Cardiac Evaluation of the Canine Athlete


A healthy heart is essential to successful performance for any athlete and this is certainly true of canine competitors. Heart disease in dogs may be present since birth (congenital conditions) or may be acquired later in life. Dogs can develop abnormalities of the heart valves or heart muscle, as well as structural deformities. Clinical signs of heart disease in dogs include exercise intolerance, fatigue, shortness of breath, fainting, discoloration of the gums, coughing and restlessness, particularly at night. Upon physical examination, a veterinarian may detect abnormalities such as a heart murmur, an abnormal heart rhythm, or a rapid or slow heart rate. If heart disease is suspected, a consultation with a veterinary cardiologist is strongly recommended in order to further define the extent of the problem. This is particularly important with working dogs and those that are actively involved in competition. A thorough cardiac evaluation is also recommended for young dogs that are about to enter into competition for the first time.

Cardiac evaluation begins with a complete physical examination and auscultation of the heart with a stethoscope. Further assessment is performed using a series of specialized diagnostic tests. These include thoracic radiographs (chest x-rays), an electrocardiogram (ECG), and an ultrasound examination of the heart, referred to as echocardiography. These tests provide different pieces of information about the overall health of a dog's heart.

Chest x-rays provide direct information regarding the size of the heart and the condition of the lungs. The larger vessels entering and leaving the heart can also be evaluated. In cases of heart failure, fluid accumulation can be detected. When x-rays are repeated over a period of time, they can help judge the effectiveness of treatment.

An electrocardiogram is a test used to record the electrical activity of the heart and to detect abnormal heart rhythms called arrhythmias. The ECG can also provide information regarding enlargement of specific chambers of the heart and the position of the heart in the chest cavity.

Echocardiography is a highly specialized, non-invasive test that allows the veterinary cardiologist to "see" inside the heart using a form of sonogram. An ultrasound probe is placed on the chest and sound waves are used to assess heart structure, chamber size, and heart valves. The ultrasound exam allows for evaluation of functional abnormalities such as weak heart muscle contractions or incompetent heart valves. A specialized test called "color flow Doppler" provides greater detail about the blood flow through the heart. This test is discussed in more detail elsewhere in this issue (see page 5).

When these tests are performed on a canine athlete, they provide complete information regarding the dog's heart. If no abnormalities are detected, the dog is cleared of any limitations due to cardiac disease. In cases where one or several tests are abnormal, the veterinary cardiologist will interpret the information and formulate a treatment plan.

 

Palladia Treatment

Palladia (toceranib phosphate) tablets

Client Information Sheet

This summary contains important information about Palladia. You should read this information before you start giving your dog Palladia and review it each time the prescription is refilled as there may be new information. This sheet is provided only as a summary and does not take the place of instructions from your veterinarian. Talk with your veterinarian if you do not understand any of this information or if you want to know more about Palladia.

What is Palladia?
Palladia, a tyrosine kinase inhibitor, is a drug used to treat mast cell tumors, a common
form of cancer that affects dogs.

Palladia works in two ways:
    • By killing tumor cells.
    • By cutting off the blood supply to the tumor.

Your veterinarian has decided to include Palladia as a part of your dog’s treatment plan
for mast cell tumor. Other types of treatment, such as surgery, drug treatment and/or
radiation may be included in the plan. Be sure to speak with your veterinarian about all
parts of your dog’s treatment plan.

What do I need to tell my veterinarian about my dog before administering Palladia?
Tell your veterinarian about all other medications your pet is taking, including: prescription drugs; over the counter drugs; heartworm, flea & tick medications; vitamins and supplements, including herbal medications.

Tell your veterinarian if your dog is pregnant, nursing puppies, or is intended for breeding purposes.

How do I give Palladia to my dog?
Palladia should be given to your dog by mouth (orally).

Palladia may be hidden inside a treat; be certain your dog swallows the entire tablet(s).

Follow your veterinarian’s instructions for how much and how often to give Palladia.
See the Handling Instructions section below in order to administer Palladia safely to
your dog.

How will Palladia affect my dog?
Palladia may help shrink your dog’s tumor. Like other cancer treatments, it can be
difficult to predict whether your dog’s tumor will respond to Palladia, and if it does
respond, how long it will remain responsive to Palladia. Regular check ups by your
veterinarian are necessary to determine whether your dog is responding as expected,
and to decide whether your dog should continue to receive Palladia.


What are some possible side effects of Palladia?
Like all drugs, Palladia may cause side effects, even at the prescribed dose. Serious
side effects can occur, with or without warning, and may in some situations result in death.
    • The most common side effects which may occur with Palladia include diarrhea,
    decreased or loss of appetite, lameness, weight loss and blood in the stool.

