Introduction: The onset of weakness in dogs may be slow or sudden. Either scenario requires attention; however, sudden, unexpected weakness generally represents a more immediate emergency.

Chronic (slowly progressive) Weakness:
Slowly progressive weakness often begins imperceptibly at first and worsens to a noticeable state over days to months. Weakness alone is a very nonspecific sign of disease, meaning that it does not point a medical professional in any certain direction. The majority of cases exhibiting weakness, however, begin to exhibit other signs of disease. Problems that simultaneously occur with weakness may include changes in behavior, weight, appetite, thirst, defecation, urination, breathing, sleeping, and heart rate. Changes in the color of mucous membranes, and problems with coughing, vomiting, balance, skin or hair coat, can also occur along with weakness. It is highly recommended that the pet owner consider what other abnormalities may be occurring when a pet begins to suffer from chronic weakness.

Acute (sudden) Weakness:
Sudden weakness problems, collapse, and fainting constitute emergency situations. Vital signs should be closely monitored until a medical professional can be contacted. Initiate cardiopulmonary resuscitation (CPR) if the animal stops breathing or the heartbeat stops (see unconsciousness on page E200).

Causative Agents: There are many different reasons for weakness in an animal. The following is a list of the some of the most common:

  1. Hypothyroidism
  2. Severe infection (bacteria, virus, or fungus)
  3. Severe blood loss
  4. Heart problems/disease
  5. Lung disease
  6. Neurologic disease
  7. Seizures
  8. Starvation/Malnourishment
  9. Dehydration (many causes)
  10. Old age
  11. Cancer

Treatment/Prevention: The treatment and prevention for all of the above problems are very specific for that particular disease or condition. Additional information can be found by referring to the specific problem in this manual. Medical attention is advised for any animal experiencing weakness.