Oral Tumors in Pets

Tumors in the mouth are common in dogs and cats, but may not be initially obvious to the owner. Tumors are classified as benign or malignant. There are also other causes of swelling of tissues in the mouth – gingival hyperplasia (generalized overgrowth of the gum tissue) is common in dogs and occasionally cats, and is not a tumor. Other non-tumorous causes of

swelling of oral tissues include local infection or collection of saliva from a damaged salivary gland. Benign tumors do not spread to other parts of the body, and generally grow more slowly than malignant tumors. Malignant tumors (cancer) invade the tissues adjacent to the tumor and may spread to other parts of the body. Sometimes even aggressive treatment is not successful.


 
Fig 1. Malignant oral tumor.                            Fig 2. Benign oral tumor.

While the visual appearance of an oral growth (its surface color and texture, the contour of the tumor and its size and location) can often give clues as to its identity, confirmation of the diagnosis (and thus an accurate prognosis and identification of appropriate treatment) requires biopsy. All oral growths should be investigated. A “wait and see” approach is not satisfactory.
Biopsy may be incisional (taking a small portion for microscopic examination, with no attempt to remove all of the swelling) or excisional (surgery to remove the tumor completely). The biopsied tissue is sent to a pathologist. If the veterinarian feels an abnormality of one of the lymph nodes in the neck, biopsy or needle aspiration of the abnormal lymph node may be recommended.
For most oral tumors (benign and malignant), surgical removal offers the best chance of cure. Surgery may need to be radical (removal of part or all of a jaw, including teeth and bone, for example). Though dogs tolerate radical surgery very well, cats may take a little longer than dogs to recover full function. 
Because there are so many types of oral tumors that can occur in dogs and cats, each with a different prognosis, management by an AVDC veterinary dental specialist or oncologist is recommended. Your regular veterinarian may take a biopsy and then refer the case to a specialist.
What can pet owners do to be pro-active about oral tumors? The key is early detection of the growth. Owners that are in the (highly recommended!) habit of brushing their pet’s teeth every day are likely to note changes in the mouth earlier. For owners not brushing daily, a weekly oral inspection by the owner is recommended, in addition to regular examination by your veterinarian. When a swelling in the mouth is noted, seek the services of your veterinarian or a veterinary dentist without delay.

Feline Dental Disease

As in dogs, periodontal disease is very common in cats. In addition, there are oral conditions that are more common in cats than in dogs.

Fig 1.  Periodontal disease surrounding teeth of a cat.
The most common is tooth resorption.


Fig 2. Tooth resorption affecting the maxillary canine tooth in a cat.


Fig 3. Tooth resorption affecting a mandibular premolar tooth in a cat.

Tooth Resorption

Feline tooth resorption typically originates in the cementum, may progress into root dentin, and then either progress through the root, into the crown, or both. Tooth resorption that can be identified on oral examination is an indication for radiographic evaluation and treatment. Intraoral radiography is required to properly evaluate this condition. Whole-mouth radiographs are recommended to evaluate other teeth in the mouth. Complete extraction is the treatment of choice for teeth that have detectable crown resorption but no radiographic evidence of root resorption. Teeth with crown resorption but radiographic signs of advanced root resorption (and no concurrent periodontal disease, periapical periodontitis or stomatitis) may be treated by subgingival amputation.  Either form of treatment should be followed by gingival closure. If there is radiographic evidence of root resorption, but no clinical resorption can be detected on oral examination, the tooth can be "monitored" or preemptively extracted.
Restoration of these teeth is not recommended. Semiannual dental examinations are recommended for all cats with previous diagnosis of tooth resorption.  Radiography should be repeated annually or more frequently as dictated by the oral examination.

