Page 1075 - Cote clinical veterinary advisor dogs and cats 4th

532 Immunodeficiency Syndromes, Dog

○ Chronic myelogenous leukemia • Genetic tests are available for some Chronic Treatment
○ Pelger-Huët anomaly: hyposegmentation congenital immunodeficiency syndromes • Humoral immunodeficiency
VetBooks.ir persistent degenerative left shift without TREATMENT • Cell-mediated immunodeficiency
○ Supportive therapy tailored to treating
of nuclei in granulocytes and monocytes;
(e.g., TNS, CLAD).
recurrent microbial infections
toxic change or any signs of illness
(incidental finding)
○ Other infectious disease that can cause Treatment Overview ○ Supportive care with frequent monitoring
for opportunistic infections; proceed with
a neutrophilic leukocytosis with a left Substantial variation in severity may exist for a aggressive treatment when warranted
shift given immunodeficiency syndrome. Therefore, ○ Dwarf Weimaraners respond to thymosin
treatment intensity, treatment success, and fraction 5 therapy (1 mg/kg SQ q 24h
Initial Database prognosis are individually variable. Some for 7 days).
Appropriate diagnostic testing based on clinical individuals require minimal treatment (inter- • Combined (B-cell and T-cell) immunodefi-
presentation: mittent antimicrobial treatment during clinical ciency
• Minimal database: CBC, serum biochemistry exacerbation), whereas in others, euthanasia is ○ Bone marrow transplantation
profile, urinalysis with culture and sensitivity, the most humane option. Control opportunistic • Phagocytic immunodeficiency
fecal exam, thoracic radiographs can reflect infections with antimicrobials and supportive ○ Bone marrow transplantation
concurrent infection (e.g., evidence of bacte- care; hospitalize when necessary.
rial pneumonia) Nutrition/Diet
• Other tests directed toward site of infection Acute General Treatment • Caloric requirements of the critically ill
(e.g., airway lavage if pneumonia, biopsy of Supportive care to treat opportunistic infections: patient may be less than those of a healthy
skin lesion) • Antibiotics are used for confirmed bacterial animal.
• Humoral (B-cell) immunodeficiency disorder: infections. Empirical antibiotics may be used ○ Resting energy requirement (RER): RER
no specific change initially, pending culture and sensitivity results. = 70 × body weight (kg) 0.75
• Cell-mediated (T-cell) immunodeficiency Antibiotic selection is based on suspected ○ RER approximation: 30 × body weight
disorder: normal/decreased lymphocyte count bacterial population of involved site. (kg) + 70
• Combined (B-cell and T-cell) immunodefi- ○ Skin: gram-positive bacteria most common; • If anorexia persists after infection treated,
ciency disorder: normal/decreased lymphocyte consider cephalosporins (cephalexin feeding tubes may be required.
count (average, 1000 cells/mcL); possibly low 22 mg/kg PO q 8-12h) or penicillins
total protein due to low globulin levels; agam- (amoxicillin 22 mg/kg PO q 8h) Drug Interactions
maglobulinemia (protein electrophoresis) ○ Oral cavity and respiratory tract • When using chloramphenicol, consider
• Functional phagocytic immunodeficiency ■ Gram-positive cocci: consider cepha- human risks (myelosuppression, aplastic
disorder: persistent leukocytosis with losporins 22 mg/kg PO, IV q 8h or anemia; wear gloves).
regenerative left shift; neutrophil count trimethoprim-sulfadiazine 15-30 mg/ • When using aminoglycosides, ensure that
> 200,000 cells/mcL kg SQ, IM, IV q 12h (lower end of patient is well hydrated and has adequate
• CLAD: marked leukocytosis; leukocytes dosage range for larger dogs) renal function.
cannot escape the vasculature ■ Gram-negative rods: trimethoprim- • Fluoroquinolones can affect cartilage in
• Cyclic neutropenia: neutrophil count within sulfadiazine 15-30 mg/kg SQ, IM, IV growing puppies.
or below reference range q 12h (lower end of dosage range for
• Trapped neutrophil syndrome: neutropenia larger dogs) or enrofloxacin 5-10 mg/ Possible Complications
kg IV q 24h or gentamicin 8 mg/kg • Sepsis
Advanced or Confirmatory Testing IV, IM, SQ q 24h • Recurring and resistant infections
If congenital immunodeficiency is suspected, ■ Bordetella infection: doxycycline 5 mg/
consult with small animal internal medicine spe- kg IV, PO q 12h or chloramphenicol Recommended Monitoring
cialist or veterinary immunologist. Functional 50 mg/kg IV, SQ, PO q 8h; enrofloxa- Monitoring of appetite, activity, temperature,
testing may require immediate assay. cin 5-10 mg/kg slow IV, IM, PO q 24 h and CBCs can aid in the early detection of
• Specific tests are tailored to the suspected ■ Mixed populations: consider fluoroqui- infection.
immunodeficiency. nolones (enrofloxacin 5-10 mg/kg PO
• CLAD: biopsy of lesion shows bacteria ± or slow IV q 24h) or beta-lactamase– PROGNOSIS & OUTCOME
necrosis but no neutrophil infiltration. resistant penicillins (amoxicillin-
• Humoral immunodeficiency: serum protein clavulanate 10-20 mg/kg PO q 12h) • Humoral immunodeficiency: fair to good
electrophoresis to evaluate immunoglobulin or macrolides (azithromycin 5-10 mg/ • Cell-mediated immunodeficiency: poor
concentrations, quantitation of serum immu- kg PO q 24h × 1-5 days) • Combined (B-cell and T-cell) immunode-
noglobulin, and serum C3 for C3 deficiency • Due to possibility of opportunistic fungal, viral, ficiency: poor. Affected animals usually die
• Cell-mediated immunodeficiency: lympho- and protozoal infections, empirical antibiotic between 2 and 4 months of age from systemic
cyte transformation (blastogenesis) evaluates therapy may be inadequate or may select for bacterial or viral infections.
the ability of the T cell to proliferate after resistant strains of bacteria; diagnostic samples • Phagocytic immunodeficiency: poor
stimulation; measurement of growth hormone for culture should be obtained before treat-
or insulin-like growth factor 1 if dwarfism ment, and judicious antibiotic use is warranted. PEARLS & CONSIDERATIONS
is suspected (available only in research • Nebulization and coupage for bacterial
laboratories) pneumonia (p. 795) Comments
• Cyclic neutropenia: bone marrow aspirate/ • Disinfection of cutaneous wounds with The diseases listed here are rare but are often
biopsy diluted (0.05%) chlorhexidine solution severe, and several have a poor/guarded prognosis.
• Functional phagocytic immunodeficiency ○ With standard 4% chlorhexidine solution,
○ Bactericidal assays: measure the ability of dilute 1 part chlorhexidine to 80 parts Prevention
neutrophils to phagocytize or kill bacteria, water to obtain a 0.05% concentration. • If molecular testing is possible, use genetic
or to generate reactive oxygen species ○ The same concentration may be used as an screening for predisposed animals.
○ Polymerase chain reaction (PCR): to iden- ear wash for otitis and as an oral antiseptic • If congenital immunodeficiency is identified,
tify affected, normal, or carrier animals rinse for stomatitis. avoid breeding related animals.

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