Pathological Findings in the Carcass of a Dog following Ovariohysterectomy, and Intestinal Resection and Anastomosis

INTRODUCTION

Necropsy and diagnostic pathology serve as invaluable tools in veterinary medicine and offer a comprehensive postmortem analysis to elucidate the underlying causes of morbidity and mortality in animals.^[1] This case report emphasizes the key role of necropsy examination and histopathological analysis in unraveling the complexities surrounding peri-and post-operative complications in veterinary surgeries. Through examination of the gross and histological findings, we aimed to unravel the pathological processes that resulted in the sudden death of a Nigerian Indigenous Dog (NID) following ovariohysterectomy and intestinal resection with anastomosis, thus, shedding light on the importance of diagnostic pathology in veterinary surgical practice.

By documenting the gross pathological changes and histopathological alterations, this report attempts to offer a deeper understanding of the underlying pathophysiological mechanisms driving peri-and post-operative complications in indigenous dog breeds. Furthermore, the insights gained from this case report may inform the development of specific peri-and postoperative management strategies and surveillance protocols, thereby enhancing patient care and outcomes in veterinary surgical settings.

CASE REPORT

The carcass of a 9-month-old NID [Figure 1a] was presented to the Necropsy Unit of the Veterinary Teaching Hospital, Ahmadu Bello University Zaria, Nigeria. The dog was reported to die suddenly 2 days after ovariohysterectomy, and small intestinal resection and anastomosis. However, the dog exhibited weakness and dyspnea, was fed with milk, administered 50% dextrose saline (intravenous), and penicillin-streptomycin injection before death.

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Figure 1:

(a) Carcass of the dog when presented, and (b) when postmortem examination commenced.

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Gross pathological findings

The gross pathological findings were hemorrhagic trachea [Figure 2a], congested and hemorrhagic lungs [Figure 2b], enlarged heart with epicardial and endocardial hemorrhages [Figures 3a and b], enlarged and congested liver [Figure 4a], enlarged spleen [Figure 4b], hemorrhage in the gastric mucosa [Figure 5], intestinal hemorrhages, and an area of hemorrhagic infarct at the intestinal anastomosed site [Figures 6a and b].

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Figure 2:

(a) Hemorrhagic trachea (T), (b) congested and hemorrhagic lungs (arrows).

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Figure 3:

(a) Enlarged heart with epicardial (black arrows), (b) endocardial (white arrows) hemorrhages.

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Figure 4:

(a) Enlarged and congested liver, (b) enlarged spleen.

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Figure 5:

Hemorrhages in the gastric mucosa (black arrows).

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Figure 6:

(a) Intestinal hemorrhages (arrows), (b) an area of hemorrhagic infarct at the intestinal anastomosed site (arrow).

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Histopathological findings

The histopathological findings were slightly thickened interalveolar walls and inflammatory cellular infiltrations [Figure 7a], cardiac hemorrhage [Figure 7b], and hepatic congestion [Figure 7c].

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Figure 7:

(a) Photomicrographs of lung, (b) heart, and (c) liver sections. Note (a) slightly thickened interalveolar walls with inflammatory cellular infiltrations (arrows), (b) hemorrhages (arrows), (c) congestion hematoxylin and eosin stain ×200.

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DISCUSSION

The presence of mild tick infestation and bilateral congested ocular mucous membranes in the dog in this report suggests a multifaceted approach to understanding the possible cause of death. The mild tick infestation may serve as an indicator of the overall health status of the dog and environmental exposure and can have significant impacts on health and productivity.^[3] While tick infestations may not directly cause death, they can lead to complications, especially if left untreated or if the dog already has underlying health issues. Ticks can cause irritation, damage the skin, and predispose animals to bacterial and fungal infections. Tick-borne diseases can result in systemic illness, including fever, anemia, and organ dysfunction,^[4] which could exacerbate the stress of surgery and compromise the ability of the dog to recover.

The bilateral congested ocular mucous membranes indicate inflammation of the ocular mucous membranes, which may reflect underlying ocular pathology or systemic conditions. Severe ocular inflammation can cause discomfort and potentially lead to complications such as corneal ulcers or secondary infections. In the perioperative period, ocular inflammation could further stress the immune system of the dog, and compromise its ability to tolerate the surgical procedures. In addition, ocular pathology can be indicative of systemic diseases or underlying conditions that may have contributed to the overall health status of the dog and prognosis.^[5]

The gross and histopathological findings described in this report are indicative of severe systemic complications following the surgical procedures in the dog. These findings might suggest the development of disseminated intravascular coagulation (DIC), a life-threatening condition characterized by widespread activation of the coagulation system leading to microvascular thrombosis and subsequent organ dysfunction and hemorrhage.^[6] DIC could occur as a complication of major surgical procedures, particularly those involving the gastrointestinal tract. The enlarged and congested organs, such as the heart, liver, and spleen, along with the hemorrhages in various tissues, are consistent with the consumptive and hemorrhagic phases of DIC.^[7] The area of infarct at the intestinal anastomosis site further indicates compromised blood flow and tissue ischemia, which can result from the microvascular thrombosis associated with DIC.^[8]

Several studies have reported similar pathological findings in dogs following ovariohysterectomy and other abdominal surgeries complicated by DIC. A study by Pearson found that 20 out of 109 dogs with complications after ovariohysterectomy had enterological problems, including vomiting, diarrhea, emaciation, and palpable abdominal masses, and these were attributed to adhesions and intestinal complications.^[9] Rubio et al.^[10] highlighted the changes in hematological and biochemical profiles in dogs undergoing ovariohysterectomy, showing notable changes in response to surgery, including hypoproteinemia and hypoalbuminemia. Hence, in the present case, the severe systemic involvement and the area of intestinal infarction suggest that the dog likely succumbed to the complications of DIC, which might have been triggered by the extensive surgical trauma and tissue damage from the ovariohysterectomy and intestinal resection and anastomosis procedures.

Furthermore, the hemorrhagic trachea, congested and hemorrhagic lungs, and cardiac abnormalities point toward potential respiratory and cardiovascular issues. The enlarged heart with hemorrhages could indicate cardiac stress or disease, while the hepatic congestion and splenic enlargement suggest possible circulatory disturbances. The presence of intestinal hemorrhages and hemorrhagic infarction at the anastomosed site indicate complications related to the surgical procedure. The surgical procedures might have placed significant physiological stress on the dog, potentially leading to complications such as sepsis, shock, or organ failure. The histopathological findings of thickened interalveolar walls, cardiac hemorrhage, and hepatic congestion further support the possibility of respiratory and cardiovascular compromise and circulatory disturbances, thus, contributing to the fatal outcome.

CONCLUSION

The combination of the gross and histopathological findings could be indicative of multiple organ failure following the surgical interventions, leading to a cascade of events culminating in the sudden death of the dog. The stress of the surgeries, along with potential complications such as sepsis, shock, and organ damage, might have likely contributed to the fatal outcome in this case. Thus, an understanding of the interplay between surgical interventions, physiological responses, and pathological changes is crucial in elucidating the sequence of events that resulted in the sudden death of the dog in this study. It is recommended that there is a need for comprehensive pre-operative assessment, and post-operative care and monitoring in veterinary surgeries.