Page 1493 - Small Animal Internal Medicine, 6th Edition

CHAPTER 94 Polysystemic Bacterial Diseases 1465

depend on the environment for nourishment. Some Myco- have been detected in cats with polyarthritis. Mycoplasma
plasma spp. and Ureaplasma spp. are considered normal spp. have also been associated with the presence of rhinosi-
VetBooks.ir flora of mucous membranes. For example, Mycoplasma spp. nusitis, lower respiratory disease, and pyothorax. In one
study of cats with upper respiratory disease in Germany, M.
have been isolated from the vagina of 75% of healthy dogs
(Doig et al., 1981), the pharynx of 100% of healthy dogs,
plasma lipophilum, and Mycoplasma hyopharyngis were
and the pharynx of 35% of healthy cats (Randolph et al., felis, Mycoplasma canadense, M. cynos, M gateae, Myco-
1993). The hemotrophic mycoplasmas, Mycoplasma hae- identified in clinically ill cats (Hartman et al., 2010).
mofelis, “Candidatus Mycoplasma haemominutum,” “Candi-
datus Mycoplasma turicensis”, Mycoplasma haemocanis, and Clinical Findings
“Candidatus Mycoplasma haematoparvum” are associated Mycoplasma spp. infection should be considered a potential
with erythrocytes and are discussed in Chapter 82. differential diagnosis for cats presented for evaluation of
Mycoplasma felis conjunctivitis in cats, M. felis upper conjunctivitis, keratitis, sneezing and mucopurulent nasal
respiratory tract infection in cats, Mycoplasma gateae poly- discharge, coughing, dyspnea, fever, lameness with or
arthritis in cats, and Mycoplasma cynos pneumonia in dogs without swollen painful joints, subcutaneous abscessation,
have been induced experimentally. The pathogenic potential or abortion. Mycoplasma spp. or Ureaplasma spp. infections
for most Mycoplasma spp. or Ureaplasma spp. is difficult to were not associated with lower urinary tract disease of cats
determine because the organisms can be cultured or ampli- in one study (Abou et al., 2006). Mycoplasma spp. or Urea-
fied from both healthy and sick animals. In one shelter study, plasma spp. infection should be considered a potential dif-
M. cynos DNA was amplified for 29.2% of healthy dogs sug- ferential diagnosis for dogs presented for evaluation of
gesting that not all strains are pathogenic (Lavan and Knesl, coughing, dyspnea, fever, pollakiuria, hematuria, azotemia,
2015). For M. cynos, genetic heterogeneity has been docu- lameness with or without swollen painful joints, mucopuru-
mented, and some strains may be more pathogenic than lent vaginal discharge, or infertility. Mycoplasma spp. and
others (Mannering et al., 2009). Ureaplasma spp. are generally not recognized cytologically
In many cases Mycoplasma spp. or Ureaplasma spp. may and usually do not grow on aerobic media; infection should
be colonizing diseased tissues as opportunists as a result of be suspected in animals with neutrophilic inflammation
inflammation induced by other causes. Other bacteria or without visible bacteria or negative aerobic culture. The
viruses are usually identified concurrently with Mycoplasma index of suspicion for Mycoplasma spp. or Ureaplasma spp.
spp. or Ureaplasma spp., making it difficult to determine infection is higher if the animal has neutrophilic inflamma-
which agent is inducing disease. Ureaplasma spp. have also tion and has been poorly responsive to cell wall–inhibiting
been cultured from the vagina (40%) and prepuce (10%) of antibiotics such as penicillins or cephalosporins.
healthy dogs (Doig et al., 1981).
Mycoplasma spp. were isolated in pure culture from 20 of Diagnosis
2900 dogs with clinical signs of urinary tract inflammation The clinicopathologic and imaging findings associated with
(Jang et al., 1984), Mycoplasma canis was isolated from 4 of Mycoplasma spp. or Ureaplasma spp. infections are similar
100 dogs (3 in pure culture) with clinical signs of lower to those induced by other bacterial infections. Neutrophilia
urinary tract disease (Ulgen et al., 2006), and M. canis was and monocytosis are common in dogs with pneumonia;
isolated from nine dogs with clinical signs of urogenital pyuria and proteinuria occur in dogs with urinary tract
disease (L’Abee-Lund et al., 2003). Some M. canis positive disease.
dogs were azotemic, suggesting pyelonephritis (Ulgen et al., Preputial discharges, vaginal discharges, chronic draining
2006), and some have been resistant to therapy (L’Abee-Lund wounds, airway washings, and synovial fluid from animals
et al., 2003). with Mycoplasma spp. or Ureaplasma spp. infections have
Multiple studies suggest that some Mycoplasma spp. can nondegenerate neutrophils as the most common cell type.
be primary pathogens of the respiratory tract of dogs. Myco- Dogs with lower respiratory tract disease and pure Myco-
plasma spp. were the only organism cultured from 7 of 93 plasma cultures have alveolar lung patterns that cannot be
dogs (Jameson et al., 1995), 5 of 38 dogs (Randolph et al., differentiated from those in dogs with mixed bacterial and
1993), and 14 dogs (Chandler et al., 2002) with lower respi- Mycoplasma cultures. In some dogs and cats with small
ratory tract disease. In one study that compared Mycoplasma airway disease evident radiographically, Mycoplasma spp. are
isolates from dogs with and without respiratory disease, M. isolated from the airways in pure culture (Chandler et al.,
cynos in the lower respiratory tract was statistically associ- 2002). Joint radiographs of animals with Mycoplasma-
ated with respiratory disease (Chalker et al., 2004). In associated polyarthritis reveal erosive or nonerosive changes
another study, 80% of dogs that developed antibodies to M. (Zeugswetter, 2007).
cynos had respiratory signs of disease (Rycroft et al., 2007). Specimens for Mycoplasma spp. or Ureaplasma spp.
In a recent study of cats with and without conjunctivitis, culture should be plated immediately or transported to the
the presence of Mycoplasma spp. DNA was associated with laboratory in Hayflicks broth medium, Amies medium with
the presence of conjunctivitis (Low et al., 2007). Both M. felis charcoal, or modified Stuart bacterial transport medium.
and M. gateae have been associated with feline ulcerative Specimens should be shipped on ice packs if the transport
keratitis (Gray et al., 2005). Mycoplasma gateae and M. felis time is expected to be less than 24 hours and on dry ice if