bluuebunny/crossref_metadata_2025 huggingface dataset:
Cambendazole for strongyle control in a pony band: Selection of a drug-resistant population of small strongyles and teratologic implications
Authors: Drudge J. H. , Lyons E. T. , Swerczek T. W. , Tolliver S. C.
Published: February 2025

Cambendazole (cbz) treatments (20 mg/kg) given at 8-week intervals were used for parasite control in a breeding band of ponies (n = 33 to 43) during the period July 1974 to August 1978. Pre- and posttreatment worm egg counts on feces were used to evaluate efficacy of treatments after every 2nd treatment interval by monitoring changes in strongyle egg counts. Initially, effective reductions (expressed as 92% to 96% fewer worm eggs) were lessened to 70% by the 9th treatment (18 months) and to 28% by the 12th treatment, and thereafter, they fluctuated between 0% and 38%. Critical tests on animals culled during the 3rd year revealed that (i) large strongyles (Strongylus vulgaris and S edentatus) were efficaciously removed, (ii) 5 species of small strongyles (Cyathostomum catinatus, Cyathostomum coronatum, Cylicocyclus nassatus, Cylicostephanus longibursatus, and Cylicostephanus minutus) exhibited some degree of resistance, and (iii) 11 species of small strongyles from 6 genera, including the 3 already named, were highly susceptible. Cylicostephanus minutus, in this population, exhibited benzimidazole resistance for the first time, whereas Cylicostephanus goldi, previously recognized as resistant in other populations (B and C) in Kentucky, was susceptible to cbz. A 2-fold increase in the drugdose rate did not increase efficacy against the cbz-resistant species of small strongyles, but a 4-fold increase efficaciously removed 93% of the resistant small strongyles.

Foaling rates in the brood band ranged between 38% and 61% for the 5 seasons. Three deformed foals occurred—1 in 1976 and 2 in 1977—among the total of 83 births. Present data did not evidence a probable week of early gestation for possible insult of the fetus by cbz treatment.
Impaired protective immunity to sarcocystosis in pregnant dairy goats
Authors: Dubey J. P.
Published: February 2025

Six 1-month-pregnant does (No. 1 to 6) were each vaccinated orally with 1,000 sporocysts of Sarcocystis capracanis and six 1-month-pregnant does (No. 7 to 12) were not vaccinated. At 82 days after vaccination, 4 vaccinated does (No. 1 to 4) and 2 nonvaccinated does (No. 7 and 8) were each challenge exposed with 1,000,000 sporocysts; 2 nonvaccinated does (No. 9 and 10) were challenge exposed with 500,000 sporocysts; and the remaining 2 nonvaccinated does (No. 11, 12) were challenge exposed with 250,000 sporocysts. Of the 4 challenge-exposed vaccinated does, doe 1 aborted on 16 days after challenge exposure (dace) and died from uterine rupture. Doe 2 died of acute sarcocystosis on 23 dace; 2 resorbed fetuses were found in the uterus. Doe 3 was killed in good health on 28 dace: 2 healthy fetuses were found in the uterus. Doe 4 gave birth to 2 premature kids on 22 dace; both doe and kids died on the same day.

Of the 2 vaccinated does which were not challenge exposed, doe 5 died 64 days after vaccination due to pregnancy toxemia; 2 resorbed fetuses were in the uterus. Doe 6 delivered a full term kid which died on the day of birth.

Of the 6 challenge-exposed non-vaccinated does, doe 7 aborted on 15 dace and the other 5 does died of acute sarcocystosis between 21 and 27 dace.

Sarcocystis was not found in products of conception of any doe.

