What is primary immunodeficiency disease?

Primary immunodeficiency refers to a congenital or genetically caused reduction in immune function, making pets more susceptible to recurrent infections. If you suspect this condition, consult a vet for examination and ongoing monitoring.

Can primary immunodeficiency be passed on to offspring?

Some forms of primary immunodeficiency are hereditary, but this varies by disease and breed. If you have breeding plans, consult a specialist vet or seek genetic counselling.

What can I observe at home to help the vet assess my pet?

Keep track of energy levels, appetite, weight changes, and bathroom habits, and take photos or videos of any infected areas or unusual behaviours — this information helps the vet assess disease progression.

How often does my pet need follow-up visits after diagnosis?

The frequency of follow-up visits depends on the condition and test results. In the short term, blood tests and clinical changes may be monitored every few weeks; long-term management requires regular check-ups and treatment adjustments.

How much do the tests and treatment usually cost?

Costs vary by clinic and region — ask your vet for an estimate before proceeding.

Disease Guide

Primary Immunodeficiency in Dogs & Cats: Symptoms, Diagnosis & Care Guide [2025]

Primary immunodeficiency is a hereditary immune system disorder that causes recurrent infections. It typically appears within the first year of life and cannot be cured — management focuses on preventing and controlling infections.

Take 1 minute to check the symptoms first

Last updated: 2026/01/05

Pethealthmap Editorial Team

Sources: WSAVA, ACVIM

When to See a Vet

Seek immediate veterinary care (emergency)

•Completely unable to stand or unresponsive, difficult to wake
•Persistent high fever with extreme weakness and immobility
•Large amounts of pus discharge or wounds that rapidly worsen and spread

Schedule a veterinary visit as soon as possible (within 24-72 hours)

•Persistently low energy with a clear decrease in activity
•Repeated skin or ear infections within a short period
•Noticeable weight loss over a short period that is more than expected

01What Symptoms Indicate Something Is Wrong?

Pets with primary immunodeficiency often show non-specific signs such as lethargy, appetite changes, and recurrent infections — monitor for persistent or worsening symptoms.

Low energy and noticeably reduced activity levels
Persistent poor appetite or short-term refusal to eat
Recurrent or difficult-to-treat skin, ear, or respiratory infections
Significant weight loss or inability to regain weight in a short period
Wounds that are slow to heal or repeatedly become infected and suppurate

Seek emergency care immediately if you notice the following symptoms:

⚠️ Complete inability to stand or unresponsiveness requires immediate veterinary attention
⚠️ Persistent high fever with severely deteriorating condition that does not improve
⚠️ Heavy discharge of pus or rapidly worsening existing wounds

02What Should You Watch for at Home? Key Observation Points and When to Seek Emergency Care

Keeping records at home helps the vet assess disease progression and prioritise examinations — consistent logging of changes is recommended.

Track daily changes in energy level and activity
Record appetite, food intake, and any episodes of refusal to eat each day
Weigh your pet regularly and log trends for comparison
Note frequency, consistency, and any abnormalities in urination and defecation
Photograph or video any problem areas on the skin, ears, or unusual behaviours
If symptoms persist or worsen, schedule a veterinary consultation

03How Does the Vet Diagnose This Condition? Common Diagnostic Tests

The vet will start with a physical examination and supplement with blood tests, immune tests, and imaging to identify secondary infections or immune dysfunction.

Full physical examination to assess whole-body and localised lesions

Complete blood count to evaluate white blood cell, red blood cell, and platelet changes

Blood biochemistry panel to assess liver, kidney, and other organ function

Immune-related tests or antibody assays to evaluate immune response

Tissue biopsy or histopathology if needed

Advanced imaging (e.g. CT scan) if required to evaluate deep lesions

Referral to a specialist hospital capable of advanced immune testing or specialist evaluation is recommended

04How Is This Condition Treated and Managed? Medications, Diet, and Home Care Guide

Treatment focuses on controlling secondary infections, supporting overall condition, and long-term monitoring of immune function and blood changes.

Treatment and supportive care direction determined by test results
Antibiotics or local treatment to control secondary infections when necessary
Hospitalisation for observation and supportive care in severe cases
Dietary management to maintain nutrition, support the immune system, and stabilise weight
Regular follow-up visits to monitor blood values and clinical symptom changes
Home care focuses on keeping your pet warm, clean, and preventing cross-infection
Referral to a specialist clinic for long-term follow-up and advanced testing as needed

05How Should You Prepare Before the Vet Visit? Key Information to Help the Vet Identify the Cause Quickly

Record when symptoms first appeared, how they have changed, and their current status

Note daily appetite, food intake, and any episodes of refusal to eat

Log frequency, consistency, and timing of any abnormal urination or defecation

List all current medications and supplements

Bring any recent test reports or imaging results (if available) for comparison

Take photos or video of symptoms or behaviours for the vet to review on the spot

Book an appointment in advance and mention that immune or blood issues need to be assessed

This content is for reference only and cannot replace a professional veterinary diagnosis. If your pet shows signs of illness, please seek veterinary care promptly.

Related Symptoms (You May Also Be Looking For)

Anorexia

Loss of appetite

Lethargy

Decreased activity