bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of insects in the transmission of bovine leukosis virus: Potential for transmission by mosquitoes
Authors: Buxton Bonnie A. , Schultz Ronald D. , Collins William E.
Published: February 2025

Bovine leukosis virus (blv) was transmitted to sheep in a simulated mechanical transmission experiment, using the following species of mosquitoes: Anopheles freeborni, A stephensi, A quadrimaculatus, and A albimanus. Mosquitoes were fed on blood taken from a blv-infected cow with persistent lymphocytosis. Mouthparts and heads of mosquitoes were removed immediately after feeding, placed in RPMI 1640 medium, and inoculated subcutaneously into sheep. Nine sheep were inoculated with mouthparts and heads from 37 to 122 mosquitoes. Infection was determined serologically. Three monthly serum samples were collected from the sheep and were tested for the presence of antibodies to blv, using the agar-gel immunodiffusion (agid) test. Sera that were negative by agid at 3 months were tested by radioimmunoassay. Results from radioimmunoassay agreed with those obtained by agid. Four of the 9 sheep developed antibody to blv. Sheep that seroconverted were inoculated with mouthparts and heads from as few as 54 mosquitoes.
Isolation of ovine lymphocytes, granulocytes, and monocytes by counterflow centrifugation elutriation
Authors: Raghunathan Rukmani , Wuest Carla , Faust Judy , Hwang Stephen , Miller Michael E.
Published: February 2025

A simple, brief 1-step counterflow centrifugation elutriation technique is described for the recovery of highly purified populations of lymphocytes and granulocytes from adult and fetal ovine peripheral blood. Monocytes are obtained as an enriched population. Lymphocyte and granulocyte recoveries average 80%, higher than with routine gradient centrifugation procedures. In this described technique, inexpensive medium is used, and it is completed in about 90 minutes. The individual blood cellular populations, when tested appropriately, demonstrate normal functional responses.
Electrophysiologic studies of the thoracic limb of the horse
Authors: Blythe L. L. , Kitchell R. L.
Published: February 2025

The cutaneous innervation of the thoracic limb was investigated in 18 barbiturate-anesthetized horses, using electrophysiologic techniques. The cutaneous area (ca) innervated by each cutaneous nerve was delineated in at least 4 horses by stroking the hairs with a small watercolor brush while recording from the nerve. Mapping of adjacent ca revealed areas of considerable overlap. The part of a ca of a given nerve supplied only by that nerve is referred to as its autonomous zone (az). In contrast to the standard textbook illustrations cutaneous branches of the axillary, radial, musculocutaneous, and ulnar nerves overlapped extensively in the antebrachium. Clinically testable az were found in the antebrachium for the caudal cutaneous antebrachial nerve of the ulnar nerve and in the carpus and manus for the cutaneous branches of the median, ulnar, and musculocutaneous nerves; az were not found for the cutaneous branches of the radial and axillary nerves.
Liver scintigraphy in ponies
Authors: Theodorakis Michael C. , Bermudez Alex J. , Manning John P. , Koritz Gary D. , Hillidge Christopher J.
Published: February 2025

Six derivatives of ethylenediamine-N,N'-bis (α-2-hydroxy phenyl) acetic acid labeled with technetium 99m were prepared and their imaging qualities evaluated in ponies. The 6 agents produced good scintigraphic images of certain structures of the liver in the pony. For each agent, 13 different scans were taken. Dorsal views of the left lateral, right lateral, and quadrate lobe were obtained with dorsal scans. Left lateral and left lateral oblique (45°) scans provided a left lateral view of the left lobe and a medial view of the right lateral lobe. Right lateral scans revealed the right lateral and quadrate lobes. Administration of 99mTc-labeled colloids which are commonly used in other species for liver scintigraphy resulted in extensive lung uptake in the pony.
Effect of feeding milk from goats fed tansy ragwort (Senecio jacobaea) to rats and calves
Authors: Goeger D. E. , Cheeke P. R. , Schmitz J. A. , Buhler D. R.
Published: February 2025

Dried tansy ragwort, which contains pyrrolizidine alkaloids (pa), was fed to lactating dairy goats. Milk containing 7.5 ng of pa/g (dry weight basis) from these goats was fed to rats and calves. Rats fed a goats' milk diet for 180 days with a calculated total pa intake of 0.96 mg/rat had swollen hepatocytes of centrilobular distribution, and biliary hyperplasia, indicating pa involvement. Rats fed tansy ragwort at dietary levels of 1%, 0.1%, 0.01% and 0.001% (corresponding to pa intakes of 39.77, 5.04, 0.52, and 0.05 mg/rat) showed swollen hepatocytes, megalocytosis, biliary hyperplasia, and fibrosis. The histopathologic changes in the milk-fed rats and those given 0.001% tansy ragwort in the diet were similar. Definitive changes in 2 calves fed goats' milk were not detected. The results with rats indicate that pa are transferred in goats' milk and may produce hepatoxic effects.
Ultrastructure of canine toxic neutrophils
Authors: Gossett Kent A. , MacWilliams Peter S.
Published: February 2025

Turpentine-induced inflammation was used as a model to study the ultrastructure of canine toxic neutrophils. Circulating toxic neutrophils contained large amounts of rough endoplasmic reticulum, but lamellar aggregates (Döhle bodies) were not observed. Cytoplasmic basophilia in Wright's stained neutrophils related to the persistence of rough endoplasmic reticulum and polyribosomes. Foamy vacuolation of the cytoplasm at the light microscopic level corresponded with irregular, electron-lucent areas which were not membrane bound. However, the presence of membrane remnants and myelin figures within lucent areas, as well as dilation and rupture of membranous structures in bone marrow precursors, indicated that these areas may have been membrane bound. In severely affected cells, there were few lysosomal granules.

