- Neutrophil lymphocyte ratio in cats as a prognostic marker for blunt trauma
- What is the neutrophil lymphocyte ratio for cats?
- 🔬 How is the NLR determined in cats?
- 🐾 When is the NLR determination advisable in cats?
- 📊 categorization of the NLR in cats
- 📊 Decision tree: NLR determination in cats
- Here are 5 frequently asked questions (FAQ) on the subject of neutrophil lymphocyte ratio (NLR) in cats
- Summary neutrophil lymphocyte ratio in cats
- Further sources:
Neutrophil lymphocyte ratio in cats as a prognostic marker for blunt trauma
A current retrospective study with 177 cats shows that the neutrophil lymphocyte ratio (NLR) could be a valuable early indicator for the extent of a trauma and the severity of the inflammatory reaction. This relationship, which has already been associated with the survival forecast in human medicine, is also becoming increasingly important in veterinary medicine.
As part of the examination, blood pictures were evaluated within 24 hours of trauma and thoracic X -rays. The results are impressive: cats with blunt trauma showed a significantly higher middle NLR (8.4) than healthy control animals (2.3). The difference in thoracic injuries was particularly striking - here the NLR was 9.2 on average, compared to 6.4 in injured cats without thoracic trauma.
A threshold of 4.45 turned out to be particularly reliable to distinguish between healthy and injured cats - with a sensitivity of 74 % and a specificity of 71 %. Even more exciting: The NLR correlated directly with the Animal Trauma Triage (Att) score. The more severe the injury, the higher the NLR - from 3.98 (mild) over 13.1 (moderately) to 28.2 (heavy).
However, the authors warn: Automated Leukocyte counts can be misleading because immature neutrophils (band cells) could incorrectly be seen as lymphocytes. Therefore, manual differential blood image evaluation is recommended - especially in the case of striking or borderline results.
These findings provide valuable information for emergency and intensive care medicine in cats. An increased NLR can help to quickly assess the severity of a trauma - and thus to plan further care more specifically.
What is the neutrophil lymphocyte ratio for cats?
The neutrophil lymphocyte ratio (NLR) is an easy-to-determine laboratory parameter that reflects the ratio of two important white blood cells in the peripheral blood: neutrophil granulocytes and lymphocytes . Both cell types play a central role in immune defense, but fulfill different tasks:
- Neutrophil granulocytes are part of the innate immune response and are quickly mobilized in large numbers for acute inflammatory reactions, infections and tissue damage. You are, so to speak, the body's “first line of defense”.
- Lymphocytes, on the other hand, belong to the specific, acquired immune defense. They are essential in combating viruses, in the formation of antibodies and in the long -term immune response.
The NLR easily results from the division of the number of neutrophils by the number of lymphocytes. An example: If a patient has 7000 neutrophils and 2000 lymphocytes per microliter blood, the NLR is 3.5.
What is the NLR used for in human medicine?
promising prognostic marker in recent years -especially because it is contained quickly, inexpensive and in almost every blood count.
1. Inflammation and infection
An increased NLR can indicate a systemic inflammatory reaction. That is why it is often used as a marker for inflammatory activity -for example in sepsis, appendicitis, bacterial infections or even covid-19. Studies showed that patients with a high NLR at Covid-19 had a higher risk of a difficult course.
2. Cardiovascular diseases
A high NLR was associated heart attack , heart failure or stroke It is considered a marker for the inflammatory status and the severity of the event.
3. Oncology (cancer medicine)
The NLR is also increasingly observed in cancer medicine. Numerous studies show that an increased NLR is associated with a poorer forecast in many types of tumor - including lung cancer, colon cancer, breast cancer and pancreatic cancer. Here a high ratio indicates a tumor -associated inflammatory reaction that could favor tumor growth and metastasis.
4. Surgery and intensive care medicine
In the preoperative assessment and in critical patients in intensive care units, a striking NLR can complications or an increased risk of death. It helps to identify patient groups with increased risk at an early stage.
