🐰🐹 Small Mammals and Pocket Pets

📚 Introduction to Small Mammal Medicine

Small mammals and pocket pets represent a diverse group of companion animals that have become increasingly popular in modern households. These animals, ranging from the intelligent and social rabbit to the nocturnal and solitary hamster, each present unique challenges and rewards in veterinary care. Unlike traditional pets such as dogs and cats, small mammals often have specialized husbandry requirements, species-specific diseases, and unique physiological characteristics that demand specialized knowledge from veterinary professionals.

The term "pocket pet" typically refers to small mammals that can be easily handled and housed in relatively compact spaces, though this is somewhat of a misnomer as many require substantial living areas for optimal health. This module covers the most common small mammal pets: rabbits (lagomorphs, not rodents), guinea pigs, hamsters, gerbils, rats, mice, chinchillas, and ferrets (carnivores). Understanding their evolutionary backgrounds, natural behaviors, and specific medical needs is crucial for providing appropriate veterinary care and client education.

🎥 Educational Video Series

🐾 Species Classification and Characteristics

• Lifespan: 8-12 years (longest of common small mammals)
• Adult Weight: 2-20 lbs depending on breed (Netherland Dwarf to Flemish Giant)
• Social Structure: Highly social, form complex hierarchies
• Activity Pattern: Crepuscular (most active dawn and dusk)
• Unique Features:
  • Cecotrophy (consuming nutrient-rich soft feces)
  • Continuous tooth growth (2mm/week for incisors)
  • Cannot vomit due to strong cardiac sphincter
  • Obligate nasal breathers
  • Fragile skeleton (7-8% body weight vs. 12-13% in cats)

• Lifespan: 4-8 years
• Adult Weight: 700-1200g (males larger)
• Social Structure: Highly social, should be kept in pairs/groups
• Unique Features:
  • Cannot synthesize Vitamin C (like humans and primates)
  • Precocial young (born fully furred with eyes open)
  • Continuously growing teeth (all 20 teeth)
  • Complex vocalizations (wheeks, purrs, rumbles)
  • Require large cage space (minimum 7.5 sq ft for one)

• Syrian/Golden Hamster (Mesocricetus auratus):
  • Lifespan: 2-3 years
  • Weight: 120-150g
  • MUST be housed alone (will fight to death)
  • Cheek pouches extend to shoulders
• Dwarf Hamsters (Phodopus spp.):
  • Lifespan: 1.5-2 years
  • Weight: 20-50g
  • Can sometimes be housed in same-sex pairs
  • Higher metabolism than Syrian hamsters
• Activity Pattern: Nocturnal (active at night)
• Unique Features: Torpor ability (temporary hibernation-like state)

• Lifespan: 2-3 years
• Adult Weight: 250-500g (males larger)
• Social Structure: Highly social, require companionship
• Intelligence: Problem-solving abilities comparable to dogs
• Unique Features:
  • Cannot vomit (no emetic reflex)
  • Excellent climbers and swimmers
  • Continuously growing incisors (yellow-orange is normal)
  • Prone to respiratory infections (Mycoplasma pulmonis)

• Lifespan: 1-2 years
• Adult Weight: 20-40g
• Social Structure: Females social, males territorial
• Reproduction: Extremely prolific (can breed at 6 weeks)
• Housing: Males produce strong odor due to pheromones

• Lifespan: 2-4 years
• Adult Weight: 70-130g
• Social Structure: Monogamous pairs in wild
• Unique Features:
  • Adapted to arid environments (concentrated urine, minimal odor)
  • Prone to spontaneous seizures (genetic)
  • Tail can deglove if grabbed (defense mechanism)

• Lifespan: 10-20 years
• Adult Weight: 400-800g
• Unique Features:
  • Densest fur of any land mammal (60 hairs per follicle)
  • Cannot get wet (fur doesn't dry properly)
  • Require dust baths for grooming
  • Heat sensitive (ideal temp 60-70°F)
  • Fur slip as defense mechanism

• Lifespan: 7-10 years
• Adult Weight: 0.7-2kg (males larger)
• Diet: Obligate carnivores (require animal protein only)
• Activity Pattern: Crepuscular, sleep 18-20 hours/day
• Unique Features:
  • Descended from European polecat
  • Cannot digest plant matter
  • Prone to adrenal disease and insulinoma
  • Require 4+ hours out-of-cage time daily
  • Illegal in some states/cities

