Table 1.
Study population characteristics of managed-care giraffe (Giraffa spp.) included in the postmortem distal limb computed tomography (CT) study (n = 21). Note: Distal limbs were collected postmortem and stored frozen prior to CT imaging.
Fig 1.
CT and gross anatomical orientation of distal limb tendons and ligaments in giraffe (Giraffa spp.) under managed care.
Sagittal (A) and transverse (B) CT images of the distal forelimb illustrate major soft-tissue structures, including the suspensory ligament, superficial digital flexor tendon (SDFT), deep digital flexor tendon (DDFT), common digital extensor tendon, and collateral ligaments. Dorsal (D), palmar (P), medial (M), and lateral (L) orientations are indicated where applicable. In panel B, color overlays denote the following structures: suspensory ligament (orange), superficial digital flexor tendon (purple), deep digital flexor tendon (red), common digital extensor tendon (yellow), and medial and lateral collateral ligaments of the fetlock (blue). Gross dissections (C, D) demonstrate corresponding soft-tissue anatomy, highlighting the suspensory ligament (arrow), the SDFT/DDFT tendon bundle (star), and the extensor tendon bifurcation (arrowhead). Together, these images provide anatomical context for interpreting CT-detected lesions in the distal limb.
Fig 2.
Anatomical course of major tendons and ligaments along the medial aspect of the distal limb in (Giraffa spp.) under managed care.
A labeled medial anatomical rendering depicts the proximal-to-distal course and relationships of major tendons and ligaments of the distal limb. Dorsal (D) and palmar (P) orientations are indicated. Structures are color-coded as indicated in the inset key. The image represents the medial aspect of the right distal limb. The image emphasizes the close spatial relationships among these structures and their role in digital stabilization during weight-bearing. This orientation aids correlation of CT and histopathology findings with functional anatomy.
Fig 3.
CT and histopathologic features of chronic laminar pathology in giraffe (Giraffa spp.) under managed care.
A) Transverse CT image at the level of the distal phalanx from a histologically unremarkable forelimb demonstrates organized laminar architecture. Dorsal (D) and palmar (P) orientations are indicated. B) A giraffe with chronic laminitis shows irregular dorsal laminar margins along the dorsal hoof wall and perilaminar soft tissue irregularity (open arrowheads) on CT, consistent with chronic laminar disruption. C) Histologic section of histologically unremarkable lamina shows thin, regularly spaced epidermal and dermal lamellae. D) Chronic laminitis is characterized histologically by widened, blunted, and disorganized laminae with expansion of interlaminar spaces (H&E, 100×). Together, these paired CT and histologic images illustrate CT–histology concordance for chronic laminar injury.
Fig 4.
CT, gross, and histologic features of pedal osteitis in (Giraffa spp.) under managed care.
A) Sagittal CT image of the distal phalanx reveals irregular osteolysis, cortical thinning, and multifocal hypoattenuating defects along the solar/palmar aspect of the distal phalanx (arrowhead), consistent with moderate-to-severe pedal osteitis. Concurrently, there is a distal phalanx (P3) fracture (arrow). Dorsal (D) and palmar (P) orientations are indicated. B) Gross appearance of a relatively unaffected distal phalanx solar surface with smooth cortical margins and minimal surface porosity. C) Affected distal phalanx solar surface demonstrates marked porosity, cortical loss, and exposure of underlying trabecular bone (arrowhead), compatible with severe pedal osteitis. D) Histologically unremarkable distal phalanx histology shows dense, well-organized trabecular bone. E) Affected distal phalanx exhibits disorganized, vacuolated trabeculae with reduced structural integrity, supporting CT evidence of chronic pedal osteitis (H&E, 100×). These findings illustrate strong CT–pathology concordance for diagnosing chronic osseous degeneration.
Fig 5.
Tendon and ligament degeneration in giraffe (Giraffa spp.) under managed care.
A) Transverse CT image through the distal digit identifies mineralization within the suspensory ligament (arrowhead). Dorsal (D) and palmar (P) orientations are indicated. B) Mineralization is also present within the superficial digital flexor tendon (SDFT) and deep digital flexor tendon (DDFT) of the palmar soft tissues; asymmetric DDFT size may reflect chronic remodeling and possible superimposed acute injury. C) Histologic section of a flexor tendon shows severe fibrosis with cartilaginous and osseous metaplasia (arrowhead), consistent with chronic degenerative tendinopathy (H&E, 100×). These CT and microscopic findings demonstrate the multifocal nature of tendon and ligament degeneration in adult giraffe and support attention to early monitoring and hoof balance.
