How I Approach... The Sneezing Cat

Sneezing is a remarkably common presenting complaint in cats, and it is important for the practitioner both to have a good overview about the possible causes when presented with an affected cat or a clowder of cats, and to be aware of the various diagnostic and therapeutic options available.

Elizabeth Rozanski
DVM, Dip. ACVIM (SAIM), Dip. ACVECC 
 

Introduction

Sneezing is a remarkably common presenting complaint in cats, and it is important for the practitioner both to have a good overview about the possible causes when presented with an affected cat or a clowder of cats, and to be aware of the various diagnostic and therapeutic options available. Sneezing represents the body’s efforts to clear irritants from the nose, and is generally an involuntary process. Some causes of sneezing are self-limiting, such as exposure to a dusty basement, while others may be more progressive and even life-limiting. Practically, I feel that it often appears to make sense to divide sneezing cats into categories of “easy” or “complex” when determining the types of investigations that should be pursued when presented with these cats; “easy” cases are typically represented by kittens with mild upper respiratory infections, whilst “complex” cases represent cats with chronic disease that stubbornly refuses to resolve, or cases where the etiology remains elusive despite extensive testing. This paper offers a brief overview for the clinician presented with a sneezing cat.

Key historical questions and physical exam

As with almost all diseases, signalment is very useful in the evaluation of a cat that is sneezing. Other key historical questions I ask include verification of exposure to the outdoors or to other cats, the duration of clinical signs, the animal’s general appetite and activity levels, and the success of any prior therapies. It is important to identify if there has been any nasal discharge, including its characteristics, and whether it is uni- or bilateral. From a physical examination perspective, fever can support the diagnosis of infection; viral infections in particular are commonly accompanied by a high fever. Facial asymmetry or lack of airflow through one or both nostrils may be identified and more directly support the identification of nasal obstruction. Severe dental disease or the presence of an oronasal fistula may direct therapeutics towards treatment of dental pathology. Enlarged mandibular lymph nodes may support a diagnosis of infection (e.g., with Cryptococcus) or neoplasia. Cats that have recent significant weight loss, or appear otherwise unthrifty, are more likely to have serious underlying disease.

Potential etiologies

A multitude of potential causes of sneeze exist, and these can be largely divided into the following subcategories:

• Foreign body/irritant. This category includes inhaled objects such as cuterebra or blades of grass (Figure 1). Inhaled nasal foreign bodies as a cause of sneezing are more commonly seen in cats with outdoor access, and cases are most commonly encountered during the warmer months. Clinical signs tend to be peracute, and concurrent gagging is also common. Many cases are self-limiting and subsequently resolve, but for cases that do not resolve, further evaluation includes (at a minimum) an oral examination under sedation, and a nasal flush is often advisable (1).
 

• Traumatic. This category includes cats with facial fractures which are most commonly due to road-traffic accidents (RTA). These cats will have sneezing due to trauma to the nasal turbinates and bleeding into the nasal cavity, often associated with facial fractures. This category rarely represents a diagnostic dilemma, although cats may refuse to eat if their nose is clogged with dried blood, and sneezing fits may result in significant hemorrhage. Advanced diagnostics are not warranted for sneezing associated with trauma, but may be useful for further evaluating the extent of the cat’s injuries.

• Infection. This is the one of the most common causes of sneezing in cats, with the most frequent agents being viral (herpesvirus, calicivirus) in origin. Bacterial infections, including Bordetella bronchiseptica, Streptococcus canis, Mycoplasma spp., and Chlamydophila felis have also been implicated as primary causes of upper respiratory tract infections in cats, although these are relatively rare. However, any case of rhinitis may become secondarily colonized by bacteria. Note that culture from a nasal swab is rarely helpful, as results typically reflect secondary colonization. For viral infections, isolation of the causal agent is challenging, and has more recently been largely replaced by PCR (polymerase chain reaction) testing. Cryptococcus infection may also result in sneezing; this is often easily documented via cytology, and serology is useful for demonstration of both infection and resolution.

• Inflammatory. Chronic rhinitis will result in the destruction of the turbinates and accumulation of mucus and debris, which may result in sneezing. Chronic rhinitis may be initially triggered by a variety of underlying diseases, but all will result in nasal discharge and sneezing (2). Histopathological evaluation may support the diagnosis of an underlying allergic cause if certain cellular infiltrates (e.g., lymphocytic-plasmacytic) are identified. Dental disease may also be considered inflammatory, or in some cases infectious. Figure 1. This blade of grass had been present in a cat’s nose for five months and was associated with paroxysms of sneezing.

• Neoplastic. Nasal neoplasia may cause sneezing, with the final diagnosis requiring histopathological sampling in order to determine tissue type (Figure 2). [...]