Suspected Vestia foetida poisoning in young goats.

CASE HISTORY: Two crossbred, castrated male goats, a 5-month-old and an 8-month-old, were observed ingesting Vestia foetida (Solanaceae). Later, the goats were seen standing splay-legged and apparently disoriented. CLINICAL FINDINGS: When examined, both goats were in sternal recumbency and had mydriasis; the younger goat had a diminished menace response. When the goats were made to stand, they were ataxic and had muscle fasciculations of the hindquarters and face. Both had halitosis consistent with the odour of crushed Vestia leaves. The animals were treated with a mixture of vitamins and intravenous diazepam. The older goat recovered but the younger goat died and was necropsied. This animal had severe periacinar necrosis and fatty change in the liver, as well as fatty nephrosis. DIAGNOSIS: Probable Vestia foetida poisoning. CLINICAL RELEVANCE: The introduction of Vestia foetida to New Zealand and the apparent palatability of the plant necessitate that veterinarians and owners be knowledgeable about its potential toxicity. Differential diagnoses for the liver lesions (in New Zealand) would include Cestrum poisoning, acute seneciosis, acute blue-green algal poisoning, and acute and chronic copper poisoning.

Effectiveness of a two-dose regimen of prostaglandin administration in inducing luteolysis without adverse side effects in mares.

Our objectives were to determine whether repeated administration of prostaglandin F2alpha (PGF2alpha) to simulate the endogenous mode of secretion would be more effective than a single injection in inducing luteolysis and enable use of smaller doses less likely to cause adverse side effects. The main study comprised 43 dioestrous mares, who were given im. either a single 10 mg dose of natural PGF2alpha (n = 22) or 2 doses of 0.5 mg PGF2, 24 h apart (n = 21). The intensity of side effects was assessed in 8 dioestrous mares given 5, 1.5, 0.5 or 0 mg PGF2alpha in consecutive cycles. Two doses of 0.5 mg PGF2alpha 24 h apart caused lysis of the corpus luteum in all mares, whether this was determined from a fall in plasma progesterone concentrations or reproductive tract/behavioural changes; and when 10 mg PGF2, was given, the corpus luteum was lysed in 17 of 22 mares i.e. a lower proportion (P = 0.0485). A single dose of 0.5 mg PGF2a was no more effective than saline in inducing luteolysis.The intensity of side effects of PGF2alpha increased with dose. Although the 0.5 mg dose was no more likely than saline to cause sweating or muscle spasms, it raised plasma cortisol concentrations and prevented the decline in heart rate seen after saline. We conclude that a 2 dose regimen of administration increases the luteolytic efficacy of PGF2alpha and thereby provides a way to minimise adverse side effects.