This is a handout received from Shirley Casey on Bordetella bronchiseptica in squirrels. This disease emerged as a pathogen last fall. The bacteria is closely related to Bordetella pertussis (whooping cough) in humans but is not the same. It is frequently seen in dogs as "kennel cough". Bordetella bronchiseptica has been documented in many mammals however, it is a new finding in squirrels.

Bordetella in Squirrels

Some rehabilitators in Northern California have reported that some squirrels in rehabilitation died rapidly and unexpectedly during the past two months with few symptoms and no obvious or common causes such as trauma or aspiration. Recent suspicions that Bordetella might be responsible for some of these deaths were confirmed by lab tests, but more tests are needed because other conditions also should be considered. This info sheet was prepared so that Bordetella might be considered a possibility when rehabilitators notice potential contagious squirrel respiratory conditions and discuss the cases with their veterinarian.

Bordetella bronchiseptica is a gram-negative bacterium, commonly found in the respiratory system. In its non-pathogenic form, it is part of the normal respiratory flora. Its virulent or disease- causing form can be activated by concurrent disease, or by the presence of stressors such as overcrowding, transportation, poor ventilation and other factors. Bordetella is a highly contagious bacterium to many animals, sometimes across species (but not currently described as zoonotic).

A sample of the symptoms described by squirrel rehabilitators with these recent sick animals in care include:
- Rapid onset of symptoms.
- Lethargy and weakness.
- Often refuse to eat and/or fight attempts to feed.
- Profuse, frequent urination, sometimes involuntary. (Note that while profuse urination often is described in the current cases, it is not a common Bordetella symptom in most species and may be a secondary condition or another disease.)
- Rapid and significant dehydration and weight loss, likely due to profuse urination and difficulty eating.
- Moderate fever.
- A variety of respiratory conditions, which can include sneezing, audible breathing and gagging or coughing. Although respiration difficulties are not uncommon with juvenile squirrels that might have aspirated, the profuse urination that has often preceded the respiratory symptoms has been very different.

Antibiotics, particularly Bactrim (e.g., TMP, SMZ), have been effective with Bordetella in rodents when used for 14-21 days. Supportive care also is essential, such as limiting activity by keeping in a small cage, providing supplemental heat, ensuring good nutrition, and minimizing stressors such as noise. Use effective hydration protocols with isotonic fluids to avoid dehydration. Due to its highly contagious nature, follow strict quarantine and sanitation protocols. Some rehabilitators also have used homeopathy and reported positive results, especially with the homeopathic remedy Phosphorus. As always, consult closely with a veterinarian on diagnostics and treatments.

More information will be available shortly in a resource handout at There is also an article on Bordetella in Young Rabbits and Squirrels in the NWRA Bulletin. Volume 24, Fall/Winter, 2006.

Shirley Casey, WildAgain Wildlife Rehabilitation, Inc. in Evergreen, CO is co-author of the Squirrel Rehabilitation Handbook. She has published and presented widely on wildlife rehab topics.
Mackenzie Goldthwait, DVM of Denver, Colorado, graduated from Tufts University School of Veterinary Medicine in 1989, with special interest in wildlife medicine. She has extensive experience with wildlife, exotics and small animals. She has been involved in writing for and training rehabilitators.

2007 Shirley Casey and Mackenzie Goldthwait, DVM