📈 Life Cycles and Reproduction

Species	Sexual Maturity	Gestation	Litter Size	Weaning Age	Special Notes
Rabbit	4-6 months	31-32 days	4-12 kits	4-6 weeks	Induced ovulators, can rebreed immediately
Guinea Pig	2-3 months	59-72 days	1-6 pups	3 weeks	Precocial young, pubic symphysis fuses at 6 months
Syrian Hamster	6-8 weeks	16-18 days	5-12 pups	3-4 weeks	Shortest gestation of common pets
Rat	5-6 weeks	21-23 days	6-12 pups	3-4 weeks	Postpartum estrus (can rebreed immediately)
Mouse	6-8 weeks	19-21 days	5-12 pups	3 weeks	Can produce 5-10 litters/year
Gerbil	10-12 weeks	24-26 days	3-7 pups	4-5 weeks	Monogamous pairs bond for life
Chinchilla	8 months	111 days	1-3 kits	6-8 weeks	Longest gestation of small mammals
Ferret	6-9 months	42 days	6-8 kits	6-8 weeks	Induced ovulators, prolonged estrus dangerous

❤️ Vital Signs and Physical Parameters

Species	Temperature (°F)	Heart Rate (bpm)	Respiratory Rate	Lifespan
Rabbit	101.3-104	180-250	30-60	8-12 years
Guinea Pig	99-103.1	230-280	42-104	4-8 years
Hamster	98-101	250-500	35-135	2-3 years
Rat	99.5-100.6	250-450	70-115	2-3 years
Mouse	98.6-100.4	420-700	60-220	1-2 years
Gerbil	99-102	260-360	85-160	2-4 years
Chinchilla	97-100	200-350	40-80	10-20 years
Ferret	100-103	200-250	33-36	7-10 years

🥘 Species-Specific Nutrition

• Diet Composition:
  • 80% hay (timothy, orchard grass - unlimited)
  • 10% vegetables (2 cups per 6 lbs body weight)
  • 5% pellets (1/4 cup per 6 lbs)
  • 5% treats (fruits, limited)
• Critical Requirements:
  • High fiber (18-22%) for gut motility
  • Calcium:Phosphorus ratio 1.5-2:1
  • Avoid high-calcium vegetables (spinach) - causes bladder sludge
• Cecotrophy: Consume soft, nutrient-rich feces directly from anus (usually at night)

• Vitamin C Requirement:
  • 10-30mg/kg daily (higher if stressed/ill)
  • Cannot synthesize (lack L-gulonolactone oxidase)
  • Sources: Bell peppers, kale, parsley
  • Supplements degrade quickly in water/pellets
• Diet:
  • Unlimited timothy hay
  • 1/8 cup pellets daily (vitamin C fortified)
  • 1 cup vegetables daily
• Scurvy Signs: Rough coat, swollen joints, dental issues, poor wound healing

• Diet: High fiber, low fat, low moisture
• Hay: Timothy or orchard grass (alfalfa too high in calcium)
• Pellets: 1-2 tablespoons daily
• Treats: Very limited (prone to GI upset)
• Water: Can develop dental issues from mineral deposits

• Commercial Diet: Lab blocks/pellets (16-20% protein)
• Supplements:
  • Fresh vegetables daily
  • Occasional protein (eggs, mealworms)
  • Limited seeds/nuts (high fat)
• Species Differences:
  • Hamsters: Hoard food in cheek pouches
  • Rats: Require more variety, enjoy puzzle feeders
  • Gerbils: Lower water requirements

• Requirements:
  • 32-38% protein (animal-based)
  • 15-20% fat
  • Less than 3% fiber
  • Cannot digest plant proteins
• Feeding:
  • High-quality ferret or kitten food
  • No dog food (lacks taurine)
  • Raw diet controversial (disease risk)
  • Multiple small meals (fast metabolism)
• Treats: Egg, cooked meat (no fruits/vegetables/dairy)

🏥 Common Veterinary Issues

• Definition: Slowing or cessation of normal GI motility
• Causes: Diet (low fiber), stress, pain, dehydration, dental disease
• Signs:
  • Decreased or absent fecal production
  • Anorexia (not eating)
  • Hunched posture, teeth grinding (pain)
  • Decreased cecotrope consumption
• Treatment:
  • Fluid therapy (subcutaneous or IV)
  • Pain management (meloxicam, buprenorphine)
  • Prokinetics (metoclopramide, cisapride)
  • Syringe feeding (Critical Care)
  • Address underlying cause
• Prevention: High-fiber diet, minimize stress, regular exercise

• Malocclusion: Misalignment causing overgrowth
• Signs: Drooling, selective eating, weight loss, facial abscesses
• Treatment: Regular trimming under anesthesia, extraction if severe
• Prevention: Appropriate diet (hay for grinding), regular checks

