Hamster diseases

What are the names and stain characteristics of Lawsonia Intracellularis

What are the names and stain characteristics of Lawsonia Intracellularis

Proliferative enteritis, transmissible ileal hyperplasia, wet tail, gram negative, obligate intracellular rod

What age hamsters are most sensitive to lawsonia infection?

weanlings less than 10 weeks

What other species does lawsonia infect?

Infects swine, guinea pigs, ferrets, horses, deer, rabbits

Clinical signs of lawsonia in hamster?

Hamster: proliferative lesions epithelium terminal ileum (ileitis). Most common gross findings are Watery diarrhea w/moist, matted fur on tail/perineum/ventral abdomen, hence wet tail/

There is high mortality in weanlings, the clinical signs show these photos, what microbe is likely?

lawsonia intracellularis

DDX for lawsonia?

Tyzzers Disease, Salmonellosis, Clostridium difficile

Prevention and control Lawsonia?

DEPOP/SANITIZE/REPOPSeparate, supportive care, Tetracycline/Enrofloxacin/TMS combos in H₂0 (only moderate success

You do a necropsy on high mortality event of hamsters and see this? What can cause this? And is this lesion always seen with this microbe?

Lawsonia, and no not always seen.

What stain is this, and what is it showing?

Warthin starry stain, showing intracellular small bacteria at apical cytoplasm of enterocytes. It is lawsonia.

What is the common name for Clostridium piliforme, what are the characterisitics of it?

Tyzzers disease, gram negative spore forming intracellular bacteria.

What species can get tyzzers?

rats, rabbits, cats, rhesus, dog, horse, GP

What age in hamsters are most affected, and what are the clinical signs?

Rough hair coat, diarrhea, high mortality weanlings/immunocompromised

What three systems do you typically see lesions of tyzzers?

intestine/liver/cardiac m.

Preferred diagnostic for tyzzers?

Serology/Fecal PCR assays available

Prevention and control of tyzzers?

Prevention key - sanitize, isolate, eliminate spores

What are the arrows showing and what pathogen commonly causes this as well as lesions on SI and cardiac SM?

Tyzzers, Multifocla necrotizing hepatitis

What are those filamentous bacteria “ pick up sticks”? What is the stain?

Warthin starry stain, Clostridium piliforme. Can also use giemsa stains.

Most common bacteria proliferation after certain ABs are given?

Clostridium deficile

What ABs cause bacterial dysbiosis in hamsters?

Ampicillin, Penicillin, Cephalosporins, Clindamycin, Erythromycin, Gentamicin, Lincomycin, Vancomycin

PORe Cilly Cins

Clinical signs and most common age group affected for C. deficile?

Juveniles to adults

unexpectedly die w/or w/o diarrhea, cecitis

+/- typhlitis, colitis

Are hamsters good models for C diff?

Yes

What disease do you commonly see diarrhea with severely hemorrhagic cecum after giving penicillin to a hamster?

C. deficile

Differentiate toxins A and B for C diff in cytologic preference?

Toxin A = mucosal damage, Toxin B = cytotoxic

Prevention / control of C diff in hamsters?

DEPOP / DECON w/chlorine dioxide / REPOP

Diag of C diff?

PCR

Is salmonella common in lab hamster pops?

No

Most common source of transmission of salmonella in hamster pops?

bedding

Most common Salmonella serovars in hamsters?

Enteriditis and typhimerium

One benefit of having a sentinal animal with contaminated bedding in regards to salmonella?

often silently shed from healthy animals chronically

Common pathology of salmonella in hamsters?

Multifocal pinpoint sized pale areas in liver (hepatic necrosis) w/o enteritis (white spots). Patchy pulmonary hemorrhage with septic thrombi (very unique to hamsters)

Found on necropsy of a sentinal animal exposed to bedding from colony animals, what is the pathogen?

Salmonella

What pathogen?

helicobacter

Characteristics of helicobacter?

gram negative, motile spiral bacteria, normal commensal in hamsters

Which helicobacter species of hamsters can cause disease in immunocompromised people?

H. cinaedi => pathogenic humans

source of infection for humans, esp. immunocompromised

Most common disease in hamsters?

diarrhea

Second most common disease in hamsters?

pneumonia

What bacteria cause pneumonia in hamsters?

Rodenibacter pneumotropicus, Streptococcus pneumoniae, other Streptococcus spp., Corynebacterium paulometabulum

Common clinical signs of bacterial pneumonia ?

depression, anorexia, nasal/ocular discharge, “chattering”, resp distress

Prevention of bacterial pneumonia?

Avoid stress, isolate infected, +/- ABCs

Characteristics of lymphocytic choriomenengitis virus?

RNA enveloped Arenavirus

Why are hamsters so important regarding zoonosis on LCMV?

Most common cause of zoonosis to humans

What species is the primary host of LCMV?

Mus musculus

Clinical signs of LCMV in hamsters?

rarely any, often silent shedders

Transmission of LCMV in hamster and what is the most common?

Vertical OR Horizontal transplantable tumors (most common), direct contact, fomites, aerosols Viral shedding primarily in urine/saliva – persists longer in urine

What ABSL do hamsters with LCMV require?

ABSL 3

What pathogen causes this, in the liver lung pancreas brain and spleen? Found incidentally after necropsy of a hamster that received a transplant tumor in the cheek pouch.

