Rodent Respiratory Disease Complex
Rodent Respiratory Disease Complex is seen commonly in rats, hamsters and guinea pigs. Affected rodents show signs of repeated sneezing, nasal discharge, brown to red eye discharge and diminished appetite. Affected rodents may also make a “chattering’ noise because of congestion. Sometimes the infection goes to the inner ear, affecting the balance center and the infected animal may develop a head tilt. Rodent respiratory disease is called a “complex” because it may be caused by a myriad of infectious agents with environmental and nutritional issues also playing a role. To confuse matters more, many of the infectious organisms involved in Rodent Respiratory Disease Complex can be subclinical (not showing up as illness, but the infected animal remains a carrier of the disease causing organisms). When a new carrier or subclinical pet is introduced to a household with preexisting pet rodents the carrier may shed infectious agents and spread disease among susceptible members of the pet colony. Subclinical cases can also become clinical (the rat starts showing signs of respiratory disease) as a result of secondary environmental stresses particularly poor cage design and care and an inadequate diet.
These two images show a guinea pig and a hamster with the typical nasal discharge seen with Rodent Respiratory Disease Complex. Most infected animals respond well to antibiotic therapy along with a change in diet and cage environment where needed.
In this rat the respiratory infection has traveled up the eustachian tube and into the inner ear where it has caused inflammation of the balance center resulting in a subsequent head tilt.
Rodent Respiratory Disease Complex may be caused by a combination of:
Viral Diseases
Sendai Virus – A type 1 paramyxovirus seen in mice, rats and hamsters that causes rhinitis, bronchitis, pneumonitis.
Corona virus – rats; known for causing mild respiratory signs, but more severe salivary gland inflammation and conjunctivitis of the eyes.
Adenovirus – pneumonia in guinea pigs, labored breathing.
Bacterial
Murine Respiratory Mycoplasmosis (MRM) is very common in rats. Infection is persistent and probably life long. Cases are worsened by increased ammonia in dirty cage, concurrent viruses, Vitamin C or A deficiency, and aging.
Cilia-Associated Respiratory (CAR) Bacillus – Primarily affects rats, but also guinea pigs, hamsters.
Corynebacterium kutscheri – Seen in rats, hamsters, mice. Usually subclinical but becomes clinical with dietary deficiencies or other concurrent infections that suppress the immune system.
Streptoccocus pneumoniae – Primarily responsible for nasal discharge and respiratory distress in rats and guinea pigs. May also lead to arthritis, and heart disease.
Streptoccocus zooepidemicus – Common in guinea pig and causes lymph node abscesses.
Bordetella bronchiseptica – Significant in guinea pigs; causing nasal discharge, pneumonia, labored breathing, and heart disease. Apparently healthy looking ‘carrier’ animals are common.
Environmental/ Nutritional: Any rodent kept in a soiled, poorly ventilated cage that results in elevated urine ammonia levels affecting cage air quality, will be more prone Rodent Respiratory Disease Complex. As well, crowded conditions with too many rodents sharing a small space or situations where rodents are fed a sub-optimal diet will predispose to Rodent Respiratory Disease Complex.
Treatment of Rodent Respiratory Disease Complex usually centers around antibiotic therapy and improving diet and cage care. In spite of the best care and nutrition it is not uncommon for this disease to recur. Fatty acid supplements such as HealX Sunshine Factor® red palm oil have been shown to prevent recurrence of clinical disease.