Why is the NLR so interesting?
What is special about the NLR is its simply accessible meaning : it is derived from a normal blood count, which is made in almost every inpatient patient anyway. So no additional test is necessary. At the same time, it provides a quick insight into the balance between acute inflammation and specific immune response , which can be very helpful, especially with acute diseases or trauma.
Human medicine has already recognized the potential of the NLR - and now veterinary studies also show that this relationship in animals could also play a valuable diagnostic and prognostic role.
The determination of the neutrophil lymphocyte ratio (NLR) in cats is a simple but extremely useful diagnostic tool, which is increasingly being considered in veterinary practice-especially when assessing acute illnesses, injuries or systemic inflammation .
🔬 How is the NLR determined in cats?
The NLR is calculated based on a complete blood count (CBC, Complete Blood Count) . This blood count can be created either using an automatic hematology analysis device or manually. Among other things, the numbers of different white blood cells (leukocytes) are recorded in a differentiated manner - including in particular:
- Neutrophil granulocytes (also divided into stick -core and segment -core)
- Lymphocytes
The actual calculation of the NLR is very uncomplicated: nlr = number of the neutrophils of the lymphocytes \ text {nlr} = \ frac {\ text {Number of neutrophils} {\ text {number of lymphocytes}} nlr = number of lymphocytes of the neutrophils
Example: If a cat has 8000 neutrophils/μl and 2000 lymphocytes/μl, the NLR: NLR = 80002000 = 4.0Nlr = \ frac {8000} = 4.0Nlr = 20008000 = 4.0
Important: The accuracy of the value depends on whether the cell numbers have been reliably determined. Automated devices can provide incorrect values for abnormal blood pictures, e.g. B. when immature neutrophils (band cells) are incorrectly recognized as lymphocytes. Therefore, in the event of abnormalities, manual differentiation is always recommended by an experienced laboratory subject or veterinarian: in.
🐾 When is the NLR determination advisable in cats?
In many clinical situations, the determination of the NLR can provide valuable information about the health of a cat , especially when it comes to better assessing the severity of a disease or a trauma:
✅ 1. With blunt trauma
As current studies show, the NLR in cats with blunt injuries (e.g. fall from great height, traffic accident) is often significantly increased. The higher the NLR value, the stronger the inflammatory reaction-which allows conclusions to be drawn about the level of injury and the need for intensive medical care.
✅ 2. If systemic inflammation or infection is suspected
An increased NLR can indicate a systemic inflammatory reaction , for example in bacterial infections, abscesses, sepsis or other inflammatory processes. In conjunction with other blood parameters (e.g. fever, CRP, fibrinogen), a comprehensive image of the immune system can be obtained.
✅ 3. For chronic diseases or cancer
In human medicine, the NLR is an established marker to assess the forecast in tumor diseases. This is also increasingly researched in veterinary medicine. In cats with lymphoma, carcinomas or other neoplasia, a striking NLR can indicate a tumor-associated inflammatory reaction .
✅ 4. For the course control
The NLR can also be used monitor disease courses or therapies If the ratio in the course of the treatment, this can be an indication of an improvement - if it increases if necessary, the therapy is adapted or searched for complications.
🧠 What should be considered when interpreted?
- The NLR is not an isolated marker , but should always be considered in the context of the clinical symptoms and other laboratory values.
- Normal ranges can vary depending on the laboratory and device setting. In studies, the NLR values of healthy cats were in the range of around 2 to 3-significantly lower values than with traumatized or sick cats.
- Stress (e.g. visiting the vet ) can also lead to a temporary increase in neutrophils and waste of lymphocytes in cats - which the NLR increases at short notice without a serious illness being available.