Early and intermediate neutrophils in the bone marrow of turpentine-injected dogs contained dilated and fragmented rough endoplasmic reticulum associated with irregular, electron-lucent areas in the cytoplasm and perinuclear space. Myelin figures were often in association with these electron-lucent areas.

These findings indicated that cytoplasmic immaturity and cellular degeneration were involved in the morphogenesis of toxic neutrophils in the dog.
Chemotactic factors for bovine leukocytes
Authors: Carroll E. J. , Mueller R. , Panico L.
Published: February 2025

An agarose method was used to determine the nature of chemotaxins for bovine leukocytes as related to coliform mastitis. Freshly collected bovine serum or plasma was frequently chemotactic, probably due to spontaneous complement activation. Fresh serum was always rendered chemotactic when activated with zymosan or when heat-killed or viable coliform bacteria were incubated in the serum. The bacteria did not contribute to preexisting activity in the serum. Escherichia coli grown in synthetic media did not generate chemotaxins, and the synthetic peptide formyl-l-methionyl-l-leucyl-l-phenyl-alanine was not chemotactic in the agarose system for bovine leukocytes. Endotoxin-treated serum had variable activity.
Epizootic of viral enteritis in dogs in Thailand
Authors: Tingpalapong Markpol , Whitmire Richard E. , Watts Douglas M. , Burke Donald S. , Binn Leonard N. , Tesaprateep Ted , Laungtongkum Songkram , Marchwicki Ruth H.
Published: February 2025

An epizootic of enteritis occurred in dogs in Thailand during 1979. Observations were made on 44 dogs that had clinical signs of enteritis or had a recent history compatible with a clinical diagnosis of enteritis. Eight of the 44 dogs died. Gross and histopathologic examinations performed on these dogs revealed that the lesions were similar to those described for canine viral enteritis. Antigens that agglutinated rhesus macaque rbc were detected in feces from 4 of 20 dogs. Cytopathic effects were observed in canine A-72 cells after their inoculation with fecal suspensions from these 4 dogs and with a fecal suspension from another dog. Cell culures inoculated with each of the suspensions produced antigens that agglutinated rbc. All hemagglutinating antigens were inhibited in the presence of feline panleukopenia virus antiserum. Using electron microscopy, parvovirus-like virions were observed in a fecal suspension from 2 dogs (1 dog that had antigen that agglutinlated rhesus macaque rbc and 1 dog hat was negative for feline panleucopenia virus). Canine parvovirus hemagglutination inhibition antibody was detected in sera from 33 of the 40 dogs examined, and canine coronavirus (cv) neutralizing antibody was found in 29 of 30 dogs. Antibody titer increases indicative of recent canine panleukopenia virus (cpv)-like virus and cv infections were observed in paired sera for 2 of 35 and for 5 of 30 of the dogs, respectively. Seemingly, the dogs in Thailand were infected with cpv-like virus and a cv, and these viruses were most likely the cause of the epizootic of viral enteritis.
Occurrence of salmonellae in animal feed ingredients in Saudi Arabia
Authors: Nabbut N. H. , Barbour E. K. , Al-Nakhli H. M.
Published: February 2025

Of 346 samples of animal feed ingredients (144 complete feed, 88 feed concentrate, 42 calcium carbonate, 30 meat meal, 29 fish meal, and 13 mixed meat and bone meal), 42 (12.13%) were contaminated with salmonellae. The rate of Salmonella contamination varied according to the nature of the feed sample. Seven (53.84%) of the mixed meat and bone meal, 14 (48.27%) of the fish meal, 12 (13.63%) of the feed concentrate, 7 (4.86%) of the complete feed, and 2 (4.76%) of the calcium carbonate samples contained salmonellae. The 49 Salmonella isolates represented 18 serotypes; the 5 most frequent serotypes in decreasing order were S lill, S new-haw, S livingstone, S kentucky, and S typhimurium. The 4 most common somatic serogroups encountered were C1, E2, B, and C3.
Scanning electron microscopic study of the small intestine of dogs from birth to 337 days of age
Authors: Hoskins J. D. , Henk W. G. , Abdelbaki Y. Z.
Published: February 2025

The surface morphology of the small intestine of dogs from birth to 337 days of age was studied by scanning electron microscopy. The small intestinal surface morphology was similar to that described for other species, except or irregular villous length in the duodenum, jejunum, and ileum of the dog from birth to 21 days of age. The absorptive epithelial cells and goblet cells were similar in morphology and distribution from birth to 337 days. Segmented filamentous bacteria were attached to the ileal mucosa of dogs 54 to 161 days of age.
Comparative prenatal development of the spinal cord in normal and dysraphic dogs: Fetal stage
Authors: Engel Harold N. , Draper Donald D.
Published: February 2025

The normal prenatal development of the canine spinal cord was examined by light microscopy in 8 fetuses with an average gestational age of 42.75 days and crown-rump lengths of 92.0 mm. The development of the spinal cord in these fetuses was comparable to the development in human etuses of 14 weeks' gestation (900) mm crown-rump length). These normal fetal developments were compared with the levelopment of the spinal cord in 10 fetuses obtained by nating severely dysraphic Weimaraner dogs. These fetuses rad an average gestational age of 42.10 days and crown-rump lengths of 96.5 mm.

