The application of various picloram formulations to cut stumps of Brachystegia spiciformis Benth., Julbernardia globiflora (Benth.) Troupin,Terminalia sericea Burch. ex DC. and Acacia karroo Hayne trees

Trees were felled 150 mm above ground level and various mixtures of picloram with 2,4‐D araine, 2,4,5‐T amine in water solution or 2,4,5‐T ester in diesel oil were applied to the freshly‐cut surfaces. Mixtures of picloram/2,4‐D amine and picloram/2,4,5‐T amine, both water soluble, gave the highest kill rates when applied to trees in the growing season (October and May). The oil emulsifiable picloram/2,4,5‐T ester formulation tended to be effective throughout the year and high kill rates were frequently obtained with applications made in June or July. Application rates of picloram/2,4‐D amine or picloram/2,4,5‐T amine (expressed as g a.e. picloram per mm girth) required to kill 80% of the trees were 0,012–0,016 for A. karroo; 0,016–0,037 for T. sericea and 0,037 for J. globiflora. Few of the treatments applied to B. spiciformis trees resulted in kill rates of more than 65%.     

The effect of ringbarking Brachystegia spiciformis Benth., Julbernardia globiflora (Benth.) Troupin and Terminaliasericea Burch. ex DC. trees at different heights with or without the addition of a pidoram/2,4‐D mixture

Trees were ringbarked at three different heights relative to ground level (1 000 mm above the ground, at ground level and 100 mm below ground level). In a separate trial, arboricide was applied at four different rates to the lower lip of the ringbarked trees either 1 000 mm above the ground or at ground level. Ringbarking without the arboricide was most effective when carried out in February and at a height of 1 000 mm above the ground. Application of a picloram/2,4‐D mixture to the lower lip of ringbarked trees in January or April resulted in higher kill rates than applications made in June or October. Using this method, somewhat less picloram was necessary than was required to effect the same kill rate to these tree species by applying the arboricide to cuts in their stem bases. In both trials, the kill rate was positively related to the amount of coppice removed.     

Leucosidea sericea — control in southern Lesotho

Tebuthiuron chemical treatments were effective in controlling Leucosidea sericea shrubs upon rangelands of the Quthing sheep stud station in southern Lesotho. Cutting treatments were also effective but more labour intensive. Repeated applications of 2,4,5‐T and fire resulted in less mortality of the shrubs and lower vigour of Eragrostis chloromelas grass than Tebuthiuron treatments.     

Study on the early effects of several weed-control methods on Parthenium hysterophorus L.

We carried out a trial in the Hluhluwe-iMfolozi Park comparing three herbicides and two manual control techniques for controlling the annual weed Parthenium hysterophorus L. The herbicides 2,4-D amine (480 g ai l^?1), metsulfuron methyl (600 g kg^?1) and picloram (240 g l^?1) were tested at three levels each. Manual control comprised hoeing and pulling out parthenium plants by hand. Treatments were applied in mid-December 2006. Surveys were conducted prior to treatment and again in March 2007. The untreated control had a mean mortality of 16% at the end of the growing season, attributed to self thinning. Parthenium mortalities above 80% were achieved with metsulfuron methyl 18–75 g ai ha^?1, picloram 270–360 g ai ha^?1 and both manual control techniques. Broadleaf species, 10 out of 15 of which were alien, were severely affected by herbicides but alien forbs appeared to benefit by the selective removal of parthenium in the manual control treatments. Native grasses filled the space vacated by broadleaf species in the plots treated with herbicide. However, none of the treatments offered lasting control because parthenium regeneration density a year later was no different to densities at the start of the trial. Successful management of parthenium rests on a strong commitment to follow-up spraying until alternative vegetation has covered and stabilised areas under treatment.     

Grass species composition,yield and quality under and outside tree crowns in a semi‐arid rangeland in south‐western Zimbabwe

Abstract

A two‐year study was conducted in lightly grazed areas of Matopos Research Station, Zimbabwe, to evaluate the impact of widely spaced trees on understorey grass composition, yield and quality. The study trees were Terminalia sericea and Acacia karroo. Ordination techniques using grass density and biomass as indices separated quadrats according to soil type but not grass species according to understorey or open areas or according to tree species. Grass yield under tree crowns was similar to open areas, in contrast with most reports where understorey areas had higher yields. The high understorey grass quality that has been reported from savanna areas exhibiting grass composition differences was not expressed. Selective grazing of palatable perennial grasses growing in association with tree crowns and their eventual replacement by low‐yielding and less‐palatable grasses that normally grow in open areas is proposed as an explanation of the unique tree‐grass interaction scenario of this study. In areas where this replacement has occurred, recovery may require management interventions.     

