---
title: Hamster — Care & Reference Manual
author: codebuddy
type: manual
llm_refined: true
refined_by: kimi
manual_v2: true
date: 2026-08-04
source_topics: exotic_pet_profile_hamster, exotic_pet_food_nrc_standard_map, exotic_nutrition_hamster_feeding, exotic_nutrition_hamster, exotic_pet_nutrition_hamster_safe_greens, exotic_nutrition_rat_mouse_chow, exotic_husbandry_hamster_housing, exotic_life_stage_hamster, exotic_behavior_hamster, exotic_enrichment_hamster, exotic_grooming_hamster, exotic_breeding_hamster, exotic_hamster_amyloidosis, exotic_health_hamster_emergency, exotic_hamster_polyomavirus_lymphoma, exotic_hamster_wet_tail, companion_species_health_omia_5017_hamster, companion_species_health_omia_4806_hamster, companion_species_health_omia_3238_hamster, companion_species_health_omia_3236_hamster, companion_species_health_omia_6674_hamster, companion_species_health_omia_4226_hamster, companion_species_health_hypertriglyceridemia_hamster, companion_species_health_omia_4387_hamster, companion_species_health_omia_6115_hamster, exotic_tox_hamster_foods, exotic_tox_hamster_penicillin, exotic_pet_legality_crosswalk_hamster, evidence_exotic_hamster_clinical, evidence_exotic_hamster_husbandry_health, evidence_exotic_hamster_toxicology
source_hash: b24a4b8d371bed32
draft: false
---

# Hamster — Care & Reference Manual

*LLM-refined manual (v2 pipeline, kimi, 2026-08-04; docs/MANUAL_V2_DESIGN.md).* This manual assembles the verified fact blocks in Pet Data Station that mention *hamster*, organised along a pet owner's journey. Every quoted fact is reproduced **verbatim** from its cited first-hand source (`[n]` superscripts; see References, each tagged with a computed trust grade per docs/topic_grading_guide.md) and is independently checkable. Guide sections (checklists, red-flag box) are orientation prose in which **every factual sentence carries its own `[n]`**; derived-summary blocks from non-Open-Access sources keep their *Paraphrased derived summary* mark. Mis-sectioned, duplicate, off-topic and image-residue fragments were removed by the v2 builder (build-gate enforced).

## Contents

1. [Species Profile](#species-profile)
2. [Life-Stage Care](#life-stage-care)
3. [Is this pet right for you?](#is-this-pet-right-for-you)
4. [Daily & Weekly Care Checklist](#daily-weekly-care-checklist)
5. [Nutrition](#nutrition)
6. [Husbandry](#husbandry)
7. [Behavior & Training](#behavior-training)
8. [Enrichment & Exercise](#enrichment-exercise)
9. [When to call a vet NOW](#when-to-call-a-vet-now)
10. [Health & Disease](#health-disease)
11. [Toxicology & Hazards](#toxicology-hazards)
12. [Grooming](#grooming)
13. [Breeding & Neutering](#breeding-neutering)
14. [Regulations & Legality](#regulations-legality)
15. [Species-Specific Health](#species-specific-health)
16. [Appendix A — Commercial Food & Regulatory Notes](#appendix-a-commercial-food-regulatory-notes)
17. [Appendix B — Research Evidence](#appendix-b-research-evidence)

## Species Profile

The profile below records this species' taxonomy, natural origin and lifespan as documented in the cited reference.

### Syrian hamster (Mesocricetus auratus) — species profile (taxonomy, geographic range, habitat, physical description, behavior, wild diet, reproduction, lifespan)

> Golden hamsters are ubiquitous worldwide as pets and research animals. [1]
> Wild populations are restricted to a small area of the Middle East. [1]
> The majority of the species' range is encompassed by the Aleppinian plateau in Syria. [1]
> Golden hamsters have also been reported in areas of Eastern Turkey. [1]
> Historically, golden hamsters probably inhabited open steppe habitat, which once characterized the Aleppinian plateau and adjacent areas. [1]
> As their range has become increasingly populated however, golden hamsters have shown an affinity for agricultural areas. [1]
> Hamster burrows are often found in legume plots or near irrigation wells. [1]
> The climate of the region inhabited by golden hamsters is seasonal. [1]
> Golden hamsters are medium-sized hamsters, with adult mass ranging from 100 to 125 g. [1]
> They are significantly smaller than common hamsters ( Cricetus cricetus ) of eastern Europe and western Asia,and larger than Roborovski's desert hamsters ( Phodopus roborovskii ) of China and Mongolia. [1]
> As with many hamsters, golden hamsters have a blunt rostrum, relatively small eyes, large ears, and a short (1.5 cm) tail. [1]
> The fur is golden-brown above, fading to gray or white on the ventral surface. [1]
> To mark their territory, hamsters will make use of scent glands on their flanks. [1]
> A great deal of information can be discerned from flank markings, including kin recognition. [1]
> Golden hamsters are omnivorous, feeding on seeds, nuts, and insects, including ants ( Formicidae ), flies ( Diptera ), cockroaches ( Blattaria ), and wasps ( Hymenoptera ). [1]
> Females indicate their receptiveness to males primarly through olfactory cues in vaginal secretions. [1]
> When the female is ready to mate, she will increase the frequency of vaginal marking, a behavior characterized by pressing the vaginal region against a surface and moving forward a few inches. [1]
> Ovulation is induced by long photoperiods (>12.5 hours) and will continue indefinitely as long as the photoperiod remains long. [1]
> Like many small rodents, golden hamsters serve as a food source for many other animals. [1]
> Abandoned hamster burrows are often used by other animals, such as toads. [1]
> Golden hamsters serve as a food source for many different predators, including foxes, mustelids, birds of prey, and snakes. [1]
> Golden hamsters avoid predation by seeking shelter in their burrows and through vigilance. [1]
> Their rapid reproductive rate means that golden hamster populations can withstand relatively high rates of predation. [1]
> Golden hamsters are listed as endangered by the IUCN because of their small geographic range and localized distribution. [1]
> The greatest threat to wild populations is human encroachment on habitat. [1]

## Life-Stage Care

Young, adult and senior care for this species, drawn from first-hand care pages and veterinary references.