Dysraphic lesions were present in all 10 of the fetuses obtained from the dysraphic matings. There was a failure of the dura mater to differentiate and separate from the periosteum of the vertebral canal in 80% of the dysraphic etuses. The ventral median fissure was absent in 70% of he dysraphic fetuses along with concomitant fusion of the ventral white columns and a disruption of the normal ar-hitecture of the gray matter. Central canal abnormalities were evident in 70% of the dysraphic fetuses. These findings ncluded the presence of diverticuli and reduction in the ize of the canal.

The dysraphic fetuses had significantly larger ratios of cray matter to spinal cord diameters, indicating less white matter development. There were no significant differences between the normal and dysraphic transverse diameter measurements of both the gray matter and the entire spinal cord. The lack of expected significance was attributed to differences in breed size. Although not significant, there was the tendency for the dysraphic fetuses to have smaller cross-ectional areas of the dorsal root ganglia in the caudal lumbar region. Furthermore, there was no prevalence for dysraphism to affect one side over the other.
Pharmacokinetics of sulfamerazine and antipyrine in neonatal and young lambs
Authors: Backer P. De , Belpaire F. M. , Bogaert M. G. , Debackere M.
Published: February 2025

The disposition of sulfamerazine after oral and after iv administrations was studied in lambs at different times after birth. There was a gradual increase in systemic clearance and plasma binding until the 9th week. After sulfamerazine was given orally, there was a marked evolution in the shape of the concentration-time curves in function of age, strongly suggesting a defective absorption rate in the first weeks after birth.

For antipyrine, too, the clearance increased gradually during the period of study, but absorption seemed to be rapid in the very young animals.
Residual protection against cattle scabies afforded by ivermectin
Authors: Meleney William P. , Wright Fred C. , Guillot Frank S.
Published: February 2025

Hereford calves were exposed to ca 200 active adult and mymphal psoroptic mites at intervals of 3 or 4 days after a single im injection of 200 μg of ivermeciin/kg of body weight, after dipping in 0.54% toxaphene, or no treatment. Mites established reproducing colonies on 11 of 13 untreated calves, on all of the toxaphene-dipped calves exposed more than 8 days after treatment, and on all, but 1, of the ivermectin-injected calves exposed more than 21 days after treatment. Mites did not survive long enough to establish reproducing colonies on any of the ivermectin-injected calves exposed through 21 days after treatment, on any of the toxaphene-dipped calves exposed through 8 days after treatment, or 2 of the control calves.
Localization of the sacral parasympathetic nucleus in the dog
Authors: Samson Mark D. , Reddy V. Krishna
Published: February 2025

The extent and location of the sacral parasympathetic nucleus was studied in 6 dogs, using light microscopy. After interruption of the pelvic nerve, chromatolytic somata were observed in thionin-stained transverse serial sections (15 μm) of appropriate spinal cord segments. Maps of the sacral parasympathetic nucleus were made by plotting the chromatolytic somata in drawings of the transverse sections of the spinal cord.

The sacral parasympathetic nucleus was observed in all 3 sacral segments of the spinal cord, and in 1 dog, it also extended into the spinal cord segment Cal. The cranial end of the nucleus was contained in the caudal one-third of spinal segment SI. The location of the caudal end was variable: it was within the middle one-third of spinal cord segment S3 in 4 dogs, in the caudal pne-third of spinal cord segment S3 in 1 dog, and in the cranial one-third of spinal cord segment Cal in 1 dog. The densest clusters of somata of this nucleus were in the middle and caudal one-third of spinal cord segment S2. The somata, for the most part, were in the intermediolateral gray column and in the lateral funiculus. A small number of isolated somata also were in the intermediome-dial gray column.
Observations of abnormalities and age-related changes in the anconeal processes of swine
Authors: Nakano Takuo , Thompson James R. , Aherne Francis X. , Christian Ralph G.
Published: February 2025

Abnormalities and age-related changes in the anconeal processes of 60 boars were studied. Postmortem examination of both cubitus joints from 25 lame adolescent boars and from 5 of their nonlame contemporaries revealed cartilaginous tissue (termed cartilage plate) of varying size between the anconeal process and the ulnar diaphysis in 8 of the lame animals. The cartilage plate was fractured in both joints from 7 of these 8 animals, and joints from 6 animals with cartilage plate were associated with lesions of the semilunar articular cartilage and bone in the proximal portion of the ulna.

Postmortem examination of the joints from 30 boars (ranging in age from 1 month before birth to 1.5 years) indicated that during growth, bone developed from the ulnar diaphysis toward the cranial tip of the anconeal process. Separate ossification centers were not observed in any of the clinically normal anconeal processes studied in this group. However, microscopic observations of 1 abnormal anconeal process from a 13-week-old boar indicated that trauma may be involved in morphogenesis of a cartilage plate. Age-dependent changes were also observed in the composition of the anconeal process.
Nasal turbinate atrophy in young mice inoculated with Bordetella bronchiseptica of pig origin
Authors: Sawata Akira , Kume Katsumi
Published: February 2025

Development of a model in experimental small animals will facilitate research on the mechanisms of nasal turbinate atrophy of swine. Atrophy of the nasal turbinate with Bordetella bronchiseptica phase I organisms of pig origin was induced by intranasal inoculation in 5-day-old or younger mice. Inoculations of phase I organisms into 10-day-old or older mice and of avirulent phase III organisms into 5-day-old or younger mice did not induce lesions of the disease, however. The lesions appeared in 40% of the susceptible-age mice which were examined at 2 weeks after inoculation and were present in 80% of the susceptible-age mice by 3 weeks. The lesions observed in young mice were similar to those reported for swine.
Proliferative, morphologic, and cytochemical characteristics of bovine bone marrow macrophage colonies in liquid culture
Authors: Al-Izzi S. A. , Maxie M. G. , Valli V. E. .
Published: February 2025

