Dr. Dara L. Kraitchman
Spontaneous Disease Models in Pets with Interventional Applications
(Montag, 16.50 Uhr, Schinkelsaal)
Introduction: In 2012, there were ~72M households with pets in the EU, and ~24% of the European households owning at least one dog or cat with an estimated annual expenditure on pets of €11 billion. Germany lags slightly below these numbers with ~13% households having pet ownership. However, there are more households in Germany with pets than children as is also the case in the USA. Due to the high degree of inbreeding in domestic dogs and cats—especially in pure-bred lines, many diseases that are prevalent in patients occur spontaneously in pets. Unlike transgenic mice where specific genes are knocked in or knocked out to cause disease, the genetic mutations in dogs and cats that leads to naturally occurring diseases is often highly variable or not yet elucidated as in human diseases. However, naturally occurring diseases in pets offers several advantages over purpose bred animals for testing new interventional therapies and devices. In particular, pets with naturally occurring diseases often have many of the underlying co-morbidities seen in human patients, are treated with a variety of medications, and experience varying environments that in turn alter genetic expression of disease. For interventional applications, dogs and cats are sufficiently large enough to enable imaging with clinical imaging equipment and pediatric or adult devices.
Methods and Results: More than 50% of dogs >10 years old will develop malignancies. Five major dog breeds are affected by transitional cell carcinoma (TCC). Interventional applications of intra-arterial (IA) administration of chemotherapeutics and photodynamic therapies and stenting can be tested in this disease model that mirrors TCC in patients. With median survival times of 10 months using current therapies, pet owners often demonstrate a willingness to explore new treatment options and the potential for post-mortem analysis of therapeutic efficacy is also likely. Mammary tumors affect both domestic dogs and cats with the ability to perform loco-regional therapy, such as high frequency ultrasound (HIFU), followed by radical mastectomy, which is the primary therapeutic option available to most pet owners.
Over 50% of the cats and dogs are obese in the US. Type I Diabetes Mellitus (DM) affects 0.5-1% of dogs and Type II DM is prevalent in cats. Dilated cardiomyopathy affects nearly 50% of the Doberman Pinschers in the US. Thromboembolic disease is relatively rare in dogs and cats. But dogs with renal disease, demonstrate a high incidence of stroke and cats with hypertrophic cardiomyopathy secondary to hyperthyroidism tend to develop aortothromboemboli rather than DVTs. Brachiocephalic and chrondrodysplastic dogs breeds, such as Pekingnese and Dachshunds, respectively, have an increased incidence of intervertebral disc disease whereas many large breed dogs, such as German Shepherd Dogs, have an increased incidence of lumbosacral stenosis relative to other breeds. Many of these spontaneously occurring diseases can be used to determine the efficacy of drug and stem cell therapies delivered using minimally invasive delivery techniques.
Summary A brief review of naturally occurring diseases in domestic dogs and cats with potential interventional applications has been presented. By using spontaneous occurring diseases in pets, the opportunity exists to better emulate human disease and design therapies that may be more successful in human clinical trials or practice while also providing new treatments to our companion animals.
Dr. Dara Kraitchman
Professor of Radiology and Radiological Science, Johns Hopkins University School of Medicine