4-year-old intact female German shepherd canine (Canis lupus familiars).The animal was presented after she fell down the steps in the house a few weeks ago. Owner noted that after the fall she has been wobbling and weak. One week before referral, the owner also reported some bloody vaginal discharge. The referring veterinarian described the patient as bright, alert, responsive, and calm. The dog was reported to have been in heat two months ago. The oral mucosa was pink with a normal capillary refill time; temperature was 101.6 o F (38.6 o C). The animal weighed 37 kg; a loss of 2 kg since last visit.
Ultrasound revealed a distended bladder; the uterus was distended with fluid in both horns. Pyometra was considered but hemogram and serum biochemical analyses were normal, except for a mild serum globulin concentration. Radiographs showed no pulmonary involvement.
Clinical pathology findings at this time: Low positive Lyme titer. CBC profile: HTC 40.3 (37-55 %); WBC 14.38 (6.5-15.90 th/ul); & neutrophils 80, lm 5%, mono 12 % eos 3 %. Mild moderate platelet clumping.
BUN creatitine within normal limits.
Total protein 8.6 (5.2-8.2)
Albumin 2.9 (2.5-4)
Globulin 5.7 (2.5-4.5)
Two days after the animals initial visit she was walking sideways, not defecating, and falling down. The animal had a mild head tilt to the left, walked in circles, and bilateral nystagmus. Vestibular disease, Lyme disease and Leptospirosis were included in the differential diagnosis. The dog was treated with tetracycline. The owner wanted an ovariohystorectomy performed on the animal. Cytology performed during surgery revealed numerous degenerated neutrophils and long thin septated fungal hyphae. The animal started fluconazol therapy. The owner was advised of the cytology findings and the owner decided on euthanasia 3 days after surgery. The animal collapsed just before arriving to the clinic and arrived unconscious. The animal was euthanized.
The postmortem examination performed by the local veterinarian revealed multifocal, white- gray well demarcated lesions in the liver, heart and kidney.Â Heart, uterus, and kidney were submitted for histopathology.Â No brain samples were submitted.
Uterus: There is a marked thickening of the endometrial wall with severe proliferation of the endometrial glands and lining epithelial cells, partially or completely occluding the uterine lumen.Â The abundant hyperplastic endometrium forms variable sized cystic dilations filled with eosinophilic acellular granular proteinaceous material admixed with variable numbers and combinations of neutrophils mixed with numerous fungal hyphae.Â The hyphae are thin (2-4 Î¼m), long (100-200 Î¼m), septate, and occasionally branch out, suggestive of Acremonium spp.Â The inflammatory reaction extends to the myometrium and to the serosal surface.
Uterus: Severe, transmural neutrophilic subacute endometritis with intralesional fungal hyphae and marked severe endometrial cystic hyperplasia.
Uterine content were submitted for microbiology:
Bulbithecium spp. (closely related to Bulbithecium hyalosporium) was isolated.Â
The anomorph of this fungus is Acremonium spp.
Mycotic uterine infections in dogs are very rare and have been associated with systemic fungal infection rather than exclusive uterine infections.Â Young German shepherds (GS) have been over represented in cases of systemic aspergillosis or acremoniosis.(4,10,12) It has been described that GS have an immunologic disorder that makes them predisposed for these type of invasions with saprophytic organisms.(6) This case described a mycotic systemic infection due to Bulbithecium spp., the anamorph phase of Acremonium.Â Unfortunately in this case no nervous tissue was submitted for histopathology to confirm that the systematic involvement explains the entire clinical presentation.Â The multifocal, well delimitated white nodules in the heart and the kidney are the classic findings in these systemic mycotic infections.Â GMS stain done on the uterus sections were positive and not necessary since the fungal hyphae and typical morphology can be seen in the H&E sections submitted for the conference.Â
The classification of Acremonium spp.Â has changed; previously it was described as hypomycetes, and currently it is classified as one of the two members under the group Dykara in the sub group Ascomycotas.Â It is still classified as Imperfect fungi (Deuteromycota), and nondematiaceous (not pigmented), but the term hyphomycetes is obsolete.
