waller, 2014), occurs 3 to 14 days after exposure t…
Shedding
- S. equishedding usually begins two to three days following the onset of pyrexia and can continue for two to three weeks in most animals. This can be longer when there is persistent infection within the guttural pouch or sinus. Following infection, horses can have an extended immunity to the disease, although this can be overcome if the bacterial challenge is very high (Galán and Tim…
Bacterial Survival
- A recent study presented at the European College of Equine Internal Medicine Congress in 2017 by A Durham showed that during the summer months, S. equisurvival appears to be up to seven days in a moist, protected environment, while in the winter, survival in buckets can be as long as 30 days. Thankfully, the bacteria are very sensitive to cleaning and strict biosecurity protocols s…
Diagnosis
- Routine blood work can be unrewarding as it will generally show a nonspecific inflammatory profile, which can include a neutrophilia, elevated serum amyloid A and decreased systemic iron. Culture, though widely available and cheap, can have reduced sensitivity and so should not always be relied upon. This can be due to lack of bacteria on the mucosa in acute cases as they have m…
Control
- Reducing exposure is the best method of control and therefore quarantine of new animals (for three weeks) and screening prior to arrival is efficacious in reducing the risk of disease. If an outbreak occurs, it is important to set in place a biosecurity control programme that should include: 1. Cessation of movement on or off the yard, which should continue for two weeks beyo…
Conclusions
- S. equiinfection is normally a mild respiratory disease that has more yard implications than it does for the individual horse. Affected horses should be closely monitored to ensure they do not progress or require intensive therapy, but the mainstay of veterinary involvement includes biosecurity implantation.