Outcome: Socialization is one method of preventing behavior problems in dogs; however, some oppose socialization before 16 wk of age due to the risk of contracting infectious diseases. The objectives of this study were to determine if puppies that attended puppy socialization classes and were vaccinated by a veterinarian at least once were at an increased risk of confirmed canine parvovirus (CPV) infection compared with puppies that did not attend classes and to determine the frequency of suspected CPV infection in puppies vaccinated at least once that attended classes with trainers. Twenty-one clinics in four cities in the United States provided information regarding demographics, vaccination, CPV diagnosis, and class attendance for puppies ≤ 16 wk of age. In addition, 24 trainers in those same cities collected similar information on puppies that attended their classes. In total, 279 puppies attended socialization classes and none were suspected of or diagnosed with CPV infection.
Impact of the study: Results indicated that vaccinated puppies attending socialization classes were at no greater risk of CPV infection than vaccinated puppies that did not attend those classes.
Publications: Stepita, M.E., Bain, M.J., & Kass, P.H. (2013). Frequency of CPV Infection in Vaccinated Puppies that Attended Puppy Socialization Classes. Journal of the American Animal Hospital Association, 49(2), 95-100. (DOI:1053526/JAAHA-MS-5825)
Outcome: Problematic behaviors are a significant reason for relinquishment, and relinquished dogs are more likely to have problem behaviors. This study utilized standardized surveys of owners (companion animal guardians) relinquishing their dogs to shelters and dog owners visiting vaccination clinics. "Relinquishing" and "continuing" owners were asked questions in the following categories: demographic information, training methods and tools, frequencies in which their dogs engaged in problematic behaviors, and attachment to their dogs. "Relinquishers"; were also asked to provide their reasons for relinquishment. The results of 129 surveys (80 relinquishing and 49 continuing) showed that relinquishers scored lower on companion animal attachment than continuing owners. Pit bull-type dogs were represented more in the relinquishing group. Relinquished dogs were no less likely to have attended training classes than continuing dogs. In both groups, owners who used punishment-based collars reported less satisfaction with their dogs' overall and leash-walking behaviors. Pit bull-type dogs were reported to be no less well behaved compared with all other breeds combined. Sixty-five percent of relinquishers reported some behavioral reason for relinquishment. Forty-eight percent of relinquishers indicated that at least 1 problem behavior was a strong influence on their decision to relinquish.
Impact of the study: Not applicable
Publications: Kwan, J.Y., & Bain, M.J. (2013). Owner Attachment and Problem Behaviors Related to Relinquishment and Training Techniques of Dogs. Journal of Applied Animal Welfare Science, 16(2), 168-83. (DOI:10.1080/10888705.2013.768923)
Outcome: In contrast to European countries, the overwhelming majority of dogs in the U.S. are neutered (including spaying), usually done before one year of age. Given the importance of gonadal hormones in growth and development, this cultural contrast invites an analysis of the multiple organ systems that may be adversely affected by neutering. Using a single breed-specific dataset, the objective was to examine the variables of gender and age at the time of neutering versus leaving dogs gonadally intact, on all diseases occurring with sufficient frequency for statistical analyses. Given its popularity and vulnerability to various cancers and joint disorders, the Golden Retriever was chosen for this study. Veterinary hospital records of 759 client-owned, intact and neutered female and male dogs, 1–8 years old, were examined for diagnoses of hip dysplasia (HD), cranial cruciate ligament tear (CCL), lymphosarcoma (LSA), hemangiosarcoma (HSA), and mast cell tumor (MCT). Patients were classified as intact, or neutered early (<12 mo) or late (≥12 mo). Statistical analyses involved survival analyses and incidence rate comparisons. Outcomes at the 5 percent level of significance are reported. Of early-neutered males, 10 percent were diagnosed with HD, double the occurrence in intact males. There were no cases of CCL diagnosed in intact males or females, but in early-neutered males and females the occurrences were 5 percent and 8 percent, respectively. Almost 10 percent of early-neutered males were diagnosed with LSA, 3 times more than intact males. The percentage of HSA cases in late-neutered females (about 8 percent) was 4 times more than intact and early-neutered females. There were no cases of MCT in intact females, but the occurrence was nearly 6 percent in late-neutered females.
Impact of the study: The results have health implications for Golden Retriever companion and service dogs, and for oncologists using dogs as models of cancers that occur in humans.
