Tag Archives: school of veterinary medicine

A vaccine for canine osteosarcoma?

Osteosarcoma is a highly aggressive bone tumor that affects at least 10,000 dogs annually in the United States, alone.

Photo by osteosarcomaindogs.org

Photo by osteosarcomaindogs.org

It is estimated that 90-95 percent of canine osteosarcoma subjects have microscopic metastatic disease (spread of cancer cells to other parts of the body at the time of diagnosis). Standard of care includes removal of the primary tumor—usually by amputation—followed by chemotherapy. Systemic chemotherapy given after amputation delays the development of metastatic disease; however, despite treatment, most dogs die of the disease within one year of diagnosis.

A new option may be available in the future if Dr. Nicola Mason’s research at the University of Pennsylvania School of Veterinary Medicine produces satisfactory results. Mason, an assistant professor of medicine and a Board-certified ACVIM Diplomate in Small Animal Internal Medicine, is evaluating the first vaccine for canine osteosarcoma.

The approach harnesses the power of the dog’s immune system, “training” it to seek out and destroy cancer cells that remain after amputation and chemotherapy.

Over a century ago, an orthopedic surgeon named William Coley recognized that human sarcoma patients with concurrent bacterial infections that caused high fevers had improved overall survival times compared to those sarcoma patients without infection. This led him to develop a therapeutic concoction of live bacteria that he injected into patients with bone sarcomas. He documented improved survival and in some cases, complete remission in individuals with the aggressive disease by using this early form of “immune therapy.”

Mason’s team is employing similar immune therapeutic strategy to treat dogs with osteosarcoma that have undergone the standard of care treatment (amputation and chemotherapy) to prevent metastatic disease. “The concept is that administration of the Listeria-based (genetically modified bacteria) vaccine will activate the patient’s immune system and educate it to recognize cells that express the target molecule,” says Mason.

Dogs are given the live bacterial vaccine intravenously, Mason explains, and it induces a mild transient fever on the day of vaccination. The dogs are usually treated as outpatients and return home the same day. “We have found highly encouraging results when the vaccine is given to patients that have no evidence of metastatic disease at the time of the study enrollment, which is three weeks after the last chemotherapy is administered. Four out of the first five dogs vaccinated are alive at least two years after their initial diagnosis, which is more than twice their expected survival duration. The vaccine has not yet shown any serious short- or long-term side effects, either.”

Mason says the results have led researchers to evaluate whether this vaccine may be able to directly target and kill the bone tumor itself, perhaps eliminating the need for amputation in the future.

Source:  American College of Veterinary Internal Medicine media release

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Behavioural problems in pet store dogs

Dogs purchased from pet stores are more likely to have a range of behavior problems than those purchased from small, non-commercial breeders, says a study by researchers at the Best Friends Animal Society and the University of Pennsylvania School of Veterinary Medicine.

The study was published in the Journal of the American Veterinary Medical Association.

The study involved 413 dogs purchased from pet stores.  Psychological and behavioral characteristics of these dogs were compared to the same characteristics in 5,657 dogs obtained from small-scale, private breeders.  (Most puppies sold in pet stores in the USA are sourced from large-scale, puppy mill type commercial breeders).

Results show that dogs obtained as puppies from pet stores showed significantly more aggression toward human family members, unfamiliar people and other dogs. Dogs purchased from pet stores were almost twice as likely to exhibit aggression directed toward unfamiliar dogs than dogs purchased from small non-commercial breeders.

The pet store dogs also a displayed greater fear of other dogs and typical events in pet dogs’ lives, had more behavior problems when left alone at home, and experienced more problems with house-soiling.  These behaviors in young adult dogs are reasons typically cited by people who surrender their pets to animal shelters.

“The results were so one-sided that in the wide range of behavior problems we included in our analysis, pet store dogs failed in every single case to even obtain one more favorable score than the comparison group of dogs” says Dr Frank McMillan of Best Friends Animal Society.

The research team acknowledges that the exact causes of the behavioral problems observed are not known; until these causes are understood, they recommend avoiding purchasing puppies from pet stores.