It was concluded that (i) a subclinical dose of S capracanis given in early pregnancy can cause fetal death without causing clinical disease in the doe, (ii) abortion can occur prior to the development of 2nd-generation meronts, and (iii) Sarcocystis-induced immunity is impaired during pregnancy.
Effects of carbon monoxide exposure on pregnant sows and their fetuses
Authors: Dominick M. A. , Carson T. L.
Published: February 2025

Miniature and domestic sows at 108 to 110 days of the gestation were exposed to atmospheric carbon monoxide (CO) concentrations of 150 to 400 ppm for 48 to 96 hours. Overall stillbirth rates were 6.7%, 34.8%, 42.3%, and 80.0% in the sows exposed to CO in concentrations of 200, 250, 300, and 350 ppm, respectively. A significant linear relationship was determined between these concentrations of CO and the resultant maternal carboxyhemoglobin (COHb) concentration (P < 0.01). The frequency of stillbirth increased significantly when maternal COHb concentration exceeded 23% saturation of hemoglobin. The COHb concentrations in new-delivered pigs (cesarean section) were greater than maternal COHb concentrations by 3 to 22%.

Common gross lesions in stillborn pigs were cherry red discoloration of the subcutaneous tissues, muscle, and viscera and accumulation of a large volume of serosanguineous pleural effusion. Hypoxic ischemic leukoencephalopathy was found in new-delivered pigs from 3 of 14 litters. Lesions included focal leukoencephalomalacia, glial-vascular proliferation, multifocal hemorrhage, and vacuolation of the neuropile. Many extramedullary hematopoietic centers were present in liver sections.
Pathologic features of leptospirosis in hamsters caused by Leptospira interrogans serovars hardjo and szwajizak
Authors: Badiola J. , Thiermann A. B. , Cheville N. F.
Published: February 2025

Two groups of 16 weanling hamsters were given leptospires of the Hebdomadis serogroup (Leptospira interrogans serovars hardjo or szwajizak) intraperitoneally. They were killed on postinoculation days (pid) 0, 2, 4, 6, 8, 10, 12, and 14. Kidneys, lungs, livers, and brains were examined by light and electron microscopy. Renal interstitial hyperemia and edema were present during the sampling period. Interstitial fibrosis and massive hemorrhages occurred in szwajizak-infected hamsters. In the liver, cellular infiltrates in portal spaces occurred in szwajizak-infected hamsters sooner than in hardjo-infected animals. Acute hepatitis was seen only in szwajizak-infected hamsters. Pulmonary hyperemia and hemorrhages were present in all infected animals. Splenic lymphoid hyperplasia and meningeal hyperemia were also common findings.

In general, lesions were more severe and developed earlier in szwajizak-infected than in hardjo-infected animals. Leptospires were cultured from blood and kidney of most szwajizak-infected hamsters. Cultures of blood from hardjo-intected hamsters were positive until pid 8, the time at which marked agglutinating antibodies were detected. Kidney cultures from hamsters killed on pid 4 onward were positive.
Immunosuppressive effects of cyclophosphamide, vincristine, and l-asparaginase in dogs
Authors: Medleau Linda , Dawe Donald L. , Calvert Clay A.
Published: February 2025

The acute effects of cyclophosphamide, vincristine, and l-asparaginase on the humoral and cell-mediated immune responses in dogs were evaluated. Dogs were given a single dose of cyclophosphamide (10 mg/kg of body weight, iv), a single dose of vincristine (0.025 mg/kg, iv), a single dose of l-asparaginase (400 U/kg, iv), or a combination of these drugs at the aforementioned dosages administered simultaneously.

The total number of leukocytes decreased significantly (P = < 0.05) on posttreatment day 3 in the cyclophosphamide-treated dogs. Antibody responses and lymphocyte blastogenesis were not affected. A transient lymphopenia on posttreatment day 1 was the only response seen in the vincristine-treated dogs. Antibody responses to sheep rbc and lymphocyte blastogenesis were suppressed in the l-asparaginase-treated dogs. l-Asparaginase did not affect the antibody response to bovine serum albumin or peripheral blood leukocyte counts. Suppressed antibody responses to sheep rbc and to bovine serum albumin, depressed lymphocyte blastogenesis, and decreased numbers of all peripheral blood leukocytes were seen in dogs given the 3 drugs in combination.
Effects of prolonged distention of retention catheters on the urethra of dogs and cats
Authors: Johnston Gary R. , Stevens Jerry B. , Jessen Carl R. , Osborne Carl A.
Published: February 2025