Bovine macrophage colonies were grown in liquid medium. Serum collected from a heifer 3 hours after injection of Pseudomonas aeruginosa endotoxin promoted the growth of macrophage colonies. The optimum concentration of postendotoxin serum was 16%. The numbers of colonies increased exponentially between 3 and 6 days of incubation and leveled off at 6 days. Monoblasts, promonocytes, and macrophages were observed in these colonies. A direct linear relationship between the number of nucleated bone marrow cells cultured and the number of colonies formed was found. The macrophage colony cells were positive for nonspecific esterase activity and were negative for chloroacetate esterase activity. Weak peroxidase activity was noticed in monoblasts, promonocytes, and occasionally in macrophages.
Anesthesia in the green sea turtle, Chelonia mydas
Authors: Wood F. E. , Critchley K. H. , Wood J. R.
Published: February 2025

Surgical anesthesia for green sea turtles weighing between 6 and 195 kg was achieved with the injectable anesthetics sodium pentobarbital, ketamine hydrochloride, and sodium thiopental. Induction of, duration of, and recovery from anesthesia varied among individual turtles.
Infectivity of Chlamydia psittaci of bovine and ovine origins for cultured cells
Authors: Dennis Michael W. , Storz J.
Published: February 2025

The infectivity of 2 strains of Chlamydia psittaci of mammalian origin were studied in mouse L cells. Infectivity was enhanced by centrifuging the chlamydial inoculum onto the cell monolayer. Infectivity increased as force of centrifugation increased. The enhanced infectivity was not caused by centrifugal sedimentation of chlamydiae, since centrifugation longer than 10 minutes and an inoculum dose larger than 0.4 ml did not further enhance infectivity. Centrifuge-enhanced adsorption was temperature dependent, because infection was not detected when stationary or centrifuge-assisted adsorption occurred at less than 15 C. Infectivity was higher in cultures centrifuged at 37 C than in cultures centrifuged at room temperature. Treatments of cells with cycloheximide, colchicine, and hydrocortisone enhanced infectivity of chlamydiae above that of untreated cells. In addition, developing chlamydial inclusions were larger and easier to observe in colchicine-treated cells. Infectivity was thought to be enhanced in colchicine-treated cells, because cells with depolymerized microtubules provided favorable conditions for the early phases of chlamydial multiplication. Treatment of cells with cytochalasin B, carbachol, cGMP, lumicolchicine, or vinblastine did not significantly alter chlamydial infectivity.
Morphologic alteration of Anaplasma marginale in calves treated with a dithiosemicarbazone
Authors: Simpson Charles F. , Neal Fred C.
Published: February 2025

Blood and clotted blood samples from 3 calves with anaplasmosis were examined by light and electron microscopies before and after the calves were treated twice with α-ethoxyethylglyoxal dithiosemicarbazone (given iv). In the treated calves anaplasma bodies were swollen and irregularly shaped and had rough surfaces when viewed by light microscopy. Posttreatment electron microscopic examinations revealed swelling and vacuolation of initial bodies of anaplasma bodies, and ballooning of the vesicular membrane surrounding the anaplasma body. Other initial bodies were ameboid in shape; this was or was not accompanied by rupture of the vesicular membrane of the anaplasma body. Necrotic, ameboid-shaped initial bodies also were seen. Some necrotic initial bodies were surrounded by a complete vesicular membrane, and others were close to a broken, curled vesicular membrane.
Interaction of bluetongue virus with preimplantation embryos from mice and cattle
Authors: Bowen R. A. , Howard T. H. , Pickett B. W.
Published: February 2025

Preimplantation embryos from mice and cattle were exposed to bluetongue virus in vitro to determine whether the virus would replicate in these early embryos and, if so, what pathologic consequences would ensue. A high proportion of zona pellucida-free, 2-cell embryos and morulae from mice, and morulae from cattle became infected. The infection was rapidly cytopathic in embryos from both species. Indirect immunofluorescence was used to demonstrate accumulation of virus antigen in the blastomeres of these embryos. The zona pellucida of both murine and bovine embryos provided effective protection from virus present in culture fluid.
Arterial baroreflex control of heart rate in the horse, pig, and calf
Authors: Slinker Bryan K. , Campbell Kenneth B. , Alexander John E. , Klavano Paul A.
Published: February 2025

The heart rate (hr) response to stepwise changes in mean arterial pressure (map) produced by methoxamine and sodium nitroprusside was studied in conscious horses, pigs, and calves. The respective steady-state arterial baroreflex sensitivities (Δ hr/Δ map expressed as beats min−1 · mm of Hg−1) were −1.20, −1.21, and −0.39 for decreasing map and −0.08, −0.91, and −0.56 for increasing map. After parasympathetic nervous system (pns) blockade with atropine, the reflex sensitivity to decreasing map in horses and the pigs decreased to −0.62 and −0.65, respectively (P < 0.05), whereas the sensitivity in calves was not significantly different from the calves’ base-line sensitivity (P > 0.05). In pigs, the sensitivity to increasing map decreased to −0.43 after pns blockade (P < 0.05). Horses and calves had a response to small increases in map similar to that observed in the absence of pns blockade. There was no additional change in hr with larger increases in map in these 2 species. These responses indicate that varying degrees of mixed pns and sympathetic nervous system activity changes mediate the baroreflex change in hr seen for increasing and decreasing map in pigs and for decreasing map in horses. Predominantly pns activity is responsible for the response to increasing map in the horses and calves, whereas predominantly sympathetic nervous system activity is responsible for the response to decreasing map in calves. Comparisons were made between the observations in these 3 species and other mammalian species.
Protective effects of antioxidants on bitterweed (Hymenoxys odorata DC) toxicity in sheep
Authors: Kim H. L. , Anderson A. C. , Herrig B. W. , Jones L. P. , Calhoun M. C.
Published: February 2025