### Hamster — life stage (owner-practical care, Merck Veterinary Manual pet-owner)

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Female hamsters should not be housed together. [2]
> Commercial rabbit pellets, which are higher in fibre than rat/mouse diets, may be fed. [2]
> Exercise balls let a hamster move over a large area while confined. [2]
> Smooth plastic or glass walls are preferred because hamsters chew wire. [2]

> Golden hamsters have relatively short life spans, 1.5 to 2 years on average. [1]
> *[Paraphrased derived summary — non-Open-Access source.]* Litters are normally 6–8 pups; offspring are weaned at about 21–28 days. [2]

## Is this pet right for you?


- **Keep them alone:** golden (Syrian) hamsters are solitary and highly territorial, and should not be kept in groups — even litter-mates can become aggressive as adults; outside breeding, single housing is safest. [1] [2]
- **They are small and omnivorous:** adult golden hamsters weigh 100–125 g and are omnivorous in the wild, feeding on seeds, nuts and insects. [1]
- **Plan for evenings:** hamsters are most active in the evening, so evenings are usually a good time for play, cage cleaning and other shared activity. [2]
- **They need your time:** a hamster needs regular play or exercise with its owner and a secure cage it cannot escape. [2]


## Daily & Weekly Care Checklist


Every day:

- A good-quality, balanced diet: a compound pellet ration or a complete pelleted diet made for hamsters, plus small quantities of greens, cleaned root vegetables and pieces of fruit such as apples. [3] [4]
- Constant fresh, clean drinking water from a bottle with a valveless sipper tube, checked every day for leaks or blockages. [3]
- Monitor how much the hamster eats and drinks each day. [3]
- Scatter or hide food around the cage to encourage natural foraging and prevent boredom. [3]
- Evening play or exercise; an exercise wheel with a solid running surface is often part of meeting exercise needs. [2]

Every week:

- Cage cleaning (evenings suit this); keep the hamster secure so it cannot escape. [2]
- Avoid generic seed mixes, which hamsters pick out and ignore the pellets. [4]
- Grapes and rhubarb are poisonous to hamsters and must not be given. [3]


## Nutrition


Feed a complete balanced pelleted diet made for hamsters (avoid generic seed mixes), with small daily amounts of greens, root vegetables and fruit, and constant fresh water. [4] [3]


The quotes below summarise this species' dietary requirements and nutrition-related disease risks, drawn from professional veterinary references.

### Hamster diet — balanced mix, safe foods and foods to avoid

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Hamsters need a good-quality, balanced diet: a compound pellet ration or a mixture of different seeds formulated to meet their needs, plus small quantities of greens, cleaned root vegetables and pieces of fruit such as apples. [3]
> In the wild hamsters eat seeds, cereals, insect larvae and larger insects; as pets they need variety containing all essential nutrients and minerals. [3]
> Constant fresh, clean drinking water is needed, preferably from a bottle with a valveless sipper tube, checked every day for leaks or blockages. [3]
> Wet or powdered food should only be given if advised by a vet (e.g. dental problems), as it can grow mould and harmful bacteria. [3]

### Hamster nutrition — omnivorous diet and seed mix

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Wild Syrian hamsters are omnivorous, eating green vegetation, seeds, fruit, and meat. [4]
> Feed a complete balanced pelleted diet made for hamsters (some brands offer a hamster/gerbil diet). [4]
> Avoid generic seed mixes, because hamsters pick out seeds and ignore the pellets. [4]
> Syrian hamsters do not fatten before hibernation and will starve if they do not wake periodically to eat. [4]
> Syrian hamsters store brown fat at the shoulders, axillae, neck, and kidneys. [4]
> Tyzzer disease (Clostridium piliforme) in Syrian hamsters usually follows stress such as overcrowding, high heat and humidity, heavy parasite load, or nutritionally inadequate diet. [4]

### Hamster safe greens & vegetables — omnivorous rodent; commercial mix staple, only incidental fresh veg/fruit

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Hamsters are omnivorous; in the wild they naturally eat a mixture of seeds, cereals, insect larvae and larger insects such as crickets. [5]
> As pets they need a good-quality, balanced and varied diet containing all essential nutrients and minerals; this is best supplied by a commercial hamster mix or pellets rather than fresh plant matter. [5]
> Safe greens include only incidental portions for hamsters: because they are omnivorous, the staple is a balanced commercial mix of seeds and cereals, and any fresh vegetables or fruits should be limited to small treat amounts rather than forming a dietary base. [5]
> Avoid sudden dietary changes and stale food, which can upset their stomach; wet or powdered food should be given only on veterinary advice (for example, dental problems), and fresh drinking water must be constantly available. [5]

### Rat, mouse, hamster and gerbil nutrition — rodent chow composition and treat limits (VIN Veterinary Partner)

> Rats, mice, hamsters and gerbils have similar dietary requirements. [6]
> The basic diet for this group should consist of a good quality rodent chow or lab block. [6]
> Rodent chows should have a minimum of 16% protein and 4 to 5% fat content. [6]
> Good quality rodent chows are considered to be fairly complete diets for this group. [6]
> Other foods can be fed in addition to the commercial pellets but should not constitute more than 20% of the total diet. [6]
> Fruit and vegetables as described for the rabbits, guinea pigs and chinchillas can be offered at a rate of about 1 teaspoon/day. [6]
> A reasonable amount of nuts and or seeds would be a total of 1 teaspoon/day for rats and about ½ teaspoon for the other species. [6]
> Pelleted food should be purchased in amounts that will be used within three months to prevent spoilage. [6]

> As a result of their diet of seeds and grains, they also disperse seeds, as seeds are often lost in the process of caching. [1]

## Husbandry


House hamsters in a secure, well-ventilated cage they cannot escape, with a water bottle and enough space for exercise plus feeding and nesting areas; evenings suit cleaning and play. [2]


Housing, environment and daily-care essentials for this species.

