1. Non Infectious, Non Neoplastic 2. Non Infectious, Neoplastic. 3. Infectious. Pituitary tumors (D) (adenomas>> carcinomas)

Transcription

1 Famous Rat Pathology (Phenotypes) Discussion Plan 1. Non Infectious, Non Neoplastic 2. Non Infectious, Neoplastic 1 Cory Brayton, D.V.M., D.A.C.L.A.M., D.A.C.V.P. Associate Professor, Molecular and Comparative Pathobiology Director, Phenotyping Core Johns Hopkins University, School of Medicine Baltimore, MD TEL: FAX: phenocore@jhmi.edu Infectious NOT Neoplastic 4 Famous Rat Phenotypes Nephropathy (D) (mineralization, Parathyroid hyperplasia) Cardiomyopathy (D) (Degeneration, fibrosis, inflammation) Arteritis polyarteritis Axonal degeneration Infectious/parasitic BOLD possible likely COD CCOD Not bold Incidental finding/phenotype to expect D Role of Diet I Role of Infectious agents? E.g. MYCOPLASMA, Trichosomoides crassicauda Neoplastic Pituitary tumors (D) (adenomas>> carcinomas) Mammary tumors (D) (fibroadenoma etc) Pheochromocytomas Hematopoietic (I) Histiocytic sarcomas Fibromas, sarcomas Adrenal cortical, Thyroid follicular or C cell; Zymbal Gland, Urinary bladder (I) 4 5 Famous Rat lesions (phenotypes) 1. Non Infectious, Non Neoplastic a. Nephropathy b. Arteritis c. Cardiomyopathy etc 2. Non Infectious, Neoplastic a. Skin Tumors (most commonly seen) b. Hematopoietic (most? Famous) c. Pituitary etc (most? Common killer) etc 3. Infectious 6 1.a. Rat Nephropathy Most common significant lesion or COD in many studies, especially Older studies/diets Ad lib feeding Gross : Lumpy bumpy kidneys LARGER then smaller AKA CPN Chronic progressive nephropathy CRD Chronic Renal Disease ORN Old rat nephropathy 7 1.a. Rat Nephropathy Glomeruli Large Mesangium Cellularity Synechiae Small Sclerotic Tubules Dilated, protein Degen, regen Mineral +/ Interstitium Inflammation Fibrosis RodentPath 7 cbrayton@jhmi.edu of 32

2 1.a. Rat Nephropathy Glomeruli Large Mesangium Cellularity Synechiae Small Sclerotic Tubules Dilated, protein Degen, regen Mineral +/ Interstitium Inflammation 8 Fibrosis RodentPath 8 9 Soft tissue mineralization Severe nephropathy. Enlarged parathyroid. Soft tissue mineralization Severe nephropathy? Enlarged parathyroids? HEART, arteries LUNG septa Soft tissue mineralization Severe nephropathy? Enlarged parathyroids? Stomach Muscle b. Arteritis, periarteritis (aka polyarteritis nodosa (PAN)) Gross: Thick, nodular, multicolored arteries, mesenteric arcade, pancreas, spermatic cord etc Histology: Inflammation neutrophilic lymphohistiocytic, transmural periarterial Mural periarterial thickening by inflammation, proliferation (fibroplasia;) hemorrhage fibrinoid, mineralization /+Thrombi laminated, recanalized etc 1.b. Rat PAN Nodular thickening Arteritis, periarteritis, chronic, lymphohistiocytic, transmural proliferative with Fibroplasia Fibrinoid Thrombi Mineral etc 15 RodentPath 15 cbrayton@jhmi.edu of 32

3 1.b. Rat periarteritis / polyarteritis Rat PAN Aka Polyarteritis Nodosa (PAN) Earliest in mesentery, pancreas, spermatic cord Most obvious in mesentery SD, SHR, hypertensive rats Nodular thickening +/ hemorrhage, 16 mineral RodentPath Earliest? In Pancreas Mesentery Spermatic cord Best gross in Mesentery Veins Spared Thrombi Fibrinoid deposition Disrupted elastic lamina Proliferation Subintimal Medial Adventitial Inflammation Rat PAN Rat PAN Disrupted elastic lamina Proliferation Subintimal Medial Adventitial Inflammation Rat crystals are blood (Hb) origin c. Rat Cardiomyopathy Cardiomyopathy Myofiber degeneration loss Replacement fibrosis Mild chronic inflammation Cf human MI +/ mineral usually with ORN 20 RodentPath = heart muscle abnormality IN pets & people Impaired function diagnosed by ECG, US Big dilated? Hypertrophic? Small fibrotic HOCM COCM RCM cbrayton@jhmi.edu of 32

4 Cardiomyopathy Cardiomyopathy IN TOX refers to spontaneous changes Typically multifocal Inflammation (Rats > mice) Myofiber degeneration /necrosis/ loss) Fibroplasia +/ collagen vs toxic myocardial degeneration Usually extensive global Jokinen & al Jokinen & al TP Etc NON neoplastic Lungs Alveolar histiocytosis White spots = foam cell foci Alimentary Ulcers gastric/duodenal Stressors, including dehydration, water / diet restriction Crystals 25 Etc: Alveolar histiocytosis Renne & Al intra alveolar macrophages containing foamy cytoplasm Often subpleural in aged animals Increased with hi fat diet Fldodh Magnuson Magnuson 1974 Rat WYD? 1. Etc Non Neoplastic A. Alveolar histiocytosis B. Acidophilic macrophage Pneumonia C. Pneumocystosis D. Induced alveolar proteinosis WYD? A. YM1 crystals B. Blood derived hemoglobin crystals C. Charcot leyden Crystals D. Oxalate crystals 26 Copyright by Society of Toxicologic Pathology Roger Renne et al. Toxicol Pathol 2009;37:5S-73S 28 cbrayton@jhmi.edu of 32