The effects of inflation of a balloon-tipped catheter in the distal part of the urethra of clinically healthy male and female dogs and cats were evaluated. Tissues were evaluated at 1 and 14 days after balloon inflation. Macroscopic and microscopic lesions were limited to the distal part of the urethra occupied by the inflated balloon in animals which were euthanatized 1 day after balloon inflation. The lesions were characterized by submucosal urethral hemorrhage. This investigation indicates that balloon inflation for 15 minutes duration in the distal part of the urethra of dogs and cats results in a mild reversible inflammatory reaction.
Identification and isolation of somatic pili from pathogenic Escherichia coli of turkeys
Authors: Nagaraja K. V. , Emery D. A. , Newman J. A. , Pomeroy B. S.
Published: February 2025

Transmission electron microscopy was performed to identify the presence of somatic pili on Escherichia coli pathogenic to turkeys. Three common pathogenic serotypes of E coli (Ola, O2a, and 078) were used.

They were cultured in tryptic soy, veal infusion, and Minca medium broth and were incubated at 37 C with and without CO2 (5%). The cultures were examined for the expression of pili after 24, 48, and 72 hours of incubation. Pili were on all strains of the 3 serotypes examined. These pili were also isolated and purified.
Isolation of the turkey heterophil and measurement of its migratory functions under agarose
Authors: Thies E. S. , Nelson R. D. , Maheswaran S. K.
Published: February 2025

A procedure for isolation of the turkey heterophil was developed. The procedure involves preliminary lysis of erythrocytes, using ammonium chloride and centrifugation of the leukocytes over a discontinuous gradient of 18% and 24% Ficoll. A minimum of 30% of the heterophils was consistently recovered from whole blood by application of this procedure. Spontaneous and chemotactic migratory responses of the isolated heterophils were assessed, using the migration under agarose technique. Supplementation of the agarose with 10% heat-inactivated turkey plasma and extension of the incubation period to 3 hours at 41 C in a 5% CO2-humidified atmosphere were required for optimal chemotaxis in response to zymosan-activated chicken serum. The heterophils did not respond chemotactically to the oligopeptide attractant, N-formyl-methionyl-leucyl-phenylalanine, and did not specifically bind a radiolabeled form of this ligand.
Experimental latent and recrudescent bovine herpesvirus-1 infections in calves
Authors: Homan E. J. , Easterday B. C.
Published: February 2025

Latent bovine herpesvirus-1 (bhv-1) infection was established in 6 calves and was demonstrated by reinduction of virus shedding after administration of corticosteroids. Latently infected calves failed to transmit bhv-1 during 4 weeks’ contact with sentinel calves.

Infected calves were killed and necropsied during latency or induced recrudescence. The bhv-1 DNA was demonstrated intranuclearly in trigeminal ganglion neurons by in situ hybridization. The bhv-1 antigen was demonstrated by immunofluorescence in trigeminal ganglion neurons during recrudescence. By electron microscopy, changes in the appearance of the Nissl bodies and a high frequency of nuclear bodies were observed in trigeminal ganglion neurons.
Development of a nonneuronal cell line derived from porcine spinal ganglia
Authors: Pirtle E. C. , Brown T. T. , Gallagher J. E.
Published: February 2025

A cell line from porcine spinal ganglion (pspg) tissue was initiated and characterized. The pspg cell line contained epithelioid, fibroblast-like, and stellate-like cells. There were numerous intercellular communications between cells in the culture. Neuronal cells were not present in the pspg cell line. The pspg cell line was aneuploid at the 5th and 45th subculture levels. Seven porcine viruses replicated in cultures of pspg cells, and 2 pseudorabies virus strains infected the cells after being diluted 10-7.
Occurrence of Staphylococcus aureus on the clinically normal canine hair coat
Authors: White Stephen D. , Ihrke Peter J. , Stannard Anthony A. , Sousa Candace , Reinke Susan , Rosser Edmund J. , Jang Spencer
Published: February 2025

Coagulase-positive Staphylococcus aureus, a bacterium normally considered to be pathogenic on the skin, was isolated from the hair of 18 of 20 dogs that had no clinical signs of dermatologic disease. Other organisms were not isolated, using aerobic culture.
Neural catecholamine deficiencies in the porcine stress syndrome
Authors: Hallberg J. W. , Draper D. D. , Topel D. G. , Altrogge D. M.
Published: February 2025

A study was conducted to compare catecholamine concentrations in nervous tissues of stress-susceptible (ss) and stress-resistant (sr) pigs that were physically stressed. Ten pigs were included in each group on the basis of results of halothane screening tests, blood typing analysis, and examination for serum creatine kinase (ck) activities at 6 weeks of age. The nervous tissues analyzed included the substantia nigra (sn) and the caudate nucleus (cn) which were taken from pigs as soon as possible after death and frozen in liquid nitrogen. Tissues were radioenzymatically assayed for dopamine, norepinephrine, and epinephrine concentrations.

