Page 991 - Clinical Small Animal Internal Medicine

97 Hemotropic Mycoplasma 929

Figure 97.1 Hemoplasma organism 10 10
VetBooks.ir with 10 M. haemofelis organisms by 10 9 8
numbers in the blood of four cats infected
3
subcutaneous inoculation on day 0 post
infection. Cats infected with M. haemofelis
often show marked fluctuations in blood 10 7
organism numbers, especially during early 10
infection. Such fluctuations, in the absence 10 6
of treatment, should be considered when
interpreting quantitative PCR results in M. 10 5
haemofelis‐infected cats. Longer term M. haemofelis organism numbers/mL blood
fluctuations in organism numbers in the 10 4
blood are seen in some M. haemofelis‐ 3
infected cats. In contrast, cats infected with 10
Ca. M. haemomintum and Ca. M. turicensis 10 2
do not show these blood organism
number fluctuations at any stage of 10 1
infection.
1

Non detected
0 10 20 30 40 50 60 70 80
Day post infection

A number of antibiotics, notably tetracycylines (pri- mediated component of anemia. However, the vast
marily doxycycline at 10 mg/kg once daily PO or 5 mg/kg majority of hemoplasma‐infected cats, including those
twice daily PO; as some formulations have been associ- that have erythrocyte‐bound antibodies confirmed,
ated with esophagitis following incomplete swallowing, respond to antibiotic treatment and supportive care
all doses should be followed with food or water) and fluo- alone without the need for corticosteroids. Indeed,
roquinolones (e.g., marbofloxacin 2–5.5 mg/kg once daily immunosuppressive doses of corticosteroids have been
PO, pradofloxacin 5 mg/kg once daily PO), have been used experimentally to exacerbate hemoplasma infec-
shown to be effective in reducing feline hemoplasma tion, so their routine use is not advised.
(especially M. haemofelis) organism numbers and cause In view of the potential for vector transmission of
resolution of clinical signs. Courses of two weeks are usu- hemoplasmas, control for fleas and ticks should also be
ally recommended although some have suggested that instigated.
longer treatment courses (up to six weeks) increase the
likelihood of eliminating infection. Pradofloxacin may be
more effective at clearing M. haemofelis than doxycy- Prognosis
cline. One recent study has suggested that clearance of M.
haemofelis infection may be possible using 28 days of With prompt and appropriate therapy, the prognosis for
doxycycline followed by marbofloxacin for 14 days if the feline and canine hemoplasmosis is good. However, the
cats remained PCR positive. disease can be fatal if untreated, due to severe hemolytic
Only limited information is available regarding the
response of canine hemoplasma infections to antibiotic anemia, collapse, and death.
therapy. Tetracycline or fluoroquinolone treatments
have both been associated with clinical improvement,
but infection has sometimes persisted. Public Health Implications
Ideally, response to antibiotic treatment in both cats and
dogs should be monitored by qPCR to ensure organism Polymerase chain reaction methods have recently docu-
numbers are decreasing with therapy but clinical improve- mented human hemoplasma infections and some have
ment usually occurs within 2–3 days of effective treatment. documented infection with veterinary hemoplasma
Affected dogs and cats may also require aggressive species such as Ca. M. haematoparvum. In view of this,
supportive treatment with crystalloids or blood products blood from potentially infected animals should be han-
(blood transfusions). dled with care and vector control initiated. Future studies
Corticosteroids have been recommended as adjunct should evaluate the zoonotic potential and transmission
treatment for hemoplasmosis, to treat the immune‐ of these emerging pathogens.