Ocular distribution and toxicity of intravitreal injection of triamcinolone acetonide in normal equine eyes

Objective  To determine ocular distribution and toxicity of a single injection of intravitreal triamcinolone acetonide (TA) in normal horses.
Animals studied  Six adult horses, donated to North Carolina State University.
Procedures  Six horses were injected intravitreally with either 10, 20, or 40 mg ( n  = 2 each) of TA. The opposite eye of each horse was injected with balanced salt solution (BSS). Ocular toxicity was assessed by biomicroscopy, tonometry, indirect ophthalmoscopy, and electroretinogram. Aqueous humor (AH), vitreous humor (VH), and plasma samples were collected. Horses were euthanized 7 or 21 days after injection and eyes enucleated for histopathology. TA concentrations in AH, VH, and plasma were measured by HPLC.
Results  Three control eyes and one TA eye developed inflammation after injection or collection of AH. Positive bacterial cultures ( Corynebacterium spp., Staphylococcus spp., and Streptococcus spp.) were obtained from three of these eyes. Other than transient corneal edema in TA injected eyes, which resolved by 7 days after injection, no other changes were observed. TA crystals were visible within the vitreous body. No evidence of TA toxic effect was noted on histopathology. TA was detected in all AH and VH samples from treated eyes following injection. Drug was not detected in the plasma.
Conclusions  There was no evidence of overt toxicity from intravitreal TA in normal horses and a single intravitreal injection resulted in TA ocular levels for 21 days. However, the risk for bacterial infections with intravitreal injection or anterior chamber aspirations in horses is high. Use of topical and systemic antibiotics after injection is recommended.     

Feeding Acacia etbaica and Dichrostachys cinerea fruits to smallholder goats in northern Ethiopia improves their performance during the dry season

Acacia etbaica Schweinf. and Dichrostachys cinerea (L.) Wight et Arn. are among the common woody browse plants that naturally grow in many arid and semi-arid rangelands in sub Saharan Africa. An experiment was conducted to compare the voluntary dry matter intake, body weight gain, nitrogen balance, carcass composition and sensory attributes of goats supplemented with different levels of A. etbaica and D. cinerea fruits. Average initial body weight of the goats was 20.4 kg (± 0.8SE) and received one of the following fruit supplementation regimes for 120 days (on body weight basis, n = 4 goats per group): (1) Control, no supplement; (2) 0.5% of A. etbaica; (3) 0.5% of D. cinerea; (4) 1.0% of A. etbaica; (5) 1.0% of D. cinerea; (6) 1.5% of A. etbaica; (7) 1.5% of D. cinerea. All groups were allowed to graze/browse during the day. Compared to A. etbaica, D. cinerea fruits contained higher amounts of crude protein (182 vs 135 g/kg DM), metabolizable energy (11 vs 8.4 MJ/kg DM), and in vitro dry matter digestibility coefficient (0.7 vs 0.6). The concentrations of acid detergent fiber (ADF), sulphuric acid solubulized lignin, and tannin (soluble and condensed) were lower (P < 0.05) in D. cinerea than in A. etbaica fruits. A. etbaica fruits, however, contained higher amounts of Na, K, Fe, and Zn concentrations than D. cinerea fruits. Dry matter intake was markedly higher in supplemented groups than in the control group without supplement. Similarly, body weight gain in the control group was negative and lower (P < 0.05) than any of the supplemented groups. During the course of the experimental period (120 days) the group placed in the 1.5% D. cinerea fruit diet gained 2.6 kg whereas the control group lost 2.0 kg. Thus, the difference between these two groups was 4.6 kg, which suggests about 22.5% increment of the goats' initial body weight. N retention was negative for the control group and varied little among the remaining treatment groups. Dressing percent increased with increased level of either type of fruit supplement, the highest (51.8%) being achieved at the 1.5% D. cinerea level. There was no difference in bone tissue across treatment groups. D. cinerea fruit intake also resulted in juicy/watery flavor and tender carcass. D. cinerea fruits appeared to have no adverse effects when included at the highest level (1.5%) and could be collected and stored as dry season supplement to smallholder goats. This study shows that poor farmers can increase goat performance substantially through supplement feeding with wild fruits. Areas in Ethiopia originally set aside for provision of ecological services and biodiversity protection can also be used for wild fruit production and feeding of small stock. The effect of increasing D. cinerea fruits above the 1.5% body weight level should be a focus of future investigation. Further work on deactivation mechanism of tannins is required for A. etbaica fruits included at levels higher than 1.0%.     

Naked oats: metabolisable energy yield from a range of varieties in broilers, cockerels and turkeys

1. Naked oats belong to the same species as 'common oats', Avena sativa, but have a non-lignified husk which readily becomes detached during harvesting. The absence of the indigestible husk can be predicted to give an increased metabolisable energy (ME) content for poultry. 2. Measurements of true metabolisable energy (TME(N)) were performed on 3-week-old broiler chicks (Cobb males), adult cockerels (ISA Brown, greater than one year old) and 7-week-old turkeys (BUT T8 males). The measurements were repeated in 2000, 2001 and 2002, with some measurements on a subset of varieties in 2004. 3. High-oil naked oat lines yielded 12% more energy (TME(N)) than wheat. Naked oats, excluding the experimental high-oil lines, yielded 8.5% more energy than simultaneously assayed wheat samples. 4. In samples from the 2004 harvest, conventional oats gave TME(N) values about 13% lower than those of wheat. 5. The addition of beta-glucanase produced an increase of about 4% in the apparent metabolisable energy (AME) of oats for broiler chickens. This effect was associated with a 70% decrease in the jejunal viscosity of broilers receiving a 500 g/kg naked-oat diet. 6. The oil content of naked oats was about 5 times greater than that of wheat, with the high-oil lines rising to more than 6 times greater. Naked oats had a lower starch content than wheat but not sufficiently lower to negate the energy benefits of the higher oil content. The crude protein (CP) contents of naked oats were similar to those of wheat, with the high-oil varieties tending to be higher in CP also.     

