Page 995 - Clinical Small Animal Internal Medicine

98 Nonhemotropic Mycoplasma, Ureaplasma, and L‐Form Bacteria 933

dose was used. Natural Mycoplasma conjunctivitis pre­ disease. Clinical findings were fever, productive cough,
VetBooks.ir dominantly occurs when infected cats are housed in and leukocytosis with a left shift. Radiographs fea­
tured alveolar and bronchointerstitial pulmonary den­
groups or in kittens soon after weaning. The clinical
signs observed may vary in severity and have been
for some pups and necropsy findings were mucopuru­
described as blepharospasm, conjunctival hyperemia, sities and mild pleural effusion. Infection was fatal
chemosis, and serous discharge followed by mucoid to lent airway exudates and hemorrhagic fibrinous necro­
sticky exudate. The cornea is usually not involved; how­ tizing bronchopneumonia. M. cynos was abundantly
ever, M. felis and M. gateae have been occasionally asso­ demonstrated at neutrophilic inflammatory sites using
ciated with ulcerative keratitis and/or keratomalacia. immunohistochemistry.

Respiratory Mycoplasma Infections in Cats Urogenital Mycoplasma Infections in Dogs

Mycoplasmas have been associated with chronic and Mycoplasmas are commonly present in the lower uro­
acute feline upper respiratory tract disease (URTD) by genital tract of dogs. They have occasionally been asso­
epidemiologic evaluation, but available data are more ciated with canine reproductive diseases including
inconclusive hypotheses than definite proofs of causality. poor conception rates, early embryonic death, fetal
Studies have also suggested that approximately 22% of resorption, abortion, weak pups, and neonatal death.
cats with lower airway disease may have a concurrent M. canis and U. canigenitalium are the species most
Mycoplasma infection. consistently associated with canine genital mycoplas­
Experimental challenge with M. felis induced pneumo­ mosis. Mycooplasma canis has been isolated from dogs
nia in kittens, emphasizing its role as a primary pathogen with urogenital disease and infertility, despite pro­
in the lower respiratory tract. Naturally occurring infec­ longed antibiotic therapy. It has also been cultured
tions with M. felis have been increasingly reported in the from the prostate, epididymis, and chronically inflamed
feline host associated with suppurative bronchitis and/or bladder wall. Experimental infection with Mycoplasma
pneumonia. Radiographic or computed tomography canis produced urethritis, prostatitis or epididymitis in
(CT) findings may include diffuse interstitial pulmonary males and endometritis or metritis in females. In a sin­
disease similar to that observed in adult human patients gle study, U. canigenitalium was associated with infer­
with M. pneumoniae pneumonia. Cats with concurrent tility in male dogs. Nevertheless, as conclusive evidence
pleural effusion show minimal signs of dyspnea and a is lacking, further studies are required to establish
nonodorous fluid is expected with uncomplicated whether M. canis or U. canigenitalium is linked to geni­
Mycoplasma pyothorax. tal tract infections and infertility.

Respiratory Mycoplasma Infections in Dogs Arthritis in Cats and Dogs Caused by
Mycoplasmas
Mycoplasmas have been isolated from 78% of tracheo­
bronchial lavages of younger dogs with pulmonary dis­ Only a few cases of naturally occurring mycoplasma
ease but may also be present in the lower respiratory mono‐ and polyarthritis in cats (M. felis, M. gateae)
tract of healthy individuals (20–25%). Consequently, and dogs (M. edwardii, M. spumans) have been docu­
the role of certain canine Mycoplasma species as patho­ mented so far. In most cases, predisposing factors such
gens in canine pulmonary disease is still a subject of as immunosuppressive therapy, acquired immunodefi­
controversy. Experimental infection with M. canis, M. ciency or traumatic bites have been identified. The
gateae, and M. spumans failed to produce pulmonary pathogenic potential of M. gateae in cats, however, has
disease. However, M. cynos has been consistently asso­ been substantiated by intravenous injection resulting
ciated with canine respiratory diseases, including in polyarthritis.
tracheobronchitis and bronchopneumonia, conditions
that have been reproduced experimentally. A more Mycoplasma Central Nervous System
recent study noted a correlation of M. cynos with canine Infections in Cats and Dogs
infectious respiratory disease (CIRD) in younger dogs
(<1 year). Dogs acquired infection during the first two Mycoplasma felis has been isolated from brain and spinal
weeks after being kenneled and seroconversion to M. cord sections of a young cat with meningoencephalomy­
cynos was correlated with the development of clinically elitis. A similar infection has been documented in a
respiratory disease. Further evidence of the primary young dog with suppurative meningoencephalitis caused
pathogenic role of M. cynos was its isolation as sole by M. edwardii, and a penetrating wound close to the
pathogen from a litter of pups with severe respiratory skull was suspected as the source of infection.