Stop Palladia immediately and contact your veterinarian if you notice any of the following changes in your dog:
   • Refusal to eat
   • Vomiting or watery stools (diarrhea), especially if more frequent than two times in 24 hours
   • Black tarry stools
   • Bright red blood in vomit or stools
   • Unexplained bruising or bleeding
   • Or if your dog experiences other changes that concern you

There are other side effects which may occur. For a more complete list, ask your veterinarian.

HANDLING INSTRUCTIONS

What do I need to know to handle Palladia safely?
Because Palladia is an anti-cancer drug, extra care must be taken when handling the
tablets, giving the drug to your dog and cleaning up after your dog.

Palladia is not for use in humans.

You should keep Palladia in a secure storage area out of the reach of children. Children should not come in contact with Palladia. Keep children away from feces, urine, or vomit of treated dogs.

If you are pregnant, a nursing mother, or planning to become pregnant and you choose to administer Palladia to your dog, you should be particularly careful and follow the handling procedures described below.

Palladia prevents the formation of new blood vessels in tumors. In a similar manner Palladia may affect blood vessel formation in the developing fetus and may harm an unborn baby (cause birth defects). For pregnant women, accidental ingestion of Palladia ay have adverse effects on pregnancy.

If Palladia is accidentally ingested by you or a family member, seek medical advice immediately. It is important to show the treating physician a copy of the package insert or label. In cases of accidental human ingestion of Palladia, you may experience gastrointestinal discomfort, including vomiting or diarrhea.

The following handling procedures will help to minimize exposure to the active ingredient in Palladia for you and other members of your household:

Anyone who administers Palladia to your dog should wash their hands after handling
tablets.

When you or others are handling the tablets:
• Do not split or break the tablets to avoid disrupting the protective film coating.
• Palladia tablets should be administered to your dog immediately after they are removed from the bottle.
• Protective gloves should be worn if handling broken or moistened tablets. If your dog spits out the Palladia tablet, the tablet will be moistened and should be handled with protective gloves.
• If the Palladia tablet is “hidden” in food, make sure that your dog has eaten the entire dose. This will minimize the potential for exposure to children or other household members.

Cleaning up after your dog:
• Because Palladia is present in the stool, urine and vomit of dogs under treatment, you must wear protective gloves to clean up after your treated dog.
• While your dog receives Palladia, place the stool, feces or vomit, and any disposable towels used to clean up in a plastic bag which should be sealed for general household disposal. This will minimize the potential for exposure to people in contact with the trash.
• You should not wash any items soiled with stool, urine or vomit from your dog with other laundry.

This client information sheet gives the most important information about Palladia. For more information about Palladia, talk with your veterinarian.

To report a suspected adverse reaction call Pfizer Animal Health at 1-800-366-5288.

Made in Italy
Distributed by Pharmacia & Upjohn Company
Division of Pfizer Inc, New York, NY 10017
Issued March 31, 2009

Nasal Cavity Cancer

Cancer of the Nasal Cavity

  • Common symptoms include nasal discharge, nose bleeds, “snorting”, or facial deformity.

  • Radiation therapy is the current standard of care for nasal tumors.

  • Median survival time after full course of radiation treatment ranges from 8 to 19.7 months.

  • Median survival time with surgery alone ranges from 3 to 6 months.

Nasal cavity tumors:

The nasal cavity is a large air-filled space above and behind the nose. Paranasal sinuses are air-filled spaces that communicate with the nasal cavity. The most common type of cancers affecting this region are carcinomas and sarcomas, both of which are locally destructive. Carcinomas form in the lining of the nose and include adenocarcinomas, squamous cell carcinoma and undifferentiated carcinoma subtypes. Sarcomas form in the cartilage, bone or connective tissue within the nose. Although less frequent, other tumor types have been reported in the nasal cavity including melanoma or mast cell tumors. The metastatic rate (spread to other organs) is considered low at the time of diagnosis but can be as high as 50% at the time of death. The most common organs to which the tumors spread are the lymph nodes and the lungs, but can also include other sites like bone, kidneys, liver, skin, or the brain.

Symptoms of nasal cavity tumors in dogs:

The average duration of symptoms before diagnosis is 3 months and include bleeding from the nose, nasal discharge, facial deformity from bone erosion and tumor growth, sneezing, difficulty breathing, or eye discharge due to tumor obstruction of the ducts. Nasal bleeding or discharge will often occur in one nostril but may affect both sides over time. Some of these symptoms overlap with other medical conditions such as fungal infection, foreign body, or inflammation but as the tumor grows, signs such as facial deformity, swelling or eye protrusion may be observed. In cases where the nasal tumor is close to the brain, the dog may suffer from seizures or behavior changes.