The ss pigs exhibited significantly greater (P < 0.001) ck activity concentrations than did those sr pigs before and after physical stress. Concentrations of dopamine, norepinephrine, and epinephrine in the cn of ss pigs were significantly lower (P < 0.05) than those in the cn of sr pigs. Similarly, the sn of ss pigs had lower dopamine, norepinephrine, and epinephrine concentrations than did the sn of sr pigs. The catecholamine deficiencies observed in the porcine stress syndrome seem to have similarities with certain human extrapyramidal diseases.
Potentiation of turbinate atrophy in pigs by long-term nasal colonization with Pasteurella multocida
Authors: Gois M. , Barnes H. John , Ross R. F.
Published: February 2025

In preliminary studies, 6 strains of Pasteurella multocida were inoculated iv into 6- to 8-week-old pigs. Strains S3 and KL2 produced severe polyarthritis and polyserositis, and strain S4 produced polyarthritis when inoculum consisted of 1011 colony-forming units. Smaller numbers of strains S3, S4, and KL2 or 1011 colony-forming units of 3 other strains resulted in mild or no disease.

Seventy 5- to 6-week-old conventional pigs were inoculated intranasally (in) over a 5- to 6-day period with 3 doses of strains S3 or KL2 or were exposed to experimentally infected pigs by contact. All pigs were free of nasal infection with P multocida, Bordetella bronchiseptica, Mycoplasma hyorhinis, and Acholeplasma spp. All pigs, except 1 group of 6, were naturally infected with Haemophilus parasuis before use. All pigs exposed to P multocida by in inoculation or contact developed nasal colonization. At necropsy 3 to 9 weeks after inoculation, 39 of 48 (81.3%) H parasuis-infected pigs, which had long-term colonization of the nasal cavities with P multocida (> 21 days), had very mild, mild, or moderate atrophy of nasal turbinates (av lesion score = 1.8). Of 22 H parasuis-positive pigs that had been short-term carriers of the organism (< 14 days), only 4 (18.2%) had very mild or mild lesions (av = 0.3). Eleven of 22 controls not infected with P multocida, but naturally infected with H parasuis, also had very mild or mild lesions (av = 0.7). Six control pigs free of H parasuis and P multocida had no lesions.

Intranasal inoculation of P multocida strain S-3 into colostrum-deprived cesarean-derived (cdcd) swine resulted in signs of acute rhinitis which lasted approximately 1 week. Six of 9 cdcd pigs became long-term carriers of the organism, but at necropsy (21, 36, or 42 days after inoculation), they had no turbinate lesions. Two of 3 cdcd pigs that were short-term carriers of P multocida had very mild lesions. None of 5 control cdcd pigs had lesions.

Seemingly, P multocida has a greater role in potentiating atrophic rhinitis than in initiating the disease, H parasuis may cause mild turbinate atrophy, and P multocida readily colonizes the nasal cavity of H parasuis-infected or -free pigs after in inoculation or contact with infected penmates.
Enhanced antibody-dependent bactericidal activity of neutrophils from calves treated with a lipid amine immunopotentiator
Authors: Woodard L. F. , Jasman R. L. , Farrington D. O. , Jensen K. E.
Published: February 2025

Calves were treated im with N, N-dioctadecyl-N′, N′-bis (2-hydroxy ethyl) propanediamine (CP-20,961) in liposomes (1.0 or 2.5 mg/kg of body weight). Peripheral blood neutrophils had increased bactericidal activity against Escherichia coli at posttreatment day (ptd) 1, 2, and 3 at the lower dosage level (P < 0.0001). This effect required the presence of antibody, but not complement. Enhanced bactericidal activity was due to neutrophils, rather than serum factors, because serum collected before treatment was as effective in the assay system as was serum collected after treatment. The number of calves with increased neutrophil bactericidal activity decreased over the test period. Whereas neutrophils from all calves (n = 8) given 1 mg/kg of body weight were more bactericidal at ptd 1, only 4 had similar responses at ptd 2 and only 3 had increased activity at ptd 3. Correlation was not noticed between agglutinating antibody titers and level of growth inhibition; antibody titers remained constant.

