Dog Diseases

According to a 2006 study by Veterinary Pet Insurance Co., the top ten canine medical conditions for which their policy holders filed claims were:

1. Skin allergies
2. Ear infections
3. Stomach upsets
4. Bladder infections
5. Benign tumors. Osteoarthritis
7. Sprains
8. Eye infections
9. Enteritis (diarrhea)
10. Hypothyroidism
You will also find all of those common canine health problems here— covered completely and comprehensively. And, whatever troubles your dog, you will find it described clearly and have a variety of treatment options to discuss with your veterinarian.

Infectious diseases are caused by bacteria, viruses, protozoa, fungi, and rick- ettsia that invade the body of a susceptible host and cause an illness. They are transmitted from one animal to another by contact with infected urine, feces, and other bodily secretions, or by inhaling pathogen-laden droplets. They may also be acquired by contact with spores in the soil that enter the body through the respiratory tract or a break in the skin. A few are sexually transmitted. Although pathogens exist everywhere in the environment, only a few cause infection. Fewer still are contagious. Many infectious diseases are species- specific. For example, a dog cannot catch a disease that is specific to a horse, and vice versa. Other infectious diseases are not species-specific, and are capa- ble of causing disease in many animals, including humans. In instances where a disease is zoonotic, public health considerations are discussed. Many infectious agents are able to survive for long periods outside the host animal. This knowledge is important in determining how to contain the spread of infection. For many diseases, the best way to prevent them is by vaccination. Immunity and vaccinations are discussed at the end of this chapter. Bacterial Diseases Bacteria are single-celled microorganisms that are noted for their ability to cause disease.
A tumor is any sort of lump, bump, growth, or swelling. Tumors that are true cancers are called neoplasms. Tumors can be divided into two broad cate- gories: benign and malignant. Benign tumors grow slowly, don't invade or destroy neighboring tissue, and don't spread to other parts of the body. These cancers aren't usually life-threatening. They are cured by surgical removal, provided that the entire tumor can be removed. Malignant tumors are poten- tially life-threatening cancers, and are also called carcinomas, sarcomas, or lymphomas, depending on the tissue where they originated. Cancers invade neighboring tissue and continue to grow in an unrestricted way. At some point, malignant cells part from the primary tumor and enter the lymphatic system or the circulatory system, and establish new colonies in other areas. This process is called metastasizing. Any new growth on your dog should be examined by a veterinarian. The majority of cancers in dogs are detected by physical examination. About half are visible as growths or sores on or beneath the skin. Perianal tumors, testic- ular tumors, mammary gland tumors, lymph gland tumors, and cancers in the mouth can be detected by inspection and palpation. Bone tumors can be rec- ognized by a swollen limb, lameness, or the appearance of a swelling that involves the bone. Internal cancers are most common in the spleen, liver, and gastrointestinal tract. Cancers in these areas often become advanced before they are even sus- pected. Usually the first signs are weight loss, a palpable mass in the abdomen, vomiting, diarrhea, constipation, or gastrointestinal bleeding. (The signs and symptoms of common tumors affecting the internal organs are discussed in the chapters dealing with these organs.) Lung cancer is rare in dogs. However, dogs are at risk from secondhand smoke. The lungs are also a frequent site for metastases. The same is true of the liver.