This retrospective observational study reviewed medical records from the University Veterinary Hospital at Qassim University, Saudi Arabia, covering the period from 2012 to 2025. A total of 27,337 clinically affected dromedary camels (Camelus dromedarius) were examined during this period. Cases were categorized into reproductive conditions (14,402 camels), surgical problems (6,825 camels), and medical illnesses (6,110 camels). Among the medically diagnosed animals, all camels with documented urinary tract disorders were included, resulting in 1,100 camels (18%). No additional inclusion or exclusion criteria were applied beyond documentation of urinary tract disorders, reflecting the retrospective nature of the dataset.

Each camel underwent a comprehensive clinical examination, including assessment of respiratory rate, heart rate, rectal temperature, mucous membrane condition, and auscultation of thoracic and gastrointestinal regions. Routine handling and restraint were performed by trained veterinary personnel, ensuring animal welfare and staff safety. For ultrasound-guided biopsies or aspirations, sedation was achieved with intravenous xylazine (2%, 0.2 mg/kg BW), and local anesthesia was administered using 10 ml of 2% procaine hydrochloride. All procedures were part of routine clinical care. Ethical approval for retrospective analysis was granted by the Ethics Committee for Animal Use at Qassim University (Buraydah, Saudi Arabia), following the Guide for the Care and Use of Agricultural Animals in Research and Teaching (26). No specific license or protocol number was assigned due to the retrospective study design.

Affected camels were classified into six clinical categories based primarily on clinical presentation and ultrasonographic observations, with supplementary information from clinical history and laboratory or histopathological confirmation when available. Because this study is retrospective, not all cases had confirmatory tests; terminology reflects the level of diagnostic certainty for each category. Table 1 summarizes the diagnostic category, diagnostic basis, confirmatory tests, and notes on limitations for each group.

All camels underwent ultrasonographic examination of the urinary tract using a SonoScape ultrasound machine (Sonoscape Medical Corp., China) with sector probes (3.5 MHz) and linear transducers (5.0 and 7.5 MHz). Standard clinical settings for depth, gain, and focus were applied consistently throughout the study period. The right kidney was visualized transcutaneously through the upper right flank, and the left kidney was imaged either transrectally or from the caudal left flank. The urinary bladder was examined transrectally. Sonographic findings—including kidney and bladder morphology, echogenic deposits, blood clots, abscesses, uroliths, or masses—were recorded systematically in the medical records. Due to the retrospective design, ultrasonographic images were not uniformly archived for re-evaluation.

When indicated, lesions were biopsied or aspirated under ultrasound guidance using a 14G × 170 mm spinal biopsy needle after aseptic preparation. Samples were immediately processed for bacteriological and histopathological investigations, depending on clinical indication and lesion accessibility.

Prior treatments, when documented, typically included antibiotics, anti-inflammatory agents, multivitamins, appetite enhancers, and intravenous fluids. Laboratory investigations—including urinalysis, urine culture, and hematological/biochemical parameters—were inconsistently recorded, limiting correlation with sonographic findings, disease severity, or treatment outcomes; this limitation is discussed further in Section 4.

Due to the retrospective and descriptive nature of this study, formal inferential statistical analyses were not performed. Data are presented as descriptive statistics, including counts, percentages, and distributions of sonographic findings across the six clinical categories, reflecting the primary objective of documenting ultrasonographic and clinical features rather than testing hypotheses or comparing treatments.

A total of 300 dromedary camels [225 females (75%), 75 males (25%)], aged between 6 months and 20 years, were presented with a primary clinical complaint of visibly discolored (reddish to brownish) urine lasting from 2 days to 1 year (Figure 1). Additional clinical signs included weakness, urine dribbling, painful urination, and abdominal pain. Case assignment to this group was based primarily on clinical observation of urine discoloration and ultrasonographic findings. Systematic urinalysis was not available to differentiate hematuria from pigmenturia or other causes of urine discoloration. Therefore, the term “hemorrhagic” is used descriptively rather than as a definitive etiologic diagnosis.