Modification of soil nutrients and micro‐climate by tree crowns in a semi‐arid rangeland of south‐western Zimbabwe

Abstract

Tree crowns in semi‐arid areas have often been found to create micro‐habitats of improved soil physical and nutrient status and reduced evapotranspiration. These encourage the growth of mesic, palatable and high yielding perennial grasses in otherwise arid environments. A two‐year study, in areas with a long history of light grazing, at Matopos Research Station sought to establish whether the soil nutrient status and micro‐climate under tree crowns are different from those in open areas, and whether the differences are affected by soil type and tree species. The study trees were Terminalia sericea and Acacia karroo. There were consistent patterns in soil nutrient status between understorey and open areas, although these patterns were largely not significant. There was also a consistent pattern in soil volumetric water content of open areas > T. sericea > A. karroo understorey areas. Tree crowns reduced solar radiation reaching understorey areas by an average of 88% and rainfall by an average of 15%. The findings on soil nutrient status are consistent with results from disturbed systems, and challenge the dogma, at least for soil nutrient status, that conservative stocking rates are beneficial.     

Die beheer van Amaranthus spp. en die invloed daarvan op Digitaria eriantha gedurende die vestigingsjaar

The control of Amaranthus spp. and the influence thereof on Digitaria eriantha during the season of establishment. Chemical control of Amaranthus spp. in newly established Smuts finger grass (D. eriantha) was investigated. A mixture of 800 ml 2,4‐D Amine+1200 ml Atrazine per ha was applied. This treatment produced a total yield of 6,1 t/ha of which 4,6 t/ha (75,4%) consisted of Smuts finger grass. The rest were weeds. In the case of no chemical control total yield amounted to 4,5 t/ha dry matter of which only 0,7 t/ha (15,5%) was Smuts finger grass. Chemical control clearly had economic advantages.     

Studies on the Animal Metabolism of Phenoxyacetic Herbicides

Gel filtration on Sephadex was applied to the study of plasma protein binding af 2,4-dichlorophenoxyacetic acid (2,4-D). Equilibrated with horse plasma and eluted with buffer pH 7.4, 2,4-D was recovered to 2 % in the plasma protein fraction (K_D 0), free 2,4-D being eluted at a K_D value of 2.2. When 50 % plasma in buffer was used as the eluant the mobility of 2,4-D increased considerably (K_D decreasing to 0.95), thus confirming the existence of a 2,4-D-protein interaction.Hydrolysis experiments in conjunction with thin-layer chromatography revealed no conjugation of 2,4-D in plasma of pigs and rats given 2,4-D amine orally and only slight conjugation, not exceeding 20 %, in urine of pigs, given 2,4-D amine orally.2,4-D butyl ester administered orally to pigs and rats was shown to be rapidly hydrolyzed to 2,4-D acid, only trace amounts of ester being detectable in body fluids and tissues.     

Proanthocyanadin (condensed tannin) content of Brachystegia spiciformis browse harvested at different stages of growth from three sites in Zimbabwe

The extractable and insoluble (bound to protein or neutral detergent fibre [NDF] proanthocyanadin (PA) of the tree species Brachystegia spiciformis (Musasa) harvested at different stages of growth from three sites with different soil types in Zimbabwe was analysed by the n-butanol-HCl method. Brachystegia spiciformis samples from one site showed significantly lower (P < 0.05) PA values than those from the other two sites. Higher (P < 0.01) proportions of insoluble PA (insoluble PA/total PA) were observed in leaves than in twigs. Substantial levels of PA were detected as bound tannins, ranging from 470–804g kg^?1. These results suggest that measurement of bound condensed tannin is necessary when identifying forages containing condensed tannins. The higher contents of PA in the leaves that were harvested when mature than in young leaves could explain why animals prefer eating young rather than mature leaves of B. spiciformis.     

