Below, please find a list of our clinical trials that we have completed involving cats.


  • Effects of Environmental Enrichment on Body Weight of Obese Cats
  • Purpose: Multimodal environmental enrichment (MEMO) recommendations provide a structured and systematic way of evaluating problem areas in indoor housed cats' environments, including ensuring the cat's feeling of safety, ensuring appropriate resources for play, climbing, and scratching behavior, and minimizing noxious sensory stimuli. These recommendations, which are personalized for each cat's environment, also can help reduce inter-cat conflicts and include use of toys and suggestions for games and enrichment, climbing and scratching towers, and the encouragement of grooming and petting by the owner. Therefore, the purpose of this 10-week study is to begin to test the effectiveness of adding a form of MEMO to standard obesity therapy in overweight or obese client-owned cats.
  • Evaluation of the Role of Lower Urinary Tract Disease in Cats with Urine-Marking Behavior
  • Outcome: With regard to variables measured via urinalysis, there were no differences between male and female cats within either group. Among cats with urine-marking behavior, there were no differences between those that only marked vertically and those that marked vertically and horizontally. Analyses of data from all cats with urine-marking behavior and control cats revealed no differences that could be associated with urine marking.
    Impact of the study on quality of care: These data suggest that urine-marking behavior by gonadectomized cats is an aspect of normal behavior. Clinicians are advised to focus on behavioral history of house-soiling cats to differentiate between urine-marking behavior and inappropriate urination; for the latter, urinalysis is appropriate to rule out lower urinary tract disorders.
    Publications: Tynes, V.V., Hart, B.L., Pryor, P.A., Bain, M.J., & Messam, L.L.M. (2003). Evaluation of the role of lower urinary tract disease in cats with urine-marking behavior. Journal of the American Veterinary Medical Association, 223(4), 457-61. (DOI:10.2460/javma.2003.223.457)
  • Evaluation of Urine Marking by Cats as a Model for Understanding Veterinary Diagnostic and Treatment Approaches and Client Attitudes
  • Outcome: Almost a third of veterinarians did not seem to correctly distinguish between urine marking (spraying) and inappropriate urination. Those that did make this diagnostic distinction reported recommending environmental management and prescribing medication significantly more often that those that did not make this distinction. Seventy-four percent of cat owners sought help from their veterinarians for urine marking; other common sources of information were the Internet and friends. Among those who did not consult a veterinarian, the most frequently cited reason was that they did not think their veterinarian could help. Among cat owners who consulted their veterinarians, 8% reported receiving advice on environmental hygiene and 4% on environmental management (limiting intercat interactions), although veterinarians who correctly diagnosed urine marking reported giving such advice 100 and 83% of the time, respectively.
    Impact of the study on quality of care: Results may serve as a model for obtaining information critical to developing veterinary continuing education and public outreach programs for animal owners for various diseases.
    Publications: Bergman, L., Hart, B.L., Bain, M.J., & Cliff, K. (2002). Evaluation of urine marking by cats as a model for understanding veterinary diagnostic and treatment approaches and client attitudes. Journal of the American Veterinary Medical Association, 221(9), 1282-86. (DOI:10.2460/javma.2002.221.1282)
  • Effects of a Selective Serotonin Reuptake Inhibitor on Urine Spraying Behavior in Cats
  • Outcome: The mean (± SE) weekly rate of spraying episodes in treated cats was 8.6 (± 2.0) at baseline, decreased significantly by week 2 (1.7 ± 0.6), and continued to decrease by weeks 7 and 8 (0.4 ± 0.2). The mean weekly spraying rate of cats receiving placebo was 7.8 (± 1.5) at baseline, decreased only slightly during week 1 (5.5 ± 1.8), and did not decline further. When treatment was discontinued after 8 weeks, the spraying rate of cats that had received treatment varied. The main adverse reaction to the drug was a reduction in food intake, which was observed in 4 of 9 treated cats.
    Impact of the study on quality of care: Administration of fluoxetine hydrochloride for treatment of urine spraying in cats can be expected to considerably reduce the rate of urine marking. The frequency of spraying before treatment is predictive of the spraying rate when the drug is discontinued.
    Publications: Pryor, P.A., Hart, B.L., Cliff, K. & Bain, M.J. (2001). Effects of a selective serotonin reuptake inhibitor on urine spraying behavior in cats. Journal of the American Veterinary Medical Association, 221(11), 1557-61. (DOI:10.2460/javma.2001.219.1557)
  • Causes of Urine Marking in Cats and Effects of Environmental Management on Frequency of Marking
  • Outcome: Male cats and cats from multicat households were significantly overrepresented, compared with the general pet cat population in California. The most commonly mentioned causative factors for urine marking were agonistic interactions with other cats outside or inside the home. Environmental management procedures resulted in an overall reduction in urine marking frequency. Among cats that marked 6 times during the baseline phase, females were significantly more likely to respond to treatment (50% reduction in marking frequency) than were males.
    Impact of the study on quality of care: Results suggest that male cats and cats from multicat households are more likely to exhibit urine marking behavior than females and cats from single-cat households. Results also suggest that attention to environmental and litter box hygiene can reduce marking frequency in cats, regardless of sex or household status of the cats, and may come close to resolving the marking problem in some cats.
    Publications: Pryor, P.A., Hart, B.L., Bain, M.J. & Cliff, K. (2001). Effects of a selective serotonin reuptake inhibitor on urine spraying behavior in cats. Journal of the American Veterinary Medical Association, 219(12), 1709-13. (DOI:10.2460/javma.2001.219.1709)
  • Control of Urine Marking by Use of Long-Term Treatment with Fluoxetine or Clomipramine in Cats
  • Outcome: Efficacy of fluoxetine and clomipramine was similar. Treatment > 8 weeks revealed increasing efficacy in reduction of marking. Return of marking after termination of fluoxetine administration occurred in most cats. Cats successfully treated initially with fluoxetine responded similarly to repeated treatment.
    Impact of the study on quality of care: Clomipramine and fluoxetine were equivalent in treating urine marking. Longer treatment increased efficacy. Most cats return to marking after abrupt drug withdrawal. A second course of treatment can be expected to be as effective as the first.
    Publications: Hart, B.L., Cliff, K.D., Tynes, V.V. & Bergman, L. (2005). Control of urine marking by use of long-term treatment with fluoxetine or clomipramine in cats. Journal of the American Veterinary Medical Association, 226(3), 378-82. (DOI:10.2460/javma.2005.226.378)


