CASE NOTES

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Epidemiological investigation of neonatal and juvenile mortality in Kalahari Red goats in Orange, 2022-2024

Angela Warrian, Team Leader Animal Biosecurity & Welfare, Central West Local Land Services

Posted Flock and Herd June 2025

INTRODUCTION

This report outlines an epidemiological investigation into a series of deaths among neonatal and juvenile Kalahari Red goats in the Central Tablelands region of New South Wales over three kidding seasons. It is an example of a case where multiple investigations of affected animals alone did not lead to the multifactorial diagnosis but where the diagnosis was obtained through analysis of the epidemiological data. The investigation explored the factors contributing to these fatalities, focusing on the relationship between management practices, nutritional deficiencies and environmental conditions.

Methods

The initial field investigations were conducted by local District Veterinarians (DVs) in the Central Tablelands LLS. The author became involved in the 2024 season. Data for this retrospective epidemiological investigation were mostly collected through a review of the Livestock Health Management System records, as well as a joint farm visit and clinical and laboratory investigation in 2024.

Cases were defined as any juvenile goat on the farm with a history of one or more of the following signs: perinatal or sudden death, diarrhoea, weakness or neurological signs in the first three months of life throughout the 2022-2024 kidding seasons.

Description of the outbreak

Initial presentation

In May 2022, the owner of the goat herd contacted the local DVs to discuss kid losses. He had recently noted multiple kids being born alive but dying within 24 hours

Approximately 50 goats and 40 sheep were running on the 20-hectare property. Kidding typically occurred between May and mid-August each year. All gates were open, allowing both species to graze across three paddocks (approximately half the property). Losses were only noted in the goat herd.

Paddocks were a mixed pasture of naturalised grasses, phalaris, clover and capeweed. Does were supplemented with household vegetable scraps and some grain offered (type unknown). Body condition score (BCS) ranged from 2 to 4/5, with about 10% displaying a curly coat.

The herd received annual 5-in-1 clostridial vaccinations inconsistently and intermittent Q-drench® (abamectin 1.0 g/L, albendazole 25.0 g/L, closantel 37.5 g/L, levamisole hydrochloride 40.0 g/L; Jurox) 2-6 weeks prior to kidding.

Clinical, laboratory 2022

Six days after the initial phone contact a doe was found dead and the DV was able to conduct a property visit. The doe was too degraded for a full autopsy, but aqueous humour was sampled with laboratory testing indicating hypocalcaemia.

In early June another doe was found recumbent and the DV conducted another visit. The doe was euthanised for autopsy. Lungs, liver and kidneys were pale, and the lungs had areas of congestion and a small area of pneumonia with abscessation in the right cranioventral lung lobe. Samples were submitted to the NSW Department of Primary Industries NSW Animal and Plant Health Laboratories at Menangle. A bacterial hepatitis and chronic mild pneumonia from lungworm were detected, as well as a high faecal worm egg count (mainly Trichostrongylus) and low serum calcium and magnesium levels.

A third doe died a few days later after exhibiting neurological signs (lateral recumbency, paddling and frothing) and moderate gaseous abdominal distention. On arrival the DV noted the doe was in good body condition. An autopsy was performed and revealed an approximately 15cm rupture of the abomasum. It was suspected the rupture was terminal or post-mortem as no peritonitis was present. No brain gross pathology was observed but histopathology found encephalitis consistent with listeriosis.

Overall, a significant number of kids died in 2022 (exact figures unknown).

Clinical 2023

In 2023, the producer reported improved condition of does pre-kidding with birth of more healthy, robust kids at good weights. Occasional early kid deaths were observed and attributed to starvation, mismothering or exposure. DVs were next contacted in late June 2023 to discuss when healthy kids started becoming unwell around five days of age, appearing weak and recumbent before dying. Further deaths occurred but were not reported for investigation.

It was estimated that there was 80-90% mortality in kids in 2023. Without examination, no definitive diagnosis was made but internal parasites, poor doe nutrition and adverse weather were suspected contributing factors.

Following this mortality event the producer provided ad libitum access to pasture hay, though consumption appeared low, along with limited oats, lentils and other grains. The herd had access to Goat Blocks (multi-mineral supplement; Furneys Stock Feeds) and Causmag AL4 (magnesium oxide; Causmag International), but the latter was not mixed with salt/lime, which likely affected intake.

Clinical, laboratory 2024

In 2024, the producer reported better kidding outcomes with does in improved body condition and more effective lactation. Despite this improvement, 25/75 kids died during the kidding season, most often within 48 hours of birth, although at the end of August seven-week-old kids began dying suddenly with no prior clinical signs noted.

One of these was a seven-week-old kid that was weak, reluctant to walk and bleating as though in pain when moved to the yard for overnight shedding. The owner speculated it may have been blind and observed it arching its neck towards its rump. After administering Vytrate® (oral rehydration fluid; Jurox), the kid seemed to improve and returned to its dam but was found dead the following morning. The DV again conducted a visit. The body position of the kid suggested possible opisthotonus, though no paddling had been observed. No gross abnormalities were noted during post-mortem, although histopathological evaluation of the brain showed a focal area of necrosis. In the absence of ongoing encephalitis/meningoencephalitis, this finding could suggest vascular changes secondary to systemic disease or septicaemia. No diarrhoea was observed, but coccidia were detected in high numbers.

