Diarrhea in older or geriatric dogs is a frequent reason for consultation in the small animal clinic. It is a clinical sign that can appear associated with multiple pathologies, not only digestive, but also related to other organs and systems. Identifying the specific cause of diarrhea will be essential to establish a specific treatment and control the process.
If you want to know more information about diarrhea in older dogs, causes and what to do we recommend that you continue reading the following article in our place.
Types of diarrhea in older dogs
Before addressing the different causes that can cause diarrhea in older dogs, we need to differentiate between the types of diarrhea that exist.
Depending on the chronicity of the process, we speak of:
- Acute diarrhea: those that last less than 3 weeks. They have a rapid and striking development, and are usually accompanied by decay and poor general condition of the animal.
- Chronic diarrhea: those that last more than 3 weeks. Intermittent diarrhea is also included in this group. They develop slowly and the general condition of the animal deteriorates more gradually.
In addition, depending on the affected intestinal section, diarrhea can also be classified as:
- Small bowel diarrhea: they are light brown or yellowish in color, the volume per stool is increased and they may contain undigested food, foam, digested blood (melena) or fat (steatorrhea).
- Large bowel diarrhea: usually have a normal color, mucus and/or fresh blood. In this case the volume per stool is normal but the frequency of defecation is increased.
Knowing the chronicity of the diarrhea and the affected intestinal segment will be essential to guide the diagnosis in these animals.
If you want to know more about the Types of diarrhea in dogs, don't hesitate to take a look at this other article that we recommend.
Inflammatory Bowel Disease or IBD
IBD is one of the most common causes of chronic diarrhea in adult and elderly dogs. It encompasses a group of diseases characterized by the development of an inflammatory response at the level of the intestinal mucosaThis inflammatory process prevents nutrients from being absorbed in the intestine, which increases the osmotic pressure at the level of the intestinal lumen, retaining water and causing chronic diarrhea.
To date it is considered an idiopathic disease, that is, of unknown origin It is believed to be a multifactorial process in the that immunological, allergic, dietary or dysbiotic mechanisms may intervene, although it is not known exactly. However, it should be noted that it has recently been discovered that E. coli bacteria are involved in histiocytic-ulcerative colitis in Boxers.
IBD can affect the small intestine (SI), the large intestine (GI), or even both portions:
- IBD Small Intestine: Chronic ID diarrhea (with mustard-colored, watery stools), bilious vomiting with stomach may be seen emptiness, weight loss and chronic abdominal pain. Abdominal pain can manifest in the form of antalgic positions (praying position) or in the form of attacks (they can be confused with epileptic seizures)
- Large Bowel IBD: Patients present with chronic IG diarrhea (with abundant mucus and fresh blood), tenesmus (urge to defecate continuously) and increased bowel movements, but vomiting and weight loss do not usually occur in this case.
For the definitive diagnosis of IBD it is necessary:
- Perform an endoscopy of the affected intestinal segment.
- Take a biopsy of the affected intestinal mucosa to perform a histopathological analysis.
The Therapeutic management of canine IBD is based on two pillars:
- Dietary treatment: a diet low in fat and low in fiber, with hydrolyzed proteins and with a 1:5 ratio should be administered or 1:10 of Omega-3 fatty acids: Omega-6.
- Pharmacological treatment: is based on the use of immunosuppressive and anti-inflammatory drugs. The treatment of choice for both types of IBD is prednisone. However, there are other drugs such as cyclosporine, azathioprine, metronidazole or sulfasalazine, which can be used both alone and in combination for the treatment of IBD. In the specific case of boxer histiocytic ulcerative colitis, the treatment of choice is the antibiotic enrofloxacin, since E. coli is involved in its pathogenesis.
Intestinal tumors
Intestinal tumors are another cause of chronic diarrhea in adult and older dogs.
As with IBD, tumors are also classified according to the section of intestine they affect. Thus, we find:
- Tumors of the small intestine: mainly carcinomas and lymphosarcomas. Both cause chronic diarrhoea, vomiting, appetite disturbance, weight loss and abdominal pain. How to take care of a dog with lymphoma? Discover the answer in the following article that we suggest.
- Large bowel tumors: These can be adenomas, carcinomas, lymphosarcomas, leiomyomas, leiomyosarcomas, or stromal tumors. In these tumors, mucus and fresh blood can be observed in stool, dyschezia (pain when defecating) and tenesmus (continuous need to defecate).
The definitive diagnosis is made by means of biopsy and histopathological analysis, since it is the only way to know exactly the type of tumor that the animal presents. The biopsy sample can be obtained by endoscopy or exploratory laparotomy.
The treatment depends on the specific intestinal tumor, although it is generally summarized in two strategies:
- Surgical Excision: For adenomas and carcinomas. The prognosis is good after surgery.
