Get answers to your questions about this form of ehrlichiosis.

On May 31, 2010, a 2-year-old 27-kg neutered male mixed-breed dog was presented to the University of Missouri Veterinary Medical Teaching Hospital's Community Practice clinic for progressive lethargy and difficulty walking of about 4 days' duration.

In many parts of the United States, infection of dogs with the pathogen Ehrlichia ewingii is far more common than infection with the better-known Ehrlichia canis.

Recent years have seen the emergence of previously undescribed respiratory infections in dogs and cats. Although these infections remain rare, the potential exists for substantial morbidity and mortality.

There are several ways to obtain samples from the airways and lower respiratory tract for cytologic evaluation and microbiologic culture. In general, samples should be handled quickly since respiratory epithelial cells degrade with some rapidity after retrieval, and samples should be handled gently to avoid damaging cell membranes.

Respiratory disease is common in dogs, and can result in a constellation of clinical signs. These clinical signs range from those that are irritating to owners (e.g., nasal discharge, stridorous panting, chronic hacking cough) to those which are life-threatening and require immediate medical attention.

Bacterial pneumonia encompasses a wide spectrum of disease from chronic to acute, unilobar or multilobar, and with clinical signs ranging from mild tachypnea or cough to rapidly progressive and fatal pulmonary infection. Cats are subject to bacterial pneumonia far less frequently than are dogs.

Cough is a common reason for dogs to be presented for veterinary care, and tracheal collapse is a common cause of chronic cough in dogs. The tracheal lumen remains open during both inspiration and expiration thanks to the support of cartilaginous rings.

Diseases of the respiratory tract are a common reason for cats seeking veterinary medical attention. Depending on the location and type of respiratory disease, the clinical signs are variable.