Mycoplasma (Feline Infectious Anemia) in Cats

Quick Answer
  • Feline infectious anemia is usually caused by hemotropic Mycoplasma bacteria, especially Mycoplasma haemofelis, which attach to red blood cells and can trigger anemia.
  • Common signs include lethargy, pale gums, weakness, fast breathing, poor appetite, fever, and sometimes jaundice. Severe anemia is an emergency.
  • Diagnosis often includes a CBC, blood smear, PCR testing, and FeLV/FIV testing because coinfections can make illness more serious.
  • Treatment usually involves doxycycline or another antibiotic chosen by your vet, strict flea control, and repeat bloodwork. Some cats with severe anemia need hospitalization and a blood transfusion.
Estimated cost: $250–$3,000

What Is Feline Infectious Anemia?

Feline infectious anemia is the older name for feline hemotropic mycoplasmosis, a blood-borne infection caused by tiny bacteria that attach to the outside of red blood cells. The species most often linked to serious illness is Mycoplasma haemofelis, though other feline hemoplasmas can infect cats too. Older resources may call this condition hemobartonellosis.

When infected red blood cells circulate, your cat's immune system may remove and destroy them. That can lead to hemolytic anemia, meaning there are not enough healthy red blood cells to carry oxygen through the body. Some cats stay mildly affected or even symptom-free carriers, while others become weak very quickly.

This is not a condition to monitor at home if your cat looks pale, tired, or short of breath. Cats can hide illness well, and anemia can become dangerous fast. Your vet can help confirm whether hemoplasma is the cause and whether your cat is stable enough for outpatient care.

Symptoms of Feline Infectious Anemia

Symptoms can come and go, especially early on, but pale gums, weakness, collapse, or breathing changes deserve prompt veterinary care. Some cats have only mild signs at first, while others become critically ill if anemia worsens quickly. Cats with FeLV, FIV, other illnesses, or heavy flea exposure may have more severe disease. If your cat seems weak or is breathing faster than normal, see your vet the same day.

How Do Cats Get Feline Infectious Anemia?

Hemoplasma organisms spread through blood exposure. Fleas are strongly suspected to be an important route, and blood-sucking parasites may help move infection between cats. Bite wounds from cat fights are also considered a likely source, especially in outdoor cats and intact males.

Less common routes include blood transfusions from an infected donor and possible transmission from a mother cat to kittens. Because some infected cats become long-term carriers, a cat may look healthy and still serve as a source of infection.

Risk tends to be higher in cats with outdoor access, flea exposure, fighting history, or concurrent diseases such as FeLV or FIV. Indoor cats are not completely risk-free, but year-round parasite control and reducing fighting exposure can lower the odds.

How Is Feline Infectious Anemia Diagnosed?

Diagnosis usually starts with a physical exam and bloodwork. A complete blood count can show whether your cat is anemic and how severe that anemia is. Your vet may also review a blood smear, but hemoplasma organisms can be hard to spot because they may detach from cells or appear intermittently.

A PCR test on blood is generally the most useful confirmatory test because it detects hemoplasma DNA. Your vet may also recommend a chemistry panel, reticulocyte count, and testing for FeLV and FIV, since coinfections can affect both treatment choices and prognosis.

Diagnosis is not only about finding the organism. Your vet also needs to decide whether the anemia is mild, moderate, or severe, and whether another disease is contributing. That is what guides whether home treatment is reasonable or whether your cat needs hospitalization, oxygen support, or a transfusion.

Treatment Options for Feline Infectious Anemia

Spectrum of Care means you have options. Here are treatment tiers at different price points.