The determination of the neutrophil lymphocyte ratio in cats is quick, simple and inexpensive -and still offers a variety of diagnostic options. Whether in acute emergencies, chronic illnesses or the course of the course: the NLR can help to better assess the condition of a cat, to support decisions and to more precise forecasts . Used correctly, it is a valuable tool in everyday veterinary life.
In order to use the neutrophil lymphocyte ratio (NLR) in cats in practice, it is helpful to classify the measurement results into categories . Even if there are no internationally uniform normal areas for cats (as is sometimes the case in human medicine), current studies provide - such as: B. that of Doulidis et al. (2024) - good indications for an initial assessment.
Below you will find a clear table for categorizing NLR values in cats , based on the current state of knowledge from literature and clinical practice:
📊 categorization of the NLR in cats
| NLR value | interpretation | Possible meaning |
|---|---|---|
| < 3,0 | Normal range (reference value of healthy cats) | Healthy cat, no evidence of acute inflammation or stress response |
| 3,0 – 5,0 | Mild increased | Easy inflammatory reaction, stress response, early disease stages possible |
| 5,1 – 10,0 | Moderately increased | Possible reference to systemic inflammation, trauma or infection |
| 10,1 – 20,0 | Significantly increased | Significant inflammatory reaction, trauma with complications, more difficult infection |
| > 20,0 | Greatly increased / critical | Possibly serious systemic disease, sepsis, very high level of inflammation |
💡 Notes on the application:
- study by Doulidis et al . As a threshold with good sensitivity and specificity to distinguish injured and healthy cats.
- Cats with thoracic trauma showed particularly high NLR values (in median 9.2), while seriously injured cats (Att score> 8) even had values up to 28.0.
- Stress (e.g. by transport or handling) can temporarily increase the ratio, so it should be taken into account in the interpretation.
🧪 Tip from practice:
If a striking NLR value is determined, it is worthwhile to add other inflammation parameters such as B. fibrinogen, CRP (if available), temperature, general behavior and other hematological findings to include in the clinical assessment.
📊 Decision tree: NLR determination in cats
<3.0 = normal
3.0 - 5.0 = slightly increased
5.1 - 10.0 = moderately increased
10.1 - 20.0 = significantly increased
> 20.0 = greatly increased
🔹 Search for source of inflammation / trauma
🔹 consider intensive monitoring
🔹 Introduce further diagnostics (e.g. X -ray, CRP, ultrasound)
🔹 Planary control
✅ What this graphic offers:
- Clear decision -making tree: leads through the most important questions & actions.
- Practical: ideal for veterinarians: inside for communication in a team or with pet owners: inside.
Here are 5 frequently asked questions (FAQ) on the subject of neutrophil lymphocyte ratio (NLR) in cats
What exactly does the neutrophil lymphocyte ratio (NLR) say about the health of my cat?
The neutrophil lymphocyte ratio (NLR) is an indirect marker for the condition of your cat's immune system. It describes the ratio between two important cell types in the blood: the neutrophils , which primarily react to acute inflammation and tissue damage, and the lymphocytes that are more responsible for targeted, adaptive immune defense - for example in viral infections or long -term immune responses.
An increased NLR value usually means that your cat's body reacts to acute stress or inflammation -be it through trauma, infection, stress or another systemic illness. At the same time, a drop in lymphocytes can be an indication of weakening the specific immune defense , as can be done with severe physical stress, chronic stress or immunomodulatory diseases.
A low or normal NLR value, on the other hand, usually suggests that the immune system works in a healthy balance. This makes the NLR a valuable component in the assessment of the general condition of a cat- especially in emergency or intensive care medicine.
When should the NLR be determined in my cat? Are there typical situations or symptoms?
The determination of the NLR is particularly useful if there is suspicion of acute or systemic illness or if your cat has recently suffered a blunt trauma (e.g. fall, accident). Even in cases in which your cat suddenly looks apathetic, has a fever, does not eat or breathes heavily , the NLR can help to narrow down the causes better.
