From Dog

Lymphopenia in dogs is defined as a reduced level of circulating lymphocytes in peripheral blood < 1 - 4.8 x 109/L.

Lymphocytes are responsible for control of infections, regulation of neoplastic conditions and autoimmunity states and numerous disorders can cause reduced levels of these leucocytes in peripheral blood.

As a consequent of lymphopenia, dogs may be more susceptibile to bacterial, fungal and viral infections, prolonged allograft survival, cutaneous anergy and abnormal antibody responses to T-dependent antigens[1].

In dogs, other hematological abnormalities may be associated with this condition such as anemia, neutropenia and thrombocytopenia.

Lymphopenia can be observed in dogs with:

- Leukemia, angiosarcoma[2]
- Canine enteric coronavirus, canine parvovirus[3], distemper virus[4]
- Leishmania spp[6], Anaplasma spp[7], Borrelia spp, Sarcocystis spp[8]
- Xylohypha spp
- Tyzzer's disease

Determination of the underlying cause(s) of this symptom and its diagnosis is essential before initiating treatment.


  1. Girndt M et al (2001) Molecular aspects of T- and B-cell function in uremia. Kidney Int 59:S206–S211
  2. Gázquez A et al (2012) Widespread epithelioid angiosarcoma with ventricular wall involvement in a dog. Histol Histopathol 27(7):865-872
  3. Decaro N et al (2012) A pantropic canine coronavirus genetically related to the prototype isolate CB/05. Vet Microbiol 159(1-2):239-244
  4. Reed LT et al (2010) Diagnostic exercise. Cerebral mass in a puppy with respiratory distress and progressive neurologic signs. Vet Pathol 47(6):1116-1119
  5. Kralova S et al (2010) Changes in lymphocyte function and subsets in dogs with naturally occurring chronic renal failure. Can J Vet Res 74(2):124-129
  6. Athanasiou LV et al (2013) Treatment of canine leishmaniosis with aminosidine at an optimized dosage regimen: A pilot open clinical trial. Vet Parasitol 192(1-3):91-97
  7. Eberts MD et al (2011) Typical and atypical manifestations of Anaplasma phagocytophilum infection in dogs. J Am Anim Hosp Assoc 47(6):86-94
  8. Sykes JE et al (2012) Severe myositis associated with Sarcocystis spp. infection in 2 dogs. J Vet Intern Med 25(6):1277-1283
  9. Griebsch C et al (2010) Evaluation of different prognostic markers in dogs with primary immune-mediated hemolytic anemia. Berl Munch Tierarztl Wochenschr 123(3-4):160-168
  10. Rodríguez-Alarcón CA et al (2012) Protein-losing enteropathy in a dog with lymphangiectasia, lymphoplasmacytic enteritis and pancreatic exocrine insufficiency. Vet Q 32(3-4):193-197