Part I — Canine biology and physiology

1. Life stages

• Neonatal (0–2 weeks) — closed eyes and ears; total maternal dependence; sensory development starts at ~week 2.
• Transitional (2–4 weeks) — eyes and ears open; first teeth; beginning of voluntary movement.
• Socialisation (3–14 weeks) — critical window for exposure to people, other dogs, environments, and stimuli. Under-socialisation in this window predicts adult anxiety and reactivity.
• Juvenile (3–6 months) — puppy vaccinations complete; deciduous teeth replaced; predictable growth curve.
• Adolescent (6–18 months) — sexual maturity; behavioural challenges characteristic of this stage; skeletal growth ends in small breeds first and giant breeds last (up to 24 months).
• Adult (1–7 years) — physiological plateau; peak of most-preventable behavioural and health conditions.
• Senior (7+ years for large breeds; 10+ for small) — decreased activity, cognitive decline in some individuals, increased screening cadence.

2. Approximate normal vital ranges (adult, at rest)

Ranges are indicative; per-dog thresholds inside the Dally app are stored on the dog record and can be edited by the owner or vet. [DRAFT — VET REVIEW PENDING for the ranges below]

Notes: puppies run higher HR (up to 220 bpm in the first month, settling by 6 months). Panting dogs may show respiratory rates of 200+ /min transiently; sustained tachypnoea at rest is abnormal. Rectal temperature above 39.5 °C is fever; above 41 °C is a veterinary emergency.

3. Systems overview

• Cardiovascular — four-chambered heart; predictable auscultation windows; sinus arrhythmia is a normal finding at rest in most dogs. Common disease patterns include mitral valve disease (small breeds, senior), dilated cardiomyopathy (large breeds), and heartworm (tropical and subtropical distribution, mosquito-borne).
• Respiratory — obligate nose breathers at rest; panting is thermal, not distress by default. Brachycephalic breeds (Bulldog, Pug, French Bulldog, Boxer) show characteristic upper-airway constraint (BOAS).
• Gastrointestinal — carnivorous evolution but omnivorous adaptation; gastric torsion (GDV) is a life-threatening large-breed emergency; megaesophagus is a specific pattern.
• Musculoskeletal — hip and elbow dysplasia are the two most economically significant breed-linked conditions (large breeds); cranial cruciate ligament rupture is the most common orthopaedic surgical presentation.
• Integumentary — coat structure varies from single-coated (Whippet) to heavy double-coated (Husky). Ear conformation (drop vs erect) predicts otitis externa risk.
• Nervous system — species-typical behaviours (predatory, social, territorial); breed-specific behavioural priors are well documented.
• Endocrine — hypothyroidism (most-diagnosed endocrinopathy) and hyperadrenocorticism (Cushing's, senior small breeds) predominate.
• Renal — chronic kidney disease is the leading senior chronic condition; hydration status is a first-line vital sign.
• Reproductive — mammary tumours are the leading spayed-vs-intact-adjusted cancer in intact females; pyometra is a spayed-preventable emergency.
• Sensory — vision (dichromatic; excellent motion and low-light); hearing (much wider frequency range than humans); olfaction (10,000-100,000× human sensitivity depending on breed); somatosensory (paw pads only significantly sweat).
• Haematological — normal PCV 37–55 %; leukocytosis, anaemia patterns are the workhorse diagnostic screen.
• Immune — MHC diversity across breeds; some purebred lines carry known immunodeficiencies (e.g., Doberman severe combined immunodeficiency).