Ultrasonographic examination revealed variable intraluminal echogenic material within the urinary bladder, irregular or thickened bladder walls, marked bladder distension, and echogenic urine within the renal pelvis. Additional sonographic findings included renal cavitary or heterogeneous parenchymal lesions consistent with abscessation, renal pelvic dilation consistent with hydronephrosis, echogenic foci with distal acoustic shadowing consistent with nephrolithiasis, collapsed bladder contours with surrounding free abdominal fluid consistent with bladder rupture, and hypoechoic peritoneal fluid with floating abdominal viscera consistent with uroperitoneum.

In several cases, overlapping sonographic features involving the kidneys and bladder were observed, highlighting the multifactorial nature of disorders presenting with urine discoloration. Bilateral renal pelvic dilation with a distended urinary bladder containing echogenic urine was documented in a subset of cases (Figure 2). No histopathological or laboratory confirmation of hemorrhage was available for this group.

This group included 332 camels, subdivided according to predominant sonographic and clinical presentation rather than confirmed etiologic diagnosis.

A total of 179 camels [145 females (81%), 34 males (19%), aged 6–17 years] presented with non-specific systemic signs including inappetence, weight loss, abdominal pain, weakness, constipation, lameness, and, in some cases, urine discoloration. Ultrasonographic examination revealed single or multiple cavitary or heterogeneous renal parenchymal lesions compressing adjacent tissue, located in the left kidney (n = 103, 57.5%), right kidney (n = 52, 29.1%), or bilaterally (n = 24, 13.4%). Lesions varied in echogenicity (hypoechoic, hyperechoic, mixed, or heterogeneous), consistent with suppurative or necrotic processes (Figures 5, 6). Ultrasound-guided aspiration was performed in a subset of cases where lesions were accessible (Figure 7). In these cases, microbiological culture yielded Gram-positive cocci arranged in grape-like clusters, with biochemical identification confirming Staphylococcus lugdunensis and Staphylococcus aureus. Cases lacking aspiration or culture were classified based on sonographic appearance alone and are therefore described as lesions consistent with renal abscessation rather than definitively confirmed abscesses.

This group included 214 camels, classified based on clear ultrasonographic evidence of urinary tract obstruction, a condition for which ultrasound is considered diagnostically reliable. Camels with urine retention (n = 119) [7 females (5.9%), 112 males (94.1%), aged 2–14 years] showed marked bladder distension and dilation of the pelvic urethra (Figure 8), with mild dilation of the renal sinus consistent with secondary back-pressure changes (Figure 9). An additional 95 camels [22 females (23.2%), 73 males (76.8%), aged 3–20 years] presented with anuria, urine dribbling, abdominal pain, and distension. Ultrasonography demonstrated echogenic foci producing distal acoustic shadowing consistent with renal calculi, along with echogenic intraluminal bladder material (Figures 10, 11). Given the characteristic acoustic shadowing and anatomical location, these findings were considered diagnostic of obstructive urolithiasis.

Seventy-three camels were included, classified based on sonographic evidence of urine leakage or traumatic disruption of the urinary tract. Sixty camels (all males, aged 3–20 years) presented with abdominal pain, anuria, urine dribbling, and progressive abdominal enlargement. Ultrasonography revealed large volumes of hypoechoic peritoneal fluid with floating abdominal organs, including intestines, liver, kidneys, and spleen, findings consistent with uroperitoneum (Figures 12, 13). Transrectal ultrasonography identified a collapsed urinary bladder with a markedly thickened wall, freely floating within abdominal fluid, consistent with bladder rupture (Figure 14). Thirteen camels [7 females (53.8%), 6 males (46.2%), aged 3 months−19 years] showed sonographic evidence of an intact but distended urinary bladder with hyperechoic intraluminal material, along with gross enlargement of the penile body and extravasated urine surrounding the urethra. An obstructing intraluminal object was visualized within the penile urethra (Figure 15), consistent with traumatic or foreign body–associated urethral obstruction.

Two female camels presented with gradual weight loss and intermittent abdominal pain. Ultrasonography revealed well-defined to irregular renal masses with variable echogenicity. In both cases, ultrasound-guided biopsy or aspiration was performed, and histopathological examination confirmed renal cell carcinoma in both cases.