Feline Stomatitis
Stomatitis is severe inflammation or ulceration of the oral epithelium, and is a debilitating disease for affected cats. Foul breath, difficulty in eating and drooling are typical clinical signs. Typically the lesions are symmetrical, and some patients have large areas of their oral cavity covered with painful, raw areas. This condition requires aggressive treatment.
Although occasional cats respond to medical treatment and meticulous oral hygiene (though this is not well tolerated by a cat with a painful mouth), for most cats, extraction of most or all of the teeth provides the best likelihood of relief. Cats that do not respond completely to extraction of all teeth can often be managed by medical treatment as needed.


Fig 4. Caudal stomatitis in a cat.

 
Fig 5. Alveolar mucositis in a cat, prior to extraction of teeth.

 
Fig 6. Following extraction of all teeth, the inflammation resolved.


Fractured Canine Teeth in Cats

Fig 1. Complicated canine tooth fracture in a cat.
The canine teeth (fangs) of cats often have fractures of the tip of the tooth. Since the pulp chamber extends very close to the tip of the tooth in cats, even small fractures can expose the sensitive pulp tissue. This inevitably leads to infection and death of the pulp tissue (endodontic disease). Any fractured canine tooth in a cat, regardless of the extent of the fracture, should be inspected closely and radiographed under sedation or anesthesia to determine whether the pulp tissue is exposed. Depending on the results of radiographic and clinical examination, the tooth can be treated with root canal therapy or extracted.

Crowns in Veterinary Patients

In human dentistry, a “crown” (a metal or metal-covered-by-ceramic covering, cemented to the crown of a damaged or abnormal tooth) is commonly used to improve the appearance of abnormal teeth and to restore function and strength to a tooth that has been damaged.

A crown is rarely medically necessary in veterinary patients, except when function is essential, as in working dogs (e.g. military, police or security dogs), although a crown may reduce the risk of failure of a restoration and recurrence of endodontic disease. Placing a crown requires an additional anesthetic episode for cementation of the crown following completion of endodontic (root canal) treatment and preparation of the tooth; this involves additional expense.


Fig 1. Metallic crown placed to help protect the tooth treated by root canal therapy. 
 

Fig 2. Tooth-colored ceramic crown on a mandibular canine tooth.

The most common crown materials for veterinary patients are cast metal alloys. They provide superior strength and require the least removal of tooth material when preparing the tooth for the crown, compared with a ceramic-covered (tooth-colored) crowns.

Information for Owners

Good oral health is an important part of good general health for your pet.

Signs of oral and dental diseases in dogs and cats:
- Bad breath.
- Loose teeth or teeth that are discolored or covered in tartar.
- Your pet shies away from you when you touch the mouth area.
- Drooling or dropping food from the mouth.
- Bleeding from the mouth.
- Loss of appetite or loss of weight (this combination can result from diseases of many organs, and early veterinary examination is important).
If you think your pet needs dental care, the College recommends that you make an appointment with your veterinarian, who will recommend a referral to an AVDC diplomate if indicated, or you may contact an AVDC Veterinary Dentist directly. Please note that the AVDC does not respond to enquiries about individual patients.

Plaque and Tartar Control

Prevention of the most common oral disease in pets (and in people!) consists of frequent removal of the dental plaque and tartar that forms on teeth that are not kept clean. The Veterinary Oral Health Council (VOHC®) awards its Seal of Acceptance to products that successfully meet pre-set criteria for effectiveness in controlling plaque and tartar deposition in dogs and cats. The VOHC is an entity of the American Veterinary Dental College. If you would like information on products that will help control deposition of dental plaque and tartar on the teeth of your pet, click Veterinary Oral Health Council.

National Pet Dental Health Campaign!

AVDC is proud to partner with the American Veterinary Dental Society, the Academy of Veterinary Dentistry, the American Veterinary Medical Association, Hill's Pet Nutrition, Inc. and the Veterinary Oral Health Council, in sponsoring activities that will help to increase understanding of the importance of oral health for our pets. For information, click National Pet Dental Health Campaign

Bite relationships in cats

This bite is right!
There are characteristics of normal occlusion in cats.  It is most important for the occlusion to be functional and comfortable.