Typical situations for an NLR determination include:
after falls or accidents in which internal injuries are not excluded,
inflammation signs or suspicion of infection (e.g. fever of unknown cause)
in chronic diseases , e.g. B. cancer, inflammatory bowel diseases or autoimmune processes
for therapy control to see how the body reacts to medication or treatments
in intensive care patients in order to monitor the course of the disease.
The NLR can therefore be a valuable part of diagnostics- however, it never replaces clinical examination or other laboratory and images. It helps to take early warning signs seriously and to initiate further diagnostic steps.
What are the causes of an increased NLR value in my cat?
An increased NLR value for a cat can have very different causes. Basically, a high NLR indicates that there is an increased inflammation or stress reaction . The following causes are possible in detail:
Acute trauma : z. B. after a fall from great height (high-rise syndrome), a traffic accident or a biting
infection : bacterial infections (e.g. abscesses, pneumonia), viral diseases with secondary bacterial component
stress reactions : transport, veterinary visit-all this can increase the NLR in the short term
: z. B. in chronic enteritis, pancreatitis or immune -mediated diseases
of neoplasia (cancer): Some tumors lead to a systemic inflammatory response that increases the NLR
medication or hormonal disorders : cortisone treatments or thyroid problems can affect the ratio
of sepsis or multi -organ failure : In very severe cases, an extremely high NLR can also Systemic derailment
is important that a single high NLR value not a diagnosis closing , but a signal that should be taken more closely-possibly by further examinations such as X-rays, ultrasound, CRP determination or fibrinogen measurement.
Are there any standard values for the NLR in cats? And when should you worry?
There are no rigid, internationally valid standard values for the NLR in cats, since the value can vary depending on the age, health state, stress level and examination method. However, studies with healthy cats show that the normal range is about an NLR from 2.0 to 3.0 .
Based on clinical experience and current research data (e.g. Doulidis et al., 2024 ), the following orientation areas can be derived:
NLR value
assessment
below 3.0
normal range
3,0 – 5,0
Slightly increased - observation recommended
5,1 – 10,0
Moderately increased - possible inflammation
10,1 – 20,0
Significantly increased - precise clarification necessary
Over 20.0
increased greatly - possible emergency
A value of over 4.45 has already been recognized in the study mentioned as a relevant increased limit value for cats with trauma. If such a value is measured, you should always search for a physical cause and, if necessary, a close -meshed monitoring should be initiated.
Can the NLR also be used for checks on sick cats?
Yes, the NLR is ideal for checking the course - especially in cats that are treated due to trauma, infection or chronic diseases. The course of the NLR over several days or weeks can help to assess the effect of therapy or to identify complications at an early stage .
An example: A cat with heavy thoracic trauma initially has an NLR from 15th after 3 days of intensive therapy, the value drops to 7, after a week to 3.5. This speaks for a positive development and decline in inflammatory activity . However, if the NLR stays high or rises again, this could complications such as infections, pleural effusion or stress due to pain .
It is important: the course of the NLR should be considered isolated always in connection with the clinical symptoms, vital parameters and other laboratory values (e.g. temperature, feeding behavior, CRP, fibrinogen, liver values, etc.). Nevertheless, it can be a very practical and fast early warning system - especially with intensely cared for cats or those with high risk.
Summary neutrophil lymphocyte ratio in cats
The neutrophil lymphocyte ratio in cats is increasingly becoming a valuable diagnostic and prognostic marker in small animal medicine. While it has been successfully used in human medicine for years to assess inflammatory processes, stress reactions and disease courses, the neutrophil lymphocyte ratio in cats increasingly focused on research and clinical application.
The neutrophil lymphocyte ratio in cats is based on the determination of two important cell types in the blood count: the neutrophils and the lymphocytes. In healthy animals there is the neutrophil lymphocyte ratio in cats in the area of around 2 to 3. In this way, an increased neutrophil lymphocyte ratio in cats be an early warning sign for inflammatory or critical processes in the body.