### Hamster housing — deep burrowing bedding (40–80 cm) for welfare

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> In the wild, Syrian hamsters inhabit dry rocky steppe or brushy slopes and dig shallow burrows. [7]
> In captivity they should be given deep, burrow-appropriate bedding. [7]
> Cages providing at least 40–80 cm (about 15–30 inches) of bedding improve Syrian hamster welfare. [7]

> Individuals will rub their flanks against a substrate to spread their scent. [1]
> *[Paraphrased derived summary — non-Open-Access source.]* Food can be scattered or hidden around the cage to encourage natural foraging behaviour and prevent boredom. [3]
> *[Paraphrased derived summary — non-Open-Access source.]* Their broad muzzles often prevent eating from feed hoppers, so pelleted food should go on the cage floor. [4]
> *[Paraphrased derived summary — non-Open-Access source.]* Once out of the cage, hamsters are hard to find and may refuse to return. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* The enclosure should be at least 6 in (15 cm) high; 8 in (20 cm) or more allows deeper bedding. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* The cage needs a water bottle with a sipping tube. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* Besides a cage, a hamster needs a balanced diet and regular play or exercise with its owner. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* Whatever cage or tank is used should be easy to clean and sanitise, well ventilated and well lit. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* Watch a hamster in an exercise ball and return it to its cage for food and especially water after a reasonable time. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* The enclosure needs enough space for exercise plus feeding and nesting areas. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* Choose bedding that is clean, non-toxic, absorbent, as dust-free as possible and easy to change. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* Evenings are usually a good time for play, cage cleaning and other shared activity. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* After keeping the home clean, the most important step is ensuring the hamster cannot escape its cage. [2]
> *[Paraphrased derived summary — non-Open-Access source.]* When a hamster is out of its cage (e.g. during cleaning), keep it in a secure container such as a second cage to stop it wandering into danger. [2]

## Behavior & Training


Hamsters are solitary and best kept singly; handle them gently from a young age, interact during their active evening hours, and never startle or roughly handle them, as they may bite. [1] [2]


Socialisation, bonding, play and preventing boredom / behaviour problems.

### Hamster — behavior (owner-practical care, Merck Veterinary Manual pet-owner)

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> A play area can use short packing tubes, provided they are wide enough for the hamster to pass through freely. [2]
> Boxes with holes cut in them also make good play areas. [2]
> Breeding females are larger than males, and their aggression can lead to a male cage-mate being injured. [2]
> Physical activity is encouraged by providing tubes and boxes to explore. [2]
> Hamsters accustomed to handling from a young age can be picked up easily and rarely bite unless startled. [2]
> Hamsters should not be kept in groups, since even litter-mates can become aggressive as adults. [2]
> Interact with a hamster during its active waking hours. [2]
> Evenings are usually good for play, cleaning and shared activity. [2]
> Hamsters are not normally aggressive but may become so if startled, suddenly awakened, ill or handled roughly. [2]
> Breeding is best left to experienced breeders, as hamsters (especially females) can be aggressive during mating. [2]

> Golden hamsters are solitary and highly territorial. [1]
> They are highly aggressive toward conspecifics except when mating. [1]
> *[Paraphrased derived summary — non-Open-Access source.]* Sexually mature females are territorial and aggressive and often fight one another. [2]

## Enrichment & Exercise

Toys, foraging, hiding and exercise to prevent boredom.

### Hamster — enrichment (owner-practical care, Merck Veterinary Manual pet-owner)

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Toilet-tube rolls make good running toys for small hamsters. [2]
> Treats such as fruit, vegetables or pet-store chews may be given but should be under 10% of the total diet. [2]
> Regular exercise keeps a hamster healthy and content. [2]
> An exercise wheel is often part of meeting exercise needs. [2]
> Choose a wheel with a solid running surface to protect feet and legs. [2]
> The wheel should be large enough for free movement and easy entry and exit. [2]

## When to call a vet NOW


- **Eating less or soiled hind-quarters:** contact a vet immediately if a hamster eats less, its droppings become moist, or its hind-quarters become soiled. [3]
- **Moist droppings or a soiled tail in a young Syrian:** proliferative ileitis ("wet tail") is the most significant intestinal disease of Syrian hamsters aged 3–10 weeks — contact a vet immediately. [7] [3]
- **Tell your vet it is a hamster:** some antibiotics, including penicillins, can be fatal to hamsters, so always remind your vet your pet is a hamster before any medication. [8]


## Health & Disease


Watch daily intake and droppings: key diseases are "wet tail" in 3–10-week Syrians, amyloidosis in long-term captives, and polyomavirus lymphoma in young Syrians. [3] [7]

Common conditions and their clinical signs, drawn from professional veterinary references. If you notice worrying signs, contact a species-experienced veterinarian promptly.

### Hamster amyloidosis: principal cause of death in long-term captive hamsters, linked to crowding/social stress

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> In long-term studies of captive hamsters, amyloidosis is the leading cause of death. [7]

### Hamster emergency signs — when to contact a vet

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Always monitor how much a hamster eats and drinks; if they start eating less, their droppings become moist, or their hind-quarters become soiled, talk to a vet immediately. [3]
> Avoid sudden dietary changes and stale food, as these can upset the stomach. [3]

### Hamster polyomavirus (HaPV) — epizootic lymphoma in young Syrian hamsters; up to 80% incidence

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Hamster polyomavirus (HaPV) causes outbreak (epizootic) lymphoma in young Syrian hamsters and skin epitheliomas in older hamsters carrying the infection. [7]
> When HaPV enters a previously unexposed breeding colony of Syrian hamsters, lymphoma spreads rapidly, affecting up to 80% of animals (Merck cites reference 2). [7]

### Hamster proliferative ileitis (“wet tail”) — most consequential intestinal disease of 3–10-week Syrians; hibernation <5°C

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Proliferative ileitis ("wet tail") is the most significant intestinal disease of Syrian hamsters aged 3–10 weeks. [7]

> *[Paraphrased derived summary — non-Open-Access source.]* Proliferative ileitis treatment corrects life-threatening electrolyte imbalance and dehydration, gives antimicrobials, and uses syringe-feeding. [4]

## Toxicology & Hazards

Substances and environmental hazards to avoid.