In vitro regeneration of Digitaria eriantha

Abstract

Embryogenic callus was obtained from immature regions of the leaf of Digitaria eriantha when grown in the dark on a MS medium supplemented with 1,0 or 2,0mg/dm³, 2,4‐D and 3–9 % sucrose. Plantlet regeneration occurred when the calli were transferred to MS medium containing 0,1 mg/dm³, 2,4‐D and 7–8 % sucrose, and placed under 16 hour photoperiod. The regenerated plantlets were successfully planted out into a mixture of sand and potting soil.     

Characteristics of night‐time sleeping places selected by golden monkeys (Rhinopithecus bieti) in the Samage Forest,Baima Snow Mountain Nature Reserve,China

We examined the criteria for sleeping place selection in a social band of Rhinopithecus bieti (black‐and‐white snub‐nosed or golden monkeys) living in the mountainous Samage Forest, Baima Snow Mountain Nature Reserve, Yunnan, China. We performed principal component analysis and found that slope aspect, tree height and trunk diameter were likely key variables influencing selection of sleeping places. Sleeping sites were preferentially located in mixed deciduous/conifer forest. The monkeys slept exclusively in evergreen trees, of which 82% were conifers (mostly Picea likiangensis and Tsuga dumosa) and 18% evergreen oaks (Cyclobalanopsis oxyodon and Quercus spp.). Sleeping trees were tall (mean 30.5 m), had high boles (mean 18.4 m), large diameters (mean 62.6 cm) and large crown areas (mean 57.9 m²). A comparative analysis of phytological and architectural features between trees in “sleeping site plots” (n= 18) and trees in “non‐sleeping‐site plots” (n= 66) revealed that diameter, crown surface area and tree height were significantly (P < 0.01) larger in the former compared with the latter. All investigated roosting sites were situated on steep mountain slopes. Valleys and mountain ridges were avoided. We also detected re‐use of roosting sites on several occasions, but not on consecutive nights. It is most likely that a mix of factors (stability of trees, access to food, unit cohesion, monitoring potential) explains the pattern of sleeping site preference, but predation at night seems to be only slightly important. Climate appears to have a profound influence on patterns of sleeping site selection in the monkeys' harsh temperate habitat. This is demonstrated by the monkeys' preference for mixed forest at medium elevations over montane fir forest at high elevations and slopes instead of ridges, with reduced exposure to wind and precipitation inherent in the former. We also emphasize the possibly substantial role that non‐environmental factors (the nature of social organization and socio‐behavioral strategies) play in determining sleeping site use in R. bieti and other primates.     

EFFECTS OF GADOXETATE DISODIUM (EOVIST®) CONTRAST ON MAGNETIC RESONANCE IMAGING CHARACTERISTICS OF THE LIVER IN CLINICALLY HEALTHY DOGS

Gadoxetate disodium (Gd‐EOB‐DTPA; gadolinium‐ethoxybenzyl‐diethylene triamine penta‐acetic acid) is a newly developed paramagnetic contrast agent reported to have a high specificity for the hepatobiliary system in humans. The purpose of this prospective study was to describe effects of Gd‐EOB‐DTPA contrast administration on MRI characteristics of the liver in eight clinically healthy dogs. Precontrast dorsal and transverse T1‐weighted spin echo, T2‐weighted fast spin echo, and transverse T1‐weighted 3D gradient echo (VIBE; volume‐interpolated body examination) pulse sequences were acquired for each dog. Dogs were assigned to four groups based on contrast dose administered (0.0125 mmol/kg or 0.025 mmol/kg), and pulse sequences acquired after contrast administration (T1‐weighted spin echo and T1‐weighted 3D gradient echo). Liver signal intensity ratios were calculated and compared between the two contrast dose groups and two postcontrast pulse sequence groups using ANOVA. No adverse effects of contrast administration were observed. All dogs exhibited homogeneous contrast enhancement of the liver with no statistical difference in enhancement between the two different contrast doses. Contrast enhancement in all dogs peaked between 1 and 10 min after intravenous injection. There was a significant difference in mean signal intensity ratios between sequences (P = 0.035) but not between doses (P = 0.421). Postcontrast signal intensities of the liver parenchyma were significantly higher for the T1‐weighted 3D gradient echo images when compared to the T1‐weighted spin echo sequences. Findings indicated that Gd‐EOB‐DTPA contrast administration is safe in healthy dogs and causes homogeneous enhancement of the liver that is more pronounced in T1‐weighted 3D gradient echo MRI pulse sequences.     