Gross Pathology and Laboratory Findings 2024

Multiple kid post-mortems undertaken prior to the author’s involvement had been largely unremarkable, with all tests for Cryptosporidia, Rotavirus, Coronavirus, Campylobacteria, Salmonella and Yersinia returning negative results, and no other significant findings recorded.

A kid post-mortem in late August 2024 detected high levels of coccidia in faecal samples despite no visible scouring and normal gastrointestinal consistency. An area of focal necrosis was identified in the brain on histopathology that may have indicated septicaemia, reflecting a debilitated, immunocompromised state.

A subsequent kid autopsy 10 days later found a high worm egg count, likely due to Haemonchus contortus and low numbers of Coccidia.

The author became involved at this point, with post-mortem findings from mid-September 2024 below.

Postmortem Findings - One-Month-Old Kid

• Previous treatments: Alamycin 1ml/10kg bodyweight (oxytetracycline, 300 mg/mL, Norbrook Laboratories) two days prior, Albendazole six days prior.
• Heavy sucking lice infestation observed.
• No abnormalities in the chest. Liver, kidney and spleen appeared normal.
• Significant Haemonchus contortus burden noted in abomasum. Multiple small (1-2mm) white circular raised lesions in the small intestine.
• Histology confirmed a parasitic abomasitis and severe coccidial enteritis, despite absence of scouring and normal gastrointestinal consistency.

Autopsy Findings - Three-Year-Old Doe

• No clinical signs of illness noted by owner. Albendazole treatment six days prior.
• Heavy sucking lice infestation present.
• Significant peritoneal effusion with fibrin, pleural effusion and marked consolidation of the right lung, with caseous pus in abscesses.
• Thickened pericardial sac (~1cm), adhered to epicardium. Extensive white discolouration in the ventral myocardium and multiple circular white foci throughout. Similar circular white foci in the right kidney and spleen (suspected septic emboli).
• Severe Haemonchus burden noted.
• Laboratory results indicated severe multisystemic inflammation and necrosis, suggestive of bacterial infection spreading via systemic circulation. No causative organism isolated from routine aerobic lung culture; Fusobacterium necrophorum suspected.

Epidemiological analysis

Figure 1 Kid births and deaths 2022-2024

Figure 2 Attack rate for kids 2022-2024

Figure 3 Breakdown of deaths by clinical manifestation 2022-2024

Between May 2022-September 2024 approximately 163 cases were identified, with 161 of those dying.

Of the 163 cases, 98 were stillborn/died within the first 48 hours (60%), 55 were healthy kids that became weak around five days to two weeks of age and died a day or two later (34%), five presented at 3-5 weeks of age with diarrhoea (three died, two recovered) and five presented as sudden death in apparently normal well-grown 7-8-week-old kids (3%).

No additional deaths have been reported in adult goats since June 2022.

Discussion

The investigation illustrates a multifactorial aetiology, with the final diagnosis resulting from a thorough analysis of epidemiological data collected over three kidding seasons, rather than from isolated assessments of individual animals.

The mortality in the herd appears to have originated from inadequate nutrition in pregnant and lactating does, compounded by the lack of effective pre-kidding drenching and high worm burdens. Contaminated pasture, combined with periparturient relaxation of resistance in does, led to high larval contamination for the kids.

Poor doe condition and parasitism likely reduced milk yield, resulting in failure of passive transfer in some kids. Reduced milk nutrition and increased grazing further contributed to larval ingestion.

Some kids that died suddenly may have been affected by anaemia due to Haemonchus contortus burdens and sucking lice, with variable coccidial involvement. Kids with scouring exhibited more pronounced coccidial infections, which were likely a significant factor in their deaths. Additionally, the compromised immune status of these kids, due to parasitism and poor nutrition, likely made them more susceptible to a variety of secondary bacterial infections and septicaemia.

This investigation highlighted the critical need for improved management practices, focusing on nutrition, parasite control and environmental considerations to mitigate future losses.

By implementing the recommended strategies, the producer could work towards stabilising the health of the herd and reducing mortality rates in future kidding seasons. Ongoing surveillance and veterinary oversight will be essential in ensuring the long-term success of these interventions.

Communication and response

Immediate action plan for the producer included:

• Drenching all animals with Zolvix Plus^TM (monepantel 25 mg/mL and abamectin 2 mg/mL; Elanco), with kids receiving an appropriate weight-based dose (at 1.5 times sheep dose). Treat all kids with Baycox^TM (toltrazuril 50 g/L; Elanco) at 20mg/kg PO.

Use in goats is off-label use for both these products, requiring a veterinary prescription.

• Relocate entire herd to neighbour’s block that has never been grazed by livestock to reduce reinfection from worms and exposure to coccidia.
• Clean out and sanitise shed and bedding where goats are housed overnight prior to the herd’s return.
• Close gates and restrict grazing to designated areas to prevent free ranging across all paddocks.

Long-term considerations:

• Upon returning home, consider strategic long-acting anthelmintic products as part of an integrated worm control program due to existing larval contamination.
• Address nutrition in long-term planning as this factor appears to be a root cause of the ongoing issue.

Acknowledgement

This investigation was completed in collaboration with Amy Master, District Veterinarian Central Tablelands and Elizabeth Macarthur Agricultural Institute (EMAI) laboratory. Ethics approval was not required as the investigation was conducted under routine surveillance and response activity. It was completed as part of the NSW Animal Health Frontline Field Epidemiology Training Program.