Lung Cancer in Dogs
by Roger Ross DVM
Respiratory Cancer
Primary cancers of the respiratory tract are not too common compared to cancers starting in other organs...BUT...the lungs are a common site of secondary tumors...cancers that have spread from other places in the body. The large majority of cancers that do occur in the respiratory system...the most common type being in the nasal sinus of dogs...are malignant, so anytime a mass is detected within the nasal passages, the larynx, the trachea, or in the thorax, we're usually dealing with a very serious disease.
Nasal Tumors: Male cats are more prone to nasal cancer for unknown reasons, and certain breeds of dogs of both sexes are predisposed: Airdales, Bassetts, Old English Sheep Dogs, Scotties, Collies, Sheperds, Keeshonds, and German Short Haired Pointers. Most of the information for this article, by the way, is from "Saunders Manual of Small Animal Medicine"...a very respected text book. But my experience differs a little in that three of the 7 or so cases of nasal cancer I've seen have been in the Artic Breeds; Malamutes and Siberian Huskies. I only mention this to highlight that any breed can get cancer and if your pet is having trouble with nose bleeds, sinus congestion, facial disfiguration, or just a snotty nose that lasts more than a week, please get your pet to your veterinarian.
Other signs include behavioral changes (possibly from pressure on the Brain), seizures, and blindness. As serious as respiratory tract cancers tend to be, great improvements and success rates have been made in their treatment...especially if detected before excessive destruction and spreading of the cancer occurs. Unfortunately, most respiratory cancers have been growing, on average, for about 3 months before symptoms are obvious. Another reason for regular check ups. By listening closely to lungs, examining the oral and nasal passages, and by the palpation of lymph nodes, your vet is likely to detect trouble in the early stages when treatment is most likely to be curative.
For cancers within the thorax...usually carcinomas of the lungs...the main initial symptom is coughing; usually harsh and non-productive. And this is interesting...a lot of lung tumors are associated with arthritic (hypertrophic osteopathy) disease; so lameness may be a first clue. The trouble with all this is that most lung cancers are in older patients, and in older patients we often expect a little arthritic lameness and a little bit of a cough. It takes vigilance and extra effort to tell the difference...and sometimes it simply requires a more complete diagnostic work-up: Multiple X rays, ultrasound, and blood work. Unlike in Western Human Medicine where all this would be routine with any patient with persistent symptoms, in Veterinary medicine we sometimes have to twist your arm a little to authorize what might very well turn out not to be productive, but is required, nonetheless, if our goal is to detect lung cancer soon enough to help the patient.
For more about cancer in general and about the great strides in treatment improvement and success rates, please check out our page about Cancer