5 WYD? A. YM1 crystals B. Blood derived hemoglobin crystals C. Charcot leyden Crystals D. Oxalate crystals 1. Etc Non Neoplastic Etc: Rat crystals Eosinophilic crystals, Rat lung; Rectangular and linear; Extracellular, alveoli and capillaries. No associated inflammation, nor resemblance to eosinophilic crystalline pneumonia Inset: Okajima stain for hemoglobin. Considered an artifact of freezing, intracardiac puncture, and barbiturate euthanasia. found only in euthanized rats and not in rats found dead or killed in snap traps. likely crystalized hemoglobin J. L. Rothenburger et al. Vet Pathol 2015; & Cause/s? A. Vaginal septa B. E coli Rats WYD? Which is Normal? Rats WYD? 6. Normal vagina, rat. 7. Vagina, rat, vaginal septum with necro-hemorrhagic fluid accumulation. 8. Vagina, rat, thin vaginal septum. 9. Vagina, rat, thick vaginal septum. 10. Vagina, rat, mucus plug accumulation in the proximal part of the vagina. 31 S. Lezmi et al. Vet Pathol 2010;48: S. Lezmi et al. Vet Pathol 2010;48: Great Rat lesions (phenotypes) 2.a. Skin Tumors Non Infectious, Non Neoplastic 2. Non Infectious, Neoplastic a. Skin / Mammary most obvious b. Hematopoietic most famous c. Pituitary most common? etc e.g. Adrenal, Thyroid, insuloma; mesothelioma; reproductive; urinary tract etc 3. Infectious 34 Mammary Fibroadenoma (F >> M) Most common tumor identified clinically Gross: small big, soft firm Often resectable Histo Mesenchymal often predominates Glands can be hard to find Fibromas Sarcomas (M > F?) Gross: small big, soft firm Histo Mesenchymal Fibrosarcoma collagen Trichrome Myxoid myxomatous bluish Alcian blue PNST like (peripheral nerve sheath tumor ) cbrayton@jhmi.edu of 32

6 2.a. Skin Tumors Mammary fibroadenoma More common in Female 40 70% incidence in SD! Associated with hi prolactin, But not necessarily pituitary tumors Case 4 RAT 18 month old female Strain: 35 RodentPath 35 c HCD Rat Mammary Tumors F344 ad lib Strain Diet F344 DR F344 SD CIT Max % SD WIS LE Fibroadenoma Adenofibroma 24 Adenoma Cystadenoma 10 Adenocarcinoma Ductular carcinoma 14 ref Thurman 94 Thurman 94 Sommer 97 Attia 95 Sommer 97 Sommer 97 Sommer Rat Mammary Tumors Associated with increased or decreased mammary tumors? Exposure to estrogen Increased prolactin levels Parity Ovariectomy Pituitary tumors Body weight (Ad lib feeding) What (2) are associated with increased pituitary and mammary tumors Estrogens & body weight 2.a. Skin Tumors 2.a. Skin Tumors Mammary fibroadenoma More common in Female 40 70% incidence in SD! Associated with hi prolactin, But not necessarily pituitary tumors Trichrome stains collagen Fibro ~ blue (Adeno (glands) ~pink/red) 43 RodentPath 43 Fibroma More likely? than fibroadenoma in male Sarcomas are invasive Myxoid PNST Osteo Hemangio (Histiocytic Sarcoma) 44 cbrayton@jhmi.edu of 32

7 2.a. Skin Tumors Other skin tumors Histiocytic sarcoma in skin Also in literature as Fibrous histiocytoma or MFH Malignant Fibrous Histiocytoma Papilloma Squamous cell carcinomas Uncommon unless induced (skin paint) Zymbal gland tumors Sebaceous gland anteroventral to external canal Sebaceous squamous feature 2.b. Rat Hematopoietic Tumors Lymphoma, leukemia, histiocytic sarcoma Arguably most Famous rat tumors everyone has heard of them LGL leukemia aka mononuclear leukemia especially F344 Other lymphomas Histiocytic sarcoma anywhere in rat Lung Lymphomas? 2.b. Rat Hematopoietic Tumors LGL leukemia aka mononuclear leukemia Especially F344 Splenomegaly (homogeneously enlarged on gross) Arise in spleen marginal zone Hepatomegaly later Leukemia circulating mononuclear cells with azurophilic granules Pale rat with watery blood Brayton Williford F344 rat LGL leukemia Diagnoses Splenomegaly Icterus Hepatopathy (neoplasia) Icterus dt? 50 Photos by E Ihms 51 Photos by E Ihms cbrayton@jhmi.edu of 32

8 Diagnosis Pigment nephropathy case 2 F344 Rat Intravascular leukocytosis Leukemia Special stains? IHC? Cause? Hemolysis Immune mediated? 52 Smear: Spherocytosis, polychromasia/anisocytosis, thrombocytopenia, neutrophilia, leukemia Photos by E Ihms Mononuclear cell leukemia LGL leukemia Heterogeneous NonT, non B, NK activity Usually Lysosyme, Esterase negative TOX PROBLEM equivocals Relevant human condition? Rare aggressive NK LGL leukemia? 2.b. Rat Hematopoietic Tumors Spleen Nodules Lymphoma Histiocytic Sarcoma? cbrayton@jhmi.edu of 32

9 2.b. Rat Hematopoietic Tumors Histiocytic Sarcoma Pleomorphic histiocytoid cells Spleen 2.b. Rat Hematopoietic Tumors Lung Lymphoma? Association with M pulmonis. 58 RodentPath RodentPath 59 2.c. Pituitary Tumors MOST common tumors in some chronic studies 30% 80% Important COD in some often Bloody Cystic Large Prolactin secreting galactorrhea month old female Long Evans Rat Axillary mass; pituitary mass Rat Brain tumors RodentPath 64 cbrayton@jhmi.edu of 32

10 65 2.c. PituitaryTumors Usually Pars Distalis Cords of epithelial cells in vascular stroma Chromophobe > acidophil or basophil Prominent nucleoli 2.b. Pituitary Tumors Usually pars distalis / intermedia / nervosa? Usually adenomas / carcinomas? Usually secrete? Most common in Males or females? age Female % Male % SD old Attia 1995 usually with mammary neoplasia in females (uterine changes suggest estrogen exposure??) SD 2y McMartin & al 1992 Wistar 110 w Nataraju estrogen induced F344 2y Thurman & al 1994 reduced by food restriction in M 68 LOBUN Hi? P ll d S d 69 2.b. Pituitary Tumors Origin of most common pituitary tumor in Human / Rat / Mouse Pars distalis Pars intermedia Pars nervosa Most common secretory product Prolactin (+ GH in human) Likely clinical Signs Galactorrhea in males; acromegalic features or growing nose in elderly humans 70 Rat Pituitary Changes Usually pars distalis Pituitary adenomas compressive May have Pseudocapsule, hemorrhage, cystic changes Chromophobes, acidophilic, basophilic, mixed Hyperplastic Foci = proliferation of cells of normal size, no evidence of pseudocapsule and no significant compression of adjacent pituitary tissue. Nodules of hypertrophic cells = larger cells without evidence of encapsulation Pituitary carcinomas are rare and require evidence of invasion or distant metastasis for their diagnosis. Rat Pituitary Changes Myths? Chromophobe adenomas that secrete prolactin Also Eosinophilic cells Estrogen influence Takekoshi & al A Histopathological Study of Multi-hormone Producing Proliferative Lesions in Estrogen-induced Rat Pituitary Prolactinoma. Acta Histochem Cytochem. 47(4): Etc Rat Endocrine Tumors Adrenal: Cortical F> M? Medullary pheochromocytoma M > F? Up to 70% in Wistar rats Some with Ganglioneuroma Thyroid: Follicular tumors thyroglobulin + / Follicular, cystic, papillary, solid Interstitial C cell (M>F) Calcitonin + more common than in mice esp in BN, WH? Islets insulinoma BN rats Vs hypertrophy in fat insulin resistant rats? cbrayton@jhmi.edu of 32