When Pasteurella multocida was incubated with neutrophils taken at the same test periods, growth inhibition was seen at ptd 3, but no inhibition was seen at ptd 1 or 2. Again, granulocytic inhibitory effects were dependent on the presence of antibody, but independent of complement activity and antibody titer. In contrast to the situation seen with E coli in which all calves responded to the drug, only 2 of 8 calves clearly had increased neutrophil activity against P multocida. In calves treated with 2.5 mg of CP-20,961 in liposomes/kg, leukocytes, rather than purified neutrophils, were tested. Although further enhancement of growth-inhibition was not seen with E coli, tests with P multocida showed enhanced neutrophil activity at ptd 1 and 3.

Administration of CP-20,961 in liposomes was clinically well tolerated at 1.0 and 2.5 mg/kg, and adverse local irritations were not seen at the site of injection. Moderate transient increases in rectal temperatures were measured at ptd 1 and 2. A neutrophilic leukocytosis was seen in treated calves at ptd 1 and 2, and neutrophil counts remained high through ptd 3.
Ferrokinetic and erythrocyte survival studies in healthy and anemic cats
Authors: Madewell B. R. , Holmes P. H. , Onions D. E.
Published: February 2025

Erythrocyte survival and ferrokinetic studies were adapted to the cat. For 5 clinically healthy 4- to 9-month-old cats, mean 51Cr-labeled erythrocyte survival was 144 hours, and mean plasma 59Fe-labeled transferrin disappearance halftime was 51 minutes. Erythrocyte use of radioiron was rapid and efficient, with 50% to 80% of labeled iron incorporated into the erythron by 100 hours after injection into the cat.

Six cats with feline leukemia virus infection were studied. For 2 cats with erythroid aplasia associated with C subgroup of feline leukemia virus, erythrocyte survival times were similar to those determined for the healthy cats, but plasma radioiron disappearance half time and erythrocyte use of radioiron were markedly diminished.
Effect of inspired air heat and humidification on anesthetic-induced hypothermia in dogs
Authors: Raffe Marc R. , Martin Frank B.
Published: February 2025

Dogs were evaluated for efficacy of inspired air heating and humidification in maintenance of body temperature during general anesthesia. Three separate trials were conducted: (i) a control group without thermal support (n = 5), (ii) a group supported only by a heated humidifier device placed in the inspiratory limb of an anesthesia circle delivery system (n = 7), and (iii) a group supported by combination of inspired air humidification and recirculating water blanket (n = 7). A significant difference (P > 0.4) was not noticed in temperature changes between control and humidifier-supported groups. A significant advantage (P < 0.05) was noticed between the combined support and the humidifier or control groups. Seemingly, during general anesthesia, use of combined thermal support is significantly better than airway humidification for maintenance of normothermia in the dog.
Comparative ultrastructural study of normal, adenomatous, carcinomatous, and hyperplastic cells of canine hepatoid circumanal gland
Authors: Isitor G. N.
Published: February 2025

Transmission electron and light microscopy studies were carried out on morphologic characteristics of cellular organelles of normal and different neoplastic cells of hepatoid circumanal glands of 16 dogs. The ultrastructural features of the reserve and transitional cells in the adenomas and carcinomas are highly suggestive of different carcinogenic stimuli for each form of hepatoid circumanal gland neoplasm. The reserve cells, in response to the carcinogenic stimuli, appear to be growing at the expense of the degenerating glandular cells.
Dose-response study of ivermectin against Dirofilaria immitis microfilariae in dogs with naturally acquired infections
Authors: Blair Lyndia Slayton , Malatesta Paul F. , Ewanciw Debra Vislocky
Published: February 2025