### Hamster non-drug poisons — household and feeding hazards

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Grapes and rhubarb can be poisonous to rodents (including hamsters) and should not be given. [3]

### Penicillin-induced disease in hamsters — latent-virus activation and endotoxin hypothesis (Green 1974, PMID 4446629)

> The association of viral activation with penicillin toxicity in guinea pigs and hamsters. [8]
> This finding has been construed as being activation of a latent virus by this antibiotic, but the relationship, if any, of the phenomenon of viral activation to the syndromes produced by penicillin and its frequent lethal toxicity is unknown. [8]
> Of some 60 guinea pigs which received injections of penicillin three developed tumors and four others were found to have gallstones. [8]
> A virus similar or identical to the guinea pig virus also has been isolated from hamsters dying of penicillin-induced disease. [8]
> It is hypothesized that the absorption of endotoxin, resulting from the well known change in intestinal flora caused by penicillin, produces a state of immunodeficiency which regularly gives rise to activation of a latent virus, and perhaps, rarely, to the development of malignant neoplasms. [8]

> Hamsters continue to be trapped and poisoned as agricultural pests. [1]

## Grooming

Brushing / bathing, nails, coat / skin and dental care.

### Hamster — grooming (owner-practical care, Merck Veterinary Manual pet-owner)

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Food and water containers should be easy to clean and sanitise. [2]
> Avoid cotton balls, whose fibres can catch in a hamster's claws or feet and cause injury. [2]
> Fresh clean water should always be available. [2]
> Check the fur around the genitals for stains from faeces, urine or vaginal discharge. [2]
> A vet can give medicines directly into the stomach or by injection under the skin or into the abdomen. [2]
> Active hamsters can be dropped or fall off tables and furniture. [2]
> Do not assume a hamster will stay still on a table while you clean. [2]

## Breeding & Neutering

Neutering / spaying, reproduction and preventing unwanted litters.

### Hamster — breeding (owner-practical care, Merck Veterinary Manual pet-owner)

*All lines in this block are paraphrased derived summaries — non-Open-Access source.*

> Hamsters are normally kept singly except when breeding. [2]
> Outside breeding, single housing is safest. [2]
> The best breeding age for hamsters is between 10 weeks and 15 months old. [2]
> Breeders use one-male/one-female pairs or one-male/multiple-female groups. [2]
> Many hamster types carry known genetic defects, so breeding without knowledge of genetic heritage is not advised. [2]
> Near delivery, pregnant hamsters may become restless and active and may show vaginal bleeding. [2]
> A secure nest lowers the chance a new mother will abandon or cannibalise her offspring. [2]
> Do not disturb mothers and litters for at least 7 days after birth, especially for first-time mothers. [2]
> Fostering abandoned pups onto another mother rarely succeeds. [2]

> *[Paraphrased derived summary — non-Open-Access source.]* Cold ambient temperatures (<10°C), lean diets, and low body weight during pregnancy increase cannibalism. [4]

## Regulations & Legality

Legality crosswalk lines for this species, where available. Jurisdiction-specific pet law is frequently a gap — see the roadmap.

### Hamster — species legality crosswalk (US/CA/FL named lists + EU/JP/CITES framework)

> Hamster — EU-IAS: Not on the landed EU Union list of IAS of Union concern (species not enumerated) — Art 7 prohibition applies only to listed species. Basis: Negative finding: enumerated scan of landed EU Union list.
> Hamster — JP-IAS: Not designated in the landed JP specified-invasive alien species list (species not enumerated) — Art 4 prohibition applies only to designated species. Basis: Negative finding: enumerated scan of landed JP designated list.

