EFFECTIVE TREATMENT AND CONTROL PROTOCOL FOR MYCOPLASMA SUIS DURING OUTBREAK SEASON

I. Overview of Mycoplasma suis disease

1.1. Characteristics and Pathogenesis of Mycoplasma suis

Mycoplasma suis (belonging to the Mycoplasma group) is an important causative agent of infectious anemia in pigs. The disease can occur in pigs of all ages, but clinical signs are most evident in piglets (Hoelzle et al., 2006).
The main pathogenic mechanism involves the bacteria attaching to the surface of red blood cells, causing deformation and destruction of these cells. This leads to increased bilirubin levels in the blood, resulting in anemia and jaundice, while also increasing the risk of secondary infections and mortality, especially during the post-weaning period.
                                                                                                                                              In addition, M. suis causes reproductive disorders in sows and weakens the immune system, making pigs more susceptible to secondary respiratory and gastrointestinal infections. Therefore, effective control of this disease not only minimizes economic losses but also contributes to improved livestock productivity (Ana et al., 2011).

1.2. Epidemiology and Transmission

Mycoplasma suis causes infectious anemia in pigs worldwide, with infection rates varying by farm conditions and management practices. It spreads vertically from sow to piglets and horizontally via contaminated blood, unsterilized tools, or blood-sucking insects, especially during dry or transitional seasons. Chronic carriers, especially asymptomatic sows, serve as persistent sources of infection, complicating control efforts.
Mycoplasma suis can spread in a variety of ways. During pregnancy or birthing, one of the primary modes of transmission is vertical from sows to piglets. Direct contact with contaminated blood can potentially spread the disease, particularly when sharing veterinary equipment like scalpels, needles, or tail docking tools that have not been properly sterilized. According to research by Zhongyang et al. (2017), the disease spreads more easily during the dry season and seasonal changes, when bloodsucking insects like flies and mosquitoes flourish.
Notably, pigs that have recovered from acute disease or large pigs infected with mild M. suis often become chronic carriers, continuing to excrete the pathogen into the environment for a long time. Herds of asymptomatic carriers of the infection become the main source of infection, especially when there are stress factors such as weather changes, poor nutrition, or long-distance transportation. This makes disease control and prevention more complicated than ever.

II. Disease manifestations

Mycoplasma suis infection reduces red blood cells, causing anemia and jaundice in pig groups, including sows, piglets, and pigs. In particular, piglets and weaned pigs infected with M. suis at high levels will show jaundice, poor development, slow growth, and are susceptible to respiratory and digestive tract infections due to a weakened immune system. Piglets infected with M. suis may tremble and have an unsteady gait due to hypoglycemia, leading to high mortality and culling rates. Meanwhile, infected sows often have no obvious symptoms. The disease usually appears in 2 forms: Acute and chronic.

2.1. Acute form

Pigs infected with M. suis show jaundice, paleness, emaciation, poor development, swollen and bruised earlobes. Piglets show signs of weak legs, tremors, unsteady gait, and sometimes convulsions. Weaned pigs and pigs infected with M. suis show signs of lethargy, convulsions, even coma, and death. Sows infected with M. suis often show additional high fever (40 - 41°C), slow mating, easy miscarriage, and increased piglet mortality at birth.

2.2. Chronic form

When pigs are infected with chronic M. suis, their physical condition is poor, showing signs of jaundice, slow growth, dry skin, ruffled hair, and severe immune system impairment, making them susceptible to secondary bacterial infections of the respiratory and digestive tracts, which makes the disease more severe.
                                                                 

2.3. Lesions

Platelet and red blood cell indices are much lower.  Blood is thin, red blood cells are deformed, and physiological function is reduced or lost.  Skin ulcers may develop on the snout, tail, and ears of young and weaned pigs.  Lesions such as a thin heart wall, flaccid heart, enlarged spleen, dark liver, effusion in the chest, pericardium, abdominal cavity, subcutaneous tissue, and enlarged lymph nodes can all be found during a postmortem examination.
                                                                           

III. Methods for managing and curing Mycoplasma suis

Tetracycline and macrolides are currently the major antibiotics used to effectively manage and treat Mycoplasma suis.  Among these, two frequently utilized active compounds are oxytetracycline and doxycycline, which are members of the tetracycline antibiotic group.  Gram-positive and gram-negative bacteria, as well as aerobic and anaerobic bacteria, can all be affected by these broad-spectrum antibiotics, although Mycoplasma is particularly susceptible.
Tetracycline antibiotics attach to the ribosome's 30-S subunit and prevent bacteria from synthesizing proteins.  This stops amino acids from being incorporated into the elongating peptide chain and stops aminoacetyl-tRNA from interacting to the receptor site on the ribosomal mRNA complex.  Protein synthesis is halted as a result, which prevents bacteria from growing and replicating.
                                                                       

3.1. Research assessing the effectiveness of oxytetracycline and doxycycline as treatments for M. suis

 According to a protocol, oxytetracycline was injected into the sows' feed three times a year for seven days in a row, and the sows were treated six weeks before farrowing, and the newborn piglets on the first day.  Strict parasite control and instrument hygiene measures were also put in place at the same time (alternating between two sets of surgical equipment and changing needles for every litter).  Additionally advised were stress reduction, good management, and the identification and removal of disease-carrying pigs.
 Both the number of weaned piglets with clinical anemia and the suckling piglet mortality rate were considerably lower three months after the control was put into place (Table 1).                                                                         In a different trial, weaned piglets aged 21–28 days, weighing an average of 5-7 kg, were treated with doxycycline both alone and in combination. These piglets had the usual clinical signs of M. suis, including anemia, pale mucosa, emaciation, and homogeneity in weight, sex, and age. For research purposes, the antibiotics employed in the study were combined with feed.

3.2. Treatment and control regimen for Mycoplasma suis

a. Hygiene - disinfection
- Spray Five-BKG, Five-BGF, Five-Perkon 3S, Five-Iodine disinfectants on barns 1-2 times a day during the epidemic.
- Disinfect tools and wounds: Five-Iodine, ...
- Do not share needles.
b. Treatment with antibiotics
- Five-Oxylin.LA:
● The product, combined with Flunixin, brings a dual effect of strong antibacterial, anti-inflammatory, and pain relief, and rapid fever reduction. With a comprehensive mechanism of action, the product is especially effective in the treatment of Mycoplasma suis, complex pneumonia, infections, acute mastitis, and MMA syndrome.
● Treatment dose: Intramuscular injection 1 dose of 1ml/10-15kg Bw. In severe cases, it can be re-injected after 3-5 days.
● Then can continue treatment with mixed antibiotics for 5-7 days. 
- Mixed antibiotic products: Five-Oxytetra 50%, TW5-Doxy 500, Five-Doflo 21,…
c. Complementary therapy
-  Five-Butasal, Five-Acemin B12, Five-Anti virus, Five-Orgamin, Beta-Glucan.C Garlic, Five-LacEnzym (garlic extract),…
                                                                         
Pig Mycoplasma suis illness is a significant problem for contemporary animal husbandry, particularly in situations with unpredictable weather and dense herds. Farmers will be more proactive in illness prevention and treatment if they have a better understanding of the disease mechanism, clinical signs, and transmission routes. One practical way to reduce harm is to use a scientific treatment regimen that combines stringent barn management with the use of the right antibiotic medications. The pig herd will develop healthily and with high growth productivity if the disease is adequately managed, laying the groundwork for consistent profits and sustained livestock development.
Mycoplasma suis can be controlled by taking prompt action with the appropriate product. Don't allow a single delay to cost the entire herd.