In dogs, ivermectin given as a single oral dose 6 weeks after they were treated with thiacetarsamide was highly efficacious against the microfilariae of Dirofilaria immitis. A dose of 0.2 mg of ivermectin/kg of body weight or 1 dose of 0.05 mg/kg appeared to completely clear microfilariae from the blood. A dose of 0.0125 mg/kg cleared microfilariae from 2 of 3 dogs, and even a dose of 0.00313 mg/kg resulted in substantial reduction of the microfilaremia.
Evaluation of the safety of flubendazole premix in swine
Authors: Campbell Barbara , Newcomb Kathleen , Guerrero Jorge
Published: February 2025

Forty-eight pigs were used to evaluate the safety of flubendazole, given as a 6% rice-hull premix. In 1 experiment, flubendazole was administered orally to 16 pigs daily for 5 days at dosages of 10 or 20 times the recommended rate. In a 2nd experiment, flubendazole was administered in the feed to 18 pigs daily for 15,16 or 17 consecutive days at dosages of 1, 3 and 5 times the recommended rate. The remaining 14 pigs received a placebo premix and served as controls. Clinical observations were made each day, and body weights and clinical laboratory values were monitored before, during and after the treatment period. In the 2nd experiment, all pigs were necropsied 1 day after the last day of treatment.

Clinical signs during the experiments consisted of soft/fluid feces, observed in pigs from all groups, and occasional vomiting from 3 pigs in the group given the 3X-exaggerated dose. Statistical differences in the frequency of loose feces and vomiting were not detected between the placebo group and flubendazole-treated groups. There were no other abnormal signs noted throughout either experiment. Results of serum chemistry analysis, hematologic examination, and histopathologic evaluation revealed no evidence of drug-related toxicity.
Pharmacokinetics and plasma protein binding (in vitro) of oxytetracycline in buffalo (Bubalus bubalis)
Authors: Varma K. J. , Paul B. S.
Published: February 2025

The pharmacokinetics of oxytetracycline given in a single dose (22 mg/kg) either iv or im was studied in 4 female buffalo calves. The half-life (t1/2) after iv administration varied between 169.02 and 216.56 minutes and that after im administration, between 630 and 990 minutes. The drug was distributed well in the body after im administration (Vdarea 1.18 to 2.15 L/kg). The total body clearances varied between 1.02 and 1.45 and between 1.17 and 1.49 ml/kg/min after the iv and the im dosings, respectively. It has been proposed that oxytetracycline is excreted mainly by glomerular filtration in the buffalo species, but tubular reabsorption also may have a small part. About 42% of the drug was bound to plasma proteins at concentrations of 2 to 20 p.g of oxytetracycline/ml. The drug dosage schedules to maintain serum levels of 0.5, 1, 2, and 5 μg/ml also are determined.
Experimental Streptococcus equi infection in the horse: Correlation with in vivo and in vitro immune responses
Authors: Nara Peter L. , Krakowka Steven , Powers Thomas E. , Garg Ramish C.
Published: February 2025

Fourteen young outbred horses, divided into 2 groups on the basis of 18-hour or 24-hour skin-test reactions to Streptococcus equi, were inoculated nasopharyngeally with virulent S equi. Animals (n = 6, group I) with evidence of previous exposure to S equi (positive dermal response and existing serum antibodies), with one exception, developed minimal or no signs of disease after inoculation. In contrast, S equi skin-test negative and seronegative horses (n = 8, group II) developed predictable and severe clinical signs of infection after their inoculation, including shedding of the organism from nasal discharges and ruptured mandibular lymph nodes. Results of the present study indicate that resistance to virulent S equi infection is correlated with existing humoral and cellular immune responses to streptococcal antigens. In susceptible horses, recovery from infection was accompanied by the appearance of humoral antibodies and the acquisition of a positive skin-test response to S equi antigens.
Influence of parasitemia level at feeding on development of Anaplasma marginale Theiler in Dermacentor andersoni Stiles
Authors: Kocan Katherine M. , Holbert Donald , Ewing S. A. , Hair Jakie A. , Barron Selwyn J.
Published: February 2025

Four splenectomized dairy calves were inoculated with a Virginia isolate of Anaplasma marginale Theiler and served as an infective source (donor) for laboratory-reared Dermacentor andersoni Stiles nymphs.

