Are the effects of second hand cigarette smoke as harmful to cats and dogs as it is to humans? I have never seen this discussed anywhere.

            This is a variation of one of the most commonly asked questions by pet owners once they are given a diagnosis of cancer in their family pet – how did this happen? Unfortunately, this is a very complicated question and there is rarely a single cause of cancer. Although it is very difficult to establish a clear cause and effect between something like second hand smoke and cancer in pets, the evidence for environmental factors being involved is mounting in veterinary medicine.

            One study revealed only a slight increase in the development of lung cancer in dogs living with a smoker and this risk did not increase with greater second hand smoke exposure. There is actually more evidence linking second hand smoke with other types of cancers in pets. Cats living in a household with a smoker have been shown to have an increased risk of developing both lymphoma and cancer of the mouth (squamous cell carcinoma). Regarding lymphoma, the risk became even greater with increased time and amount of exposure to the smoke. It is suspected that cats are at greater risk of problems from second hand smoke because the smoke settles on their fur which is then ingested during their fastidious grooming habits. This results in ingestion of the carcinogens with high concentrations in the oral cavity.

            Along with these findings in cats, there is concern over environmental factors being linked to cancer in dogs. There is some evidence of a potential increased risk of bladder cancer in dogs that have been exposed to certain types of herbicides and pesticides. There is also a reported increased incidence of lymphoma, cancer of the tonsils, and cancer of the nasal passages in dogs that live in urban areas as opposed to rural settings.

            Despite all of these reports of possible environmental causes of cancer in pets, there have been no definitively proven links. Cancer takes time to develop; often extended periods of exposure to a carcinogen are needed in order for the damage to be done that can ultimately result in cancer. This means that pets may be less affected by these situations compared to humans who can potentially have decades of exposure to second hand smoke and other dangerous substances. However, it does make sense for pet owners to take any precautions possible to try to limit their four-legged family members’ exposure to potential carcinogens. This preventative strategy combined with regular examinations by your veterinarian is the best way to try to ensure your pets stay healthy.  

Stephen Brenn, DVM, DACVIM (Oncology)

Dr. Brenn received his DVM degree from the College of Veterinary Medicine at North Carolina State University. He then completed an internship at the New Haven Central Hospital for Veterinary Medicine and remained in Connecticut to live and practice general medicine. He recently completed a three year residency in oncology at the Animal Medical Center in New York City. Dr. Brenn enjoys music, sports, and spending time with his two sons.

Feeding and Exercising the Pregnant Dog 

Q: My three year old female Labrador retriever mated with my neighbor’s dog about four weeks ago.  Her abdomen is getting larger, so I am fairly certain she is pregnant.  What type of food should I feed her and how much?  What restrictions are there on the amount of exercise that she should be allowed?

A:  It is very important that you take her to a veterinary hospital as soon as possible for a complete examination.  The veterinarian will evaluate her individual condition and determine if she is pregnant or if there might be another problem.  The duration of pregnancy (gestation period) in the dog is approximately 63 days.  A pregnant dog will require an increased amount of food mainly during the last half of pregnancy.  Usually, we do not change the type of food that she normally eats providing it is a good balanced commercial dog food.  She should be fed her regular maintenance diet for the first four weeks of pregnancy.  Then, gradually increase the amount of food by twenty to fifty percent over the last five weeks.  A good way to do this is to increase the amount of food by ten percent per week during the last five weeks.  She will be eating about fifty percent more than her normal amount of food when she gives birth (whelping).  It is best not to let her become overweight as this could make the delivery of her puppies more difficult.  Most pregnant dogs will weigh about twenty percent more than their pre-breeding weight at the end of gestation.  This will vary depending on the size of the litter.  Labrador retrievers often have seven or eight puppies.  During milk production (lactation) and nursing, the new mother will need to eat up to two to three times as much food.  The demand on her body is the greatest in the first four weeks of nursing.  It is best to increase the amount of food by increasing the number of feedings to three or four times a day.  Some veterinarians recommend adding a puppy or growth formula type diet to the regular diet during the nursing period.  This must be done gradually as many dogs will get diarrhea if their diet is changed too abruptly.  In most cases, the regular food is adequate as long as the amount is increased.  A general vitamin and mineral supplement may be given daily. 

The expectant mother should be given regular periods of controlled moderate exercise to promote good muscle strength and general condition.  Frequent walks on a leash for fifteen to twenty minutes would be a good exercise for her.  Prolonged strenuous exercise such as running to chase a ball and leaping in the air should be avoided.  Pregnancy and whelping in the dog is an enjoyable experience for a pet owner.  However, complications can occur.  If you have any questions or problems, consult with your veterinarian.

William Lucker, DVM

Dr. Lucker graduated from the University Of Pennsylvania School Of Veterinary Medicine in 1966. He completed a fourteen month internship in small animal medicine and surgery at the Henry Bergh Memorial Hospital of the ASPCA in New York City. He remained there another year as a resident staff veterinarian. After practicing in the Morristown area for three years, Dr. Lucker joined the staff of Oradell Animal Hospital in 1971. Dr. Lucker is a general practitioner with special interests in cardiology and obstetrics. He has received numerous continuing education certificates from the New Jersey Veterinary Medical Association. He sees appointments at Oradell Animal Hospital as well as our Hasbrouck Heights office. Dr. Lucker enjoys fishing, skiing and photography.

