The digestive system is prone to infection through bacteria, parasites, viruses and other organisms which can enter the body easily through the mouth. Infections can spread in many ways but they are commonly spread by contamination of food and water or direct contact with the feces. Dogs have a number of intestinal microorganism in the digestive system, as do humans. The purpose of some these microorganisms is to aid the digestion, while other are used to help prevent infection. These microorganisms are beneficial to the system and are present from the time the dog is a few hours old. These microorganism are found in small numbers and if the numbers increase suddenly then it can cause an infection. This can happen if the immune system is weakened, the conditions are unhygienic or there is undue stress. Diagnosis, in this case, is dependent on identifying which organism caused the disease. In order for the organism to be identified, a fecal sample, or more than one fecal sample, will need to be examined in a laboratory.
A common cause of problems in the digestive tract is parasites. There are several types of parasite which can infect and cause disease in the digestive system. Some parasites have a direct life cycle. This means that no other host is needed. The eggs and larvae are expelled in the fecal matter, where they develop to an infective stage and are then ingested by the dog. Other parasites need an intermediate host, for example an insect. The dog can become infected if it ingests the intermediate host or the parasite after it leaves the intermediate host. The extent or a parasitic infection depends on various factors such as the species of the parasite, the age of the animal, the natural resistance of the animal, diet and overall health. Parasites can cause disease or decrease fitness. Some species can also pass to humans. Parasitic infection can be confused with other illnesses. The vet should have a knowledge of the seasonal cycles of parasitic infection and examine the feces for eggs and larvae. Blood tests can show some species of parasite.
Other digestive disorders are not caused by parasites, but can be caused by overeating, a poor diet, injury, chemicals or the ingestion of a foreign object. Enzyme deficiencies, digestive tract damage such as gastric ulcers or a birth defect can also be causes of digestive system disease. Symptoms such as vomiting and diarrhea can be caused by kidney disease, liver disease or adrenal gland disease. It can be difficult to find the cause of disorders such as gastric torsion, which is when the stomach twists, and other diseases as the exact cause of these is uncertain. In cases where the problem is not parasitic or infectious, it is usually only one animal who is afflicted. However diseases related to overeating or the ingestion of poison can affect multiple animals in the same environment.
When determining the treatment for a sick dog, the cause of the problem must be eliminated. It is also important for the animal to be relieved of pain, for any abnormalities to be corrected and for healing to occur. Eliminating the cause can mean administering drug to kill bacteria or parasites. An antidote may need to be administered in the case of poison. Surgery may be necessary to correct any displacement of the organs o any defects. Some cases may require a drug treatment to ease diarrhea or constipation. This is decided on a case by case basis as they may not beneficial in every case. Diarrhea can help the dog eliminate harmful organisms and their toxins and can act as a defense mechanism. Also, the drugs available for this do not give consistent results. However, it is important to replace fluid and electrolytes lost through diarrhea or vomiting as the loss can put the dog at risk or dehydration. It may be necessary to relieve any distention through a stomach tube or surgery. Pain relief may be administered, but a dog who has been given pain medication will need to be carefully monitored. This is because pain medication can mask a worsening condition.
If the disease is infectious, the animal would be treated with a medication to kill the bacteria or parasite. There are no drugs available currently to treat viral diseases. Antibiotics are drugs which can be used to treat bacterial infections. These are usually given orally for several days until signs of marked improvement are exhibited. There is some uncertainty in the usefulness of antibiotics on digestive system disease. If there is an immediate or high risk or septicemia, which is blood poisoning, the the antibiotic can be administered by injection. The vet will decide if antibiotic medication is advisable based on the suspected diagnosis, previous results, whether or not it would be beneficial and the cost of the treatment. Anti-parasitic drug are available in the case of a parasitic infection. The response time to the treatment is quick and most cases only require a single treatment, except in the event of reinfection or severe parasitic damage. This is because the drugs are effective and there is a greater understanding of the life cycles of parasites.
It is better to prevent problems by practicing good hygiene and sanitation. The dog should have adequate space and the space should be cleaned regularly and thoroughly. The diet should be a high quality food stuff. The dog should have access to adequate shelter and housing. This will ensure that the dog does not suffer undue stress.