Dog-associated risk factors for human plague

Plague is a rare but often fatal zoonosis endemic to the western United States. Previous studies have identified contact with pets as a potential risk factor for infection. We conducted a matched case-control study to better define the risks associated with pets at both the household and individual levels. Using a written questionnaire, we surveyed nine surviving plague patients, 12 household members of these patients, and 30 age- and neighbourhood-matched controls about household and individual exposures. Overall, 79% of households had at least one dog, 59% had at least one cat and 33% used flea control, with no significant differences between case and control households. Four (44%) case households reported having a sick dog versus no (0%) control households [matched odds ratio, (mOR) 18.5, 95% confidence interval (CI) 2.3-infinity], and four (44%) patients reported sleeping in the same bed with a pet dog versus three (10%) controls (mOR 5.7, 95% CI 1.0-31.6). Within case households with multiple members, two (40%) of five patients slept with their dogs versus none (0%) of 12 healthy family members (P=0.13). The exposures to cats were not significant. Sleeping in the same bed as a pet dog remained significantly associated with infection in a multivariate logistic regression model (P=0.046). Our findings suggest that dogs may facilitate the transfer of fleas into the home and that activities with close extended contacts with dogs may increase the risk of plague infection.     

Extensive umbilical herniation of the large colon in a foal

A 5‐month‐old Warmblood cross colt was presented with focal swelling of the ventral abdomen extending from the umbilicus to the scrotum in the absence of colic signs. Palpation and ultrasound examination revealed the presence of incarcerated large intestine within the subcutaneous space adjacent to the caudal ventral abdomen and prepuce. Surgery was performed and revealed that the umbilical hernia sac had ruptured, and confirmed that the left dorsal and ventral colon were present in the subcutaneous space. The mild degree of vascular compromise of the large colon did not necessitate resection and so it was replaced within the abdomen. The abdominal wall defect was closed and the subcutaneous dead space was reduced by using a walking suture pattern. Herniation of the large colon through the umbilicus with dissection through the subcutaneous tissues of the ventral abdominal wall and prepuce has not been previously reported in foals. Ultrasonography permits differentiation of herniated small intestine from large intestine.     

Pharmacokinetics of liposomal encapsulated buprenorphine suspension following subcutaneous administration to cats

We investigated the effects of liposome encapsulation at prolonging the systemic exposure of buprenorphine following subcutaneous administration in cats. Seven healthy male cats were dosed intravenously with 0.02 mg/kg buprenorphine solution (STD‐BUP), followed 14 days later by a subcutaneous injection of 0.2 mg/kg buprenorphine as a liposomal suspension (SUS‐BUP) containing drug molecules both in liposomes and the suspending vehicle. Buprenorphine time plasma concentration data for both dosing routes were analyzed simultaneously with four compartmental models. Goodness of fit was assessed both graphically and with the Akaike information criterion. The time‐course of intravenous STD‐BUP was biphasic, with a 4.39 h average terminal half‐life. The subcutaneous SUS‐BUP produced plasma buprenorphine concentrations above 0.5 μg/L for more than 96 h, with three distinct peaks in the first 15 h. The model with best fit comprised a central and a peripheral compartment, plus three subcutaneous absorption compartments: one of dissolved drug molecules that were absorbed through a first‐order process, and two of liposome‐encapsulated drug molecules that were transferred to the solution compartment through separate zero‐order processes. Liposomes effectively prolonged the systemic exposure of buprenorphine in cats.     

Sedative effects of dexmedetomidine,dexmedetomidine–pethidine and dexmedetomidine–butorphanol in cats

The purpose of this study was to assess the clinical effects of dexmedetomidine, both alone and combined with pethidine or butorphanol, in cats. A prospective randomized blind study was performed. Thirty cats were randomly assigned to three groups of 10 animals: D: dexmedetomidine (20 μg/kg IM); DP: dexmedetomidine (10 μg/kg IM) and pethidine (2.5 mg/kg IM); DB: dexmedetomidine (10 μg/kg IM) and butorphanol (0.4 mg/kg IM). Quality of sedation, analgesia, muscle relaxation and the possibility of performing some clinical procedures were compared using a multifactorial scale. Sedation, analgesia and muscle relaxation increased progressively over time and did not differ in the three protocols. The three protocols facilitated the completion of several clinical procedures. The clinical variables studied showed a similar behaviour in the three protocols and remained close to the baseline, except for a drop in heart rate in protocol D. In conclusion, dexmedetomidine, either alone or combined with pethidine or butorphanol, offers suitable sedation, analgesia and relaxation to perform various clinical procedures in cats.