## Species-Specific Health

### Hamster — Atherosclerosis (hereditary; OMIA-verified species predisposition)

> Species: Mesocricetus auratus / Phodopus spp. (hamster) [9]
> Summary: Hamsters have been used as models for dyslipidemia and atherosclerosis for many decades. Xian et al. (2022) summarise their research relating to several CRISPR/Cas9 genetically engineered hamster models for dyslipidemia, created by targeting low density lipoprotein receptor (LDLR) (Wu et al., 2019), lecithin cholesterol acyl transferase (LCAT) (Dong et al., 2018), ApoC2 (Gao et al., 2020), ApoC3 (Guo et al., 2020), and adenosine triphosphate-binding cassette transporter A1 (ABCA1) (Wei et al., 2019) genes. This entry includes references to studies involving gene edited organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Evidence (references)** - 2022. Genetically engineered hamster models of dyslipidemia and atherosclerosis. Methods Mol Biol — PubMed:PMID35237980 | DOI:10.1007/978-1-0716-1924-7_26 — OMIA Phene_Article / Article - 1987. The hyperlipidemic hamster as a model of experimental atherosclerosis. Atherosclerosis — PubMed:PMID3689479 | DOI:10.1016/0021-9150(87)90106-7 — OMIA Phene_Article / Article - 1950. Experimental cholesterol arteriosclerosis. II. Changes produced in golden hamsters and in guinea pigs. Am Heart J — PubMed:PMID14770982 | DOI:10.1016/0002-8703(50)90323-1 — OMIA Phene_Article / Article - 2019. Heterozygous Ldlr-deficient hamster as a model to evaluate the efficacy of PCSK9 antibody in hyperlipidemia and atherosclerosis. Int J Mol Sci — PubMed:PMID31779098 | DOI:10.3390/ijms20235936 — OMIA Phene_Article / Article - 2018. Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis. Metabolism — PubMed:PMID29526535 | DOI:10.1016/j.metabol.2018.03.003 — OMIA Phene_Article / Article - 2020. ApoC2 deficiency elicits severe hypertriglyceridemia and spontaneous atherosclerosis: A rodent model rescued from neonatal death. Metabolism — PubMed:PMID32562799 | DOI:10.1016/j.metabol.2020.154296 — OMIA Phene_Article / Article - 2020. Inactivation of ApoC3 by CRISPR/Cas9 protects against atherosclerosis in hamsters. Circ Res — PubMed:PMID32951534 | DOI:10.1161/CIRCRESAHA.120.317686 — OMIA Phene_Article / Article - 2019. Impact of cholesterol on ischemic stroke in different human-like hamster models: A new animal model for ischemic stroke study. Cells — PubMed:PMID31487778 | DOI:10.3390/cells8091028 — OMIA Phene_Article / Article - 2023. Depleting LCAT aggravates atherosclerosis in LDLR-deficient hamster with reduced LDL-Cholesterol level. J Adv Res — PubMed:PMID37923248 | DOI:10.1016/j.jare.2023.10.016 — OMIA Phene_Article / Article - 2025. ApoL1 risk allele accelerates high-fat diet-induced atherosclerosis in LDLR-/- hamsters. Genes Dis — PubMed:PMID39669548 | DOI:10.1016/j.gendis.2024.101379 — OMIA Phene_Article / Article - 2025. Loss of LCAT function aggravates metabolic associated steatohepatitis (MASH) in golden Syrian hamster. Clin Sci (Lond) — PubMed:PMID41195480 | DOI:10.1042/CS20257764 — OMIA Phene_Article / Article - 2026. AAV gene therapy for homozygous familial hypercholesterolemia: a phase 1 trial. Nat Med — PubMed:PMID42243546 | DOI:10.1038/s41591-026-04441-3 — OMIA Phene_Article / Article - 2022. Genetically engineered hamster models of dyslipidemia and atherosclerosis. Methods Mol Biol — PubMed:PMID35237980 | DOI:10.1007/978-1-0716-1924-7_26 — OMIA Phene_Article / Article - 1987. The hyperlipidemic hamster as a model of experimental atherosclerosis. Atherosclerosis — PubMed:PMID3689479 | DOI:10.1016/0021-9150(87)90106-7 — OMIA Phene_Article / Article - 1950. Experimental cholesterol arteriosclerosis. II. Changes produced in golden hamsters and in guinea pigs. Am Heart J — PubMed:PMID14770982 | DOI:10.1016/0002-8703(50)90323-1 — OMIA Phene_Article / Article - 2019. Heterozygous Ldlr-deficient hamster as a model to evaluate the efficacy of PCSK9 antibody in hyperlipidemia and atherosclerosis. Int J Mol Sci — PubMed:PMID31779098 | DOI:10.3390/ijms20235936 — OMIA Phene_Article / Article - 2018. Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis. Metabolism — PubMed:PMID29526535 | DOI:10.1016/j.metabol.2018.03.003 — OMIA Phene_Article / Article - 2020. ApoC2 deficiency elicits severe hypertriglyceridemia and spontaneous atherosclerosis: A rodent model rescued from neonatal death. Metabolism — PubMed:PMID32562799 | DOI:10.1016/j.metabol.2020.154296 — OMIA Phene_Article / Article - 2020. Inactivation of ApoC3 by CRISPR/Cas9 protects against atherosclerosis in hamsters. Circ Res — PubMed:PMID32951534 | DOI:10.1161/CIRCRESAHA.120.317686 — OMIA Phene_Article / Article - 2019. Impact of cholesterol on ischemic stroke in different human-like hamster models: A new animal model for ischemic stroke study. Cells — PubMed:PMID31487778 | DOI:10.3390/cells8091028 — OMIA Phene_Article / Article - 2023. Depleting LCAT aggravates atherosclerosis in LDLR-deficient hamster with reduced LDL-Cholesterol level. J Adv Res — PubMed:PMID37923248 | DOI:10.1016/j.jare.2023.10.016 — OMIA Phene_Article / Article - 2025. ApoL1 risk allele accelerates high-fat diet-induced atherosclerosis in LDLR-/- hamsters. Genes Dis — PubMed:PMID39669548 | DOI:10.1016/j.gendis.2024.101379 — OMIA Phene_Article / Article - 2025. Loss of LCAT function aggravates metabolic associated steatohepatitis (MASH) in golden Syrian hamster. Clin Sci (Lond) — PubMed:PMID41195480 | DOI:10.1042/CS20257764 — OMIA Phene_Article / Article - 2026. AAV gene therapy for homozygous familial hypercholesterolemia: a phase 1 trial. Nat Med — PubMed:PMID42243546 | DOI:10.1038/s41591-026-04441-3 — OMIA Phene_Article / Article - 2022. Genetically engineered hamster models of dyslipidemia and atherosclerosis. Methods Mol Biol — PubMed:PMID35237980 | DOI:10.1007/978-1-0716-1924-7_26 — OMIA Phene_Article / Article - 1987. The hyperlipidemic hamster as a model of experimental atherosclerosis. Atherosclerosis — PubMed:PMID3689479 | DOI:10.1016/0021-9150(87)90106-7 — OMIA Phene_Article / Article - 1950. Experimental cholesterol arteriosclerosis. II. Changes produced in golden hamsters and in guinea pigs. Am Heart J — PubMed:PMID14770982 | DOI:10.1016/0002-8703(50)90323-1 — OMIA Phene_Article / Article - 2019. Heterozygous Ldlr-deficient hamster as a model to evaluate the efficacy of PCSK9 antibody in hyperlipidemia and atherosclerosis. Int J Mol Sci — PubMed:PMID31779098 | DOI:10.3390/ijms20235936 — OMIA Phene_Article / Article - 2018. Loss of LCAT activity in the golden Syrian hamster elicits pro-atherogenic dyslipidemia and enhanced atherosclerosis. Metabolism — PubMed:PMID29526535 | DOI:10.1016/j.metabol.2018.03.003 — OMIA Phene_Article / Article - 2020. ApoC2 deficiency elicits severe hypertriglyceridemia and spontaneous atherosclerosis: A rodent model rescued from neonatal death. Metabolism — PubMed:PMID32562799 | DOI:10.1016/j.metabol.2020.154296 — OMIA Phene_Article / Article - 2020. Inactivation of ApoC3 by CRISPR/Cas9 protects against atherosclerosis in hamsters. Circ Res — PubMed:PMID32951534 | DOI:10.1161/CIRCRESAHA.120.317686 — OMIA Phene_Article / Article - 2019. Impact of cholesterol on ischemic stroke in different human-like hamster models: A new animal model for ischemic stroke study. Cells — PubMed:PMID31487778 | DOI:10.3390/cells8091028 — OMIA Phene_Article / Article - 2023. Depleting LCAT aggravates atherosclerosis in LDLR-deficient hamster with reduced LDL-Cholesterol level. J Adv Res — PubMed:PMID37923248 | DOI:10.1016/j.jare.2023.10.016 — OMIA Phene_Article / Article - 2025. ApoL1 risk allele accelerates high-fat diet-induced atherosclerosis in LDLR-/- hamsters. Genes Dis — PubMed:PMID39669548 | DOI:10.1016/j.gendis.2024.101379 — OMIA Phene_Article / Article - 2025. Loss of LCAT function aggravates metabolic associated steatohepatitis (MASH) in golden Syrian hamster. Clin Sci (Lond) — PubMed:PMID41195480 | DOI:10.1042/CS20257764 — OMIA Phene_Article / Article - 2026. AAV gene therapy for homozygous familial hypercholesterolemia: a phase 1 trial. Nat Med — PubMed:PMID42243546 | DOI:10.1038/s41591-026-04441-3 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:108725 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:108725 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:108725 (type: trait) — OMIA Group_OMIM (via OMIA_ID) [9]

