Protozoa are organisms that consist of a single cell. They can be parasitic or they can be free living. They can, on occasion, cause disease.
Amebiasis In Dogs
Entamoeba histolytica is the amoeba which causes Amebiasis. Amebiasis in dogs causes the large intestine to become inflamed. The inflammation of the large intestine can lead to persistent diarrhea. Amebiasis is common in tropical and subtropical areas of the world and can be prevalent in disaster times. It is commonly found in humans. Humans are a natural host and are a source of infection for domestic animals. It is not as common in dogs and cats and is rarely seen in other mammals.
Food and water can become contaminated with fecal matter. The fecal matter can contain infective cysts, a dormant form of the parasites. Dogs can become infected by ingesting the contaminated food and water.
The parasite lives in the large intestine. There may be no symptoms, or the parasite can invade the intestinal lining which can cause wounds, bleeding and inflammation. The animal may have severe diarrhea. Amebiasis can be fatal, or a long term illness. On occasion, it may improve spontaneously. The symptoms of a long term infection includes appetite loss, diarrhea, straining to defecate and weight loss. The amoebae may infect the liver, lings, kidneys, brain, the skin around the anus, genitals and other organs as well as the large intestine. The symptoms can be continuous, intermittent and they may be similar to other large intestine diseases in dogs.
Amebiasis is diagnosed by testing a sample for fecal matter for either active of dormant Entamoeba histolytica. If the infection is outside the intestine, it may be more difficult to detect. The veterinarian may also use a colonoscopy procedure to examine the large intestine. The veterinarian may prescribe a medication treatment program, and all instructions should be followed carefully. Medication have not yet been fully evaluated as to their effectiveness in treating Amebiasis. Treated dogs may also continue to shed amoebae after the treatment has been completed.
Coccidiosis can be caused by several species of protozoa. It is when the protozoa invade and destroy the intestinal tissues. It is relatively common. Many infected dogs do not show any symptoms of illness, but some infected dogs can show signs of illness. It is more common in puppies or dogs in weakened states. It can be prevalent in dogs with poor sanitation, poor nutrition, overcrowded conditions or after a stressful event, for example weaning. Infection occurs from the ingestion of the infective eggs, which are known as oocysts. The oocysts come from the feces of an infected animal but are not infective themselves until they have further developed. Development needs specific conditions to occur.
The common symptoms of infection in severe cases include diarrhea which can be bloody, dehydration and weight loss. The veterinarian will test a fecal sample, examine the intestines and take a detailed history to confirm diagnosis. It is common for the infection to end by itself after a few weeks but medication can reduce the chances of reinfection and spread of the disease. The dogs should be isolated to prevent other animals from becoming infected.
There are several things which can reduce the risk of infection. Sanitation is extremely important and feces should be removed often. The feed and water should be kept free of fecal contamination. Cages, runs and utensils should be cleaned and disinfected on a daily basis. It is also important to have any insects and pests controlled.
Giardiasis In Dogs
The protozoal species Giardia causes a long term intestinal infection known as Giardiasis. It is found in all areas of the world and affects most domestic and wild mammals, human and many birds. It is common in dogs, reportedly thirty nine per cent of pet and shelter dogs are infected. There is a higher infection rate in young dogs.
The protozoa attach themselves in the small intestine and multiply. The cysts are passed in the fecal matter. Giardiasis is transmitted by spreading from the feces to the mouth. An infected dog may shed cysts continuously for several days or weeks or it may be intermittent. It is not clear if the same species of Giardia can infect humans and domestic animals, but it appears that some species infect many mammals while other species can only infect one species of mammal.
The infection may not cause any symptoms or there may be continual or intermittent diarrhea, vomiting and weight loss. The diarrhea may be soft, pale, poorly formed, and have a foul odor. It is unusual for diarrhea related to Giardiasis to be watery or bloody. Giardiasis also causes malabsorption of nutrients and therefore, must be distinguished from other conditions that can cause malabsorption. A sample of fecal matter will be tested for the presence of Giardia cysts or Giardia antigens. The veterinarian will prescribe a drug or drug combination to treat Giardiasis. There is also a vaccination available in some countries. Studies show that it is possible that the vaccine reduces the number of shed cysts, the time length of the shedding and the signs of infection.
Dogs can be infected and reinfected from the cysts in the fecal matter, especially dogs in crowded conditions. It is important for feces to be removed often from kennels, cages, runs and yards. Doing this can limit the contamination of the environment. The feces needs to be disposed of properly and it is important for the owner or any person in contact with the animals to thoroughly wash their hands. Cysts are inactivated by disinfectants. Quaternary ammonium compounds, steam, boiling water and household bleach mixed to one part bleach to sixteen parts water or one part bleach to thirty two parts water can be used to disinfect kennels, run surfaces and concrete yards. The solution should be left for five to twenty minutes before rinsing. The cysts are susceptible to drying, and areas need to be thoroughly dried after cleaning. It is impossible to disinfect grass yards or runs, therefore they should be considered to be contaminated for around a month after an infected dog had access. The dogs should be shampooed and rinsed well as doing this can help remove cysts that may be on the hair.