Diagnosis of nasal cavity tumors:

To confirm a diagnosis of nasal tumors, the veterinarian will typically perform a physical exam, imaging and biopsy. Advanced imaging techniques such as CT scan and MRI are superior tools for evaluating the extent of tumors in the nasal cavity as well as for planning radiation therapy treatment. In order to definitively confirm the presence of a nasal tumor, a tissue biopsy should be obtained. This can usually be completed with a small fiberoptic instrument in a procedure called a rhinoscopy. Once diagnosis is confirmed as cancer, it is usually recommended to stage the disease (determining how extensive it is) so that an appropriate treatment plan can be developed by the veterinary oncologist. Staging of nasal tumors usually includes lymph node aspiration (to determine whether the tumor spread to the nearby lymph nodes), chest radiographs (to determine whether the tumor spread to the lungs) and blood tests/urinalysis (to determine the overall health of the pet and if the pet is well enough to undergo treatment).

Does cancer cause pain in dogs?

Pain is common in pets with cancer, with some tumors causing more pain than others. In addition to pain caused by the actual tumors, pets will also experience pain associated with cancer treatments such as surgery, radiation therapy or chemotherapy. Untreated pain decreases the pet’s quality of life, and prolongs recovery from the illness, treatment or injury. It is, therefore, essential that veterinary teams taking care of pets with cancer should also play a vital role in educating pet owners about recognizing and managing pain in their pets. The best way to manage cancer pain in pets is to prevent it, a term referred to as preemptive pain management. This strategy anticipates pain ahead of time and administers pain medication before the pet actually experiences pain, thus ensuring the pet’s maximum comfort.

Treatment options for nasal cavity tumors:

Because nasal cancer begins to invade the bone early, surgery (called rhinotomy) alone is not sufficient to control the cancer and is not usually recommended. Radiation therapy directly to the affected area is currently the treatment of choice for nasal tumors and has been shown to improve survival times. The advantage of radiation therapy is that it treats the entire nasal cavity together with the affected bone and has shown the greatest improvement in survival. At this time, it is uncertain whether surgical removal of the tumor prior to radiation therapy provides even better benefit to the patient. The radiation therapy is typically delivered in 10 to 18 treatment sessions over the course of 2 to 4 weeks, thus requiring commitment from the pet owners to complete the course of radiation treatment. More recent protocols involving one treatment per week for 3 weeks has demonstrated efficacy as well. It has been shown that megavoltage radiation therapy results in better survival compared to cobalt radiation therapy. The use of CT imaging prior to initiating radiation therapy can be of tremendous help for effectively directing radiation only toward the affected area while sparing normal healthy tissue. It should be emphasized that radiation therapy is remarkably well-tolerated in animals and usually can reduce or resolve disease symptoms in a short period of time.

For pets unable to undergo radiation therapy, chemotherapy is an option, but one with limited efficacy that does not improve overall survival times. If the tumor is small and did not invade surrounding tissues, surgical removal may be an option; however, very few dogs meet this criteria at the time of diagnosis. As mentioned above, surgical removal of large and/or invasive tumors does not provide any substantial benefit.

 

What are the side effects of radiation therapy?

Unfortunately, radiation therapy will affect some normal tissues that cannot be excluded from the radiation field (the area scheduled for irradiation). The amount of damage will depend on the daily dose of radiation, total radiation and how much of the tissue is being treated. Immediate side effects of radiation therapy usually include inflammation of the oral cavity (mouth), inflammation of the nasal cavity, shedding of the skin, and eye dryness. It is very important to prevent any additional damage to the area caused by the pet’s pawing or licking so Elizabethan collars should be used as needed. The majority of animals tolerate this therapy surprisingly well.

Prognosis for dogs with nasal cavity tumors:

One study of 139 dogs showed that without treatment, the average survival time is 95 days. Another study showed that dogs that underwent surgery alone had a median survival of 3 to 6 months, which is comparable to that reported for no treatment. Prognosis of dogs who show symptoms of nasal bleeding appears to be worse (medial survival of 88 days) compared to those without it (medial survival of 224 days). The median survival time after a full course of radiation treatment alone ranges from 8 to 19.7 months and 43 to 60% of dogs are alive 1 year after radiation and 11 to 44% are alive 2 years after radiation. The use of CT imaging to plan radiation treatment can increase the survival range to 11 to 19.7 months. Although radiation therapy alone is able to provide local control of nasal tumors for approximately 10 months, and thus prolong the patients’ overall survival, most dogs will eventually die or are humanely euthanized as a result of local disease progression.

 

Several characteristics are associated with poorer outcomes (shorter survival) in dogs with nasal tumors such as the patient being over 10 years old, having a tumor-induced facial deformity, presence of lymph node or other organ metastasis, or lack of resolution of clinical signs after radiation therapy.