Feline Panleukopenia: Symptoms & Treatment Overview

Most cats diagnosed with this disease are quite young, with the majority not exceeding two years of age, with the peak age range being between 3 and 16 months, with half of them being younger than 12 months.

The Feline Enteric Coronavirus (FECV, FCoV) is the primary cause of Feline Enteritis, which is a type of coronavirus that affects cats. However, it's important to note that the Feline Coronavirus Group is not a single virus but a genus that includes many different strains and serotypes. Among these, the most common is the Feline Enteric Coronavirus (FCoV).

Coronaviruses are RNA viruses, meaning their genetic material is composed of RNA rather than DNA. One significant difference between RNA and DNA is that RNA is unstable, leading to constant mutations in the virus. This instability is a major reason why there is currently no effective drug to treat Feline Enteritis.

Coronaviruses mutate rapidly, often outpacing the immune system's ability to adapt. This rapid mutation, combined with the virus's ability to recombine with other genetic material, contributes to the difficulty in completely eradicating the virus with vaccines or the immune system.

Compared to other feline RNA viruses like the Feline Calicivirus, the Feline Coronavirus can reach up to three times the size difference (120 nanometers). Currently, there are two main types of Feline Coronavirus: Type I, which is the original form, and Type II, which is believed to be a hybrid of feline and canine coronaviruses.

Both Type I and Type II coronaviruses have two forms:

1. Nonpathogenic form, which can cause diarrhea and inflammation at most, and these coronaviruses typically remain in a cat's large intestine without causing harm.

2. Pathogenic form, where the virus mutates and gains the ability to leave the intestines and affect other organs, posing a threat to the cat's life. This is what leads to Feline Panleukopenia, or Feline Enteritis.

Transmission of Feline Enteritis

Feline Enteritis is not highly contagious, as only a small amount of the virus is released when a cat shows symptoms. However, the Feline Coronavirus can spread through contaminated environments.

During acute infection with the coronavirus (not necessarily leading to Enteritis), large amounts of the virus are present in the saliva and feces of the infected cat. Direct contact can spread the virus, with primary infection lasting 718 months, during which the virus is shed at its highest rate. Most cats will shed the virus in their feces for 23 months, with some shedding for longer.

Transmission can also occur between queens and kittens, usually when the kittens are between 5 and 8 weeks old.

In multicat households, if one cat has the coronavirus, it is likely that other cats will have it as well. The virus can survive in dry environments for up to 7 weeks, has an envelope, and is relatively fragile, making it easily inactivated by disinfectants.

Symptoms of Feline Enteritis

The initial symptoms of infection are often subtle, with signs such as a lack of energy, decreased appetite, and dull, disheveled fur often being the first indicators. Rapid weight loss can also be a warning sign, although these symptoms are also common in many other cat illnesses, making it difficult to pinpoint the exact cause.

The progression of wet Feline Enteritis is generally as follows:

1. Persistent lowgrade fever, which may initially be suspected as a bacterial infection, leading to antibiotic treatment. However, the fever does not respond to antibiotics, indicating a possible viral infection.

2. After a period of infection with the Enteritis virus, the cat may develop anemia (nonregenerative anemia).

3. Fluid accumulates in the chest, causing the cat to have difficulty breathing.

4. Abdominal fluid builds up, giving the cat an applelike appearance. The cat may not feel discomfort when touched, as the abdomen is distended.

Some cases of Feline Enteritis are "dry," meaning there is no fluid accumulation or ascites, and the progression of the disease is slower. These cases are particularly prone to being confused with other diseases.

Wet Feline Enteritis

Wet Feline Enteritis is the most common type, characterized by the presence of fluid in the abdomen and chest.

The fluid produced is not a result of the virus's destruction but rather the cat's immune system's response to the virus invasion. This overreaction leads to the release of a fluid mixture, which becomes ascites. This ascites is thick, yellowish, and contains proteins, white blood cells, and plasma.

