Canine Mycoplasma cynos

Several viruses, bacteria, and other microorganisms are considered to be the pathogens responsible for canine infectious respiratory disease. Clinically, it is also common to isolate multiple pathogens simultaneously. Moreover, experimental infections induced by a single pathogen often result in mild or subclinical forms of the disease, further suggesting that the illness is caused by the combined action of several distinct pathogens. Many of these microorganisms play crucial roles in the development of canine infectious respiratory disease, including canine parainfluenza virus, canine adenovirus, and Mycoplasma species, among others.

Researchers have identified the Mycoplasma species present in the respiratory tracts of dogs with and without CIRD. Mycoplasmas were cultured from tonsil, tracheal, and bronchial lavage samples, and their specific types were determined using PCR and sequencing. In situ hybridization revealed the presence of Mycoplasma cynos in ciliated tracheal epithelial cells—this is the only Mycoplasma species associated with CIRD, though it is found exclusively in the lower respiratory tract. This article will provide a brief overview of Mycoplasma cynos.  

Mycoplasma cynos, a mycoplasmal species widely found in dogs, primarily infects canine animals—including dogs, wolves, and foxes. It is one of the most common mycoplasmas observed in domesticated canines. Mycoplasma cynos is a small bacterium, measuring about 0.3 micrometers in diameter. Unlike many other bacteria, it lacks a cell wall; instead, its cell membrane is coated with membrane proteins that play a critical role in its pathogenicity. This bacterium can cause respiratory infections and conditions like conjunctivitis in affected animals. As an oligotrophic bacterium, Mycoplasma cynos exhibits relatively limited metabolic capabilities and relies heavily on nutrients provided by host cells for growth and reproduction.

Mycoplasma cynos is primarily transmitted through direct contact, respiratory droplets, and contaminated environments. Infected dogs can easily spread the bacteria to other dogs when they cough, sneeze, or share items that have been exposed to the pathogen. When Mycoplasma cynos infects a dog, it may cause respiratory symptoms such as coughing, sneezing, and nasal discharge. It can also lead to conjunctivitis, resulting in redness, swelling of the eyes, and increased discharge.

Mycoplasma cynos infection can cause various harms and effects, specifically as follows:

Mycoplasma cynos infection leads to damage of respiratory epithelial cells and may cause mucous and inflammatory cell infiltration. The infection triggers an inflammatory response in lung tissue, characterized by infiltrating inflammatory cells, thickening of alveolar walls, and accumulation of exudates. Mycoplasma cynos infection results in cellular damage in both the upper respiratory tract and lungs, initiating an inflammatory cascade that includes the recruitment of inflammatory cells and the release of pro-inflammatory cytokines—processes that can ultimately lead to tissue injury and pathological changes. These pathological alterations form the basis for the symptoms and clinical manifestations observed in infected dogs.

Infection with Mycoplasma cynos can lead to cellular changes in cell cultures, including restricted growth, increased apoptosis, and altered expression of cytokines and cell surface molecules. It may also affect the immune system, influencing cytokine production and cellular immune responses. Additionally, the infection could impact gene expression, either by modulating or directly altering the levels of specific genes. Furthermore, Mycoplasma cynos is known to cause respiratory infections in dogs, as well as other systemic diseases such as pneumonia and rhinitis.

Mycoplasma cynos infection may have multifaceted implications for research, affecting the reliability of cell-based experimental results, as well as immunological, molecular biological, and pathological studies. Therefore, during experiments, it is crucial to carefully screen for or address potential Mycoplasma cynos contamination.

For infections caused by Mycoplasma cynos, closely monitor your dog's health and conduct regular disease surveillance and testing. If an infection is detected, promptly implement appropriate treatment measures and control its spread to minimize harm and impact on your pet. It’s also crucial to consult with a veterinarian about effective preventive strategies, as this can significantly reduce the risk of infection.

The 2022-2023 testing data from Suzhou Xishan Biotechnology Co., Ltd. show that the positive rate for Mycoplasma cynos was 24%. These figures clearly indicate that Mycoplasma cyno infection is highly prevalent in domestic dog kennels. Given the widespread nature of Mycoplasma cyno infections, laboratory animal facilities and professionals should pay close attention to this issue.

References

1. Overview of Research on Respiratory Viruses Associated with Canine Infectious Tracheobronchitis

2. Diagnosis of Canine Infectious Respiratory Diseases

3. Mycoplasma maculosum and Mycoplasma spumans Dog

4. 2017 Canine Infectious Respiratory Disease – CIRD – Technical Bulletin

5. 2004 Mycoplasmas associated with canine infectious diseases

6. S. Rosendal; "Mycoplasma Cynos, A New Canine Mycoplasma Species", 1973.