Pyometra is inflammation of the uterus that has variable symptomology from genitourinary disease to non-specific systemic disease.Â In the dog, pyometra is associated with cystic endometrial hyperplasia predisposed for by luteal activity (progesterone).Â During this phase, progesterone inhibits the intrauterine leukocyte response, decreases muscle contractibility and stimulates development and secretion of endometrial glands.(2,8) Clinically, pyometra can be associated with or without vaginal discharge depending on whether the cervix is closed or open.Â If the cervix is closed, the prognosis is more serious since the possibility of septic or uterine peritonitis exists.(2,9)
Fungi are a very variable group of eukaryotic organisms that belong to the fungi kingdom.(7) The old classification was based on morphologic microscopic features that classified the kingdom in 6 phyla.Â Classification of fungi is confusing and based on several criteria including formation of hyphae, pseudohyphae, or yeast forms.Â Another feature important in classification is the presence of a sexual stage of reproduction (teleomorph stage) or the absence of sexual reproduction (anamorphous stage).Â Biochemical and physical properties can be used to distinguish different species.Â However, more recently, molecular genetics and DNA analysis have played a role in taxonomy.(7)
Unfortunately, at the present time, there are no agreements on specific rules for an international system to facilitate the fungal nomenclature.Â There are some efforts to create an organized fungal classification scheme.(7)
The kingdom of Fungi is classified in 7 or 8 phyla or subdivisions.(5)
|II||Chytridiomycota||presence of a flagella||Protists-??|
|IV||Ascomycota||Yeast, septate hyphae and/or pseudohyphae Septate hyphae Yeast or filamentous morphology.Â Imperfect fungi= Deuteromycota||Perfect fungi Sexual spores = ASCOSPORES Imperfect fungi No sexual spores||Histoplasma, Pichia, Candida, Aspergillus, Cladosporidium, Alternaria Sacharomyces|
|V||Basidiomycota||Imperfect fungi = Deuteromycota||Imperfect fungi No sexual spores||Cryptococcus Malassezia|
|VI||Neocallimastigomycota||Anaerobic organisms||Perfect fungi Sexual spores = BASIDIOSPORES|
|VII||Glomeromycota||Perfect fungi Sexual spores = ZYGOSPORES Zygomycota||Perfect fungi Sexual spores = ZYGOSPORES.Â Non-septate hyphae||Mucor,Rhizopus Absidia Mortierella|
|VIII||Oomycota||Cellulose-walled fungi-like- organims||Pythium, Saprolignea|
Uterus: Endometritis, necrotizing, diffuse, severe, with marked cystic endometrial hyperplasia and numerous fungal hyphae.
The contributor mentioned the predisposition of German shepherd dogs to disseminated infection with saprophytic fungi, and conference participants discussed Aspergillus terries as the most common culprit, with reported lesions including pneumonia, myositis, myocarditis, endometritis, encephalitis, nephritis, splenitis, osteomyelitis, and lymphadenitis due to hematogenous spread of the fungal aleurospores.3 In addition to bacterial and rare fungal and viral causes of endometritis in dogs, a differential diagnosis should include other non-infectious etiologies such as pseudopregnancy, caused by retained corpora lutea which can contribute to cystic endometrial hyperplasia-pyometra complex, and placental sub-involution, which manifests as necrosis and hemorrhage of the endometrium with invasion of trophoblasts into adjacent myometrium and blood vessels, producing a hemorrhagic vaginal discharge.(11)
In mares, a reported fungal cause of abortion is fescue grass toxicity caused by Neotyphodium (formerly Acremonium) coenophialum.Â This fungal endophyte infects grass and produces the ergot alkaloid ergovaline, which causes dysmaturation of foals and infrequent abortion.Â Ergovaline, in addition to its well known alpha-2 adrenergic agonistic effects causing vasoconstriction seen in fescue foot in cattle, is a potent dopamine D2 receptor agonist which blocks prolactin, which is important in maintaining the corpus luteum and mammary gland growth and milk production.Â The lack of prolactin with decreased progesterone and increased estradiol in the mare during pregnancy can lead to fetal death.Â Fetal death also occurs from suffocation due to a thick edematous placenta that does not rupture at the cervical star.Â The mares are also agalactic with minimal colostrum, and if the foal survives to term, they often die due to failure of passive transfer.Â
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2.Â Bonagura JD, Kirk RW.Â Kirks Current Veterinary Therapy XII, Small Animal Practice. W.B.Â Saunders Co; 1995.Â
3.Â Bruchim Y, Elad D, Klainbart S.Â Disseminated aspergillosis in two dogs in Israel.Â Mycoses.Â 2006;49(2):130-3.
4.Â Day MJ, Eger CE, Shaw SE, Penhale WJ.Â Immunologic study of systemic aspergillosis in German shepherd dogs. Veterinary Immunology and Immunopathology.Â 1985;9(4):335-347.
5.Â Deacon, JW.Â Modern Mycology 3rd ed.Â Oxford, UK: Blackwell Science; 1997.
6.Â Foley JE, Norris CR, Jang SS.Â Paecilomycosis in Dogs and Horses and a Review of the Literature.Â Journal of Veterinary Internal Medicine. 2002;16(3):238-243.Â
7.Â Hibbett DS, et al.Â A higher level phylogenetic classification of the Fungi.Â Mycological Research.Â 2007;111(5):50947.
8.Â McGavin DM.Â Pathologic Basis of Veterinary Disease 4th ed.Â Mosby/Elsevier; 2007.Â
9.Â Noakes DE, Dhaliwal GK, England GC.Â Cystic endometrial hyperplasia/pyometra in dogs: a review of the causes and pathogenesis.Â J Reprod Fertil. 2001;57 (Suppl):395-406.
10.Â Pedersen NC.Â A review of immunologic diseases of the dog.Â Veterinary Immunology and Immunopathology. 1999;69 (2-4):251-342.
11.Â Schlafer DH, Miller RB.Â Female genital system.Â In: Maxie MG, ed.Â Jubb, Kennedy, and Palmers Pathology of Domestic Animals. 5th ed.Â Vol 3.Â Philadelphia, PA: Saunders Elsevier; 2007:537-8.
12.Â Simpson KW, Khan KN, Podell M, et al.Â Systemic mycosis caused by Acremonium sp in a dog.Â J Am Vet Med Assoc. 1993;203(9):1296-9.