Short Takes: January 2012

A Study on Feline Stomatitis
Chronic gingivostomatitis (FCGS) is a significant disease of cats causing ulcerative, painful lesions in the mouth. Unfortunately, the cause of this condition is not always clear, but feline calicivirus has been speculated to play a part in some cases. Medical treatment of this condition has largely remained unsuccessful. 

Interferon is a protein produced by animals to fight virus infections, and investigators examined the potential of this substance — which can be produced artificially and given orally — to treat FCGS. Only cats with known active FCV were included in the study (“Comparative efficacy of a recombinant feline interferon omega in refractory cases of calicivirus-positive cats with caudal stomatitis; a randomized, multi-centre, controlled, double-blind study in 39 cats,” Journal of Feline Medicine and Surgery, 2011). 

They compared cats that were treated with anti-inflammatory drugs, and clinical signs — including pain — were assessed for 90 days. The investigators found that treatment with topically applied (oral) interferon daily led to improvement in both the clinical appearance of the lesions as well as pain scores, comparable to anti-inflammatory and immunosuppressive drugs. Interferon may be an appropriate treatment for FCGS related to feline calicivirus infection.

Injection-Site Sarcoma Study
This study (“Radical excision with five-centimeter margins for treatment of feline injection-site sarcomas; 91 cases (1998-2002),” Journal of the American Veterinary Medical Association, 2011) is a retrospective case series of 91 cats with injection-site sarcomas (ISS). The authors evaluated the outcomes of radical excision of the ISS by local recurrence and metastasis rates, survival times and complications associated with surgery. 

The rates for local recurrence of feline ISS after treatment range between 26 to 59 percent. (However, there are no current studies evaluating the outcome of consistently performed radical excision without adjuvant treatment for feline ISS.) For this study, radical excision was defined as tumor resection including 5-cm margins surrounding the palpable tumor edge and two fascial planes or bone deep to the tumor. The overall median survival time was 901 days. Fourteen percent of the cats had local tumor recurrence; 18 percent displayed evidence of metastasis after surgery. 

Metastasis significantly affected overall survival, with pulmonary metastasis as the most common form. The study reported a major complication rate of 11 percent, with wound dehiscence being the most commonly encountered problem; however, none of the complications were fatal. 

The recurrence rate appeared to be substantially less than rates reported with less aggressive surgeries, indicating that radical excision may be important as a means to achieving an improved outcome in the treatment of injection-site sarcomas in cats.

Factors That Impact Viruses
Cats are susceptible to a number of viruses that, unfortunately, can cause significant disease. The living conditions and behavior of various cat populations will impact their susceptibility and risk of exposure to these viruses. 

The investigators of the study (“When cats’ ways of life interact with their viruses: a study in 15 natural populations of owned and unowned cats (Felis silvestris catus),” Preventive Veterinary Medicine, 2011) examined 15 populations of non-sterilized and unvaccinated cats living in the same area of France. These populations had two different lifestyles — owned (sheltered and fed, socialized) and unowned (no shelter or food provided, unsocialized). 

Blood samples were tested for exposure to feline herpesvirus (FHV), calicivirus (FCV), parvovirus (FPV), immunodeficiency virus (FIV) and leukemia virus (FeLV). Not surprisingly, the unowned cats were more likely to have been infected with FHV, FCV and FIV — these viruses generally require direct contact between cats, including fighting. The owned cats were more likely to have been infected with FPV. 

For each virus, the likelihood of having been infected varied with the feline population. For example, FIV infection was more likely in older, male, unowned cats; FHV was more likely to infect kittens at an earlier age in unowned versus owned populations; FPV infection was more likely in owned populations perhaps because of shared environments in human settlements.

Failure to consider these aspects can skew results of epidemiologic analyses. Pooling different types of cats in a single sample without taking behavior and lifestyle into account could give a misleading picture of the epidemiology of their viruses.