Diagnosis of Feline Enteritis

There is no specific diagnostic test for the Enteritis virus. Determining whether a coronavirus has mutated to the point of causing Enteritis requires doctors to make an inference based on the actual situation and limited test results, which can lead to a high rate of misdiagnosis.

Here are some diagnostic criteria that can be used as references, but they must be combined to make a judgment:

1. The presence of a high amount of globulin and inflammatory cells (neutrophils, macrophages, lymphocytes) in the fluid suggests a high likelihood of Enteritis.

2. Detection of macrophages in the fluid using immunostaining, with these macrophages being of the type that fights coronaviruses, indicates a high likelihood of Feline Panleukopenia.

3. High levels of coronavirus antibodies detected through antibody titers suggest a high likelihood of Enteritis if there are also clear symptoms of the disease.

4. Cats with Enteritis often have a low lymphocyte count, which can be detected through a blood test.

5. The A/G (albumin/globulin) ratio in biochemical indicators is often low in cats with Enteritis. The globulin (Globulin Protein) level may be elevated, and this can be combined with other symptoms to determine if Enteritis is present.

6. Other blood test indicators. The level of albumin (Albumin/ALB), one of the main protein indicators in the blood, may decrease due to chronic inflammation caused by Enteritis.

Diagnosis of Feline Enteritis

Coronavirus antibody or antigen detection can only tell us if a cat has the coronavirus, but it cannot differentiate between the deadly Enteritis virus and the harmless common coronavirus, which is a significant reason for the frequent misdiagnosis of Enteritis.

1. The presence of the coronavirus in pleural or peritoneal fluid suggests a high likelihood of Enteritis.

2. High levels of the coronavirus detected in body tissues outside the intestines suggest a very high likelihood of Enteritis.

Testing Kits for Feline Enteritis

There are commercially available test kits for Feline Enteritis. However, these kits can only detect the presence of the coronavirus in cats and cannot differentiate between the deadly Enteritis virus and the harmless common coronavirus.

Treatment and Prevention of Feline Enteritis

Treatment of Feline Enteritis

Currently, there is no effective treatment for Feline Enteritis. Treatment usually involves supportive care, such as good nursing and nutrition, and reducing inflammation. Many scientists are researching treatments for Enteritis, but there is no effective drug yet. In China, the drugs GC376 and GS441 are available. If a cat is diagnosed with Enteritis, GS441 is usually tried first. The injectable form is an oilbased solution and can be painful (there is now a tablet form available, which is more expensive but less painful, and better accepted by small cats). The injection dose is 0.30.5 ml/kg body weight per day at a concentration of 15 mg/ml. It is important not to inject into the same area repeatedly, as this can lead to tissue fibrosis, making it difficult to inject later. After the first week of injections, the cat should be taken to the vet for a followup, and if the indicators have not improved, it may be necessary to change the medication.

Draining Fluids and Protein Supplementation

Cats with Enteritis often have fluid in their chest and abdomen, which needs to be drained. This makes the cat more comfortable and allows for easier breathing. However, the fluid will reaccumulate, so it may need to be drained again. Repeated draining can lead to significant protein loss, so it is important to provide highprotein foods, such as canned food and meat, in the diet.

Forced Feeding

Cats with Enteritis often have poor appetite and energy. It is important to offer food that the cat enjoys. Some veterinarians may prescribe "prescription food," but this is not particularly helpful for Enteritis. If the cat does not like the food, it should not be forced to eat it.

Companionship and Environment

Cats with Enteritis need a quiet, comfortable environment. It is best to avoid noisy environments and strangers, as well as other cats and dogs. Cats with Enteritis are often more clingy during this time and may enjoy more attention and conversation, even if they do not understand what you are saying.

Prevention of Feline Enteritis

There are not many good prevention methods, but the following are emphasized:

1. Keep the environment clean.

2. Clean the feces daily and regularly clean and disinfect the litter box.

3. Isolate new cats when they arrive.

4. Provide appropriate nutrition.

5. Minimize stress in cats.