Antidotal effects of the 2 antioxidants butylated hydroxyanisole (bha) and ethoxyquin (eq) were evaluated in bitterweed (Hymenoxys odorata DC) toxicosis in sheep. Bitterweed contains a toxic sesquiterpene lactone, hymenoxon, the toxicity of which is reduced by cysteine. Both bha and eq are known to induce hepatic glutathione production in rodents. Treatment of sheep with eq (2.5 g/sheep/day for 9 days before poisoning) gave significant protection from toxic doses of bitterweed, but the protective effect of bha was insignificant. Of 6 sheep given eq in the feed, 5 survived 7 doses of bitterweed (4 g/kg/day or higher for 7 days), whereas 5 of 7 controls and 4 of 7 sheep given feed with added bha died. The added eq in the feed decreased the serum alkaline phosphatase activity and total protein, albumin, and calcium concentrations. Seemingly, eq is the first protective agent with field application potential for bitterweed toxicity.
Effects of concurrent subclinical infections by coccidia (Eimeria christenseni) and intestinal nematodes (Trichostrongylus colubriformis) on apparent nutrient digestibilities and balances, serum copper and zinc, and bone mineralization in the pigmy goat
Authors: Frandsen John C.
Published: February 2025

Subclinical infections by the intestinal nematode Trichostrongylus colubriformis were established in 7 pigmy goats by inoculating each with 4,000 infective larvae 5 days/week for 18 weeks. At the start of the 14th week, 3 of the goats were orally inoculated daily with 10,000 sporulated oocysts of the coccidium Eimeria christenseni for 6 days, producing subclinical infections. During selected weeks, the goats were placed in metabolism cages to monitor feed consumption and collect orts, feces, and urine. Samples of rib, vertebra, and tibia were removed at time of death, on day 126. The superimposition of the coccidial infections on the nematode infections did not affect apparent ash, nitrogen, organic matter, or dry matter digestibilities; balances of nitrogen or phosphorus; serum copper or zinc concentrations; liveweights or feed conversion efficiencies. Mean calcium balances remained positive, although they were reduced during the first week of the superimposed coccidial infections. The mineralization of the matrix of the tibia and 4th lumbar vertebra was less in the goats with the superimposed coccidial infections than in those infected only with nematodes. Presence of the superimposed infections was associated with a decrease in the mean moisture and lipid contents of the tibia.
Regional distribution of pulmonary ventilation and perfusion in the conscious dog
Authors: Amis T. C. , Jones Hazel A. , Rhodes C. G. , Heather J. D. , Hughes J. M. B.
Published: February 2025

Measurements of the regional distribution of pulmonary ventilation per unit alveolar volume and perfusion per unit alveolar volume were made in healthy conscious standing Greyhound dogs, using steady-state inhalation or infusion (iv) of the radioactive gas 81Krm (half-life 13 s) combined with inhalation equilibration and clearance of the longer-lived radioactive gas 85Krm (half-life 4.4 hours). During tidal breathing, ventilation and perfusion were uniformly distributed in the lungs of the dogs.
Plasma kinetics of digoxin in the cat
Authors: Bolton G. R. , Powell W.
Published: February 2025

The biological half-life of digoxin was 33.3 ± 9.5 hours in 6 cats after a single iv injection. Longer half-lives were obtained after chronic oral administration, indicating that digoxin elimination is capacity-limited in the cat. The mean percentage of urinary excretion of digoxin after a single iv dose was 45% ± 9.7% over a 10-day period.

Toxic plasma concentrations ranged from 2.4 to 2.9 ng/ml, and 5 of 6 cats had clinical signs of toxicosis at concentrations > 2.6 ng/ml.

Prolongation of the PQ interval was seen on the ecg at nontoxic plasma concentrations in 4 of 6 cats. The most striking ecg evidence of digoxin toxicosis was ST-segment elevation seen in 3 of the 6 cats.
Changes in body fluid compartments, tissue water and electrolyte distribution, and lipid concentrations in rhesus macaques with yellow fever
Authors: Liu C. T. , Griffin M. J.
Published: February 2025