Especially after blunt trauma-for example after a fall, a car accident or other injuries-the neutrophil lymphocyte ratio in cats a clear correlation with the severity of the clinical image. In a retrospective study with 177 cats, it was found that the neutrophil lymphocyte ratio in cats was significantly higher in seriously injured animals than in slightly injured or healthy animals.
A specific limit of 4.45 for the neutrophil lymphocyte ratio in cats was able to differentiate with good sensitivity and specificity between healthy and injured animals. neutrophil lymphocyte ratio in cats significantly, especially in thoracic trauma It is therefore recommended to use the neutrophil lymphocyte ratio in cats not only for initial assessment, but also to control the course in patients with internal or traumatological problems.
In addition, the neutrophil lymphocyte ratio in cats provide important information in dealing with chronic inflammation, immune-mediated diseases and even tumor diseases. Studies show that the neutrophil lymphocyte ratio in cats in neoplasia is often significantly increased-a sign that tumor-associated inflammation also plays a role.
It is therefore helpful for veterinarians to anchor neutrophil lymphocyte ratio in cats Since it is calculated based on a simple blood count, the neutrophil lymphocyte ratio inexpensive and quickly available in cats-without additional laboratory costs or waiting times. However, it is important that manual differentiation is recommended in the case of striking values in order to avoid misinterpretations by machine counts. reliably evaluate the neutrophil lymphocyte ratio in cats
In emergency medicine, the neutrophil lymphocyte ratio in cats also provides rapid notes as to which animals should potentially be cared for intensive medicine. neutrophil lymphocyte ratio in cats be important when assessing the forecast
A decisive advantage: the neutrophil lymphocyte ratio in cats can be followed over time. In stationary patients, repeated blood pictures can be seen whether the ratio improves or worsens - and thus draw conclusions about the course of therapy. If the neutrophil lymphocyte ratio in cats drops, this can indicate successful treatment; If it stays high or continues to rise, special vigilance is required.
Also animal owners: inside benefit from a simple explanation of the neutrophil lymphocyte ratio in cats , since it helps to make the need for diagnosis or inpatient surveillance more understandable. Especially in communication around seriously ill animals, the neutrophil lymphocyte ratio in cats help make well-founded decisions.
In summary, it can be said that the neutrophil lymphocyte ratio in cats is an uncomplicated but highly informative marker for health. It can perform valuable services in acute and chronic diseases, in emergency care and in the course of the course. The increasing clinical and scientific relevance shows that the neutrophil lymphocyte ratio in cats has found its permanent place in modern veterinary medicine-and will become more important in the future.
Further sources:
- Ay cd. Neutrophil to lymphocyte ratio as a forecastic biomarker in puppies with acute diarrhea. J Vet Emerg Crit Care (San Antonio) . 2022; 32 (1): 83-89. Doi: 10.1111/VEC.13159
- Conway EA, DEL Valle CP, Waugh EM, French A, Ridyard Ae. Retrospective Investigation of the Neutrophil-to-Lymphocyte Ratio in Dogs with Pneumonia: 49 Cases (2011-2016). J Vet Emerg Crit Care (San Antonio) . 2021; 31 (4): 490-497. Doi: 10.1111/VEC.13067
- Johnson mm, Gicking JC, Keys there. Evaluation of Red Blood Cell Distribution Width, Neutrophil-to-Lymphocyte Ratio, and other Hematologic Parameters in Canine Acute Pancreatitis. J Vet Emerg Crit Care (San Antonio) . 2023; 33 (5): 587-597. DOI: 10.1111/VEC.13325
- Dourmashkin LH, Lyons B, Hess RS, Walsh K, Silverstein DC. Evaluation of the neutrophil-to-lymphocyte and Platelet-to-lymphocyte ratios in critical ill dogs. J Vet Emerg Crit Care (San Antonio) . 2023; 33 (1): 52-58. DOI: 10.1111/VEC.13269