- Chemotherapy: in lymphosarcomas. In these cases, despite treatment, the prognosis is guarded. We tell you more about Chemotherapy in dogs: side effects and medications in this post on our site.
Intestinal polyps
Intestinal polyps are hyperplastic growths of non-tumor origin that usually appear on the mucosa of the colon or rectum and, occasionally, on small intestine. They are pedunculated masses, solitary or multiple, which usually present ulcerated intestinal mucosa.
These polyps appear more frequently in middle-aged dogs and can produce the following symptoms:
- Chronic diarrhea.
- Tenesmus: continuous need to defecate. We leave you the following article on why My dog poops a lot: causes and solutions, below.
- Hematochezia: rectal bleeding.
- Melena: dark stools due to the presence of digested blood.
- Vomiting.
Your diagnosis requires the performance of endoscopy, biopsy and histopathologyto confirm that it is a non-tumor lesion.
The treatment of intestinal polyps is surgical and consists in the resection of the affected part of the intestine.
Chronic kidney disease (CKD)
CKD is a pathology characterized by the progressive and irreversible loss of renal function. It is one of the most important diseases in geriatric dogs. So much so, that it is the third leading cause of death in these animals.
Despite being a pathology that affects the kidneys, it produces a very varied symptomatology that can affect multiple devices and systems, including digestive. Among other things, in dogs with CKD there is an accumulation of urea and creatinine in the blood (azotemia), which can lead to diarrhea.
Although it is an incurable disease, a nephroprotective treatment should be institutedto slow the progression of the disease, as well as symptomatic treatment to alleviate the animal's clinical signs (including diarrhoea). Specifically, the therapeutic management of CKD includes:
- Medical treatment: hydroelectrolyte and acid-base balance must be restored through fluid therapy, as well as treating hypertension with vasodilators.
- Dietary treatment: a “renal diet” containing high levels of Omega-3 fatty acids, antioxidants and soluble fiber should be provided, as well as reduced levels of sodium, phosphorous and protein.
Liver diseases
Bile s alts are essential for the formation of micelles and absorption of fats at the intestinal level. When there is a liver pathology that decreases the production of bile s alts or prevents bile from reaching the intestine (cholestasis), there is no proper digestion of fats and a picture of small intestine diarrhea appears.
Specifically, diarrhea usually appears accompanied by other non-specific clinical signs (such as vomiting, polyuria and polydipsia or weight loss) in the first stage of the disease, before symptoms suggestive of liver disease (such as jaundice, ascites, or hepatic encephalopathy) appear.
The therapeutic management in this case will be aimed at establishing a specific treatment of the hepatic or biliary pathology that is causing the diarrhoea, and may include:
- Pharmacological and/or surgical treatment.
- Liver protectors: such as ursodeoxycholic acid, silymarin, etc.
- Dietary management: a specific diet should be designed for each patient, although in general it will be a highly digestible diet, rich in carbohydrates carbon of easy assimilation and moderate in fat.
Exocrine pancreatic insufficiency
One etiology that we must never forget in dogs with diarrhea is exocrine pancreatic insufficiency. During the course of this disease, there is a deficit in the synthesis and secretion of pancreatic enzymes, which are essential for the digestion of carbohydrates, proteins and fats.
The absence of these enzymes prevents nutrients from being digested and absorbed, producing a maldigestion syndrome – malabsorption. As a consequence, the following symptoms can be observed:
- Chronic diarrhea of small intestine.
- Weight loss Marked.
- Voracious appetite: this is the frequency of polyphagia, coprophagia and pica behavior.
Therapeutic management consists of the administration of pancreatic enzymes mixed with food. It is a treatment for life, although the prognosis is good and the animals usually improve greatly after starting the administration of enzymes.
You can read the following article on Exocrine pancreatic insufficiency in dogs: symptoms and treatment for more information on the subject.
Other causes
Throughout this article, we have described the main causes of diarrhea in older dogs. However, there are other aetiologies that can also produce this clinical sign in dogs, regardless of their age:
- Sudden changes in diet: Dogs have a digestive system that is especially sensitive to changes in diet. For this reason, whenever we make a change from one feed to another, it is important to mix the new feed with the previous one, and to increase the amount of the new feed as the animal tolerates it. In the case of homemade rations, whenever a new food is introduced it should be done in small quantities
- Improper diet: Diarrheal processes frequently occur when caregivers share food with their pets. For this reason, the contribution of any food that is not part of the usual diet of dogs should be avoided, to avoid the appearance of digestive alterations.
- Infectious gastroenteritis: both bacterial (such as salmonellosis) and viral (such as canine distemper).
- Intestinal parasites: by protozoa, nematodes or cestodes, in those animals that are not properly dewormed.