11 Etc Rat Endocrine Tumors Pheochromocytoma Adrenal Pheochromocytoma (medullary) Often Bloody Large Invade Vessels (ORN also here) ~80% Wistar!! ~30% SD & F344 Often bloody Invades vasculature Pheochromocytoma Ganglioneuroma packeted neuroendocrine pattern Look like Ganglion cells Usually w pheo Also in Trp53 TM mice Reproductive: 2. etc tumors Testes: Interstitial C cell (F344!!) > Sertoli, seminoma Vagina /cervix / uterus polyps, stromal tumors Urinary tract Kidney renal carcinoma (LE rats, Eker rats); nephroblastoma Ureter/Bladder BN rats T crassicauda? Mesothelioma especially F344 Etc. 2.c. OTHER Rat Tumors Mesothelioma 82 Spermatic cord disseminates Another tumor? Likely Strain? RodentPath 82 cbrayton@jhmi.edu of 32

12 68040 Another expected finding in F344 male >1yo? 55. Rat testis. Adenoma, Leydig cell. 56. Rat testis. Adenoma, Leydig cell. Differing cellular characteristics with pale foamy vacuolated cells and small basophilic fusiform cells. 57. Rat testis. Adenoma, Leydig cell, retiform. 58. Rat testis. Adenoma, Leydig cell, retiform. 59. Rat testis. Carcinoma, Leydig cell. 60. Rat testis. Carcinoma, Leydig cell. Creasey & al Photos by E Ihms 84 Creasy et al. Toxicol Pathol 2012;40:40S-121S Copyright by Society of Toxicologic Pathology Interstitial Cell Tumors Aka Leydig cell tumors Most common testicular tumor in? 1. Rat 2. Cat 3. Dog 4. Bull Hyperplastic lesions focal/diffuse? Size? Usually more diffuse Usually < 3 seminiferous tubules in diameter Rat seminiferous epithelium PAS. PAS stains carbohydrates and emphasizes the glycoproteins contained in the acrosomes (A). Acrosomes, which cap the nuclei of spermatids (St a), play an important role in the fertilization of the oocyte. Note the presence of basophilic residual bodies (R) along the surface of the epithelium. These cytoplasmic bodies separate from the spermatozoa, as these cells detach from the seminiferous epithelium (see Figure 15.10). These residual bodies are eliminated by the phagocytic activity of Sertoli cells. Some pachytene spermatocytes (Sc) are also labelled. Note that the thin limiting membrane of rat tubules is composed of a single layer of myoid cells (My). Stain: PAS Hematoxylin Magnification: Creasy et al. Toxicol Pathol 2012;40:40S-121S Copyright by Society of Toxicologic Pathology WYD 87 Creasy et al. Toxicol Pathol 2012;40:40S-121S Copyright by Society of Toxicologic Pathology 90 cbrayton@jhmi.edu of 32

13 Granulosa Cell tumor wo female Rat SD with Thy1:GFP transgene Synonym(s) Tumor, sex cord stromal, benign, granulosa cell type. Non cystic, solid proliferative lesion larger than a CL. Cell morphology resembles normal granulosa cells. >70% granulosa cells. (+ Stromal component) Variable luteinization Atypia can be Minimal. Mitotic figures may be rare few. Call Exner bodies uncommon. Cystic, microfollicular, solid, trabecular but usually NOT subclassified by pattern. Hemorrhage necrosis lipofuscin in larger tumors. Benign: Compressive Malignant: Invasion/metastasis, size, hemorrhage, necrosis, atypia 91 Dixon&al female Repro INHAND 2014 JTP wo female Rat wo female Rat SD with Thy1:GFP transgene SD with Thy1:GFP transgene WYD? Likely strain? EKER rat (or LE ) Hereditary RCC Tsc2 (tuberous sclerosis2) tumor suppressor gene insertion mutation Autosomal dominant Homozygous lethal Arose in inbred Wistar Mcdorman & Wolf 2002 Tox Path 96 Who is this famous rat? What is its famous mutation? cbrayton@jhmi.edu of 32

14 Rat Zymbal s gland what is it? multilobulated sebaceous holocrine gland located anterior ventral to the ear canal 3 4 lobules each have intralobular ducts (Squamous epithelium) that empty into the excretory duct and then into ear canal. Do mice have it? How common are spontaneous tumors? Not very common but ~ 1% or less in aging studies in various strains Zymbal s gland neoplasia? WYD? Types Sebaceous cell adenoma, Squamous cell papilloma, Carcinoma of sebaceous and/or ductal epithelial origin Causes of Zymbal s gland neoplasia? target organ of many carcinogens incidence a high as 67% (versus 0% in controls) E.g.2 Acetylaminofluorine, Tris carbonium pamoate, urethan, heterocyclic amines, benzene, 3 3 dichlorobenzidine, 4 aminostilbene, azoxymethane, methychorlanethrene, and cupferron WYD? QUIZ WYD? cbrayton@jhmi.edu of 32

15 Etc. spontaneous conditions in recent literature: PubMed SEARCH vet pathol [jo] 2015 mice vet pathol [jo] 2015 rats toxicol pathol [jo] 2015 mice jaalas [jo] 2015 mice toxicol pathol [jo] 2015 rats jaalas [jo] 2015 rats j comp path [jo] 2015 mice j comp path [jo] 2015 rats Comp med [jo] 2015 mice Comp med [jo] 2015 rats lab anim [jo] 2015 mice lab anim [jo] 2015 rats 1. Pets 2. Lunch 3. Toxicity What are rats good for? PK! 4. Cancer 5. Behavior 6. Metabolic dz What are rats good at? Amazing Rats! SURVIVAL ayer_detailpage&v=0t2vpbf6kp Great Rat lesions (phenotypes) Non Infectious, Non Neoplastic 2. Non Infectious, Neoplastic 3. Infectious a. Viruses b. Bacteria c. Eukaryota a. Fungi b. Protozoa c. Metazoa a. Helminths b. Arthropod cbrayton@jhmi.edu of 32