### Hamster — Cancer, TP53-related (hereditary; OMIA-verified species predisposition)

> Summary: Miao et al. (2021) describe a cancer phenotype in TP53 knockout golden Syrian hamsters. This phene includes references to studies involving genetically modified organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 398298960 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2021. Cancer spectrum in TP53-deficient golden Syrian hamsters: A new model for Li-Fraumeni syndrome. J Carcinog — PubMed:PMID34729050 | DOI:10.4103/jcar.jcar_18_21 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:109800 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:114480 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:137215 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:601626 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:211980 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:260350 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:614470 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:202300 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:114500 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:114550 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:607107 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:259500 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:614740 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:137800 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:191170 (type: gene) — OMIA Group_OMIM (via OMIA_ID) - OMIM:190070 (type: gene) — OMIA Group_OMIM (via OMIA_ID) - OMIM:151623 (type: trait) — OMIA Group_OMIM (via OMIA_ID) [10]

### Hamster — Coat colour, black tremor (hereditary; OMIA-verified species predisposition)

> Summary: "The hamster black tremor (bt) mutation induces a black coat color and a defective myelination in the central nervous system (CNS) that manifests as a tremor." (Kuramoto et al., 2002) _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 392710362 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene - OMIA molecular-genetics note: Kuramoto et al. (2002) reported "an approximately 10-kb DNA fragment, which had 557-bp direct repeats in both ends and was flanked by the identical 6-bp target duplication sequences, [that] was inserted into exon 24" as a likely causal variant. **Evidence (references)** - 2002. Insertional mutation of the Attractin gene in the black tremor hamster. Mamm Genome — PubMed:PMID11773967 — OMIA Phene_Article / Article - 1986. [Genetical analysis and characterization of a new mutant, black tremor appearing in the Syrian hamster]. Jikken Dobutsu — PubMed:PMID3732409 | DOI:10.1538/expanim1978.35.2_175 — OMIA Phene_Article / Article - 2003. Myelin-deficiency in the cochlear nerve of the 'bt' mutant hamster. Hear Res — PubMed:PMID12583878 | DOI:10.1016/s0378-5955(02)00550-6 — OMIA Phene_Article / Article - 2003. Sustained hypomyelination and high serum thyroid hormone in aged black tremor hamster. Jpn J Vet Res — PubMed:PMID14621228 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:603130 (type: gene) — OMIA Group_OMIM (via OMIA_ID) [11]

### Hamster — Duper (hereditary; OMIA-verified species predisposition)

> Summary: Lee et al. (2022): "The duper mutation is a recessive mutation that shortens the period length of the circadian rhythm in Syrian hamsters. These animals show a large phase shift when responding to light pulses.. we identified duper as an early nonsense allele of Cryptochrome 1 (Cry1) leading to a short, unstable protein." _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 392717204 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2011. Duper: a mutation that shortens hamster circadian period. J Biol Rhythms — PubMed:PMID21775287 | DOI:10.1177/0748730411411569 — OMIA Phene_Article / Article - 2011. Effects of the duper mutation on circadian responses to light. J Biol Rhythms — PubMed:PMID21775288 | DOI:10.1177/0748730411411570 — OMIA Phene_Article / Article - 2022. duper is a null mutation of cryptochrome 1 in Syrian hamsters. Proc Natl Acad Sci U S A — PubMed:PMID35471909 | DOI:10.1073/pnas.2123560119 — OMIA Phene_Article / Article - 2023. Adult neurogenesis is altered by circadian phase shifts and the duper mutation in female Syrian hamsters. eNeuro — PubMed:PMID36878716 | DOI:10.1523/ENEURO.0359-22.2023 — OMIA Phene_Article / Article - 2024. Neuroendocrine effects of the duper mutation in Syrian hamsters: a role for Cryptochrome 1. Front Physiol — PubMed:PMID38444761 | DOI:10.3389/fphys.2024.1351682 — OMIA Phene_Article / Article [12]

### Hamster — Fluorescent protein, transgenic (hereditary; OMIA-verified species predisposition)

> Summary: Shigeta et al. (2025) used CRISPR/Cas9 technology to knock in a red fluorescent reporter. This phene includes references to studies involving gene edited or genetically modified organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Evidence (references)** - 2025. Generation of knock-in Syrian hamsters via zygote microinjection using CRISPR/Cas9 genome editing. Genesis — PubMed:PMID40964963 | DOI:10.1002/dvg.70027 — OMIA Phene_Article / Article - 2025. Generation of knock-in Syrian hamsters via zygote microinjection using CRISPR/Cas9 genome editing. Genesis — PubMed:PMID40964963 | DOI:10.1002/dvg.70027 — OMIA Phene_Article / Article - 2025. Generation of knock-in Syrian hamsters via zygote microinjection using CRISPR/Cas9 genome editing. Genesis — PubMed:PMID40964963 | DOI:10.1002/dvg.70027 — OMIA Phene_Article / Article [13]