Table 2.
Digit-level prevalence of major computed tomography (CT) findings in managed-care giraffe (Giraffa spp.) (n = 146 digits). Abbreviations: DIP = distal interphalangeal; PIP = proximal interphalangeal; SBC = subchondral bone cyst-like lesion; DDFT = deep digital flexor tendon; SDFT = superficial digital flexor tendon; P3 = distal phalanx.
Table 3.
Animal-level prevalence of selected lesions by age group in a necropsy-based cohort of managed-care giraffe (Giraffa spp.). Note: Values represent the number (%) of affected animals within each age group and reflect a necropsy-based convenience sample enriched for animals with documented lameness, hoof overgrowth, or suspected distal limb disease. Findings describe lesion occurance within the sampled cohort and should not be interpreted as population prevalence estimates for managed-care giraffe. Abbreviations: DIP = distal interphalangeal; DDFT = deep digital flexor tendon; SDFT = superficial digital flexor tendon; P3 = distal phalanx.
Table 4.
Digit-level prevalence of tendon and ligament lesions by age group in managed-care giraffe (Giraffa spp.). Note: Values are n/N (%), where n is the number of affected digits and N is the number of digits scored for that lesion within each age group. Denominators varied by lesion because not all digits were scored for every lesion category. Findings reflect a necropsy-based convenience sample. Abbreviations: DIP = distal interphalangeal; DDFT = deep digital flexor tendon; SDFT = superficial digital flexor tendon; PIP = proximal interphalangeal.
Table 5.
Distribution of computed tomography (CT)-based severity scores (0–3) for major distal limb lesions in managed-care giraffe (Giraffa spp.) (digit-level). Note: Severity scores are CT-based ordinal grades; % moderate-to-severe (≥2) indicates the proportion of digits assigned severity scores of 2 or 3. Abbreviations: DIP = distal interphalangeal; DDFT = deep digital flexor tendon; SDFT = superficial digital flexor tendon.
Table 6.
Distribution of computed tomography (CT)-based severity scores for tendon and ligament lesions in managed-care giraffe (Giraffa spp.) (digit-level). Note: Values are percent of digits; collateral ligament values are presented as ranges because fetlock, PIP, and DIP collateral ligaments were scored separately and are presented as ranges within this condensed table. Abbreviations: DIP = distal interphalangeal; PIP = proximal interphalangeal; DDFT = deep digital flexor tendon; SDFT = superficial digital flexor tendon.
Table 7.
Co-occurrence of key distal limb lesions at the digit- and foot-level in managed-care giraffe (Giraffa spp.). Each medial and lateral digit was treated as an independent observational unit. Analyses were restricted to observations with non-missing scores for both lesions in each pairing (complete-case analysis). Fisher’s exact tests were used for binary presence/absence comparisons, and Spearman rank correlation (ρ) was used for ordinal severity grades, as indicated. Digit-level analyses are exploratory due to clustering within feet and individuals. Presence was defined as computed tomography (CT) score ≥1. Abbreviations: DIP = distal interphalangeal; OA = osteoarthritis; P3 = distal phalanx.
Fig 6.
Navicular apparatus disease with cystic and sclerotic change in the distal limb of a giraffe (Giraffa spp.) in managed care.
Sagittal postmortem computed tomography (CT) image of the palmar aspect of the distal forelimb demonstrating navicular apparatus pathology. Dorsal (D) and palmar (P) orientations are indicated. The distal sesamoid (navicular) bone exhibits irregular flexor cortical erosions, widened synovial invaginations, and cystic change involving both the flexor surface and the central spongiosa region of the bone (arrowheads). There is loss of normal trabecular architecture with surrounding sclerosis, consistent with chronic osseous remodeling. These CT features are characteristic of navicular apparatus disease. In this limb, the digital cushion appears compressed and displaced toward the palmar aspect relative to the solar plane of the foot (star), compared with the normal digital cushion alignment described in free-ranging giraffe.