16 FELASA 2014 recommendations Rats Viruses FELASA 2014 recommendations Rats Bacteria & Fungi 3 month testing 1. Parvovirus Kilham rat virus 2. Parvovirus Rat minute virus 3. Parvovirus Rat parvovirus 4. Parvovirus Toolan sh 1 virus 5. PVM 6. Rat coronavirus (SDAV) 7. Rat theilovirus 8. Hantaviruses x Annual testing 1. MAD1 (FL) 2. MAD2 (K87) 3. Reovirus type 3 4. Sendai virus 3 month testing 1. Clostridium piliforme 2. Helicobacter spp. + H bilis 3. Mycoplasma pulmonis 4. Pasteurella pneumotropica 5. Strep b haemolytic (not group D) 6. Streptococcus pneumoniae Annual testing 1. CAR bacillus 2. Pneumocystis spp. 3. Salmonella spp. 4. Streptobacillus moniliformis NO FUNGI FELASA 2014 recommendations RATS Other Agents Bacteria etc 1. Bordetella bronchiseptica 2. Corynebacterium kutscheri 3. Encephalitozoon cuniculi 4. Klebsiella oxytoca, 5. Klebsiella pneumoniae 6. Other Pasteurellaceae 7. Pseudomonas aeruginosa 8. Staphylococcus aureus Unlikely in contemporary colonies Found in healthy animals & Too common to practically exclude Rat Serology: Results Pritchett Corning, K. R., J. Cosentino, et al. (2009). "Contemporary prevalence of infectious agents in laboratory mice and rats." Lab Anim 43(2): Prevalence % Agent (assay abbreviation) Method N NA Europe Total Adenovirus (MAV 1 and 2) Serology 35, Hantaviruses (HANT) Serology 23, Lymphocytic choriomeningitis virus (LCMV) Serology 37, Parvovirus generic assay (NS-1) Serology 63, H-1 (Toolan's) Serology 79, Rat virus (RV, KRV) Serology 86, Rat minute virus (RMV) Serology 47, Rat parvovirus (RPV) Serology 85, Pneumonia virus of mice (PVM) Serology 79, Rat coronavirus (RCV/SDAV) Serology 82, Rat respiratory virus (RRV) Histopathology na 6.36 Rat theilovirus (RTV, GD-VII) Serology 35, Reovirus-3 (REO-3) Serology 72, Sendai virus (SEND) Serology 80, Virus prevalence Rats (P car) RRV Parv NS-1 RTV Virus type a Sample type Family or genus No. of pools Most similar species Known Serum Anelloviridae 22 Unclassified anellovirus Serum Bocavirus 9 Porcine bocavirus Serum Mastadenovirus 1 Murine adenovirus A Serum Parvovirus 19 Kilham rat virus Fecal Bocavirus 16 Porcine bocavirus Fecal Calhevirus 10 Calhevirus 1 Fecal Cardiovirus 21 Boone cardiovirus / Rat theilovirus 1 Fecal Circovirus 21 Pig stool-associated circular ssdna virus Chicken anemia virus Fecal Hunnivirus 19 Ovine hungarovirus Fecal Mamastrovirus 19 Rat astrovirus / Murine astrovirus Fecal Mastadenovirus 18 Murine adenovirus A Fecal Parvovirus 24 Kilham rat virus Fecal Rotavirus 3 IDIR agent Fecal Other 31 Novel Serum Arterivirus 2 Porcine reproductive and respiratory syndrome virus Serum Hepacivirus 16 Rodent hepacivirus Serum Orbivirus 3 African horse sickness virus / Epizootic hemorrhagic disease virus Serum Pegivirus 15 Rodent pegivirus Serum Pestivirus 4 Bungowannah virus / Classical swine fever virus Fecal Hepeviridae-like 1 Hepatitis E virus / Betatetravirus Fecal Kobuvirus 19 Mouse kobuvirus / Aichi virus Fecal Parechovirus 5 Ljungan virus / Sebokele virus Fecal Phlebovirus 1 Echarate virus Fecal Picobirnavirus 22 Human picobirnavirus / Otarine picobirnavirus Fecal Picornaviridae 33 Feline picornavirus / Bat picornavirus Fecal Rosavirus 20 Rosavirus M-7 S i NYC rats 201 cbrayton@jhmi.edu of 32

17 127 3.a. Rat Viruses Boring usually subclinical seroconversion 1. Parvoviruses Seroconversion = only sign? 2. Rat Theilovirus Seroconversion = only sign? 3. SDAV clinical Disease Cowpoxvirus ZOONOTIC Pet rat reports Not in standard surveillance or FELASA lists 128 Rat Parvoviruses (RV, H 1, RMV, RPV 1a) Parvoviridae nonenveloped SS DNA viruses. Incidence: low.? Transmission: Direct contact, fomites. Clinical: Usually none; except maybe RV Pathology: Usually none; except maybe RV Diagnosis: serology MFI, IFA; fecal PCR (or mesenteric nodes) 129 Rat Parvoviruses (RV, H 1, RMV, RPV 1a) No disease recognized in natural infections by Toolan s H1 virus Rat Parvovirus 1 Rat Minute virus Rare disease in natural infections by Kilham rat virus aka Rat virus (RV) Immune effects? Lymphotropic/lympholytic? Tumor effects? oncolytic? RPV 1a is a Model oncolytic agent Transient? biliary hyperrplasia? 130 Pathology, organ distribution, and immune response after single and repeated intravenous injection of rats with clinical grade parvovirus H1. Parvovirus H1 (H1PV) natural host is rat. Nonpathogenic except in rat and hamster fetuses and newborns. Strongly oncolytic in human cancer models Clinical grade H1PV was produced according to Good Manufacturing Practices. Minimal effects (IgG & biliary hyperplasia) in rats Due to the confirmation of the favorable safety profile of H1PV in a permissive animal model, a phase I/IIa clinical trial of H1PV in brain tumor patients could be initiated. Geletneky & al 2015 Comp Med. Rat Parvoviruses Rat Virus (RV) Clinical: usually none; may cause: fertility, fetal resorption, small litters, runting. Juvenile young adult male: lethal hemorrhage Pathology: usually none infects actively replicating cells CPE cytolysis IN utero infection: cerebellar hypoplasia in young males hemorrhage, thrombi, infarction Notably: Scrotal hemorrhage Liver multi focal degeneration/ necrosis, hypertrophy Rat cerebellar hypoplasia dt experimental RV in utero cbrayton@jhmi.edu of 32