Conservative

$250–$700
Best for: Stable cats with mild anemia, normal hydration, and no breathing distress who can take medication at home.
  • Office exam
  • CBC/packed cell volume and blood smear
  • FeLV/FIV testing if status is unknown
  • Oral antibiotic therapy, commonly doxycycline, as directed by your vet
  • Strict year-round flea control
  • Home monitoring for gum color, appetite, breathing, and energy
  • One follow-up recheck CBC or PCV
Expected outcome: Often fair to good when anemia is mild and treatment starts early. Many cats improve clinically within days to 1-2 weeks, but some remain carriers or can relapse later.
Consider: Lower upfront cost, but it depends on close home monitoring and good medication compliance. It may not be enough for cats with marked anemia, dehydration, poor appetite, or concurrent illness.
Most Common

Standard

$700–$1,600
Best for: Most symptomatic cats that are sick enough to need a fuller workup but are not in immediate transfusion-level crisis.
  • Comprehensive exam and repeat vital checks
  • CBC, chemistry panel, reticulocyte count, and PCR testing
  • FeLV/FIV testing
  • Antibiotic therapy selected by your vet, often doxycycline
  • Antinausea support or appetite support if needed
  • Fluids if dehydration is present
  • Two or more recheck blood tests to track red blood cell recovery
  • Prescription flea prevention for all pets in the home when appropriate
Expected outcome: Good for many cats when the infection is identified and anemia is monitored closely. Outcome depends on anemia severity and whether FeLV, FIV, or another disease is also present.
Consider: More testing improves decision-making, but raises the cost range. Some cats need repeated visits, and antibiotics may control the organism without fully clearing carrier status.

Advanced

$1,600–$3,000
Best for: Cats with severe anemia, collapse, marked weakness, pale or white gums, rapid breathing, or significant concurrent disease.
  • Emergency exam and stabilization
  • Hospitalization with oxygen support if needed
  • Blood typing and crossmatch when indicated
  • Blood transfusion for severe or life-threatening anemia
  • IV catheter placement, IV or carefully selected fluid support, and intensive monitoring
  • Expanded diagnostics for concurrent disease or complications
  • Repeat CBC/PCV checks during hospitalization and after discharge
Expected outcome: Guarded at presentation if anemia is severe, but many cats can stabilize with timely supportive care and then continue recovery at home. Prognosis is more cautious when FeLV, FIV, or other major illness is involved.
Consider: Highest cost range and the most intensive care. Hospitalization can be stressful, and transfusions carry risks, but this tier may be the safest option for critically ill cats.

Cost estimates as of 2026-03. Actual costs vary by location, clinic, and individual case.

Questions to Ask Your Vet About Feline Infectious Anemia

Bring these questions to your vet appointment to get the most out of your visit.

  1. How anemic is my cat right now, and is home care safe? The severity of anemia helps determine whether your cat can be treated as an outpatient or needs hospitalization.
  2. Do you recommend PCR testing, or do the bloodwork findings already strongly support hemoplasma? PCR is often the most useful confirmatory test, but your vet may tailor testing based on urgency and budget.
  3. Should my cat be tested for FeLV and FIV today? These infections can make hemoplasma disease more serious and may change prognosis and follow-up plans.
  4. What is the safest way to give doxycycline to my cat? Cats can develop esophageal irritation or stricture if tablets or capsules are given improperly.
  5. What signs mean I should come back immediately or go to an emergency hospital? Breathing changes, worsening weakness, or very pale gums can mean anemia is becoming dangerous.
  6. How often do you want to recheck bloodwork? Repeat CBC or PCV testing helps confirm that red blood cells are recovering.
  7. Could my cat remain a carrier after treatment, and what does that mean for the future? Some cats improve clinically but may still test positive later or relapse during stress or illness.

How to Prevent Feline Infectious Anemia

The most practical prevention step is consistent flea control all year long. Because blood exposure and parasites are important in transmission, keeping fleas under control lowers risk for your cat and for other pets in the home. Ask your vet which flea preventive fits your cat's age, health status, and lifestyle.

Keeping cats indoors or supervising outdoor time can also help by reducing flea exposure and cat-fight injuries. If your cat does go outside, prompt treatment of wounds and regular preventive care matter.

If your household includes multiple cats, talk with your vet about testing and prevention strategies, especially if one cat has anemia or a history of fighting. Cats that have had hemoplasma infection may need closer monitoring during future illness, stress, or immune suppression.

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