Clinical Symptoms of Cat FIP

Wet FIPCats under 2 years old are highly suspected of having feline infectious peritonitis when ascites or pleural effusion was found in their body.

Dry FIPDry FIP usually has a long subclinical period and needs observed combining with its clinical signs. Symptoms include periodic fever, lethargy, loss of appetite and weight loss, growth retardation, dry hair and that were not responsive to antibiotic therapy. And blood biochemistry contributes to the diagnosis of FIP, FCoV titer≥1:3200 can be reasonably inferred to be FIP.

Dry to WetThe two forms of FIP are somewhat interchangeable, when it has been observed in experimental infection, the dry form always follows a brief bout of effusive disease. In the terminal stages of naturally occurring dry FIP, immunity can completely collapse and the disease reverts to a more effusive form.

 

Clinical symptoms of Wet FIP

a) Growing abdomen, and ultrasound or X-rays indicate the presence of ascites.
b) Breathing is getting faster and faster, and ultrasound or X-rays indicate the presence of pleural effusion.
c) Ascites with pleural effusions.

The usual symptoms will be a), b), c) one of the three.

  • Anorexia, fatigue, sleepiness,

  • Weight loss,

  • Periodic fever, persists more than 4 days (＞102.5℉),

  • A high coronavirus titer,

  • Non-regenerative anemia,

  • Increased absolute neutrophils,

  • Decreased absolute lymphocytes,

  • Decreased ALB, increased GLOB, A:G≤6,

  • Jaundice, TBIL increased, etc.

Fluid analysis (Ascites, pleural effusion)

✔ Yellow   ✔ Yellow-green   ✔ Light yellow   ✔ Deep yellow   ✘ Milk-white   ✘ Blood-red


Rivalta test-positive ascites, pleural effusion.

RTPCR-positiveascites, pleural effusion, CSF, stool, serum/plasma ect. 

*  When the Rivalta test result is negative, the possibility of FIP can be reasonably excluded. However, reading of the test is subjective and results are therefore somewhat dependent on the evaluator.

   RT-PCR, a commonly used diagnostic test, has about 30% false negative results. A positive result of the test is highly indicative of the presence of FIPV, a negative result can not be used to exclude the disease, especially when only serum, plasma and stool samples are available. 

Although many FIP cats have characteristic CBCs, albumin and globulin levels and A:G, but not every cat will fully match the above parameters, which still need consider combined with age, origin, clinical signs and physical examination. The results are considered comprehensively. If these common abnormalities and clinical symptoms are generally consistent, it can be reasonably diagnosed as feline infectious peritonitis. 

Clinical symptoms of Dry FIP

  • Anorexia, fatigue, sleepiness,

  • Weight loss,

  • Periodic fever, persists more than 4 days.( 102.5℉),

  • Non-regenerative anemia,

  • Increased absolute neutrophils,

  • Decreased absolute lymphocytes,

  • Increased TP, increased GLOB, decreased ALB, A:G≤6,

  • A high coronavirus titer,

  • Continued widespread mesenteric lymph nodes enlargement,

  • Inflammatory granuloma in multiple organs,

  • Mild ascites sits around the organs in the abdomen,

  • Jaundice, increased TBIL, etc.
    ✔ Ocular lesions (uveitis)
    ✔ Neurological signs lesions (Its 'clinical feature is rest tremor, rear limb weakness, rigidity, bradykinesia and postural instability. Confusion, urine or fecal incontinence, seizures, convulsions, paralysis, disorientation and shock may be seen in the late stages).

Although many FIP cats have characteristic CBCs, albumin and globulin levels and A:G, but not every cat will fully match the above parameters, which still need consider combined with age, origin, clinical signs and physical examination. The results are considered comprehensively. If these common abnormalities and clinical symptoms are generally consistent, it can be reasonably diagnosed as feline infectious peritonitis.

Recognizing the Stages for Wet FIP or Dry FIP

Wet FIP

▶︎ Early stage

Young cats (≤2 years old) with periodic fever, lethargy, loss of appetite, weight loss, growth retardation, dry hair, and ineffective antibiotic treatment, needs raise the doubts about FIP.  Clinical symptoms of diarrhea or constipation may also occur in some FIP cases.

FIP usually leads to leukocytosis, increased neutrophils, decreased lymphocytes, elevated serum total protein, hyperglobulinemia and hypoalbuminemia, A: G≤0.6.