18 clinical grade parvovirus h1 (H1PV) RAT THEILOVIRUS (RTV1) nonpathogenic except in rat and hamster fetuses and newborns natural host is rats IV in adult rats No significant pathology! Antivirus Ig G Studied for oncolytic brain tumor treatment! Geletneky & al. (2015). Picornaviridae non enveloped, SSRNA virus. Incidence: Incidence of infection is moderate. Transmission: Fecoral Clinical: usually none Pathology: usually none Diagnosis: Serology MFI, IFA; fecal PCR Rat coronaviruses SDAV RCV RCV causes respiratory infection SDAV infects upper respiratory tract, Submandibular + parotid glands sialoaedintis Harderian + exorbital glands dacryoadenitis, Pulmonary disease is possible in young rats. Clinical: Usually none, or classic SDA Neck swelling Sialoadenitis Porphyrin oculonasal discharge DacryoAdenitis Also exophthalmos keratitis &corneal ulcers. 137 Rat coronaviruses SDAV RCV Etiology: enveloped RNA virus Rat coronavirus (RCV or Parker s rat coronavirus) Sialodacryoadenitis virus (SDAV) Incidence: low. Transmission: highly contagious by aerosol etc. Clinical & Pathology findings: can be none worst in immunodeficient w SDAV Diagnosis: Serology MFI, IFA; PCR in acute dz SDAV from Harderian or submandibular gland. RCV from lung 138 Rat coronaviruses SDAV RCV Gross: Large salivary glands + EDEMA Large Cervical lymph nodes Rhinitis, maybe pneumonia Occasional eye lesions (keratoconjunctivitis, corneal opacities, megaloglobus, hypopyon, hyphema, etc.) Histology: Necrosis of gland & ductal epithelium of parotid and submaxillary and lacrimal glands Squamous metaplasia common during healing Then fibrosis in chronic disease Sublingual gland usually spared 139 SDAV CLINICAL Disease!! in competent animal Hi morbidity (Outbreak) Swollen neck Salivary gland edema Chromodacryorrhea Consider dehydration & stressors RodentPath 139 cbrayton@jhmi.edu of 32

19 3.a. Rat Viruses Summary WYD? Figure 2. Skin. Cause? 141 Boring usually subclinical seroconversion Historically significant SDAV not so common but still around Zoonotic Cowpox pet rats Hantavirus wild rodents LCMV wild rodents, immunodeficient 142 A. Breithaupt et al. Vet Pathol 2012;49: B. 6) Pharynx 7) Pharynx 8) Lung 9) Lung 10) Skin 11) Brain Name the inclusion 143 A. Breithaupt et al. Vet Pathol 2012;49: B. NYC Rats Firth & al 2014 Virus type a Sample type Family or genus No. of pools Most similar species Known Serum Anelloviridae 22 Unclassified anellovirus Serum Bocavirus 9 Porcine bocavirus Serum Mastadenovirus 1 Murine adenovirus A Serum Parvovirus 19 Kilham rat virus Fecal Bocavirus 16 Porcine bocavirus Fecal Calhevirus 10 Calhevirus 1 Fecal Cardiovirus 21 Boone cardiovirus / Rat theilovirus 1 Fecal Circovirus 21 Pig stool-associated circular ssdna virus Chicken anemia virus Fecal Hunnivirus 19 Ovine hungarovirus Fecal Mamastrovirus 19 Rat astrovirus / Murine astrovirus Fecal Mastadenovirus 18 Murine adenovirus A Fecal Parvovirus 24 Kilham rat virus Fecal Rotavirus 3 IDIR agent Fecal Other 31 Novel Serum Arterivirus 2 Porcine reproductive and respiratory syndrome virus Serum Hepacivirus 16 Rodent hepacivirus Serum Orbivirus 3 African horse sickness virus / Epizootic hemorrhagic disease virus Serum Pegivirus 15 Rodent pegivirus Serum Pestivirus 4 Bungowannah virus / Classical swine fever virus Fecal Hepeviridae-like 1 Hepatitis E virus / Betatetravirus Fecal Kobuvirus 19 Mouse kobuvirus / Aichi virus Fecal Parechovirus 5 Ljungan virus / Sebokele virus Fecal Phlebovirus 1 Echarate virus Fecal Picobirnavirus 22 Human picobirnavirus / Otarine picobirnavirus Fecal Picornaviridae 33 Feline picornavirus / Bat picornavirus 3 Fecal Rosavirus 20 Rosavirus M Fecal Sapovirus 13 Human sapovirus / Porcine sapovirus Table 2. Incidents/outbreaks identified by the review, by zoonotic agent and animal category. 3.b. Bacteria Mostly opportunists today Most research rats are immune sufficient 1. Gram positive: S aureus ~ 23% 2. Helicobacters ~ 6% 3. Gram Negative: P pneumotropica > others Halsby KD, Walsh AL, Campbell C, Hewitt K, Morgan D (2014) Healthy Animals, Healthy People: Zoonosis Risk from Animal Contact in Pet Shops, a Systematic Review of the Literature. PLoS ONE 9(2): e doi: /journal.pone Mycoplasmosis should be rare now. M pulmonis usually with CARbacillus in Chronic Respiratory Disease cbrayton@jhmi.edu of 32

20 Rat Bacteriology: Results 2009 Pritchett Corning, Cosentino & Clifford 2009" Bacterial prevalence Rats PREVALENCE % J facilities Bacterium Method N NA Europe Total NH 07 Bordetella bronchiseptica Culture Cilia-associated respiratory bacillus Serology 26, Corynebacterium kutscheri Culture Helicobacter genus (any sp.)* PCR Gram Helicobacter hepaticus PCR Helicobacter bilis PCR Klebsiella oxytoca Culture Klebsiella pneumoniae Culture Culture nt 0.06 Mycoplasma pulmonis Serology 81, ? PCR nt 0.29 Culture Pasteurella multocida Pasteurella pneumotropica Culture Other Pasteurella spp. Culture Salmonella sp. Culture Staphylococcus aureus Culture ~40% Streptobacillus moniliformis Culture Streptococcus pneumoniae Culture Streptococcus sp. β-haemolytic, Group B Culture Streptococcus sp. β-haemolytic, Group G Culture Clostridium 151 piliforme ~2% H hep H bil H any P pneum S aureus Staphylococci in rats Gram positive cocci S aureus, S xylosus Incidence: VERY common Transmission: contact, fomites, wounds Clinical & Pathology Findings: Usually none Opportunistic infections Diagnosis: Culture, PCR, histopathology Staphylococci in rats Common isolates from normal skin or Dermatitis Furunculosis in nude rats Helicobacters in rats Gram negative, microaerophilic spiral motile H. bilis, ganmani, H. muridarum, H. rodentium, H. trogontum H. typhlonius Incidence: The incidence of infection is moderate. Incidence: pretty common Transmission: fecal oral Clinical & Pathology Findings: Usually none Diagnosis: Fecal PCR 156 Helicobacters in rats Identified by PCR Uncertain significance Hepatobiliary dz? Zoonotic concern? H spp, H ganmani > H hepaticus or bilis H bilis in nu/nu rats Proliferative and ulcerative typhlitis, colitis, proctitis Haines, D.C., et al., Inflammatory large bowel disease in immunodeficient rats RodentPath 156 naturally and experimentally infected with Helicobacter bilis. Vet Pathol, (3): p cbrayton@jhmi.edu of 32