Rhesus macaques were inoculated subcutaneously with 40 plaque-forming units of yellow fever (yf) virus. To identify pathophysiologic mechansisms of yf, rectal temperatures and evidence of viremia were observed daily; physiologic and biochemical changes were studied on postinoculation day (pid) 5. Marked viremia was detected on pid 2 through 5, and fever was first observed on pid 4. On pid 5, blood and plasma volumes and circulatory K+ values increased, whereas rbc volume, pcv, and plasma cholesterol concentration decreased. Total lipids (mainly triglycerides) accumulated in the liver of inoculated macaques; alterations in hepatic content of water, electrolytes, and trace metals were also observed. Certain parts of the cns, skeletal muscle, skin, heart, diaphragm, and renal cortex were affected, with changes noticed in water, electrolyte, trace metal, and lipid concentrations. These tissue changes indicated that cellular metabolism was altered and that the transport mechanisms of cell membranes of certain tissues were modified by yf virus or the disease process caused by the virus. Terminal hypoglycemia (57.6 ± 12.1 mg/dl) was observed. The yf-induced intracellular dehydration of the medulla oblongata at the later stage of illness may depress the cardiovascular and respiratory centers, thus contributing to death of rhesus macaques infected with yf virus.
and brucellar titers in frozen bovine sera after 20 years of storage
Authors: Moorhouse P. D. , Hugh-Jones M. E. , Barta O. , Swann A. I.
Published: February 2025

Generally good agreement was obtained between the rankings of sera titers when originally tested (T1), and those of the same sera 20 years later (T2). At the later time, the majority of samples (88%) were in, or within 1 dilution factor of their classification at T1. Test results for Brucella abortus and Leptospira interrogans var pomona antibodies demonstrated that original titers, in the upper-lower limits of 20 to 50, had decreased over a wale range (202 to 902 ), and the later tests show that the greater the original titer, the greater the proportional decrease. Thus, titers of 20,000 at T1 had decreased by 49% to 99% and those of 200,000, by 95% to 99.8%. Variations in T2 test results were noted between some samples which had given identical results at T1.

A decrease in titer over time has been demonstrated. An estimate of the expected half-lives of sera of differing initial Leptospira antibody titers is that for each unit increase in login of the initial titer, the half-life is reduced by about 50%. The heterogeneity of the immune response is postulated as the reason for this variation.
Indirect hemagglutination for the diagnosis of Heterobilharzia americana infections in dogs
Authors: Goff W. L. , Ronald N. C.
Published: February 2025

An indirect hemagglutination test was developed for the diagnosis of canine schistosomiasis. Specific-pathogen-free dogs and dogs infected with a variety of other helminths were experimentally infected with Heterobilharzia americana. Sera collected at various times after the dogs were exposed to cercariae were evaluated.

Glutaraldehyde-fixed sheep erythrocytes sensitized with whole adult worm antigens provided a stable antigen substrate when tested over a period of months. The test produced sensitive and specific diagnosis at an appropriate serum dilution. Serum dilutions < 1:80 from dogs with other helminth infections resulted in nonspecific agglutination. By postexposure day 60, coinciding with the end of the prepatent period, serum titers of dogs infected only with H americana equaled, and then surpassed, those of the other dogs.
Variation in age at death of dogs of different sexes and breeds
Authors: Bronson Roderick T.
Published: February 2025

A retrospective study of necropsy data for 2,002 dogs showed that the mean age at death of neutered dogs of both sexes exceeded that of intact dogs, but the differences were not significant. A wide variation in mean age at death of 56 breeds and cross breeds, 3.0 to 9.9 years, was found. This variation was not correlated with mean breed body weight. An attempt was made to explain the variability by finding diseases to which dogs of the short-lived breeds were particularly susceptible. This was not possible in general, since the samples of each breed were small and the total number of diseases from which they died so large. Dogs of long-lived breeds died of diseases appropriate to their age, particularly cancer, 39% of the sample. In the sample as a whole, cancer accounted for 20% of deaths at 5 years and increased to and remained between 40% and 50% from 10 to 16 years of age.
Diagnosis of Fasciola hepatica infections in sheep by an enzyme-linked immunosorbent assay
Authors: Zimmerman G. L. , Jen L. W. , Cerro J. E. , Farnsworth K. L. , Wescott R. B.
Published: February 2025

An enzyme-linked immunosorbent assay (elisa) was evaluated for diagnosis of Fasciola hepatica infections in sheep maintained under isolation and drylot conditions. Sheep were exposed to various numbers (100 to 500) of metacercariae, and blood was collected for assay at regular intervals thereafter. The elisa values of controls were low and varied little. Although the elisa detected antibodies to the flukes as early as postinoculation week (piw) 2, elisa values suggested as diagnostic (1.75 times control values) did not occur until piw 6 to 8. Positive diagnosis of the infections by fecal examination for fluke eggs was not established until after piw 10. Results also indicated that elisa values were generally not correlated with magnitude of infection, concurrent nematode infections, or husbandry practices.
Effects of promethazine on hemorrhagic shock in the dog
Authors: Goetsch Dennis D. , Wilson Robert C. , Huber Thomas L.
Published: February 2025

SUMMARY AND CONCLUSIONS

The effects of pre- and post-treatment with promethazine, an antihistamine, in hemorrhage-shocked dogs were investigated. Survival to 6 hours was enhanced in the dogs given (im administration) the H1-receptor antagonist at 1 hour before hemorrhage was induced when compared with survivals of saline-treated control dogs (3 of 5 dogs vs 1 of 5 dogs). Furthermore, 4 of 5 dogs given (iv administration) promethazine at 30 minutes after the initial hemorrhage survived. Promethazine treatment by either route increased mean arterial pressure among surviving dogs throughout the 6-hour experimental period.