### Hamster — Hypercholesterolaemia (hereditary; OMIA-verified species predisposition)

> Summary: Guo et al. (2018) "generated Ldlr-ablated hamsters using CRISPR/Cas9 technology". Thus these animals are genetically-modified organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 392710827 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2019. Dietary cholesterol is highly associated with severity of hyperlipidemia and atherosclerotic lesions in heterozygous LDLR-deficient hamsters. Int J Mol Sci — PubMed:PMID31323736 | DOI:10.3390/ijms20143515 — OMIA Phene_Article / Article - 2018. LDL receptor gene-ablated hamsters: A rodent model of familial hypercholesterolemia with dominant inheritance and diet-induced coronary atherosclerosis. EBioMedicine — PubMed:PMID29289533 | DOI:10.1016/j.ebiom.2017.12.013 — OMIA Phene_Article / Article - 2021. Dietary-induced elevations of triglyceride-rich lipoproteins promote atherosclerosis in the low-density lipoprotein receptor knockout Syrian golden hamster. Front Cardiovasc Med — PubMed:PMID34796210 | DOI:10.3389/fcvm.2021.738060 — OMIA Phene_Article / Article - 2023. LDLR heterozygous deletion reduces hamster testicular cholesterol toxicity via AMPK/Sirt1/PGC-1α pathway. Toxicol Lett — PubMed:PMID37459939 | DOI:10.1016/j.toxlet.2023.07.009 — OMIA Phene_Article / Article - 2025. ApoL1 risk allele accelerates high-fat diet-induced atherosclerosis in LDLR-/- hamsters. Genes Dis — PubMed:PMID39669548 | DOI:10.1016/j.gendis.2024.101379 — OMIA Phene_Article / Article - 2025. Fat-1 ameliorates metabolic dysfunction-associated fatty liver disease and atherosclerosis through promoting the nuclear localization of PPARα in hamsters. Research (Wash D C) — PubMed:PMID40052160 | DOI:10.34133/research.0577 — OMIA Phene_Article / Article - 2024. Development of a hamster model of spontaneous hypertriglyceridemia in diabetes. Animal Model Exp Med — PubMed:PMID39529532 | DOI:10.1002/ame2.12490 — OMIA Phene_Article / Article - 2026. SiRNA-based inactivation of Angptl3 alleviates high-fat diet-induced MAFLD and atherosclerosis in LDLR-deficient hamsters. Lipids Health Dis — PubMed:PMID41787476 | DOI:10.1186/s12944-026-02916-3 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:143890 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:606945 (type: gene) — OMIA Group_OMIM (via OMIA_ID) [14]

### Hamster — Hypertriglyceridemia (hereditary; OMIA-verified species predisposition)

> Disorder: Hypertriglyceridemia [15]
> Summary: Shen et al. (2024): Acute seizure models were established both in vivo and ex vivo using wild-type and Apolipoprotein C2 knockout ( Apoc2 −/− ) hamsters.. Hypertriglyceridemic Apoc2 −/− hamsters exhibited reduced seizure frequency and decreased cortical neuron excitability." This study involves gene edited or genetically modified organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 398298976 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2020. ApoC2 deficiency elicits severe hypertriglyceridemia and spontaneous atherosclerosis: A rodent model rescued from neonatal death. Metabolism — PubMed:PMID32562799 | DOI:10.1016/j.metabol.2020.154296 — OMIA Phene_Article / Article - 2024. Decreased neuronal excitability in hypertriglyceridemia hamsters with acute seizures. Front Neurol — PubMed:PMID39811454 | DOI:10.3389/fneur.2024.1500737 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:608083 (type: gene) — OMIA Group_OMIM (via OMIA_ID) - OMIM:207750 (type: None) — OMIA Group_OMIM (via OMIA_ID) [15]

### Hamster — Severe combined immunodeficiency disease, X-linked (hereditary; OMIA-verified species predisposition)

> Summary: This disorder in hamsters has been produced by targeted disruption of the IL2RG gene (natural mutations in which cause X-linked SCID in dogs and humans). Thus, the reports in this entry concern a genetically-modified organism (GMO) _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 392706634 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2020. Generation and characterization of an IL2RG knockout Syrian hamster model for XSCID and HAdV-C6 infection in immunocompromised patients. Dis Model Mech — PubMed:PMID32651192 | DOI:10.1242/dmm.044602 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:300400 (type: trait) — OMIA Group_OMIM (via OMIA_ID) - OMIM:308380 (type: gene) — OMIA Group_OMIM (via OMIA_ID) - OMIM:312863 (type: trait) — OMIA Group_OMIM (via OMIA_ID) [16]

### Hamster — Woodhouse-Sakati syndrome (hereditary; OMIA-verified species predisposition)

> Summary: Ma et al. (2024): "As a model to explore the role of Dcaf17 in the male reproductive system, we created Dcaf17-deficient male golden hamsters using CRISPR-Cas9 technology, the results of which demonstrate that deletion of Dcaf17 led to abnormal spermatogenesis and infertility." This study involves gene edited or genetically modified organisms (GMO). _Derived from OMIA database dump (omia.xml, local); structured fields — each value is verbatim from the disorder's source file `pdf-raw/omia/<phene_id>.txt`:_ **Associated gene(s)** - Gene: Entrez Gene ID 398298945 (no symbol in OMIA GeneSynonym) — OMIA Phene_Gene **Evidence (references)** - 2024. Single-cell RNA Sequencing reveals the important role of Dcaf17 in spermatogenesis of golden hamsters. Biol Reprod — PubMed:PMID39239833 | DOI:10.1093/biolre/ioae132 — OMIA Phene_Article / Article - 2024. Correction to: Single-cell RNA sequencing reveals the important role of Dcaf17 in spermatogenesis of golden hamsters. Biol Reprod — PubMed:PMID39376075 | DOI:10.1093/biolre/ioae144 — OMIA Phene_Article / Article **Comparative medicine (human OMIM)** - OMIM:612515 (type: gene) — OMIA Group_OMIM (via OMIA_ID) - OMIM:241080 (type: trait) — OMIA Group_OMIM (via OMIA_ID) [17]

## Appendix A — Commercial Food & Regulatory Notes

How pet-food regulatory standards treat this species (reference material, demoted from the main flow).

