Signs of Disease in Dogs

Vancouver Vets: How to recognize first signs of disease in dogs in the early stages of illness.

People suffering from disease will recognize in themselves any changes from the normal state and report them as symptoms.  In veterinary medicine the term clinical signs is used instead of symptoms, to indicate that what is being reported is based on observation of the patient by someone else (often the owner), and not on a direct report from the patient.

The dog owner recognized disease as a change in the dog’s normal state.  The more skilled an owner is at recognizing the normal state, the more likely it is that changes from normal state will be detected early in the course of disease.  Skills in recognizing the normal state are gained through experience and study.  Opportunities for gaining such experience include living and working with dogs at home, and in specialized situations in the many activities wherein dogs and people work together.  Many owners gain additional information about the normal state by reading books and articles dealing with dogs, through discussions with other dog owners, especially those who have special interests and experience with dogs, and through discussions with our Vancouver Vet Clinic veterinarian and members of the Vancouver veterinary  clinic staff, especially during visits for routine health care.

Activity level, appetite, water intake, urination and defecation are frequently altered when disease is present.  Normal activity includes greeting, investigating, guarding, playing and sleeping.  Most activity is spontaneous, but some is encouraged by owners, such as going for walks, training or playing. Dogs that are suffering from disease tend to withdraw from their usual activities and to spend more time resting and sleeping.  The more closely the owner lives and works with the dog, the more likely it is that changes in activity level will be recognized.

The body has only a limited number of ways of responding to disease-causing agents: thus the clinical signs of disease are much fewer than are the causes of disease. Clinical signs are useful as an indicator that disease is present, but usually are not specific enough to define the underlying cause of the disease.  At our Vancouver Animal Hospital, the veterinarian will be able to diagnose a condition causing signs of disease. For example, one of the responses to a bacterial infection is fever, but not all fevers are due to bacterial infection.  Other causes of fever include cancer, immune–mediated disease, inflammation, and infectious agents other than bacteria (viruses, fungi, parasites).  Thus, fever is a sign of the disease, or even of the particular body system involved. In other cases, the body system involved is obvious, but the cause of the disease is not.  For example, seizures indicate that the brain is involved, but do not indicate whether there is a primary disease in the brain or whether the brain is simply being affected secondarily by disease in another organ 9such as the liver).  The benefit of recognizing the clinical signs of disease lies in the opportunity to alter the natural course of the illness, either by effecting a cure (if a cure is possible) or by implementing  appropriate therapy to ameliorate the severity of the disease.  On our Vancouver Animal Hospital blog, some of the common clinical signs of disease are described in detail, and their significance in terms of body systems involved ,  as well as some possible causes.