  • Biomarker Assessment of Feline Hypertrophic Cardiomyopathy
  • Purpose of the Study: In human heart disease, traceable substances in the blood, referred to as biomarkers, are used to assess severity of a common heart disease called hypertrophic cardiomyopathy (HCM). Recent research identified biomarkers associated with inflammation that are elevated in HCM patients. Studies have also investigated biomarkers in cats, such as B-type natriuretic peptide (BNP), that correlate with the severity of heart disease. Only one previous study has attempted to identify the level of an inflammatory biomarker in cats with heart failure. Although the study identified elevated levels of this biomarker, there have been no multimarker studies using inflammatory biomarkers in feline HCM. This study compared concentrations of three individual inflammatory biomarkers and BNP in cats with and without HCM. The goal was to determine the ability of multiple biomarkers to identify and assess, and hopefully correlate to, the degree of heart disease in cats. Early identification of this disease will lead to earlier treatment and potentially prevention of the development of heart failure.
    Evaluation of the Efficacy of Timolol Ophthalmic Suspension to Transiently Decreased Heart Rate and Improve Echocardiographic Analysis in Cats
    Purpose of Study: Because of patient “nerves” (called sympathetic tone), many cats have elevated heart rates while they are in hospital, which makes important cardiac measurements difficult to obtain. Although timolol is used in pets and humans with glaucoma, this commonly used eye drop may also slightly decrease an already elevated heart rate. Therefore, the purpose of the trial was to investigate the use of timolol to help improve our ability to measure heart function using echocardiogram (cardiac ultrasound).
    Publications: Gunther-Harrington, C.T., Ontiveros, E.S., Hodge, T.E., Visser, L.C., & Stern, J.A. (2016). Effects of 0.5% Timolol Maleate Ophthalmic Solution on Heart Rate and Selected Echocardiographic Indices in Apparently Healthy Cats. Journal of Veterinary Internal Medicine, (DOI: 10.1111/jvim.13931)