Front view of a comfortable bite.  Dr.
Kressin was holding this cat and the
right upper canine became hidden by
the lower lip.  Note the position of the
upper and lower incisors and the
relationship between the canine teeth.



Right side view. Note the interdigitation
of the premolar teeth.



Left side view.

Dr. Kressin recommends that owners and their veterinarians routinely examine their cat's mouths during the developmental period and throughout life.  Make it a habit to brush your cat's teeth as you do your own!  Notice the relationship of the upper and lower jaws and how the teeth align.  This is called the bite evaluation or the occlusal evaluation.  Malocclusion is an abnormal occlusion (abnormal bite).

Does your cat have the normal number of teeth?  You can view a dental chart we use for cats and read additional information about bite evaluation.  Sometimes extra teeth or supernumerary teeth can result in abnormal bite relationships.  Supernumerary teeth may contribute to tooth crowding and to the development of periodontal disease.  Occasionally, teeth grinding may result from supernumerary teeth.

Is the bite right and does it matter?

The bite is absolutely important.  Our goal is to make the bite right and confortable for pets!

The occurance of malocclusions in cats is less common than in dogs; however, they do occur.  The resulting malocclusion may be minor and functional or major malocclusions can result in traumatic bites to the cat's oral tissues.  The trauma from teeth hitting teeth or teeth hitting soft tissue can be uncomfortable or even result in other problems.  When the bite is not right, teeth crowding or gingival trauma may contribute to the development of periodontal disease.

This bite is not right!



Harry Potter; wry bite.  Both lower mandibles (jaws)
are shorter than normal.  The left lower mandible
is shorter than right mandible.  The lower right
secondary (adult) canine strikes the palate (roof
of the mouth).  The left lower canine has not
erupted completely.  This traumatic occlusion can
result in a hole in the palate.

Harry Potter's owners and veterinarian noticed the problem developing.  Surgical extraction of the primary (baby) canines helps avoid the interlock between upper and lower teeth.  This allows (but does not guarantee) for normal jaw growth.  The interlock prevents normal jaw growth and development.

This bight is not right.


Both mandibles are longer than normal
resulting in a traumatic malocclusion.



The left upper canine interferes with the
left lower canine.  The lower canine is
malpositioned as a result of the trauma.

         

A traumatic malocclusion.                          Alternate view.



Alternate view of the lower canine
teeth striking the upper lip.  There is
a disparity in jaw length.  The upper
jaws are relatively shorter than the lower
jaws.  The lower canines traumatize
the upper lip!

         

Disparity of jaw length.                            The mandibles appear longer than the maxillas.

         

Oral mass developed secondary to                       Alternate view.
the traumatic occlusion.

Open mouth jaw locking is an emergency.  Dr. Kressin has seen this occur from super-eruption of the upper canine teeth in cats.  It is usually associated with chronic periodontal disease and alveolar osteitis.  The upper canine tooth and the lower canine tooth came into occlusal contact and the cat was unable to close the mouth.

Open mouth jaw locking may also be due to TMJ dysplasia, TMJ luxation or the entrapment of the mandibular coronoid process with the zygomatic arch.  Dental radiography or computed tomography can be very helpful in evaluation of the TMJ.  This is not a common condition in cats but has been reported in the oriental breeds.

A dental consultation is recommended if there are persistent primary teeth, dental interlock or a traumatic malocclusion

Brush my Dog's WHAT?

Proper position of toothbrush against tooth

What would happen if you stopped brushing your own teeth? Even if you only ate hard food as most dogs do, there still would be problems. You should be brushing your dog's teeth at least twice weekly, daily if you can manage it. It's not as difficult as you might imagine.
What are the benefits? Brushing removes the daily accumulation of plaque from the teeth. Even though dogs do not commonly get cavities, they do suffer from periodontal disease. If untreated the gum disease can lead to pain and loss of teeth.

