Gastrointestinal
Urine
Cat’s urine can reflect the severity of the cat’s condition, and detecting cat’s urine has strong medical value
We offer free GS medicine to help cats survive
Yellow urine
Pathogeny
1.Dehydration
Pathophysiology: FIP can cause dehydration due to reduced water intake, fever, and fluid loss through effusion in wet FIP.
Mechanism: Dehydration leads to concentrated urine, resulting in a deeper yellow color. The kidneys attempt to conserve water by reabsorbing more fluid, which increases the concentration of urochrome, the pigment responsible for the yellow color in urine.
2.Hyperbilirubinemia
Pathophysiology: Liver involvement in FIP, especially in the wet form, can lead to hyperbilirubinemia, an excess of bilirubin in the blood.
Mechanism: Bilirubin is a byproduct of hemoglobin breakdown, usually processed by the liver. When the liver is compromised by FIP, it can lead to an accumulation of bilirubin, which is then excreted in the urine, causing a yellow to orange hue, a condition known as bilirubinuria.
3.Hemolysis
Pathophysiology: Hemolysis, or the breakdown of red blood cells, can occur as a complication of FIP, leading to increased levels of hemoglobin breakdown products.
Mechanism: Hemolysis increases the levels of bilirubin, which the liver may not adequately process due to FIP-related liver damage. This excess bilirubin is excreted through the urine, contributing to a yellow or even darker urine color.
4.Medications
Pathophysiology: Certain medications used to manage FIP, such as corticosteroids or antibiotics, can affect liver function and hydration status.
Mechanism: Medications may lead to liver stress or dehydration, both of which can cause yellowing of the urine. For example, drugs metabolized by the liver may increase bilirubin levels, or diuretics may lead to concentrated, yellow urine due to reduced fluid volume.
5.Inflammation and Infection
Pathophysiology: FIP causes widespread systemic inflammation, which can affect multiple organ systems, including the urinary tract.
Mechanism: Inflammation may impair the kidneys’ ability to concentrate urine effectively, leading to variations in urine color. Additionally, secondary infections, which are common in immunocompromised FIP cats, can lead to changes in urine characteristics, including color.
Reference picture
More pictures of hematuria
Click on the blue text to view
Haematuria
Pathogeny
1.Renal Involvement and Glomerulonephritis
Pathophysiology: FIP can cause immune-mediated damage to the kidneys, particularly affecting the glomeruli, leading to glomerulonephritis.
Mechanism: The immune complexes formed as a result of the body’s response to the coronavirus can deposit in the glomeruli (the filtering units of the kidneys). This deposition leads to inflammation and damage to the glomerular membrane, causing leakage of red blood cells into the urine, resulting in hematuria. This condition is often seen in the dry form of FIP, which can involve the kidneys directly.
2.Vasculitis
Pathophysiology: FIP is known to cause vasculitis, an inflammation of the blood vessels, which can affect various organs, including the kidneys and urinary tract.
Mechanism: Vasculitis leads to increased permeability of blood vessels, including those in the kidneys and urinary tract. This increased permeability can cause blood cells to escape into the urine, leading to hematuria. This is a common feature in both wet and dry forms of FIP due to widespread systemic inflammation.
3.Urethral or Bladder Inflammation (Cystitis)
Pathophysiology: FIP can compromise the immune system, making the cat more susceptible to secondary bacterial infections such as cystitis (bladder infection) or urethritis (inflammation of the urethra).
Mechanism: Inflammation or infection of the bladder or urethra can lead to irritation and damage to the urinary tract lining, causing bleeding and the presence of blood in the urine. While FIP itself doesn’t typically cause these infections directly, the immunosuppression associated with FIP makes secondary infections more likely.
4.Coagulopathies
Pathophysiology: FIP can cause disruptions in normal blood clotting mechanisms, leading to a condition known as coagulopathy.
Mechanism: Coagulopathies in FIP may result from liver dysfunction, which impairs the synthesis of clotting factors, or from disseminated intravascular coagulation (DIC), a severe and often fatal complication of FIP. These clotting disorders can lead to spontaneous bleeding, including hematuria, as the kidneys and urinary tract may become sites of hemorrhage.
5.Interstitial Nephritis
Pathophysiology: FIP may also cause interstitial nephritis, a condition characterized by inflammation of the kidney’s interstitial tissue.
Mechanism: The inflammatory response in the kidney’s interstitial tissue can cause damage to blood vessels and renal tubules, resulting in the leakage of blood into the urine. Interstitial nephritis is often seen in the dry form of FIP, which tends to involve multiple organ systems, including the kidneys.
6.Toxicity from Treatment
Pathophysiology: Some treatments for FIP, particularly experimental antiviral drugs, may cause renal toxicity, contributing to hematuria.
Mechanism: Drugs that are nephrotoxic can cause direct damage to the renal tissues, leading to bleeding within the kidneys and subsequent hematuria. Monitoring for signs of hematuria is essential during treatment to adjust dosages or discontinue harmful medications.
Reference picture
More pictures of hematuria
Click on the blue text to view
Green urine
Pathogeny
1.Bilirubin Metabolism Disorders
Pathophysiology: FIP can cause liver dysfunction, leading to alterations in bilirubin metabolism.
Mechanism: When the liver is compromised due to FIP, the breakdown of hemoglobin may result in excessive bilirubin production or improper conjugation. In some cases, excessive biliverdin, a green bile pigment that is a precursor to bilirubin, can accumulate in the blood and be excreted in the urine, leading to a greenish tint. This is especially likely if the liver’s ability to convert biliverdin to bilirubin is impaired.
2.Bacterial Infections and Pseudomonas
Pathophysiology: Cats with FIP are immunocompromised and more susceptible to secondary infections, including those caused by Pseudomonas bacteria.
Mechanism: Pseudomonas aeruginosa is known to produce a pigment called pyocyanin, which can give urine a greenish color. This type of bacterial infection may occur as a secondary complication in FIP cats, particularly if they develop urinary tract infections (UTIs). The presence of pyocyanin in the urine would indicate a severe infection, requiring immediate medical intervention.
3.Medication and Dye Excretion
Pathophysiology: Certain medications or diagnostic dyes used in the treatment or assessment of FIP can cause urine discoloration.
Mechanism: Some medications, particularly those used experimentally in FIP treatment, or substances like methylene blue, may be excreted by the kidneys and alter urine color. If a cat has received such treatments, the green color could be due to the renal excretion of these compounds. This type of discoloration usually resolves once the medication is discontinued.
4.Oxidative Damage
Pathophysiology: FIP leads to systemic inflammation and oxidative stress, which can result in cellular and tissue damage.
Mechanism: Oxidative damage to red blood cells (hemolysis) can produce abnormal byproducts that may be excreted in the urine. In rare cases, these oxidative byproducts can interact with other substances in the urine to produce a greenish hue. This process may be more prominent in severe, systemic cases of FIP where oxidative stress is significant.
5.Bile Duct Obstruction
Pathophysiology: FIP can cause inflammation in various organs, including the liver and bile ducts.
Mechanism: Obstruction or inflammation of the bile ducts due to FIP can lead to the abnormal release of bile pigments into the bloodstream, some of which may be excreted in the urine. If biliverdin is excreted instead of being converted to bilirubin, it may cause the urine to appear green. This situation is indicative of significant hepatic or biliary involvement and requires urgent veterinary attention.
Reference picture
More pictures of hematuria
Click on the blue text to view
Leave a Reply