FIP - Differential diagnoses 2

Read about diseases that are often confused with FIP. Free continuation of the article on differential diagnoses of FIP.

Toxoplasmosis Transmission / epidemiology: Obtained by vertical transfer (in young cats) or by hunting or eating raw meat
Clinical symptoms: Cats may have involvement of the liver, lungs, nervous system, muscles and / or pancreas. Symptoms include lethargy, anorexia, dyspnoea (pneumonia and / or pleural effusion), jaundice, abdominal discharge, uveitis (especially posterior) and / or neurological symptoms
Diagnostic examination: Clinical toxoplasmosis is less common than FIP and is usually not associated with severe hyperglobulinemia or a decreased albumin / globulin ratio, which often occurs in FIP. Hyperbilirubinaemia may occur. Serology (high IgM titer or rising IgG titer) may be useful in diagnosis. The organisms can be found by sampling and microscopic examination of, for example, the lung or lymph nodes. PCR can also be performed on such samples to detect the presence of Toxoplasma gondii DNA. In cases with neurological symptoms, cerebrospinal fluid (CSF) PCR may be performed.
Treatment: If toxoplasmosis is suspected, trial treatment with clindamycin may be initiated to determine if a positive reaction occurs.
Lymphocytic cholangitis (LC) Epidemiology: It has been thought that Persian cats may be predisposed to the disease, but recent studies have not confirmed the predisposition to this breed.
Clinical signs: Often associated with jaundice. Some cats with LC have abdominal discharge
Diagnostic examination: The nature of the effusion is similar in terms of protein concentration to FIP (i.e. high), although the number of cells in LC is usually higher than the number observed in FIP. Hyperglobulinemia can also be observed in LC. Both LC and FIP cases can be hyperbilirubinemic. In contrast to FIP, LC is also usually associated with a marked increase in liver enzymes, especially cholestatic markers (i.e., alkaline phosphatase and gamma-glutamyltransferase), compared to the milder or moderate increase that occurs in FIP cats. Furthermore, cats with LC are usually not as ill as those with FIP; for example, they may be polyphagic rather than anorexic
Neoplasia (eg lymphoma, abdominal cancer) Epidemiology: Lymphoma can affect young cats, but occurs in cats of all ages. Older cats usually have additional neoplasms. Focal lesions of FIP in the gut or (especially mesenteric) lymph nodes can manifest themselves very similarly to cases with apparently solitary neoplasms of these organs.
Clinical symptoms: Lymphoma can affect multiple body organs and, like FIP, can lead to lymphadenopathy and / or biquavian effusions. Cats are often systemically ill
Diagnostic examination: Sampling of affected tissues or effusions followed by cytology may confirm the diagnosis of lymphoma rather than mixed inflammatory cells, which usually occur in cytological sampling of FlP-affected tissues. Other neoplastic lesions (eg carcinomas) can be diagnosed by effusion cytology
Pancreatitis Clinical symptoms: Cats may experience anorexia, jaundice and weight loss. Severe fever is not a common symptom, although it can occur in cases of acute pancreatitis that are associated with severe pain and / or sepsis.
Diagnostic examination: Hyperbilirubinaemia may occur. In acute cases, a small amount of abdominal fluid is sometimes present (usually with high protein and high cell counts [non-degenerate neutrophils], as opposed to high protein and low cell effusion in FIP). Pancreatitis can be diagnosed by ultrasonography and pancreatic measurements. feline pancreatic lipase.
Treatment: Trial treatment with antiemetics and analgesics may be used
Retroviral infection Epidemiology: Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) infections are more common in adults than in young cats, but age-related immunity plays a role in FeLV infection, with younger cats being more susceptible to infection. Both cats are more likely to have external viruses. FeLV affects both males and females, while males have an increased risk of FIV infection.
Clinical signs: Both FeLV and FIV infection may be associated with pyrexia, lethargy, lymphadenopathy and / or uveitis.
Diagnostic examination: FIV infection can be associated with severe hyperglobulinemia. Please note that retroviral positivity may be a risk factor for the development of FIP
Mycobacterial infection including tuberculosis (TB) Epidemiology: There are geographical differences in prevalence and infection is usually associated with outdoor access and hunting
Clinical symptoms: Lymphadenopathy, respiratory symptoms and / or uveitis, as well as wet non-healing wounds, may occur. Affected cats may be in relatively good condition despite the disease, and pyrexia and anorexia are not common symptoms, although acute manifestations such as shortness of breath may occur. Mycobacterial infections that affect the lungs usually affect the lung parenchyma compared to pleural effusion as in FIP.
Diagnostic examination: Mycobacterial infection is usually not associated with the severe hyperglobulinemia or decreased albumin / globulin ratio observed in FIP. Hypercalcaemia may occur. The cytology of the affected lymph nodes or organs shows inflammatory changes (marked macrophages, but inflammation may be similar to FIP with pyogranulomatous changes). Ziehl-Neelsen staining of cytology or biopsy specimens may be positive and specimens may be sent for culture (although positive culture results may take up to weeks in slow-growing organisms, and cultivation may be impossible with some mycobacterial species). An interferon gamma test is available, which is performed on blood samples and helps diagnose suspected cases of feline TB.
Pyothorax Clinical symptoms: It may be associated with pyrexia. Pleural effusion is seen
Diagnostic examination: Chest effusion analysis reveals a very high number of cells due to marked neutrophilic inflammation with degenerative changes and the possible presence of intracellular bacteria, although any previous antibiotic treatment may cause the presence of bacteria not to be confirmed. Unique effusion.
Sepsis It can be associated with many conditions; for example with septic peritonitis, pyothorax, pneumonia, pyelonephritis
Clinical symptoms: Pyrexia (although low temperatures may occur in cats), tachycardia or bradycardia, tachypnoea, and other symptoms associated with the source of sepsis may occur in cats.
Diagnostic examination: Leukocytosis, neutrophilia and hyperbilirubinaemia (in the absence of increased liver enzymes) may be present.
Septic peritonitis Clinical symptoms: They may be associated with pyrexia. Presence of abdominal effusion
Diagnostic examination: Abdominal effusion analysis reveals a very high number of cells due to marked neutrophilic inflammation with degenerative changes and possibly intracellular bacteria, although any previous antibiotic treatment may cause bacteria not to be detected. Unique effusion. Glucose concentration in abdominal effusion is lower than blood concentration (> 1.1 mmol / l)
Congestive heart failure (CHF) Clinical symptoms: Bicavitary effusions are possible in the pleural and peritoneal spaces, although pleural effusions are much more common in abdominal CHFs than abdominal effusions, and separate abdominal effusions are very rare in feline CHFs. The presence of gallop, arrhythmia and possibly heart murmur increases the suspected CHF index. Jugular vein distension may be present in right-sided CHF.
Diagnostic examination: The fluid is a modified low protein transudate, unlike the fluid observed in FIP. Echocardiography confirms heart disease and CHF.
Rabies In countries where rabies is endemic, it must be considered a differential diagnosis in unvaccinated cats with neurological symptoms, especially acute behavioral changes and progressive paralysis.
Edited by Tasker S and Dowgray with permission from BSAVA Publications, Gloucester