Publications: Torres de la Riva, G., Hart, B.L., Farver, T.B., Oberbauer, A.M., Messam, L.L.M., Willits, N., & Hart, L.A. (2013). Neutering Dogs: Effects on Joint Disorders and Cancers in Golden Retrievers. Public Library of Science One, 8(2), e55937. (DOI:10.1371/journal.pone.0055937)
Outcome: The degree to which owners were attached to their dog was associated with city of residence, owner age, and whether owners were completely satisfied with their dog's behavior. Owners residing in the guardian city had a lower attachment score. There was no significant difference in the percentage of dogs vaccinated against rabies in each city, nor was there any difference in the percentage of licensed dogs. Attachment scores did not differ between participants who visited mobile versus free-standing clinics. Owners with > 1 dog in their household reported a higher degree of attachment to the study dog than did owners of 1 dog.
Impact of the study: Dog owners residing in a city where owners were legally designated as an owner/guardian were no more attached to their dog than those living in a city without such a designation. Although results did not indicate a negative impact of the term guardian, its use was not associated with an enhanced bond between owner and dog.
Publications: Helms, T.D. & Bain, M.J. (2009). Evaluation of owner attachment to dogs on the basis of whether owners are legally considered guardians of their pets. Journal of the American Veterinary Medical Association, 234(7), 896-900. (DOI:10.2460/javma.234.7.896)
Outcome: Analyses revealed significant differences in 2 areas of reported problem behavior between the confidential and nonconfidential information groups: owner-directed aggression and stranger-directed fear. Compared with client-owned–group data, significantly more relinquished shelter dogs in the confidential information group were reported to have ownerdirected aggression, stranger-directed aggression, dog-directed aggression or fear, stranger-directed fear, nonsocial fear, and separation-related behaviors.
Impact of the study: Among persons relinquishing dogs to a shelter, those who believed questionnaire responses were confidential reported owner-directed aggression and fear of strangers in their pets more frequently than relinquishers who believed responses were nonconfidential. Confidentiality had no apparent effect on the reporting of other assessed behavioral problems. Results suggest that behavioral questionnaires may sometimes provide inaccurate information in a shelter setting, but the information may still be useful when evaluating behavior of relinquished dogs.
Publications: Segurson, S.A., Serpell, J.A., & Hart, B.L. (2005). Evaluation of a behavioral assessment questionnaire for use in the characterization of behavioral problems of dogs relinquished to animal shelters. Journal of the American Veterinary Medical Association, 227(11), 1755-61. (DOI:10.2460/javma.2005.227.1755)
Outcome: Sexually intact male dogs were significantly less likely than neutered dogs to progress from mild impairment (i.e., impairment in 1 category) to severe impairment (i.e., impairment in 2 categories) during the time between the first and second interviews. This difference was not attributable to differences in ages of the dogs, duration of follow-up, or the owners' perceptions of the dogs' overall health.
Impact of the study: Results suggest that the presence of circulating testosterone in aging sexually intact male dogs may slow the progression of cognitive impairment, at least among dogs that already have signs of mild impairment. Estrogens would be expected to have a similar protective role in sexually intact female dogs; unfortunately, too few sexually intact female dogs were available for inclusion in the study to test this hypothesis. There may be a need to evaluate possible methods for counteracting the effects of loss of sex hormones in gonadectomized dogs.
Publications: Hart, B.L. (2001). Effect of gonadectomy on subsequent development of age-related cognitive impairment in dogs. Journal of the American Veterinary Medical Association, 219(1), 51-56. (DOI:10.2460/javma.2001.219.51)
Outcome: Age by sex interactions for dogs with impairment in any category were not significant, and, therefore, data on castrated males and spayed females were pooled for analyses across ages. The prevalence of age-related progressive impairment was significant in all categories. The percentage of 11- to 12-year-old dogs with impairment in 1 category was 28% (22/80), of which 10% (8/80) had impairment in 2 or more behavioral categories. Of 15- to 16-year-old dogs, 68% (23/34) had impairment in 1 category, of which 35% (12/34) had impairments in 2 or more categories. There were no significant effects of body weight on the prevalence of signs of dysfunction in the behavioral categories.
