The term brachycephalic comes from the Greek words brachy, meaning “short” and cephalic, meaning “head.” Brachycephalic dog breeds have flat faces with shortened muzzles. Unfortunately, the shortened muzzles and snouts often mean that the throat and breathing passages are also undersized or flattened. The term Brachycephalic Obstructive Airway Syndrome, or BOAS, refers to multiple anatomic abnormalities that can lead to breathing difficulties and other health problems for these dogs.
As many as six anatomic abnormalities make up BOAS. Not all dogs have all six abnormalities, but the more a dog has, the greater their clinical signs. The table below lists the medical names for the abnormalities followed by their definition.
Nose holes are too narrow or collapse inward during inhalation
Extended nasopharyngeal turbinates
Air filtering bones inside the nose extend into the back of the throat
Elongated soft palate
Roof of the mouth is too long
Voice box collapses, making air passage difficult
Windpipe is too narrow for the dog’s size
Everted laryngeal saccules
Pouches inside the voice box turn inside out and block airflow
All of these anatomic abnormalities lead to a decrease in air flow in and out of the lungs. The abnormalities associated with BOAS cause affected dogs to easily overheat because they cannot effectively cool themselves through panting. Stress, anesthesia, and exercise are also difficult for these dogs. Finally, dogs with BOAS often have lower blood oxygen levels as compared to non-brachycephalic breeds.
Urethral obstructions occur when the urethra (the tube through which urine exits the body from the bladder) is blocked. These blockages can be caused by plugs (a buildup of protein, cells, or minerals from the bladder), urinary stones, and/or inflammation. While both male and female cats can develop a urethral obstruction, it is most often seen in males because of their longer and narrower urethra.
Urethral obstructions are a life-threatening emergency. If the blockage lasts too long and urine is unable to exit the body, the buildup can damage the kidneys and cause the bladder to rupture.
Like humans, dogs and cats have baby teeth, called deciduous teeth, that are replaced by permanent teeth as the puppy and kitten grow and develop. The deciduous teeth begin to erupt around 2 to 3 weeks of age while the permanent adult teeth erupt between 3 to 7 months in dogs and 3 to 6 months in cats. When puppies and kittens lose their baby teeth, you might notice blood on their gum, lip, or tongue. This is normal. You may or may not find little teeth scattered around on the carpet or floors. If your pet swallows them, they will not cause any problems.
There are four types of teeth found in mammals:
Incisors – incisors sit at the front of the mouth and help the animal cut and grasp food
Canines – canines sit behind the incisors and are used to stab and tear food
Premolars – premolars sit behind the canines and are used to grind food
Molars – molars sit at the back of the mouth and are used to grind food
A tooth is divided into two parts – the crown and the root. The crown is the visible part of the tooth outside of the gum, while the root lies within the gumline and anchors the tooth in the mouth.
Normally, as the permanent tooth begins to develop, it will push against the root of the deciduous tooth. The body will then break down the deciduous tooth root until it can no longer be anchored in the mouth and eventually falls out. In some cases, however, the deciduous teeth remain in the mouth even as the permanent teeth come in. This is called persistent deciduous teeth and requires the surgical removal of the remaining deciduous teeth (see photo below).
While extraction of persistent deciduous teeth can be tricky due to their long roots, it is important to remove the retained teeth as soon you or your veterinarian notices them as they can cause the permanent teeth to become misaligned or displaced in the mouth, leading to future dental problems and an increased risk for periodontal disease. The teeth typically affected are incisors and canines and are usually seen in small, toy breed dogs. The dental x-ray above shows a Maltese with retained incisors and canine teeth. The photo of the extracted teeth below shows the roots that did not dissolve. The third photo shows the puppy’s perfect smile after removal of the retained deciduous teeth.
Dogs and cats have a third eyelid, called the nictitating membrane or nictitans. This shiny, pink membrane is tucked behind the lower eyelid and pops up when a pet is sedated or sick, has a mass behind or under the eye, or has a neurological condition. The nictitans contains a gland that is responsible for tear production. Cherry eye is a condition where the gland within the third eyelid protrudes from its normal position, resulting in a red, swollen mass near the inner eyelid that kind of looks like a little red cherry. It is believed to be caused by weak tissue fibers failing to hold the gland in place. One or both eyes can be affected, and improper treatment of this condition can result in dry eye.
Cancer is not one disease, but hundreds. Cancer can be grouped into three main categories:
Carcinomas – carcinomas are formed by epithelial cells, which are the cells that cover the inside and outside surfaces of the body. Tumors of the anal gland and mammary gland are common carcinomas in dogs and cats.
Hematopoetic tumors – blood cancer, or hematopoetic tumors, include leukemia and lymphoma.
Sarcomas – sarcomas are tumors formed by cells from bone and soft tissues, including muscle, fat, blood vessels, lymph vessels, and fibrous tissue (such as tendons and ligaments). Examples of sarcomas in dogs include soft tissue sarcoma, hemangiosarcoma, and osteosarcoma.
Osteosarcoma is the most common bone tumor in dogs, accounting for 85% of all canine skeletal tumors. While osteosarcoma is also the most common bone tumor in cats, primary bone tumors are relatively uncommon in cats to begin with. Osteosarcoma is also far less aggressive in cats than it is in dogs.
Osteosarcoma typically develops on the limbs (the forelimbs more often than the hindlimbs), but can also occur on the skull, rib cage, and spine. A rare form of osteosarcoma occurs outside the skeleton in the muscles, liver, or spleen. Osteosarcoma is a particularly aggressive tumor in dogs, with 75-90% of patients eventually having the tumor cells metastasize (spread) to other areas, particularly the lungs and other bones. In cats with osteosarcoma, around 40% will metastasize.