21 157 Rat Helicobacters H bilis in nu/nu rats Proliferative and ulcerative typhlitis, colitis, proctitis 1. Colon 2. Cecum Haines, D.C., et al., Inflammatory large bowel disease in immunodeficient rats RodentPath 157 naturally and experimentally infected with Helicobacter bilis. Vet Pathol, (3): p Pasteurella pneumotropica Gram negative, short pleomorphic rod Poor gram staining on histo Incidence: common in mice & rats Transmission: aerosol, fecal oral, contact Clinical: Often none, opportunist Conjunctivitis, respiratory, reproductive tract infections Pathology: often none Inflammation necrosis, inconspicuous bacteria Diagnosis: PCR most sensitive, specific Feces + infection sites 3.b. Bacteria summary 1. Gram positive: S aureus ~ 23%! (S xylosus) Dermatitis, Abscesses, opportunist infections 2. Helicobacters ~6% Enterohepatic lower GI Tract 3. Gram Negative: P pneumotropica Opportunists, inflammatory lesions, abscesses + HISTORICAL RARE + Zoonotic 3.b. Bacteria summary HISTORICAL RARE Mycoplasma pulmonis + CARbacillus (CRD) Cl Piliforme megaloileitis + liver necrosis Salmonella enterica typhimurium liver necrosis C kutscheri pseudotuberculosis (abscessed Lymph nodes +/ pneumonia) Klebsiella pneumoniae Murine Respiratory Mycoplasmosis Pneumonia Bronchiectasis Neutrophilic chronic + upper respiratory disease Perivascular peribronchiolar lymphocytic cuffing M pulmonis & CARbacillus are lymphocyte mitogens Murine Respiratory Mycoplasmosis M pulmonis & CARbacillus MRM, Chronic Respiratory Disease of rats M pulmonis mollicutes Tiny, lack a cell wall Cilia associated respiratory (CAR) bacillus Gram negative filamentous rod, motil Similar to Flavobacterium, Flexibacter Incidence: Rare now; historical significance cbrayton@jhmi.edu of 32

22 Brayton Rat CARbacillus Wild Urban Rats WYD? Cause? Lymphoplasmacytic cuffs, lung Increased macrophages in adjacent alveoli Significantly associated (P.02) with CARbacillus and M pulmonis J. L. Rothenburger et al. Vet Pathol 2015; Wild Urban Rats Norway (Rattus norvegicus) and black rats (Rattus rattus) BALT hyperplasia Peribronchiolar and perivascular lymphocytic cuffs may not actually be inflammatory lesions but rather inducible BALT ibalt, May be response to M. pulmonis, a recognized B and T cell mitogen in rats, or to antigens of CARBacillus which was identified more commonly WYD? Cause? Wild Urban Rats 5. Nose, rhinitis Lumen purulent exudate Submucosa Lymphocytes and plasma cells 6. Nose, rhinitis Basophilic bacilli between cilia (tangled cilia) Inset: Steiner s silver stain. Black filamentous bacteria among the cilia. CARBacillus 165 J. L. Rothenburger et al. Vet Pathol 2015; J. L. Rothenburger et al. Vet Pathol 2015; Other mycoplasmas Rat WYD? Mycoplasma haemomuris (Hemobartonella muris) Extracellular RBC parasite infectious anemia or splenomegaly in rodents. Dx by PCR, blood smear transmitted by rat louse Polyplax sp Mycoplasmas in tissue culture Common Most are NOT transmissible to rodents a) Pneumonia b) Bronchopneumonia c) Interstitial d) Embolic e) M pulmonis f) CARbacillus g) Streptococcus pneumoniae h) Corynebacterium kutscheri i) Murine Pseudotuberculsosis cbrayton@jhmi.edu of 32

23 Wild Urban Rats URI Cause (s) Lymphoplasmacytic cuffs, lung Associated with what agents? 171 J. L. Rothenburger et al. Vet Pathol 2015;52: Rothenburger et al. Vet Pathol 2015;52: b. Bacteria Zoonotic Human/rodent helicobacters? 175 H bilis? hepaticus? ganmani? Leptospirosis rat urine contaminated water Salmonella enterica typhimurium RBF = rat bite fever due to Spirillum minus spirillary RBF, sodoku, Haverhill fever Streptobacillus moniliformis Streptobacillary RBF Yersinia pestis? black plague Via rat fleas? 176 Helicobacter pylori, Helicobacter bilis, Helicobacter hepaticus, Helicobacter ganmani. trend of a higher presence of Helicobacter spp. in patients with biliary tract cancers compared with normal controls or those with benign biliary diseases Shen & al 2014 Fatal Rat Bite Fever in a Child San Diego County, California, CDC.gov Healthy 10yo boy rigors, fevers, vomiting, headaches, leg pains, death PCR Pos Streptobacillus moniliformis (Lung, liver, epiglottis) owned 2 pet rats; 1 PCR Pos oropharyngeal swab Streptobacillus moniliformis Nearly all domestic and wild rats carry S. moniliformis. Elliot % of NYC R norvegicus Firth& al Or may be not. Blaming gerbils from Asia now. cbrayton@jhmi.edu of 32

24 3.c. Eukaryotes 1. Fungi & Protists P carinii (RRV common) T mentagrophytes Ringworm unlikely E cuniculi microsporidia unlikely 2. Protozoa Entamoebae & flagellates > Giardia & Spironucleus 3. Helminths Pinworms S muris > S obvelata etc Bladder worm T crassicauda unlikely Cestodes (Hymenolepis, Rodentolepis, Cysticercus) 4. Arthropods Mites Fur mites & mesostigmatid > Fleas & lice Rat Eukaryota: Results Pritchett Corning, K. R., J. Cosentino, et al. (2009). "Contemporary prevalence of infectious agents in laboratory mice and rats." Lab Anim 43(2): PREVALENCE % Agent Method N NA Europe Total Encephalitozoon cuniculi Serology 22, Lice Direct nr 0.00 Mites Direct Oxyurids* Aspiculuris tetraptera Direct Syphacia muris Direct Syphacia obvelata Direct Protozoa Chilomastix sp. Wet mount nr 1.65 Entamoeba sp. Wet mount nr 3.18 Giardia sp. Wet mount Hexamastix sp. Wet mount nr 4.60 Monocercomonoides sp. Wet mount nr 0.09 Retortamonas sp. Wet mount nr 0.17 Spironucleus sp. Wet mount nr 0.19 Trichomonads Wet mount nr Fungi Pneumocystis (formerly protozoan) P carinii & P wakefieldii in rats P carinii = RRV Trichophyton mentagrophytes Ringworm no recent reports Microsporidian (also formerly in protozoa) Encephalitozoon cuniculi UNLIKELY Unless rats or mice from pet store 184 Pneumocystis carinii Typical pneumocystosis in immunodeficient Formerly known as RRV, Rat Respiratory Virus in immunocompetent mice Not a virus It s a fungus Used to be classified as protozoan Pathology in competent rats is very different from findings in immunodeficient animals that can not clear the agent RADIL scientists prove there is no RRV; instead it s P. carinii fulfilled Koch s postulates by proving that P. carinii is an etiologic agent of the idiopathic pneumonia historically associated with rat respiratory virus ( RRV ) infection. AALAS Albers T M et al. Vet Pathol 2009;46: cbrayton@jhmi.edu of 32