Dentistry and Oral Surgery

  • Outcome of Orthograde Root Canal Treatment in Cats
  • Purpose of Study: Long-term evaluation of root canal treatments by evaluating the dental x-rays is essential to assess the appropriateness of this treatment modality in cats. In receiving care of a specialized nature such as root canal treatment, patients need and deserve treatment that meets the standard of care and this study allowed us to understand the efficacy of such treatment if rendered. Although root canal treatment is commonly performed in dogs and humans with a high success rate, the purpose of this study was to evaluate the success rate of root canal treatment in cats, as we believe this treatment is just as appropriate for cats and with a similar high success rate.
    The Diagnostic Yield of Dental Radiographs and Cone-beam Computed Tomography in Cats with Dental Disorders
    Purpose of Study: Because of the highly detailed images, cone-beam computed tomography (CBCT) scans are commonly used as diagnostic tools in human medicine with great success; however, these scans are only now being introduced to the veterinary field. Therefore, the purpose of this study was to establish CBCT scans as the ideal imaging modality for mesaticephalic and brachycephalic cats with dental disorders.


Internal Medicine

  • Identifying the Genetics behind Feline Infectious Peritonitis
  • Purpose of Study: Feline Infectious Peritonitis (FIP) is an infectious disease that kills 1 in 100 to 1 in 300 of all cats in the U.S. However, the incidence is 5 to 10 times greater among young cats coming from catteries and shelters. It is a disease that is 100% lethal, and is heartbreaking for breeders and for the families that lose affected kittens and young cats. The purpose for this study is to find genetic markers to identify FIP susceptible cats and to use these markers to breed for resistance. In order to identify favorable or unfavorable genetic traits, we need to concentrate our studies on bloodlines within breeds of cats that are either inordinately susceptible or seemingly resistant. Such bloodlines exist in virtually all breeds of cats.

    Clinical trial of Protease Inhibitor KT-147 to Treat Naturally Occurring FIP

    Purpose of Study: Since it’s discovery and characterization over a half century ago Feline Infectious Peritonitis (FIP) continues to be a progressive and invariably a fatal disease primarily of young cats and kittens. Recently, in small-scale experimental trials, a novel antiviral (KT-147) has been shown to be an effective treatment of this devastating disease. 

    This trial closed in December 2016.

  • Field study of a New Once-a-Day Medical Therapy for the Reduction of Hyperglycemia and Hyperglycemia-Associated Signs of Diabetes Mellitus in Cats
  • Purpose of Study: Feline diabetes is a metabolic disease that causes high levels of sugar in the bloodstream. The purpose of this study was to assess the effectiveness of a new, once-per-day insulin for feline diabetes.


  • Finding the Best Sample Collection Method for Infectious Keratitis in Cats
  • Purpose of Study: If your veterinarian has a suspicion that your pet is suffering from infectious keratitis (infection of the cornea) or a deep corneal ulcer, they will recommend taking a swab sample from the surface of your pet’s cornea in order to see what type of infection your pet has. Historically at UC Davis, we have used a topical anesthetic named proparacaine, that is applied to the surface of the eye before any samples are taken to minimize discomfort. Recently, a concern has been raised that proparacaine may inhibit growth of infectious organisms in the laboratory after a corneal swab sample is obtained. This means that even if your pet has a corneal infection, we may not be able to get a positive result based on culture results if proparacaine has been used before sample collection. Therefore, the purpose of this study was to determine the best procedure to follow when collecting culture samples, thereby ensuring an appropriate diagnostic work up and treatment plan.
    Measurement of Tear Famciclovir and Penciclovir Concentrations Following Oral Administration of Famciclovir to Cats Outcome: Oral administration of 40 mg of famciclovir/kg to cats resulted in penciclovir concentrations within the tears that are likely to be effective against FHV-1 and at the ocular surface. This is highly unusual for an orally administered drug of any type, especially an antiviral drug.
    Impact of the study on quality of care: This study has completely changed our approach to cats with corneal signs of herpes infections. Based on data from this study, we now are more likely to administer oral famciclovir than a topical eye drop or ointment, which many cats and owners prefer.
    Publications: Thomasy, S.M., Covert, J.C., Stanley, S.D., & Maggs, D.J. (2012). Pharmacokinetics of famciclovir and penciclovir in tears following oral administration of famciclovir to cats: a pilot study. Veterinary Ophthalmology, 1-8. (DOI:10.1111/j.1463-5224.2011.00984.x)