Impact of the study: Data collected provide estimates of the prevalence of various degrees of age-related behavioral changes associated with cognitive dysfunction in dogs. Age-related behavioral changes may be useful indicators for medical intervention for dogs with signs of cognitive impairment.
Publications: Neilson, J.C., Hart, B.L., Cliff, K.D., & Ruehl, W.W. (2001). Prevalence of behavioral changes associated with age-related cognitive impairment in dogs. Journal of the American Veterinary Medical Association, 218(11), 1787-91. (DOI:10.2460/javma.2001.218.1787)
Outcome: Between interviews, 22% (16/73) of dogs that did not have impairment in a category at the time of the first interview developed impairment in that category by the time of the second interview. Forty-eight percent (13/27) of dogs that had impairment in 1 category at the time of the first interview developed impairment in 2 or more categories by the time of the second interview and were significantly more likely to develop impairment in 2 or more categories, compared with dogs that initially had impairment in 0 categories. Dogs with 1 sign of dysfunction in orientation were significantly more likely to develop impairment in that category, compared with dogs that had 0 signs of dysfunction in orientation.
Impact of the study: Age-related behavioral changes in dogs are progressive. Clinicians should consider trying to predict which dogs are most likely to become progressively impaired during the subsequent 6 to 18 months.
Publications: Bain, M.J., Hart, B.L., Cliff, K.D. & Ruehl, W.W. (2001). Prevalence of behavioral changes associated with age-related cognitive impairment in dogs. Journal of the American Veterinary Medical Association, 218(11), 1792-5. (DOI:10.2460/javma.2001.218.1792)
Purpose: We were investigating the role of a common canine genetic variant on the condition of pulmonary hypertension. This genetic variant was being evaluated to see if it impacted the severity of disease or the response to the oral medication, sildenafil citrate, the most commonly used drug for the treatment of this condition. Information provided by this study will provide better guidelines for the treatment of dogs with pulmonary hypertension.
Purpose: Sotalol is considered by most veterinary cardiologists to be one of the most effective and well-tolerated medications for longterm control of potentially life-threatening ventricular arrhythmias (abnormal and rapid heartbeats arising from the pumping chambers). Sotalol may decrease heart function (pumping ability) but it is currently unknown to what extent, if any, it does so. Therefore, the purpose of this clinical trial was to determine the effect of a single standard dose of sotalol on heart function and rhythm in dogs diagnosed with ventricular arrhythmias.
Outcome: "Familial subvalvular aortic stenosis (SAS) is one of the most common congenital heart defects in dogs and is an inherited defect of Newfoundlands, golden retrievers and human children. Although SAS is known to be inherited, specific genes involved in Newfoundlands with SAS have not been defined" (Stern et al. 2014). After examining over 300 dogs, Dr. Stern identified a mutation in the phosphatidylinositol-binding clathrin assembly protein (PICALM), a protein that is found in the canine heart, that is associated with the development of SAS in Newfoundland dogs and determined that this particular mutation is passed down to their puppies.
Impact of the study: The ability to test for presence of this PICALM insertion may impact dog-breeding decisions and facilitate reduction of SAS disease prevalence in Newfoundland dogs. Understanding the role of PICALM in OFT development may aid in future molecular and genetic investigations into other congenital heart defects of various species (Stern et al. 2014).
Publications: Stern, J.A., White, S.N., Lehmkuhi, L.B., Reina-Doreste, Y., Ferguson, J.L., Nascone-Yoder, N.M., & Meurs, K.M. (2014). A single codon insertion in PICALM is associated with development of familial subcalvular aortic stenosis in Newfoundland dogs. Human Genetics, 133(9), 1139-48. (DOI 10.1007/s00439-014-1454-0)
Genetic Tests: Coming soon to the UC Davis Veterinary Genetics Laboratory!
Dentistry and Oral Surgery
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 brachycephalic dogs with dental disorders.
Purpose: Upper airway obstruction in the Norwich Terrier is a devastating respiratory disorder that can limit exercise ability and even lead to collapse. The purpose of this trial evaluated the upper airway in a large group of Norwich Terriers (with and without obvious clinical abnormalities) and to characterize the genetics of this condition.
Purpose: Recurrent (more than 3 per year) urinary tract infections (UTI) are problematic for dogs and continual administration of antimicrobial therapy could lead to bacteria becoming resistant. Therefore, the purpose of this trial was to investigate a novel non-antibiotic treatment for recurrent UTIs in dogs.