The effect of seeding rate and weed control on the establishment of Rhodes grass in the Eastern Cape

Abstract

The effect of four seeding rates (3; 6; 12 and 24 kg/ha), four methods of weed control (nil, mowing, 4 l/ha of 2,4‐D amine and hand weeding) and two times of cutting (late boot stage and end of season) on the establishment and yield of a Rhodes grass pasture was investigated. The experiment was first sown in 1980 and repeated in the same form in 1982.

Mother and daughter plants were counted and the canopy cover of Rhodes grass was estimated a year after seeding. Subsequently, the experiments were harvested a number of times.

Seeding rate, weed control and cutting affected the density of plants. The higher densities affected the yield of the pasture initially only. The value of using more than 3 kg/ha of commercial certified seed is doubtful. The use of adequate measures to control weeds does seem to be economically justified.     

Aminopyralid Constrains Seed Production of the Invasive Annual Grasses Medusahead and Ventenata

Invasive annual grasses, such as medusahead (Taeniatherum caput-medusae [L.] Nevski), ventenata (Ventenata dubia [Leers] Coss.), downy brome (Bromus tectorum L.), and Japanese brome (Bromus japonicus Thunb. ex Murr.), are negatively impacting millions of hectares of US rangelands. Amino acid synthesis inhibitor and photosynthesis inhibitor herbicides are sometimes used to control invasive annual grasses. Conversely, growth regulator herbicides are generally considered ineffective against invasive annual grasses. However, in a recent study of pre-emergence herbicide applications, the growth regulator aminopyralid appreciably reduced medusahead cover, primarily by killing emerging medusahead plants. Additionally, in recent studies of postemergence herbicide applications, we found the growth regulators aminopyralid, dicamba, and picloram drastically reduced downy brome and Japanese brome seed production. In these postemergence studies, growth regulators sterilized the plants without otherwise greatly affecting them. The purpose of this greenhouse study was to extend our growth regulator/plant sterility research from downy brome and Japanese brome to medusahead and ventenata. Each tested aminopyralid rate and application growth stage (late seedling, internode elongation, heading) reduced medusahead seed production to nearly zero. Picloram also reduced medusahead seed production, but not quite as consistently as aminopyralid. With ventenata, aminopyralid applied at the seedling stage reduced seed production ∼ 95–99%. Beyond the seedling stage, however, ventenata responses to aminopyralid were highly variable. Picloram had low activity against ventenata seed production. These results contribute to a growing body of evidence suggesting it may be possible to use growth regulators to control invasive annual grasses by depleting their short-lived seedbanks.     

Tolerance evaluation of overdosed dietary levels of 25‐hydroxyvitamin D3 in growing piglets

Forty‐eight, cross‐bred (GL × LW × P) piglets were used in a 42‐day tolerance trial to assess the effects of feeding diets supplemented with vitamin D or increasing levels of 25‐hydroxyvitamin D₃ (25‐OH‐D₃). Six‐week‐old piglets (24 castrate males, 24 females) were used. Two replicate groups of 6 piglets were randomized by weight and allocated to four dietary treatments. The control group (T1) was supplemented with 50 μg vitamin D₃/kg feed. The experimental groups received 25‐OH‐D₃ at the recommended dose (T2: 50 μg/kg = 1x), at 250 μg/kg (T3: 5x) or at 500 μg/kg (T4: 10x) respectively. Feed intake and daily weight gain were measured weekly, and the animals were examined by a veterinarian daily. After 42 days, body mass, blood, urine, bone and tissue samples were analysed and a pathology examination conducted. Dietary treatments had no significant effect on final body mass or daily weight gain. The 25‐OH‐D₃ plasma concentration in T1 was 17 ± 3 ng/ml (mean ± SD) while the respective values of the experimental groups were significantly increased in T2, T3 and T4. Tissue concentrations of 25‐OH‐D₃ were higher in liver and muscle for T3 and T4 and in skin for T4 than in T1. However, neither gross pathology nor histology, nor blood and urine characteristics, nor bone parameters were affected by dietary treatments. Weight of organs as well as dry matter, ash and calcium content of kidneys remained unaffected by dietary 25‐OH‐D₃ intake. Furthermore, no changes were observed for general indicators of health. The results of this study demonstrated that feeding piglets with 25‐OH‐D₃ at 5 or 10 times the recommended level had no adverse effects on any of the biological parameters measured. It was concluded that 25‐OH‐D₃ can be regarded as a supplement with a very high safety margin when used at the recommended level.     