Dental technician brushing dog's teeth

How to brush teeth? Step one is to pick an appropriate pet toothbrush. Save yourself time by not buying a child's toothbrush which is usually too hard for dogs. The ideal dog toothbrush will have a long handle, an angled head to better fit the mouth and extra soft bristles. Another option is the finger toothbrush that fits over the tip of your finger.
Step two is to select an appropriate toothpaste. The best pet toothpastes contain enzymes that help control plaque. Try to avoid toothpastes with baking soda, detergents, or salt sometimes found in human pastes. Fluoride may be incorporated to help control bacteria. Rather than placing the paste on top of the brush try to place it between the bristles. This allows the paste to spend the most time next to the teeth.
Step three is to get the brush with paste into your dog's mouth and all the teeth brushed. Most pets accept brushing if they are approached in a gentle manner. If you can start when they are young, it's quite easy, but even older pets will accept the process. Start slowly, you can use a washcloth or piece of gauze to wipe the teeth, front and back in the same manner you will eventually be using the toothbrush. Do this twice daily for about two weeks and your dog or cat should be familiar with the approach. Then take the pet toothbrush, soak it in warm water and start brushing daily for several days. When your pet accepts this brushing, add the toothpaste.
The toothbrush bristles should be placed at the gum margin where the teeth and gums meet at a 45 degree angle. The movement should be in an oval pattern. Be sure to gently force the bristle ends into the area around the base of the tooth as well as into the space between the teeth. Ten short back-and-forth motions should be completed, then the brush should be moved to a new location. Cover three to four teeth at a time. Most attention should concentrated on the outside of the upper teeth.
In summary, small animal home care should include daily (or at least every other day) brushing, using an enzymatic pet toothpaste. Taking an active role in the care of your dog's dental care will help reduce dental disease, bad breath and potential life threatening heart and kidney disease. Everyone wins.

Dental Anatomy

Incisors -- Dog There are four types of teeth in small animals: incisor, canine, premolar, and molar. Nature designed each to serve a special function. Incisors are named first, second and third; or central, intermediate, and lateral, based on their location in the mouth. There should be six incisors in the maxilla (upper jaw) and six in the mandible (lower jaw). Incisor teeth are used for shearing and grooming. Normally, the lower canine should intersect the upper lateral incisor and upper canine There are two large canine teeth located in the mandible and two in the maxilla. The canines are designed to grasp and tear with great pressure. Premolar teeth have sharp edges used for shearing. In the dog, there are four premolar teeth on either side of the upper and lower jaws. Dogs have four molars in the upper jaw and six in the lower. Molars have a flat surface used for grinding. Normal interdigitation of premolars Lower first and second molars effected with periodontal disease Lower canine, third and fourth premolars, and molar in a cat The cat has three premolars on each side of the upper jaw identified as second, third, and fourth; and two lower premolars on each side of the lower jaw, called third and fourth. Cats have one upper and lower molar on each side. The primary or deciduous incisors erupt at one to three weeks of age while the primary canines erupt at three to four weeks. The remaining temporary premolars and molars should emerge by ten weeks. The first premolar and all the molars erupt only as adult teeth. The remaining premolars, canines, and incisors appear in the oral cavity first as primary (temporary, deciduous, or baby) teeth. Secondary (adult) teeth usually appear at four months. Adult incisors appear first followed by canines, premolars, and molars. The complete adult dentition should be present in most breeds by eight months of age. Upper third and fourth feline premolars A tooth is composed of a portion above the gum line called crown and a section below the gum line called the root. Enamel, the hardest mineralized tissue found in the body, covers the crown. Cementum, which is attached to the periodontal ligament, covers the root. Dentin, softer than enamel, makes up the bulk of the tooth. Inside, the pulp is composed of live tissue, that contains nerves, blood vessels and lymphatics.