Wet FIP usually has ascites or pleural effusion. The increase of ascites will cause the abdomen growth gradually and softer touch. When you gently tap its abdomen, water waves will sway, and the increased pleural effusion will also cause faster breathing. Pleural effusion can be drained, but ascites typically should not be drained unless it affects breathing.

▶︎ Mid stage

Along with the condition development, above symptom will aggravate gradually. Or cause chronic non-regenerative anemia (HCT≤24%), hyperbilirubinemia, urine is golden yellow to dark yellow; increased ascites or pleural effusion may cause difficulty breathing, When the cat begin abdominal respiration, it need to be sent to the doctor in time; meanwhile the appetite will be further reduced, it can only eat a small amount of food.

▶︎ Late stage

As the virus destroys and impairs the function of immune cells and condition has worsened. infected cats can develop other signs symptoms such as severe anemia (HCT≤16%), when HCT≤14%), timely blood transfusion is recommended. Loss the ability of self-feeding, walking unstable, ataxia, which may cause serious icteric and hemolytic anemia. The median survival of wet FIP is only 8 days, so early diagnosis is very important, the treatment of wet FIP is relatively easy. By timely treatment, the clinical symptoms are reversible, and the quality of life can be fully restored to the healthy level. However, in the late stage of wet FIP, irreversible damage such as multiple organ failure may occur. About 50% of the cats in this stage may still die within 1 to 7 days after treatment.

Dry FIP

▶︎ Early stage

Young cats (≤2 years old) with periodic fever, lethargy, loss of appetite, weight loss, growth retardation, dry hair, and ineffective antibiotic treatment, needs raise the doubts about FIP.  Clinical symptoms of diarrhea or constipation may also occur in some FIP cases.

FIP usually leads to leukocytosis, increased neutrophils, decreased lymphocytes, elevated serum total protein, hyperglobulinemia and hypoalbuminemia, A: G≤0.6.

Dry FIP usually has a long subclinical period, which will gradually form granuloma in various organs. This may cause not only swelling of liver, kidney and testicles but enlargement of intestinal lymph nodes, and extensive purulent peritonitis. In addition, renal medullary ring signs are also common in dry FIP.

▶︎ Mid stage

As the disease progresses, above symptom will aggravate gradually. Or cause chronic non-regenerative anemia (HCT≤24%), jaundice, urine is golden yellow to dark yellow.

Some dry FIP can cause eye lesions, mainly uveitis. The eyeball becomes cloudy due to the aqueous humor exudation of the fluid fibers and cellular components. The iris texture is no longer clear, and sometimes a yellow-white small clot is formed. As the inflammatory product increases, a floating white turbidity can be seen in the vitreous, choroid Yellow-white granulomatous nodular plaques may appear in the blood vessels. When the virus invades the optic nerve system, it will be more difficulty to treatment. 

▶︎ Mid-late stage

As the virus destroys and impairs the function of immune cells and condition has worsened. infected cats can develop other signs symptoms such as severe anemia (HCT≤16% ), when HCT≤14%, timely blood transfusion is recommended. Other than this, infected cats may deteriorate into neurological signs and symptoms such as nystagmus, resting tremor, unable to jump to high places, rear limb weakness, bradykinesia and postural instability. FIP can also cause aseptic meningitis or meningitis epidemic, when the virus has penetrated the blood-brain barrier into the central nervous system (CNS), the treatment will be much more difficult than expected.

▶︎ Late stage

Rigidity, confusion, urine or fecal incontinence, convulsions, seizures, tremor, paralysis, disorientation, and shock may be seen in the late stages. When symptoms emerge, cats is often already in an advanced disease stage where the central nervous system is affected and Indicated a poor outcome. Although some cats completely reversed the condition and returned to a healthy through treatment at this stage, there was also a recurrence rate of about 30% after stopping the drug.

We would especially grateful to Niels C. Pedersen, Diane Addie, Yunjeong Kim, Hui-Wen Chang, Carol Johnson DVM, Heather Lorimer et al for their long-term research on FIP, which gave us a deeper understanding of this deadly disease. We also want to express our highest appreciation to many owner and cats for challenging the traditional "impossible" during the FIP treatment. They have suffered many hardships, but also found many hopes, and finally created miracles of life again and again.