Camels in this group were classified based on visibly discolored urine and ultrasonographic evidence of intraluminal echogenic material or bladder wall abnormalities. In the absence of systematic urinalysis, these cases reflect disorders presenting with urine discoloration rather than confirmed hemorrhagic disease, as alternative causes (hemoglobinuria, myoglobinuria, pigmenturia) cannot be excluded.

The wide range of sonographic findings—including echogenic intravesical material, bladder wall irregularity, renal pelvic dilation, cavitary renal lesions, and free abdominal fluid—illustrates the multifactorial nature of urine discoloration syndromes. Structures interpreted as blood clots may also represent sediment, inflammatory debris, or mass-like lesions. Concurrent renal abnormalities highlight overlap between bladder- and kidney-associated disease. Despite these limitations, ultrasonography remains clinically valuable for localizing lesions, identifying concurrent abnormalities, and guiding diagnostics such as aspiration or biopsy. The findings align with previous camelid reports (27, 28) while reinforcing cautious terminology.

This group encompasses camels classified primarily on the basis of characteristic bladder- and lower urinary tract–related sonographic findings, rather than confirmed inflammatory or infectious etiologies. Bladder wall thickening, corrugation, and echogenic intraluminal material are non-specific and may reflect inflammation, infection, crystalluria, or early obstruction. The absence of urinalysis or culture in most cases precludes differentiation between these causes.

In male camels with balanitis, ultrasonography primarily demonstrated secondary urinary outflow dysfunction, including bladder distension and pelvic urethral dilation (32). Similarly, cases identified as urinary bladder paralysis were based on marked bladder distension with intact walls and intraluminal echogenic material, without evidence of mechanical obstruction. Lack of neurologic, metabolic, or laboratory confirmation requires interpretation as sonographically apparent bladder atony rather than confirmed neurogenic disease.

Renal cavitary and heterogeneous parenchymal lesions constitute a substantial subset, with microbiological confirmation available in some cases via ultrasound-guided aspiration (Staphylococcus lugdunensis, S. aureus). Lesions lacking microbiological confirmation should be interpreted as sonographically consistent with abscessation rather than confirmed abscesses, as similar appearances may reflect necrosis, chronic hematomas, or other focal pathologies. Ultrasonography provides reliable lesion localization, assessment of size and laterality, and guidance for aspiration, supporting its central role in suspected renal infection.

Obstructive disorders are among the most reliably defined by ultrasonography, due to characteristic acoustic features of uroliths and predictable anatomic consequences. Predominantly affecting males, findings such as echogenic foci with distal acoustic shadowing, bladder distension, urethral dilation, and renal pelvic enlargement are considered diagnostic of obstruction, and laboratory confirmation is not strictly required. Despite incomplete dietary and metabolic data, these sonographic patterns remain highly applicable in clinical practice (5, 29).

Traumatic urinary tract disorders exhibited distinctive sonographic features, particularly in uroperitoneum and bladder rupture (33). Hypoechoic peritoneal fluid with floating viscera is diagnostic of urine leakage, and transrectal ultrasonography effectively identified bladder collapse and rupture sites. Outcome data were insufficient to correlate severity with prognosis, but ultrasonography proved rapid, non-invasive, and reliable in emergency presentations.

Urinary tract neoplasia was rare (30). Inclusion was restricted to histopathologically confirmed cases, avoiding reliance on ultrasonography alone. While sonographic features were documented, ultrasound was not considered diagnostic of neoplasia without tissue confirmation. The small number of cases precludes generalizations regarding prevalence or tumor behavior, but provides reference images and reinforces the need for biopsy or aspiration when mass lesions are detected (34, 35).

The study's strengths include a large sample size, long observation period, and consistent ultrasonographic methodology performed by the same clinical team using standardized protocols. Limitations are summarized as follows: the retrospective design, inconsistent availability of laboratory, microbiological, neurologic, and histopathological data, incomplete treatment and follow-up documentation, and lack of uniform image archiving. These limitations mean that many diagnostic labels represent clinically suspected syndromes rather than confirmed diseases, with inevitable overlap between categories. They are not methodological failures but reflect real-world clinical practice, where ultrasonography often serves as the primary diagnostic modality.