Source:  BusinessWire media release

See my related post about the ASPCA’s No Pet Store Puppies initiative

 

 

 

Pain management in dogs with bone cancer

A single injection eased severe, chronic pain caused by late-stage bone cancer in dogs, according to a study in the November issue of Anesthesiology. Dogs with bone cancer that received a neurotoxin injection had significantly more pain relief than those that got standard care without the injection.

“Dogs are part of the family and we do everything we can to relieve them of pain and discomfort when they are sick,” said Dorothy Cimino Brown, D.V.M., School of Veterinary Medicine, University of Pennsylvania, Philadelphia. “In addition to sharing emotional attachments with our dogs, humans share many of the same ailments our pets suffer when fighting cancer. By studying the positive pain relief this treatment afforded dogs, we are hopeful it may also be effective for humans.”

A radiograph of a dog's leg with a cancerous lesion. (Credit: Image courtesy of American Society of Anesthesiologists (ASA))

A radiograph of a dog’s leg with a cancerous lesion. (Credit: Image courtesy of American Society of Anesthesiologists (ASA))

The owners of 70 dogs enrolled their pets in this study. Half the dogs received an injection of a neurotoxin, called substance P-saporin (SP-sap), as well as standard care. The other half (i.e., the control group) received standard care without the neurotoxin injection. The average age of the dogs was between 8 and 9 years and their average weight was 90 pounds.  Multiple breeds participated in the study, including: Rottweilers, Labrador Retrievers, Golden Retrievers and mixed breeds.

The evolution of bone cancer pain in dogs parallels what occurs in humans, with the frequency and intensity of pain increasing over weeks and months. As the cancer advances, both canine and human patients experience life-altering pain, which greatly affects their daily activities and quality of life. The standard treatment for dogs with late-stage bone cancer can include opioids, steroids, and palliative radiation. All of these treatments can have negative side effects.

Within six weeks of beginning the study, 74 percent (26) of the dogs in the control group needed to be “unblinded” (i.e., their status in the study revealed) and their pain relief regimen adjusted compared to 24 percent of the dogs (eight) in the group that received the injection. This was a statistically significant difference.

Other study results included a 6 percent increase in pain severity scores for dogs in the control group, while the dogs in the SP-sap group had no change in pain severity score.  In addition, the dogs in the control group had an 8 percent increase in how pain interferes with their typical activities, while the SP-sap dogs had a 5 percent improvement in this pain impact score. Finally, one dog in the control group responded with improved lameness, while 6 dogs in the SP-sap group became less lame. While these secondary study results were not statistically significant because they were only assessed two weeks after injection, they are promising.

Source:  American Society of Anesthesiologists media release

OCD – dogs and humans are not that different

The structural abnormalities in the brains of dogs suffering from canine compulsive disorder (CCD) are similar to the abnormalities found in humans suffering from obsessive compulsive disorder (OCD) according to new research.

A collaboration between veterinarians at the Cummings School of Veterinary Medicine at Tufts University and researchers at the McLean Imaging Center at McLean Hospital, in Belmont, Massachusetts have published their findings in Progress in Neuro-Psychopharmacology & Biological Psychiatry.

The study involved 16 Doberman Pinschers, 8 with CCD and 8 without.  Dogs with CCD engage in repetitious and destructive behaviors such as flank- and blanket-sucking, tail chasing, and chewing,  whereas people with OCD tend to have repetitious behaviors that interfere with their daily life.

Here’s a video of a German Shepherd with CCD engaging in a circling behavior:

“While the study sample was small and further research is needed, the results further validate that dogs with CCD can provide insight and understanding into anxiety disorders that affect people.  Dogs exhibit the same behavioral characteristics, respond to the same medication, have a genetic basis to the disorder, and we now know have the same structural brain abnormalities as people with OCD,” said Nicholas Dodman, BVMS, DACVB, professor of clinical sciences at the Cummings School of Veterinary Medicine at Tufts University.

It should be noted that the research also provides insight into dog behavior and management.  In some cases, a dog labelled as ‘bad’ or ‘destructive’ may actually have a biological basis for their problems.

Source:  TuftsNow media release