It was concluded that histamine actions on H1 receptors may be one of the factors affecting the ultimate outcome of severe hemorrhagic shock in dogs and that promethazine may be of value in blocking these adverse histamine effects.
Circulating carrier erythrocytes: Slow-release vehicle for an antileukemic drug, cytosine arabinoside
Authors: DeLoach John R. , Barton C.
Published: February 2025

The human anti-cancer drug cytosine arabinoside (ara- C) was encapsulated in canine erythrocytes. When these autologous carrier cells were injected into dogs, the drug was slowly released into plasma. Erythrocyte encapsulation increased the plasma half-life of ara-C in dogs about 50-fold over that of the injected free drug. The whole blood halflife of encapsulated drug was 4.6 days and the elimination constant was 0.150 day−1. Erythrocyte encapsulation holds promise as a drug-delivering technique for treatment of some human and animal diseases, particularly with drugs that are highly toxic or have normally short biological halflife. It also could be used to sustain given concentrations of drugs.
Circulating endotoxin-like substance(s) and altered hemostasis in horses with gastrointestinal disorders: An interim report
Authors: Meyers K. , Reed S. , Keck M. , Clem M. , Bayly W.
Published: February 2025

Twenty-three horses with clinical signs of gastrointestinal disease were evaluated once or serially during the course of the disease for the presence or absence of circulating endotoxin-like substances (et+ or et-) and whether the horses were negative, positive, or very positive for serum fibrin/fibrinogen degradation products (fdp-, fdp+, or fdp++). In addition, platelet count, activated partial thromboplastin time (aptt), and 1-stage prothrombin time (ospt) were measured. When examined initially, 5 horses were et-/fdp-, 8 were et-/fdp+, 7 were et+/fdp-, 3 were et+/fdp+, and none was et+/fdp++. Eight horses were evaluated serially and the following changes were noted: 1 et-/fdp- horse became et+/fdp++; 1 et-/fdp- horse became et-/fdp+; 1 et-/fdp- horse became et+/fdp-; 2 et-/fdp+ horses became et+/fdp++; 1 et+/fdp- horse became et+/fdp+ (++); and 2 et+/fdp- horses became et-/fdp-. At the last examination, 4 horses were et-/fdp- and all survived; 7 were et-/fdp+ and only 1 was euthanatized; 5 were et+/fdp- and only 2 were euthanatized; and 7 were et+/fdp+ or ++, and 5 horses died or were euthanatized. The relationship between et and fdp is discussed and a working model of endotoxemia and gastrointestinal disease in the horse is presented.
Effect of Corynebacterium parvum on bone marrow macrophage colony production, peripheral blood leukocytes, and histologic changes of tissues in calves
Authors: Al-Izzi S. A. , Maxie M. G.
Published: February 2025

An iv injection of formalin-killed Corynebacterium parvum in calves did not cause a marked increase in the number of bone marrow macrophage colonies or peripheral blood monocytes, granulocytes, or lymphocytes. In treated calves, the spleen increased in weight and there were macrophage infiltrations in liver, lungs, spleen, and lymph nodes. Lymphoid hyperplasia was observed in bronchial-associated lymphoid tissue, cortical areas of the thymus, and in primary and secondary follicles and the paracortical area of lymph nodes.
Anthelmintic efficacy of febantel against gastrointestinal helminths in calves
Authors: Ciordia H. , McCampbell H. C. , Stuedemann J. A.
Published: February 2025

Three dosage levels of febantel were tested for anthelmintic activities in calves under field conditions. A total of 20 feeder calves affected with naturally occurring gastrointestinal parasites were used in the controlled test. The calves were allotted to 4 groups of 5 each on the basis of degree of parasitism, body weight, age, and sex. Calves in groups II through IV were treated with febantel paste formulation at dosage levels of 5, 7.5, and 10 mg/kg of body weight; calves in group I were used as nonmedicated controls. Calves were euthanatized and necropsied 7 days after treatment. Medications were 97% to 100% effective against the adult forms of Haemonchus placei, Trichostrongylus axei, Cooperia pectinata, C oncophora, Nematodirus spathiger, and Oesophagostomum radiatum; 93% to 98% against Ostertagia ostertagi; and 78% to 95% against Trichuris sp. There were no differences in efficacies of the 3 dosage levels used against adult worms. Efficacy varied from 61% to 96% against larvae of O ostertagi. Activity was not detected against the tapeworm Moniezia benedeni. Medicated cattle did not show signs of intoxication.
Papillomatosis of the bovine teat (mammary papilla)
Authors: Olson Robert O. , Olson Carl , Easterday Bernard C.
Published: February 2025

A 4th of 667 cattle examined at a Wisconsin abattoir had teat papillomas. Excised teat papillomas were sorted by gross morphologic characteristics into 3 groups: (i) atypical filiform, (ii) atypical flat, and (iii) typical fibropapilloma. Bovine papilloma virus capsid antigen was detected in thin-section slides of the 3 groups of teat papillomas by peroxidase-antiperoxidase assay. The bovine papilloma virus involved with the atypical papillomas could not be characterized by molecular hybridization, because enough pure virus could not be harvested. Homogenates of the 3 groups of teat papillomas were inoculated on 2 ponies and 4 calves. Typical fibro-papillomas were produced on the 4 calves, and fibromas, on the 2 ponies. Atypical papillomas were produced only in 2 heifers.
Radiographic morphometry and radiographic photodensitometry of the femur in the Beagle at 13 and 21 months
Authors: Delaquerriere-Richardson L. , Anderson C. , Jorch U. M. , Cook M.
Published: February 2025