25 RRV Fig. 1. Percentage of 8 rats sampled each week that had gross lung lesions consistent with interstitial pneumonia. Fig. 4. Lung; rat 7 weeks after exposure. Fig. 2. Lung; rat 7 weeks after exposure. 189 Albers T M et al. Vet Pathol 2009;46: Albers T M et al. Vet Pathol 2009;46: Pneumocystis Pneumocystis carinii Formerly known as Rat Respiratory Virus 192 Only 4 spp?: In rats P carinii P wakefieldiae In mice P murina In humans P jirovecii (ICBN) Li & al Common (~6%) Consider this with seronegative lung disease Relationship to BN rat allergic? Pneumonia? Diagnosis by pathology Now ELISA + PCR Gross patchy lung lesions resolve Be concerned about Sendai, Mycoplasma Histology perivascular interstitial pneumonia mostly mononuclear Resolves completely 194 Pcp vs Brown Norway Pneumonia BN used to Model allergic/reactive airway disease asthma Consider stimulants/irritants in bedding, environment PCR neg for Pc These control BAL were similar to OVA treated FELASA Rat annual testing Parasites /protozoa Protozoa 1. Entamoeba 2. Giardia 3. Spironucleus 4. Tritrichomonas muris Ectoparasites 1. Fleas 2. Mesostigmatid mites 3. Polyplax 4. Radfordia Helminths 1. Aspiculuris 2. Syphacia 3. Hymenolepis 4. Rodentolepis cbrayton@jhmi.edu of 32

26 Protozoa Helminths 197 Mostly commensals & pests Small intestine potentially pathogenic Giardia Spironucleus Coccidia Large Intestine Entamoebae Trichomonads Chilomastix etc Most Least common: 1. Hexamastix sp. 2. Entamoeba sp. 3. Chilomastix sp. 4. Trichomonads 5. Spironucleus sp. 6. Retortamonas sp. 7. Monocercomonoides sp. 8. Giardia sp. 198 Nematodes Pinworms Bladder threadworm T crassicauda Rat Lungworm A cantonensis Hepatic capillariasis Calodium hepaticum Cestodes Cysticerci intermediate hosts Hymenolepid (Rodentolepis, Hymenolepis) 199 Pinworms Syphacia muris >>>> S obvelata Tape test, eggs flat on 1 side S muris eggs are smaller x µm. S obvelata eggs x µm more curve Larvae + adults in cecum Adults in colon Eggs on perineum Diagnosis: Tape test? Direct exam? PCR is increasingly efficient 200 Syphacia muris Meade & Watson JAALAS 2014 recommend that perianal tape testing be as close as possible to the peak egg shedding time of 1400, to maximize sensitivity Sex of the host had no consistent effect on egg shedding. Egg shedding showed periodicity, decreasing to 0 at 2 to 3 wk intervals. Neither cecal examin nor tape tests alone reliably predicted pinworm infestation, Eggs aged up to 7 mo remained viable, Gaseous chlorine dioxide ClO2 was an effective ovicidal agent, kill rate of 99.7%. 202 Arthropods 3.c. Eukaryotes Summary Fur mites Radfordia ensifera (look like Myocoptes) Expected 1. Fungi Incidence: low. P carinii (RRV common) Distribution: intrascapular dorsal cervical 2. Protozoa the usual Entamoebae & flagellates > Giardia & Spironucleus Clinical Signs: usually none 3. Helminths the usual Diagnosis: fur pluck etc, PCR more reliable Pinworms S muris > S obvelata etc Mesostigmatid mites blood sucking 4. Arthropods the usual Ornithonyssus bacoti Fur mites Radfordia & mesostigmatid Laelaps echidninus Lice Historical / unexpected Zoonotic Polyplax spinulosa is the sucking louse of rats 203 cbrayton@jhmi.edu of 32

27 2016 Brayton 5 POLA Rat Path 3.c. Eukaryotes Summary Des escargots pour le dîner? Historical/unexpected in laboratory rats Fungi & Protists Unlikely T mentagrophytes Ringworm E cuniculi microsporidia Helminths Unlikely but GREAT LESIONS A cantonensis rat lungworm C hepaticum hepatic capillariasis T crassicauda Bladder threadworm Cysticercus fasciolaris where s the cat? Rodentolepis nana, Hymenolepis diminuta Arthropods Unlikely but important disease (?) 204 Fleas xenopsylla black plague? Lice polyplax Mycoplasma haemomuris 205 Angiostrongyus cantonensis Calodium hepaticum Hepatic capillariasis (Capillaria hepatica) Wild rats etc rodents, AND rabbits Rat lungworm Wild rats etc Snail intermediate host dog, human etc infections Embryonated and non embryonated strongyle eggs in lungs 206 Askjpc.org Urban rats Capillarid eggs with bipolar plugs Simoes & al Trichosomoides crassicauda (Bladder threadworm) Trichosomoides crassicauda Bladder threadworm Incidence: rare (in Laboratory rats). Distribution: Urinary bladder, ureter renal pelvis. Clinical Signs: Usually None Pathology: Proliferative cystitis, calculi, worms Diagnosis: eggs in urine, fecal PCR; Path Still around. Female: ~10 mm! Male ~1mm in female repro tract eggs: ~50x70µ, brown, w bipolar plugs cbrayton@jhmi.edu of 32