LCMV

DDX and diagnostic for LCMV?

Amyloidosis, PCR

Sendai virus (respirovirus) characteristics?

Parapoxviridae, respirovirus, RNA enveloped.

natural host of respirovirus?

Mouse

Age group most affected?

newborn pups

Diagnosis of respirovirus

PCR, IFA, ELISA

You do histo on a newborn hamster pup that died suddenly. See peribronchial cuffing and these Ag accumulations in the lungs?

respirovirus

Can hamsters get adenovirus?

Yes, they can get mouse adenovirus (DNA nonenveloped)

What is hamster polyomavirus common name and what are its characteristics?

Transmissible lymphoma and are DNA nonenveloped.

What is the tropism for hamster polyomavirus?

keratinocytes and lymphocytes

What are the two syndromes of polyomavirus in hamsters?

Naïve juveniles: Multisystemic lymphoma mesentery, intestines, liver, kidney, thymus

3mos-1yr: Trichoepitheliomas on face, feet, neck, back, flank, abdomen

Common clinical presentation of hamster polyomavirus?

thin with palpable masses in the abdomen

You have a 1 year old hamster with this presentation and histologically shows this, what is the pathogen?

Hammster polyomavirus

Juvenile hamster < 3 mo presents with palpable masses and low BCS, on necropsy you find enlarged mesenteric LNs. What disease is this?

Hamster polyomavirus

What are the characterisitcs of hammster parvovirus?

DNA nonenveloped

What do you see with weanling hamsters with parvovirus?

Suckling/weanling hamsters (2-4weeks old): runted, malformed or missing incisors, enamel hypoplasia of the incisor

Can animals be reinfected with parvovirus?

No, humoral immunity protects

Are adults clinically affected by parvovirus?

No

You find a weaning hamster with missing incisors and enamel hypoplasia, what is the pathogen?

Hamster parvovirus

Three most common protozoa found in hamsters

Spironucleus muris, Tritrichomonas muris, Giardia muris

Do protoza cause disease in hamsters?

None have been shown to be associated with significant lesions

What diagnostic is being shown, what are you trying to diagnose?

tape test, pin worm

Are hamsters susceptible to pin worm infection, and do they typically show clinical signs?

Infection very common, but no clinical signs usually occur.

Common pinworms in hamsters?

Syphacia mesocriceti, S. criceti, S. stroma, S. peromysci, S. obvelata (from mice), S. muris (from rats), Aspicularis tetraptera (esp. Siberian dwarf hamsters) and Dentostomella translucida

What is the species?

Syphacia mesocriceti

Most common zoonotic tapeworm in hamsters?

Rodentolepis nana (dwarf tapeworm)

Life cycle information for rodentolepis nana?

Direct (14-16 dys) OR Indirect LC – flour beetle/flea intermediate host

Which is larger? Hymenolepis diminuta or R. nana?

Hymenolepis diminuta Larger than R. nana

Which parasite and where does it preference?

R. nana, prefer lower intestine.

what pathogen? and where does it preference?

H. Diminuta, upper SI

What pathogen is causing this? And how would you treat?

Likely demodex species, alopecia on rump and back with dry, scaly skin

TX: Topical amitraz, oral ivermectin/weekly cleaning w/selenium and benzoyl peroxide shampoo

Which demodex species in C shaped in hamster and where does it infect on skin?

Demodex criceti, invade epidermal pits, 24 hour life cycle

Which demodex species is A shaped in hamsters and where does it like to infect on the skin?

Demodex aurati, invades the hair follicles.

Which species is this in hamsters?

Demodex aurati, pointy A end

What species is this in hamsters?

D. criceti, round end

Are females or males more likely to get neoplasia in hamsters?

Females, but still very rare

Most common malignant neoplasia of hamsters

Malignant Lymphosarcoma

Which cancer is polyomavirus most associated with in hamsters?

malignant lymphosarcoma

Most common benign cancers in hamsters?

intestinal polyp, adrenal adenoma, splenic hemangioma, islet cell pancreatic, hepatic ademona, mammary fibroadenoma

What two diseases are the most common cause of death in older hamsters?

Amyloidosis and nephrotic syndrome

Is amyloidosis sex dependent?

Yes, predominantly females

Two amyloid proteins of concerns of hamsters?

AA and AP

Which hormone is important for inactivation of which amyloid protein in hamsters?

Testosterone inhibits growth of AP amyloid. Thats why females are more predisposed to disease.

Organs involved in amyloidosis in hamsters?

liver, kidney, stomach, adrenal, thyroid, spleen

Clinical signs of amyloidosis in hamsters?

Extensive SQ edema, ascites, hydrothorax, ↓ albumin, ↑globulin, proteinuria, hypercholesterolemia, ↑ creatinine

What is being described here and what is the disease in hamsters?

SQ edema and pallor congested kidneys associated with amyloidosis.

What is the stain and what is being shown here?

Congo red stain for amyloidosis

What organ system is this, and what is being shown?

glomeruli of kidney with amyloid deposits

What is being shown here?

Polycystic disease in an aged hamster. Common in hamsters over 1 year of age

Most common areas affected by polycystic disease in hamsters?

liver and epididymis

Find these cardiac and abdominal findings on necropsy of an aged APA hamster? What is it?

Thromvbi in the left atrium due to blood stasis, results in jelly hams or SQ edema in abdomen.