A study was made of x-ray morphometry and x-ray photodensitometry of bones of 2 small groups of healthy standardized colony-raised male research Beagles, ages 13 and 21 months. The morphometry and photodensitometry results were correlated to other variables of interest. The total width of the femur and its optical density to x-rays increased significantly with age and body weight, but not so the length of the femur nor the combined cortical thickness (cct). This last measurement (cct) did not increase in parallel with the whole length of the bone either. The cct/width ratio decreased as body weight increased. The clear-cut increase in the optical density of the whole bone is therefore explained by the age-related variations in bone envelope activity.
Bentiromide:xylose test in healthy cats
Authors: Sherding R. G. , Stradley R. P. , Rogers W. A. , Johnson S. E.
Published: February 2025

The N-benzoyl-l-tyrosyl-p-aminobenzoic acid (bentiromide):xylose test for simultaneous evaluation of pancreatic exocrine function and intestinal absorptive function was studied in 8 clinically healthy cats. Plasma p-aminobenzoic acid (paba) and xylose concentrations were determined before, and at 30, 60, 90, 120, 150, and 180 minutes after, a solution of bentiromide (1 g/100 ml) and d-xylose (10 g/100 ml) was given orally at a dosage of 5 ml/kg of body weight.

The peak plasma concentrations for paba occurred between 60 and 120 minutes, with highest mean value at 90 minutes (7.5 ± 3.2 μg/ml), and for xylose between 30 and 120 minutes, with the highest mean value at 60 minutes (42.6 ± 17.8 mg/dl). Large sd in plasma paba and xylose concentrations indicated marked individual variation between healthy cats.

It was concluded that (i) large variations between clinically healthy cats may limit the diagnostic usefulness of the bentiromide:xylose test in the cat, and (ii) guidelines for interpretation of plasma paba and xylose concentrations reported previously for clinically healthy dogs could not be applied to cats because values were lower in cats.
Mycoplasma gateae arthritis and tenosynovitis in cats: Case report and experimental reproduction of the disease
Authors: Moise N. Sydney , Crissman James W. , Fairbrother John F. , Baldwin Charles
Published: February 2025

Polyarthritis and tenosynovitis were diagnosed in a cat. Clinical signs of 2 months' duration included swollen limbs, painful joints (sensitive to touch), lameness, and pyrexia. Laboratory test data revealed hypogammaglobulinemia, hypoalbuminemia, leukocytosis, and mild anemia. The cat was euthanatized and necropsied; there were chronic necrotizing fibrinopurulent tenosynovitis and arthritis with bone and cartilage erosions. Cultural examinations of synovia were positive for Mycoplasma gateae, but bacterial and viral cultural examinations were negative.

Organisms propagated from the M gateae isolate were inoculated iv into 6 specific-pathogen-free cats—3 of these being subjected to immunosuppression induced with azathioprine. The 6 inoculated cats became lame 5 to 9 days later, and 5 became febrile. Cultural examinations of the pharynx in 4 cats were positive for M gateae and in 3 cats, the organism was isolated from various joints. Microscopically, arthritis and tenosynovitis were identified in all cats. Two specific-pathogen-free cats were used as controls (noninoculated); these did not become lame, had negative M gateae cultures, and were free of histopathologic abnormalities. Reproduction of disease with recovery of the causative agent indicates the pathogenicity of this particular isolate of M gateae in the cat when inoculated iv.
Effect of antioxidants on the proliferative response of canine lymphocytes in serum from dogs with vitamin E deficiency
Authors: Langweiler Marc , Sheffy Ben E. , Schultz Ronald D.
Published: February 2025

The in vitro effect of vitamin E and 3 other antioxidants—ethoxyquin, 2-mercaptoethanol, and ascorbic acid—on proliferation of canine lymphocytes was examined. Lymphocytes from 2 groups of dogs given a vitamin E-deficient diet or whelped from a bitch fed such a diet were cultured with pooled samples of serum from dogs fed a vitamin E-deficient diet or whelped from a bitch fed such a diet, or normal canine serum, and stimulated with phytohemagglutinin. Added vitamin E enhanced the responsiveness in serum from the dogs with vitamin E deficiency, but not in normal canine serum. A similar effect was noted with added ethoxyquin and 2-mercaptoethanol. Ascorbic acid had no effect on proliferation in either serum pool. These results indicated that depressed lymphocyte responsiveness seen with serum from vitamin E-deficient dogs may, at least in part, be due to a loss of antioxidant activity in this serum.
Absorption in calves of amoxicillin, ampicillin, and oxytetracycline given in milk replacer, water, or an oral rehydration formulation
Authors: Palmer G. H. , Bywater R. J. , Stanton A.
Published: February 2025

Oxytetracycline, amoxicillin or ampicillin suspended in milk replacer, water, or a glucose-glycine-electrolyte solution (gges) was orally given to calves (n = 64).

Oxytetracycline suspended in milk replacer gave lower relative bioavailability than when suspended in water (P < 0.01) or in gges (P < 0.001). Seemingly, the 63% binding (only partly reversible) of oxytetracycline suspended in milk replacer was responsible for low serum concentrations, whereas the greater water absorption from the gges was responsible for improved uptake of antibiotic.

Amoxicillin suspended in milk replacer had a delayed absorption, compared with that suspended in water, but the relative bioavailabilities from milk replacer and water were similar. In contrast, peak serum concentration and bioavailability were higher (P < 0.05) when amoxicillin was suspended in gges than when suspended in water. Binding of amoxicillin with milk replacer was comparatively low (16%) and was reversible.

Ampicillin suspended in gges gave a higher peak serum concentration (P < 0.05) than when suspended in milk replacer.

It, therefore, appeared that these antibiotics were more bioavailable when suspended in gges than when suspended in water or especially in milk replacer. Oxytetracycline was bound particularly strongly to milk replacer.