### Exotic / specialty pet food — AAFCO recognizes no nutrient profiles for exotics; standards defer to NRC species reports

> As an AAFCO-recognized nutrient profile or nutritional authority: [18]
> For dogs, the AAFCO Dog Food Nutrient Profiles; [18]
> For cats, the AAFCO Cat Food Nutrient Profiles; [18]
> For specialty pets, the nutrient recommendations approved by the Committee on Animal Nutrition of the National Research Council of the National Academy of Sciences [18]

## Appendix B — Research Evidence

Peer-reviewed papers indexed for this species (reference material). Entries whose abstract did not mention the species by name, or were flagged off-topic at source, were omitted as likely mis-clustered.

### Evidence cluster — Hamster (Mesocricetus auratus) husbandry, health & nutrition (peer-reviewed, Europe PMC)

> **PMID 42071946 (2026, Animals: an open access journal from MDPI)** — Occurrence and Genetic Diversity of Cryptosporidium spp. in Pet Rodents from Yunnan, China: Identification of Zoonotic Subtypes in Hamsters. (opening): Cryptosporidium spp. are common protist pathogens, and the growing popularity of pet rodents raises concerns about their potential role in zoonotic parasites transmission. However, epidemiological data on Cryptosporidium spp. in pet rodents in Yunnan Province is scarce. To examine the occurrence of Cryptosporidium spp. in pet rodents in Yunnan, we collected 762 fecal samples from four rodent species across four cities. Nested PCR and DNA sequencing were used to characterize the species and subtypes of Cryptosporidium. The occurrence of Cryptosporidium spp. in guinea pigs ( Cavia porcellus ), Siberian dwarf hamsters ( Phodopus sungorus ), Syrian hamsters ( Mesocricetus auratus ) and fancy rats ( Rattus norvegicus domestica ) was 18.7% (80/426), 17.3% (36/207), 12.5% (15/120), 0% (0/9), respectively, with an overall rate of 17.2% (131/762). According to regions, the positivity rate of Cryptosporidium spp. in Zhaotong city, Kunming city, Yuxi city and Qujing city was 21.0%, 17.9%, 16.8% and 10.5%, respectively. In terms of sampling location, the occurrence of Cryptosporidium spp. in pet markets, farms and shops was 19.5%, 18.6% and 0%, respectively. Sequence analysis of the small subunit ribosomal RNA ( SSU rRNA) gene identified six Cryptosporidium species/genotypes: Cryptosporidium homai ( n = 52), Cryptosporidium wrairi ( n = 30), Cryptosporidium sp. hamster genotype ( n = 25), Cryptosporidium andersoni ( n = 20), Cryptosporidium parvum ( n = 5), and Cryptosporidium muris ( n = 1). Further subtyping of C. andersoni isolates using multilocus sequence typing (MLST) revealed a single subtype, with all isolates identified as A3A4A2A2. All five C. parvum isolates were identified as subtype IIdA15G1 based on the gp60 gene. Our findings demonstrated the presence of the zoonotic C. parvum IIdA15G1 subtype in pet rodents, suggesting that these animals, particularly hamsters, may serve as reservoirs for human-pathogenic Cryptosporidium species. These results underscore the need for improved biosecurity and husbandry practices in the pet rodent trade to mitigate public health risks. *[CC BY — Open Access, verbatim with attribution.]* [19]

## References

[1] https://animaldiversity.org/accounts/Mesocricetus_auratus/  
    *grade B: T3 professional reference, verbatim (computed per docs/topic_grading_guide.md §4)*
[2] https://www.merckvetmanual.com/all-other-pets  
    *grade B: T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)*
[3] https://www.rspca.org.uk/adviceandwelfare/pets/rodents/hamsters/diet  
    *grade C: T4 expert organisation, paraphrase (computed per docs/topic_grading_guide.md §4)*
[4] https://www.merckvetmanual.com/exotic-and-laboratory-animals  
    *grade B: T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)*
[5] https://www.rspca.org.uk/  
    *grade C: T4 expert organisation, paraphrase (computed per docs/topic_grading_guide.md §4)*
[6] https://veterinarypartner.vin.com/default.aspx?pid=19239&catId=254109&id=4952897  
    *grade B: T3 professional reference, verbatim (computed per docs/topic_grading_guide.md §4)*
[7] https://www.merckvetmanual.com/exotic-and-laboratory-animals/rodents/hamsters  
    *grade B: T3 professional reference, paraphrase (computed per docs/topic_grading_guide.md §4)*
[8] https://pmc.ncbi.nlm.nih.gov/articles/PMC2595098/  
    *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)*
[9] https://omia.org/OMIA000080/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[10] https://omia.org/OMIA001990/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[11] https://omia.org/OMIA001645/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[12] https://omia.org/OMIA001643/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[13] https://omia.org/OMIA002737/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[14] https://omia.org/OMIA000499/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[15] https://omia.org/OMIA002915/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[16] https://omia.org/OMIA000899/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[17] https://omia.org/OMIA002894/10036/  
    *grade pending: ungraded, verbatim (computed per docs/topic_grading_guide.md §4)*
[18] AAFCO — Dog / Cat / Specialty-Pet Food Nutrient Profiles (NRC for specialty pets) — https://www.aafco.org/  
    *grade A: T1 government/standard, verbatim (computed per docs/topic_grading_guide.md §4)*
[19] https://pubmed.ncbi.nlm.nih.gov/42071946/  
    *grade A: T2 peer-reviewed, verbatim (computed per docs/topic_grading_guide.md §4)*

## Supplement Data Roadmap

*Known gaps in this manual, machine-checked against the published text on every build; an item appears only while the gap is still real.*

- **Root-domain reference(s)**: https://www.rspca.org.uk/, https://www.aafco.org/ — these point to a source home page rather than the exact page; being fixed.