A case of lymphadenopathic theileriosis in a five-months pregnant jersey cross-bred: Clinical, cytological and therapeutic observations

Introduction

Tropical theileriosis of cattle, caused by Theileria annulata, is a tick-borne haemoprotozoan disease of major economic importance in tropical and subtropical regions (Gharbi et al., 2011) [3] . The schizont stage of T. annulata invades bovine lymphocytes and macrophages, producing the characteristic "Koch's blue bodies" visible in cytological or histological smears (Gupta et al., 2016) [1] . These schizonts induce lymphocytic proliferation, leading to lymph node enlargement, anaemia, emaciation, and weakness (OIE, 2019) [6] . Cross-bred and exotic breeds such as Jersey and Holstein-Friesian are highly susceptible and often exhibit severe clinical manifestations (Al-Hosary et al., 2018) [2] . Early diagnosis and prompt administration of specific antiprotozoal therapy are crucial for a favourable prognosis (Gill et al., 2015) [4] . This paper reports a case of lymphadenopathic theileriosis in a five-months pregnant Jersey cross-bred, emphasizing cytological diagnosis and successful therapeutic management.

Materials and Methods Animal and History

A five-months pregnant Jersey cross-bred was presented to the Teaching Veterinary Clinical Complex, Tirunelveli, with a history of gradual enlargement of superficial lymph nodes (prescapular and prefemoral), decreased feed intake, hind-limb weakness with tremors, and passage of soft faeces coated with mucus.

Clinical Examination

On clinical examination, the animal appeared dull and depressed with poor body condition. The superficial lymph nodes were enlarged, firm, and movable. The hind limbs showed weakness and fine tremors. The mucous membranes were pale, and the faeces were soft and coated with mucus, without visible blood. Rectal temperature remained within normal limits.

Cytological Examination

Fine-needle aspiration cytology (FNAC) was performed on the enlarged prescapular lymph node using a 22-gauge needle. Smears were air-dried, fixed in methanol, stained with Leishman stain, and examined microscopically. The smears revealed numerous large lymphocytes and occasional lymphoblasts containing intracytoplasmic, blue-staining schizont inclusion bodies (Koch's blue bodies), (Figure 1) (Figure 3), along with 5-10% eosinophils and a few monocytes (Figure 2). These findings were diagnostic of lymphoproliferative theileriosis (Gupta et al., 2016) [1] .

Therapy

The cow was treated as follows  Oxytetracycline: @ 10 mg/kg intravenously once daily for 5 days  Supportive therapy  Injection Chlorpheniramine maleate, 12.5 mL intramuscularly  Injection Meloxicam, 25 mL intramuscularly  Injection Tribivet, 20 mL intramuscularly  Bolus Ecotas (probiotic and rumen supplement) for 4 days

Follow-up

The animal was monitored daily for improvement in feed intake, lymph node size, and reduction in tremors. A reexamination was conducted on Day 5 post-treatment.

Results

On presentation, the prescapular lymph nodes measured approximately 8 cm in diameter. The animal exhibited marked anorexia and reluctance to walk. Faecal material was soft and covered with mucus. Cytological examination confirmed Theileria annulata infection by the presence of Koch's blue bodies in lymphocytes. By Day 4, feed intake improved, and hind-limb tremors subsided. By Day 5, the lymph nodes had regressed significantly, and faeces returned to normal consistency. The animal was clinically normal (Figure 4), indicating complete recovery. No adverse drug reactions were observed, and pregnancy was maintained uneventfully.

Discussion

The clinical signs of lymphadenopathy, anorexia, weakness, and tremors in this case correspond with previous reports of bovine tropical theileriosis (Gharbi et al., 2011; Gupta et al., 2016) [3,1] . The cytological detection of Koch's blue bodies within lymphocytes is pathognomonic for Theileria annulata infection (Al-Hosary et al., 2018; OIE, 2019) [2,6] . These findings reaffirm the diagnostic value of FNAC as a rapid, field-applicable test in endemic regions. The use of oxytetracycline, along with supportive therapy, likely minimized secondary bacterial infections and improved systemic resilience. Cross-bred cattle, particularly Jerseys, are known to be more susceptible to theileriosis due to limited tick resistance and higher physiological stress during pregnancy (Durrani et al., 2011) [5] . Therefore, theileriosis should be considered a differential diagnosis in pregnant cross-bred heifers presenting with lymphadenopathy and weakness.

Conclusion

Cytological identification of Koch's blue bodies in lymphocytes provides a rapid and reliable diagnosis of Theileria annulata infection. Early treatment with oxytetracycline and supportive care led to complete recovery in this five-months pregnant Jersey cross-bred heifer. Early detection and timely intervention remain vital for the successful management of bovine tropical theileriosis in cross-bred cattle under field conditions.

Acknowledgement

AcknowledgementsThe authors acknowledge the facilities and assistance provided by the Teaching Veterinary Clinical Complex, Veterinary College and Research Institute, Tirunelveli.

References

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