Role of the ejaculatory bulb in biosynthesis of the male pheromone cis‐vaccenyl acetate in Drosophila melanogaster

In Drosophila melanogaster, the male ejaculatory bulb is the site of synthesis of a male‐specific pheromone, cis‐vaccenyl acetate, which functions as both an attractant and an anti‐aphrodisiac. This long monounsaturated acetate is structurally similar to a number of shorter gland‐synthesized moth pheromones. The cell monolayer that forms the Drosophila male ejaculatory bulb wall is responsible for the production and secretion of cis‐vaccenyl acetate into the seminal fluid. When dissected bulbs were incubated with sodium [14‐C]‐acetate (or deuterated acetate), a labeled acetate ester was synthesized. The labeled acetate ester co‐migrated with cis‐vaccenyl acetate in thin layer chromatography. Incubation of the abdomens of males from which the ejaculatory bulbs had been removed, or the abdomens of females, with radiolabeled acetate did not yield any acetate ester, but did yield other lipid products, including hydrocarbons. When the isolated labeled acetate ester was hydrolyzed, no radioactive vaccenol was formed. This strongly suggests that the acetyl group is incorporated via a transacetylation reaction, but that the vaccenyl moiety is not synthetized in the blub. The transacetylation enzyme activity was localized in the microsomal subfraction of the bulb homogenate, and its affinity for vaccenol was not very different from that reported for monounsaturated alcohol substrates in moths.     

Excess dietary tryptophan mitigates aflatoxicosis in growing quails

A biological assay was carried out to evaluate the impact of dietary tryptophan (TRP) in aflatoxin B₁‐contaminated diets (AFB₁‐D) on performance, blood parameters, immunity, meat quality and microbial populations of intestine in Japanese quails. Six experimental diets were formulated to include two levels of dietary TRP; 2.9 (moderate high: MH‐TRP) and 4.9 g/kg (excess: Ex‐TRP); and three levels of AFB₁ (0.0, 2.5, and 5.0 mg/kg). Each experimental diet was fed to the one of the six groups of birds from 7 to 35 days of age in a completely randomized design with 2 × 3 factorial arrangement. Decrease in feed intake, body weight gain and gain:feed in birds fed 5.0 mg/kg AFB₁‐D was restored to the control level by 4.9 g TRP/kg of the diet. The hepatic enzymes in blood were elevated in quails fed on AFB₁‐D but attenuated by 4.9 g TRP/kg of the diet (Ex‐TRP; p ≤ .01). High serum uric acid in birds challenged with AFB₁ significantly decreased by Ex‐TRP (p ≤ .01). The skin thickness to 2,4‐dinitro‐1‐chlorobenzene challenge suppressed by AFB₁ but increased by Ex‐TRP diet (p ≤ .02). The AFB₁ increased the malondialdehyde in meat, whereas TRP efficiently diminished malondialdehyde production (p ≤ .01). The greatest drip loss and pH in meat were observed in the birds fed 5.0 mg/kg AFB₁‐D but Ex‐TRP augmented the adverse effects of AFB₁ (p ≤ .01). The Ex‐TRP reduced the total microbial and Escherichia coli counts (p ≤ .01). The adverse effect of AFB₁ on ileal Lactic acid bacteria was completely prevented by Ex‐TRP (p ≤ .03). This study showed that tryptophan supplementation could be considered as a powerful nutritional tool to ameliorate the adverse effects of AFB₁ in growing quails.     

The effect of 25‐hydroxyvitamin D3 and phytase inclusion on pig performance,bone parameters and pork quality in finisher pigs