Neurology and Neurosurgery
Outcome: Alaskan Husky Encephalopathy (AHE) has been previously proposed as a mitochondrial encephalopathy based on neuropathological similarities with human Leigh Syndrome (LS). We studied 11 Alaskan Husky dogs with AHE, but found no abnormalities in respiratory chain enzyme activities in muscle and liver, or mutations in mitochondrial or nuclear genes that cause LS in people. A genome wide association study was performed using eight of the affected dogs and 20 related but unaffected control AHs using the Illumina canine HD array. SLC19A3 was identified as a positional candidate gene. This gene controls the uptake of thiamine in the CNS via expression of the thiamine transporter protein THTR2. Dogs have two copies of this gene located within the candidate interval (SLC19A3.2 – 43.36–43.38 Mb and SLC19A3.1 – 43.411–43.419 Mb) on chromosome 25. Expression analysis in a normal dog revealed that one of the paralogs, SLC19A3.1, was expressed in the brain and spinal cord while the other was not. Subsequent exon sequencing of SLC19A3.1 revealed a 4bp insertion and SNP in the second exon that is predicted to result in a functional protein truncation of 279 amino acids (c.624 insTTGC, c.625 C>A). All dogs with AHE were homozygous for this mutation, 15/41 healthy AH control dogs were heterozygous carriers while 26/41 normal healthy AH dogs were wild type. Furthermore, this mutation was not detected in another 187 dogs of different breeds.
Impact of the study: These results suggest that this mutation in SLC19A3.1, encoding a thiamine transporter protein, plays a critical role in the pathogenesis of AHE.
Publications: Vernau, K., Runstadler, J.A., Brown, E.A., Cameron, J.M., Juson, H.J., Higgins, R.J., Ackerley, C., Sturges, B.K., Dickinson, P.J., Purschner, B., Giulivi, C., Shelton, D., Robinson, B.H., DiMauro, S., Bollen, A.W., & Bannasch, D. (2013). Genome-Wide Association Analysis Identifies a Mutation in the Thiamine Transporter 2 (SLC19A3) Gene Associated with Alaskan Husky Encephalopathy. Public Library of Science One, 8(3): e57195. (DOI:10.1371/journal.pone.0057195)
Genetic Tests: DNA test for Alaskan Husky Encephalopathy
Purpose of Study: We have been evaluating ways to activate the immune system into recognizing that a tumor is foreign and attacking it. The purpose of this study is to determine if injecting this investigational drug (Interleukin-12 plasmid or pIL-12 that is administered using electroporation) prior to surgery will help activate the immune system and help stop the tumor from coming back or spreading. This therapy is under investigation in the United States for treatment of cancer and has not been approved for sale by the US FDA for human or veterinary use.
Purpose of Study: The purpose of this study was to develop better methods to treat advanced cancer, specifically to find ways to activate the immune system to attack cancer.
Purpose of Study: The overall goal of this project was to develop and investigate a novel functional imaging technique for pulmonary function (gas exchange) based on computed tomography (CT) to increase therapeutic gains of lung cancer radiotherapy. Specifically, to develop a physiologically accurate CT-based gas exchange imaging technique. The long-term goal of the study was (1) to reduce pulmonary toxicity of radiotherapy to healthy lung tissue (2) and make the CT gas exchange imaging available for routine use in radiotherapy. There is no radiotherapy included in this study. It was done to gather preliminary data and is funded by the RSNA (Radiological Society of North America).
Purpose of Study: Lymphoma, the most common hematopoietic tumor of dogs, is an aggressive disease. Although studies in dogs with lymphoma have demonstrated the safety and efficacy of Rabacfosadine (VC-007), a limited number of dogs have been treated once every three weeks. Furthermore, anecdotal reports suggest reduction in the incidence and severity of adverse effects when used with concurrent low-dose corticosteroid therapy. For this reason, clinical evaluation of Rabacfosadine (VC-007) given once every 21 days was be performed in dogs with lymphoma.
Purpose of Study: This clinical trial evaluated the safety and effectiveness of rapamycin when given to dogs with osteosarcoma or soft tissue sarcomas. Rapamycin is a drug currently approved for immunosuppression during preparatory and maintenance regimens for organ and bone marrow transplant in human patients. Early work with rapamycin suggests that this agent may also have anti-cancer properties by inhibiting (reducing the effects of) an important pathway in cancer progression known as mTOR. Preclinical studies of rapamycin in mice as well as recent data using analogous drugs in human patients (rapalogs) suggest that mTOR blockade may be effective in the treatment of several cancers, including osteosarcoma and soft tissue sarcoma.