Oradell Animal Hospital, located in Paramus, NJ, has graciously donated lifetime veterinary care for K.D. Lang, the service dog obtained for 9 year old Danny Garofalo who has Duchene’s Muscular Dystrophy and is wheelchair dependent. 

Danny received K.D. thanks to the combined efforts of the Mickey’s Kids Foundation, a charity run by Hasbrouck Heights residents Tom and Michelle Meli who raised the money for K.D. to come to New Jersey.  They work with Canine Assistants, a Georgia-based charity that breeds, trains and places service dogs across the country.

How does K.D. help Danny? On a daily basis K.D. performs tasks that range from retrieving his shoes and clothes, to opening cabinets and doors to even making his bed.

Mickey’s Kids is having a fundraiser event scheduled for March 16, 2012.  For more information and photos on Mickeys Kids Foundation, please visit their Facebook page at “Mickeys Kids Charitable Foundation”.

February is National Pet Dental Health Month. Some studies claim that only 1 in 10 pet owners properly look after their pets’ teeth, leading to an even more startling statistic: 80% of dogs and 70% of cats have periodontal disease by the age of 3. In hopes of educating Fort Lee pet owners on the importance of proper dental care, Patch interviewed Dr. Donna Bucciarelli, DVM, and Fort-Lee Oradell veterinary hospital’s resident dental care expert.

Bailey DB, Rassnick KM, Kristal O, Chretin JD, Balkman CE. Phase I dose escalation of single-agent vinblastine in dogs. Journal of Veterinary Internal Medicine 2008;22:1397-1402.

Background: Vinblastine (VBL) is commonly used in dogs at a dosage of 2.0 mg/m². The minimal toxicity observed at this dosage indicates that higher dosages might be well tolerated.

Hypothesis: The maximum tolerated dosage (MTD) for a single VBL treatment is higher than the previously published dosage of 2.0 mg/m².

Animals: Twenty-three dogs with lymphoma or cutaneous mast cell tumors.

Methods: Dogs received 1 single-agent VBL treatment IV. The starting dosage was 3.0 mg/m², and dosages were increased in increments of 0.5 mg/m² in cohorts of 3 dogs. Hematologic toxicity was assessed with weekly CBCs. Gastrointestinal toxicity was assessed from medical histories from owners. Once the MTD was determined, additional dogs were treated with VBL at that dosage. Dogs whose cancers responded to VBL continued to receive treatments q2–3 weeks.

Results: VBL dosages ranged from 3.0 to 4.0 mg/m². Neutropenia was the dose-limiting toxicity, with the nadir identified 7 days after treatment and resolving by 14 days after treatment. The MTD was 3.5 mg/m². Sixteen dogs were treated at this dosage, and 3 experienced severe toxicity characterized by asymptomatic grade 4 neutropenia, febrile grade 4 neutropenia, and death. Gastrointestinal toxicity was mild and self-limiting. Preliminary evidence of antitumor activity was identified in 2 of 12 dogs with lymphoma treated at the MTD.

Conclusions and Clinical Importance: In dogs, single-agent VBL is well tolerated at a dosage of 3.5 mg/m² IV. At this dosage, the minimum safe treatment interval is q2 weeks, and adjunct treatment with prophylactic antibiotics should be considered.

Key words: Canine; Chemotherapy; Oncology; Oncology treatment.

Rassnick KM, Bailey DB, Flory AB, Balkman CE, Kiselow MA, Intile JL, Autio K. Efficacy of vinblastine for treatment of canine mast cell tumors. Journal of Veterinary Internal Medicine 2008;22:1390-1396.

Background: The optimal dosage and clinical efficacy of vinblastine (VBL) for treatment of mast cell tumors (MCTs) in dogs has not been established.

Hypothesis: Single-agent VBL has antitumor activity against MCTs in dogs.

Animals: Fifty-one dogs with nonresectable grade II or III cutaneous MCTs.

Methods: Prospective, open clinical trial. Dogs were systematically allocated (by hospital record number) to receive IV treatment with VBL at a dosage of 2.0 mg/m² (weekly for 4 treatments then biweekly for 4 treatments; VBL 2.0) or treatment with VBL at a dosage of 3.5 mg/m² (biweekly for 5 treatments; VBL 3.5). The primary outcome measure was reduction in tumor size.

Results: Twenty-five dogs were allocated to the VBL 2.0 group and 26 were allocated to the VBL 3.5 group. In the VBL 2.0 group, 3 (12%) had a partial response (PR) for a median of 77 days (range, 48–229 days). Overall response rate in the VBL 3.5 group was 27%. One dog (4%) had a complete response for 63 days and 6 dogs (23%) had a PR for a median of 28 days (range, 28–78 days). Toxicoses were uncommon in the VBL 2.0 group. Twelve (46%) dogs in the VBL 3.5 group had < 500 neutrophils/µL 7 days after treatment; 2 dogs with neutropenia developed concurrent fevers.

Conclusions and Clinical Importance: VBL, when used as a single-agent, has activity against MCTs in dogs although the response rate is lower than those reported for VBL-containing combination protocols. Further, findings suggest VBL at a dosage of 3.5 mg/m² should be considered for use in future phase II/III trials.

Key words: Chemotherapy; Dog; Oncology.