28 210 Hymenolepid cestodes Rodentolepis nana = dwarf tapeworm R microstoma in bile ducts usually mice? Hymenolepis diminuta = rat tapeworm Incidence: rare. Transmission: ingested intermediate hosts fleas, flour beetles, cockroaches Direct cycle: Rodentolepis only. Ingested eggs. Distribution: Small intestine larva in mucosa. Clinical: Usually none Diagnosis: Fecal flotation; Path Hymenolepid cestodes Diagnostic morphology: Rodentolepis nana Adults mm + armed rostellum Strobelocerci (cysticerci) in lamina propria Eggs: 40 60u, oval 2 membranes; 3 pairs polar filaments Hymenolepis diminuta Adults: 10 60x3 4 wide without hooks Eggs: µm, yellow, spherical ZOONOTIC POTENTIAL? 211 ZOONOTIC POTENTIAL? Rodent tapeworms (& humans) Rodentolepis (Hymenolepis) nana common tapeworm in children SAME? Species WAS common in rats, mice Still found in pet stores & wild rodents Roble & al 2012 Human isolates do NOT infect mice, rats Macnish & al 2002 Tough to do the human infection expt Cysticerci (Strobilocerci) Cysticercus fasciolaris (Cysticercus taeniaformis, Strobilocercus fasciolaris) Mice rats = INTERMEDIATE host Cat/carnivore = DEFINITIVE host Incidence: should not occur Transmission: ingestion of cat/carnivore feces Distribution: liver. Clinical Signs: usually none Diagnosis: Path: Cysticerci in liver WYD? Figure 1. Liver; wild rat. Coinfection with Calodium hepatica and Cysticercus fasciolaris.hepatic Parasites in Korean Wild Rats (Rattus norvegicus) and Their Association With Pulmonary Arteriolar Medial 214Hypertrophy 215 J.-Y. Yi et al. Vet Pathol 2009;47: Taenia Larval forms in Intermediate Hosts Cysticercus intermediate host cystic structure with a single scolice Taenia saginata, Taenia solium, Taenia hydatigena, Taenia pisiformis, Taenia crassiceps, Taenia hydatigena and Taenia ovis Strobilocercus (everted) scolice + body (strobila) + bladder Taenia taeniaeformis uses a strobilocercus form Coenurus numerous scolices (inverted) per cyst Taenia multiceps, Taenia serialis and Taenia cbrayton@jhmi.edu of 32

29 Sarcoma? Strobilocercus fasciolaris 3.c. Eukaryotes summary Zoonotic Pneumocystis? Species specific Giardia? (G muris vs G lamblia) Hymenolepis / rodentolepis tapeworms? Syphacia? Angiostrongylus cantonensis Beware of snails Fleas Xenopsylla cheopis Yersinia pestis? Beware of gerbils Rat testing FELASA Recommendations pdf Immune deficient, gnotobiotics & other needs may warrant different testing. 219 FELASA Rats annual testing by SEROLOGY 1. RCV (SDAV) 2. Parvovirus(es) NS 1 3. Parvovirus KRV 4. Parvovirus H 1 5. Parvovirus RPV 6. Sendai 7. PVM 8. REO3 9. RTV 10. MAD1 11. MAD2 12. Hantavirus (Seoul) Mycoplasma pulmonis Clostridium piliforme 12 viruses + 2 bacteria FELASA Rat/Mouse testing RATS By BACTERIOLOGY 1. Bordetella bronchiseptica 2. Corynebacterium kutscheri 3. Pasteurella pneumotropica 4. Salmonella spp. 5. Streptococcus pneumoniae 6. β hemolytic Streptococcus By MOLECULAR DIAGNOSTICS Helicobacter 1. Helicobacter spp. 2. H. hepaticus 3. H. typhlonius 4. H. bilis 5. H. rodentium 6. H. ganmani 7. H. mastomyrinus Streptobacillus moniliformis Not so much rat breeding in research facilities More all in, all out studies More clean rats from commercial vendors Try pet stores to see good infectious disease. A few more rat lesions cbrayton@jhmi.edu of 32

30 Cotton rats WYD? Pregnant females Hemochorial placentation Trophoblast emboli La Perle, & al (2014). Cotton rat WYD? 223 Laperle et al. Vet Pathol S. Lezmi et al. Vet Pathol 2010;48: Key Largo Woodrats (Neotoma floridana smalli) Neotoma sp 225 WYD? Causes? S. P. Terrell et al. Vet Pathol 2011;49: /5 also had signs of diabetes Patchy glomerular immunoreactivity for IgG in 2 cases, but Not IgA and IgM CPN. ad libitum high protein diet. 226 S. P. Terrell et al. Vet Pathol 2011;49: WYD? What are these rats used to study? Psammomys obesus Heterocephalus Glaber WYD? 1. Conspecific trauma 2. Calcinosis cutis 3. Calcinosis circumscripta 4. Calcinosis circumscripta 5. CPN 6. CPN 227 T. J. Steinbach, and J. D. Kane Vet Pathol 2012;50: M. A. Delaney et al. Vet Pathol 2013;50: cbrayton@jhmi.edu of 32

31 Heterocephalus Glaber 229 WYD? 6. Testis 7. ICH 8. Liver 9. Hemosiderosis 10. Adrenal cortex hyperplasia 11. Heart myofiber variation 12. Normal lungs M. A. Delaney et al. Vet Pathol 2013;50: Figures 1 6. Heterocephalus glaber WYD?? M. A. Delaney et al. Vet Pathol 2015;53: RAT WYD RAT Acute Vacuolation, pyknosis, hemorrhage Chronic Lipid laden macrophages 231 De Jonghe et al. Toxicol Pathol 2015;43: Copyright by Society of Toxicologic Pathology 232 De Jonghe et al. Toxicol Pathol 2015;43: Copyright by Society of Toxicologic Pathology WYD Match # to letter: 1) Benign granular cell tumor, 2) Benign granular cell tumor - PAS 3) Medulloblastoma 4) Malignant highgrade astrocytoma 5) Malignant highgrade oligodendroglioma, 6) Malignant lowgrade-mixed glioma Bertrand et al. Toxicol Pathol 2014;42: Copyright by Society of Toxicologic Pathology Bertrand et al. Toxicol Pathol 2014;42: Copyright by Society of Toxicologic Pathology cbrayton@jhmi.edu of 32

32 Figures 1 6 RATS Tissue? Diagnoses? Cause? 235 Bertrand et al. Toxicol Pathol 2014;42: Copyright by Society of Toxicologic Pathology 236 J. L. Rothenburger et al. Vet Pathol 2015;52: RATS HYPOGEOMYS ANTIMENA Tissues? Diagnoses? Cause? g/doi/full/ / R1.1 Species? Developmmental stage? J. L. Rothenburger et al. Vet Pathol 2015;52: Figures HYPOGEOMYS ANTIMENA g/doi/full/ / R1.1 WYD? 239 cbrayton@jhmi.edu of 32