Purpose of Study: This clinical trial assessed the safety and effectiveness of three newly developed chemotherapy agents (indenoisoquinolines) when given to dogs with lymphoma. Although this class of compounds has shown efficacy in a variety of cancers, interest in developing new topoisomerase I inhibitors, indenoisoquinolines, are currently being evaluated in human patients as agents with improved drug stability and measurable blood levels. This study was the first time the indenoisoquinolines are being assessed in dogs with cancer.
Purpose of Study:Spontaneous Chronic Corneal Epithelial Defects (SCCEDs) or indolent ulcers cause ocular discomfort and require multiple procedures to assist in their healing. It is seen more frequently in Boxers in comparison to many other breeds. The purpose of this study was to characterize this disease with advanced imaging techniques and identify the genetic components.
Purpose of Study: Dry eye (keratoconjunctivitis sicca) is a common ocular disease in dogs that leads to discomfort and vision loss. Mesenchymal stem cells (MSCs) have been proven to reduce inflammation and differentiate into a variety of cell types. Since the most common cause of dry eye in dogs is an immune-mediated inflammatory response targeted against tear producing glands, this study was designed to determine if treatment with MSCs will cause local, long term control of tear gland inflammation and dry eye.
Purpose of Study: The purpose of this study is to evaluate ophthalmic imaging equipment and determine if the equipment can provide greater diagnostic capabilities and improve overall animal care and diagnostics.
Purpose of Study: Myopia, or near-sightedness, is an inherited condition in the Labrador retriever, affecting about 15% of the breed. We propose to identify the region of the dog genome associated with myopia in the Labrador retriever. In order to do this, we will collect DNA samples (blood), A-scan, and quantitative noninvasive measurements of the refractive state (where the eye is focused). The entire genome will be evaluated for an association with myopia.
Purpose of Study: The primary purpose of this study was to test two investigational medications to determine if either one, or both, work to potentially decrease signs of pain of osteoarthritis in dogs.
Soft Tissue Surgery
Purpose of Study: Commonly referred to as “bloat”, gastric dilation and volvulus (GDV) is a life-threatening syndrome that occurs when a dog’s stomach becomes distended with air and/or food and rotates. The rotation of the stomach restricts outflow of stomach contents and more importantly causes a reduction in the blood flow to the stomach wall causing death of the tissues. This disease is considered universally fatal if left untreated. Additionally, if the stomach wall is devitalized from lack of blood flow, significant post-operative care may be necessary making this surgery cost prohibitive for many owners and resulting in humane euthanasia. Performing a gastropexy has been shown to virtually eliminate the possibility of a subsequent torsion. Therefore, the goal of this study was to the evaluate if a minimally invasive gastropexy (using a T-fastener) is a viable method of performing gastropexies in dogs predisposed to developing GDV.
Purpose of Study: The objective of this study is to evaluate alternative treatment options, including transnare cryoablation, for patients with nasal tumors. Radiation therapy is still considered the gold standard of treatment for this disease, however clients who do not wish to pursue radiation therapy may be eligible for participation in this study.
IMPORTANT! Because the initial responses during the clinical trial were good and because of continued client interest, Dr. Steffey is continuing to offer this procedure as a treatment option through the U.C. Davis Veterinary Medical Teaching Hospital! Additional information about the procedure can be found on the Transnare Cryoablation: Information for Clients (PDF).
Purpose of Study: The purpose of this study was to evaluate the impact of imaging findings on surgical decision-making in dogs with colonic and rectal disease of any kind (cancer or non-cancer). This part of the body can be a very difficult region examine with current imaging methods, which also do not provide optimal spatial information important if a surgical procedure is needed. In early studies, we have demonstrated the safety and efficacy of the CT pneumocolonography procedure in normal dogs, but it is important that we learn to accurately interpret the imaging findings for a wide variety of disease processes in clinical patients so that our CT diagnoses are accurate. Our goal was to compare the imaging findings obtained with CT pneumocolonography with the current standard of care of colonoscopy and colonoscopic biopsies.