The objective of this study was to investigate the effects of supplementing both phytase and 25‐hydroxyvitamin D₃ (25‐OH ‐D?) on pig performance, nutrient digestibility, carcass characteristics, bone parameters and pork quality in finisher pigs. The experimental design was a 2 × 2 factorial comprising of four dietary treatments. One hundred and twenty pigs (60 male, 60 female) were blocked according to live weight and sex and allocated to the following dietary treatments: low P (4.81 g/kg) diet (basal) (T1); low P diet + phytase (T2); low P diet + 25‐OH ‐D? (T3) and low P diet + phytase + 25‐OH ‐D? (T4). Pigs supplemented with phytase had a lower average daily feed intake (ADFI ) (2.45 kg vs. 2.59 kg; p  < 0.05) and lower feed conversion ratio (FCR ) (2.74 kg/kg vs. 2.85 kg/kg; p  <  0.05) compared to pigs offered the nonphytase diets. Pigs offered phytase diets had a higher (p  <  0.05) coefficient of apparent total tract digestibility (CATTD ) of ash, phosphorous (P) and calcium (Ca) compared with pigs offered the nonphytase supplemented diets. Pigs offered the 25‐OH ‐D₃ diets had a higher CATTD of N and ash. Pigs offered the phytase diets had increased (p  <  0.05) bone DM , ash, Ca, P and density compared to the nonphytase diets. There was a significant interaction (p  <  0.05) between phytase and 25‐OH ‐D₃ on cook loss. Pigs offered 25‐OH ‐D₃ had increased cook loss over the basal diet; however, there was no effect on cook loss when phytase and 25‐OH ‐D₃ were offered in combination compared to the phytase only diet. Pigs offered 25‐OH ‐D₃ exhibited higher (p  <  0.05) Warner Bratzler shear force values and lower (p  <  0.05) pork lightness (L *) surface colorimeter values. In conclusion, there was no benefit to offering a combination of phytase and 25‐OH ‐D₃ on pig performance, bone parameters or pork quality.     

Documentation of In Vivo and In Vitro Aerobic Resistance of Feline Tritrichomonas foetus Isolates to Ronidazole

Background: The mainstays of treatment for clinically important trichomonad infections are the 5‐nitroimidazoles. Metronidazole resistance of feline Tritrichomonas foetus is presumed because of common treatment failure, and tinidazole does not consistently eradicate infection. To date, ronidazole is the only drug demonstrated as effective for treatment of cats infected with T. foetus. Objective: To document in vivo treatment failure and identify underlying causes and in vitro conditions of resistance of feline T. foetus to ronidazole. Animals: Two intact male Abyssinians failing ≥5 courses of treatment with increasing doses of 5‐nitroimidazole drugs. An intact male Abyssinian documented to clear infection after treatment with a single course of ronidazole. Methods: T. foetus isolates were cultured from feces and tested in vitro for susceptibility to ronidazole under aerobic and anaerobic culture conditions. A urogenital nidus of T. foetus infection was investigated by culture, polymerase chain reaction, or immunohistochemical testing of urogenital specimens. Results: Resistance to ronidazole under aerobic conditions was uniquely identified in T. foetus isolated from cats with well‐documented treatment failure. Treatment failure could not be attributed to reinfection, inappropriate treatment protocol, or presence of a urogenital nidus of infection. Conclusions and Clinical Importance: Clinical resistance to metronidazole, low efficacy of tinidazole, and present documentation of in vivo and in vitro resistance to ronidazole in some cats are consistent with a high level of cross resistance of feline T. foetus to 5‐nitroimidazole drugs. Current lack of alternative drugs with clinical efficacy against feline T. foetus suggests that active investigation of other treatment approaches is warranted.     

VEGF and MMP‐9: biomarkers for canine lymphoma

Vascular endothelial growth factor (VEGF) and metalloproteinase (MMP) 2 and 9 are useful biomarkers in human lymphoma. During cancerogenesis, transforming growth factor beta (TGF‐β) stimulates VEGF and MMPs production. VEGF and TGF‐β plasma levels were tested by ELISA, MMP‐2 and MMP‐9 by gelatine zymography in 37 dogs with lymphoma, 13 of which were also monitored during chemotherapy. Ten healthy dogs served as control. Lymphoma dogs showed higher act‐MMP‐9 (P < 0.01) and VEGF (P < 0.05), and lower TGF‐β than controls, and a positive correlation between act‐MMP‐9 and VEGF (P < 0.001). Act‐MMP‐9 and VEGF were significantly higher in T‐cell lymphomas, and in stage V compared with stages III–IV disease, regardless of immunophenotype. VEGF was higher in high‐grade compared with low‐grade T‐cell lymphomas. No correlation was found between cytokines levels at presentation and outcome. During chemotherapy, act‐MMP‐9 and VEGF decreased in B‐cell lymphomas (P < 0.01), suggesting a possible predictive role in this group of dogs.