• Cause: Pasteurella multocida bacteria
• Signs: Nasal discharge, sneezing, conjunctivitis, head tilt
• Treatment: Long-term antibiotics (enrofloxacin, penicillin)
• Note: Often chronic, recurrent condition

• Signs:
  • Rough hair coat
  • Swollen, painful joints
  • Reluctance to move
  • Poor wound healing
  • Dental issues
• Diagnosis: Clinical signs, dietary history
• Treatment: Vitamin C supplementation (50-100mg daily)
• Prevention: Fresh vegetables, fortified pellets

• Common Pathogens: Bordetella bronchiseptica, Streptococcus pneumoniae
• Signs: Nasal discharge, dyspnea, anorexia
• Risk Factors: Stress, poor ventilation, overcrowding
• Treatment: Antibiotics, supportive care

• Cause: Lawsonia intracellularis bacteria
• Signs:
  • Watery diarrhea
  • Matted, wet fur around tail
  • Dehydration
  • Lethargy, hunched posture
• Treatment: Antibiotics (tetracycline), fluids, supportive care
• Prognosis: Often fatal if not treated quickly
• Risk Factors: Stress, weaning, overcrowding

• Cause: Mycoplasma pulmonis (endemic in pet rats)
• Signs: Sneezing, porphyrin staining, dyspnea, clicking sounds
• Treatment: Antibiotics (doxycycline + enrofloxacin)
• Note: Cannot be cured, only managed

• Incidence: Very common in females (up to 50%)
• Types: Usually benign fibroadenomas
• Treatment: Surgical removal
• Prevention: Early spaying reduces risk

• Signs: Hair loss (tail/rump), vulvar swelling, pruritus
• Cause: Adrenal gland hyperplasia/neoplasia
• Treatment: Surgery, deslorelin implant
• Prevalence: Affects up to 70% of ferrets

• Definition: Pancreatic beta cell tumor
• Signs: Hypoglycemia, weakness, pawing at mouth, seizures
• Diagnosis: Blood glucose <60mg/dL
• Treatment: Prednisone, diazoxide, surgery

• Types: Juvenile (viral) vs. adult onset
• Signs: Lymphadenopathy, weight loss, dyspnea
• Treatment: Chemotherapy protocols

🏠 Housing and Environmental Requirements

Species	Minimum Cage Size	Temperature Range	Humidity	Special Requirements
Rabbit	12 sq ft + exercise area	60-70°F	30-70%	Litter box, hiding spots, toys
Guinea Pig	7.5 sq ft (single), 10.5 sq ft (pair)	65-75°F	30-70%	No wire bottom, hiding houses
Syrian Hamster	450 sq inches floor space	65-75°F	40-60%	6+ inches bedding for burrowing
Rat	2.5 cubic feet per rat	65-80°F	40-70%	Multiple levels, hammocks
Mouse	200 sq inches per mouse	65-80°F	30-70%	Ventilation important (ammonia)
Gerbil	10 gallons per pair	65-75°F	30-50%	Deep bedding, sand bath
Chinchilla	24"×24"×24" minimum	60-70°F (max 75°F)	30-40%	Multiple levels, dust bath
Ferret	24"×36"×24" + playtime	60-70°F	40-65%	Ferret-proof room for play

🛡️ Preventive Care and Wellness

• Rabbits:
  • RHDV2 vaccine (where available) - annual
  • Myxomatosis vaccine (Europe/UK) - every 6-12 months
  • No vaccines available in some regions
• Ferrets:
  • Rabies vaccine - annual (required by law in many areas)
  • Canine distemper vaccine - annual
  • Use ferret-approved vaccines only
• Other Species: No routine vaccines available or recommended

• Rabbits:
  • Spay females by 6 months (80% uterine cancer risk by age 3)
  • Neuter males by 4-5 months (reduce aggression, spraying)
• Guinea Pigs:
  • Males: Neuter to allow mixed-sex housing
  • Females: Only if medically necessary (higher risk)
• Ferrets:
  • Essential for females (prevent fatal aplastic anemia)
  • Males: Reduce odor and aggression
  • Consider deslorelin implant as alternative
• Rats:
  • Spay females to prevent mammary tumors
  • Neuter males to reduce aggression

• External Parasites:
  • Mites: Common in all species
  • Fleas: Rabbits, ferrets susceptible
  • Treatment: Selamectin (Revolution) safe for most
• Internal Parasites:
  • Pinworms: Common in rabbits, rats, mice
  • Coccidia: Rabbits, guinea pigs
  • Regular fecal testing recommended

🚨 Emergency Situations