Two donor calves developed higher parasitemias during tick feeding than did the 2 other donor calves. One month after molting, adult ticks were incubated at 37 C for 2.5 days to stimulate development of colonies of A marginale, and homogenates of gut were made from ticks fed on each donor calf.

Eight susceptible, splenectomized dairy calves (2 per donor calf) were each inoculated iv with the gut homogenates collected from 50 adult ticks and were monitored for patent A marginale infection. Gut tissues from these same groups of ticks were processed for histologic studies. Homogenates from ticks infected on donor calves with lower parasitemias caused infections with longer prepatent periods (av, 43.25 days) than did similar homogenates made from ticks infected by feeding on donor calves with higher parasitemias (av, 31.0 days). Also, sections of gut tissues from ticks infected at the lower parasitemias contained fewer (av, 0.65) colonies/0.001 mm2 of tissue examined than did those from ticks infected at higher parasitemias (av, 6.31).
Serum chemical values in hypothermic and rewarmed young calves
Authors: Olson D. P. , South P. J. , Hendrix K.
Published: February 2025

Serum chemical values were determined in cold-stressed Holstein bull calves ranging from 1 to 7 days of age. The animals were anesthetized and cold-stressed until their core body temperature (colonic) was lowered 10 C. Animals were then rewarmed in warm water, with heat pads or heat lamps, or were allowed to recover naturally (unassisted) at room temperature. Blood samples were collected at selected intervals during cooling and recovery. Increases (P < 0.05) were observed in the concentrations of glucose, calcium, phosphorus, iron, alkaline phosphatase, aspartate aminotransferase, lactate dehydrogenase, total protein, albumin, total globulin, serum urea nitrogen, uric acid, total bilirubin, indirect bilirubin, and cholesterol in the cold-stressed calves during cooling. Concentrations of chloride and insulin decreased (P < 0.05) during the same period. Changes observed in many of the serum chemical values during rewarming were generally the reverse of the respective changes that occurred during cooling, although insulin values became exceedingly high in some cases midway or near the end of recovery. Serum enzyme values also remained high during most of recovery. Data did not indicate a clear advantage of one method of rewarming over the other methods used in terms of return of the serum chemical values to normal.
Effects of vaccination on lesion development in pseudorabies virus-challenged swine
Authors: Alva-Valdes R. , Glock R. D. , Kluge J. P. , Keune C. M.
Published: February 2025

The effects of vaccination against pseudorabies virus (prv) infection were studied in 93 barrows. Commercial attenuated and inactivated prv vaccines were used. The protection provided was evaluated by the comparison of clinical signs, gross lesions, and microscopic lesions among vaccinated and nonvaccinated pigs after challenge exposure with a sublethal dose of prv. Histopathologic changes are described for the cns and other tissues.

Neither the modified live- nor the inactivated-prv vaccines prevented clinical signs or microscopic lesions in pigs after challenge exposure. However, both vaccines diminished the severity of clinical signs and microscopic lesions in the animals for a period of up to 8 months after they were vaccinated. Protection against clinical signs and microscopic lesions was absent in the pigs 10 months after the vaccination.
Electrophysiologic and behavioral studies of the cutaneous nerves of the concave surface of the pinna and the external ear canal of the dog
Authors: Whalen L. R. , Kitchell R. L.
Published: February 2025

The investigation used 2 methods to study the cutaneous innervation of the concave surface of the pinna of the dog: electrophysiologic and behavioral. The cutaneous innervation of the external ear canal was studied, using electrophysiologic methods. On one side of each dog, the area of remaining sensitivity for the 3 internal auricular branches of the facial nerve (InAuB-fn) was determined by sectioning the rostral auricular nerve, dorsal cutaneous branch of the second cervical nerve, and great auricular nerve and then examining the dogs 1 week later. The cutaneous area (ca) of each branch of the InAuB-fn was then determined electrophysiologically. These individual ca were combined to obtain a composite cutaneous area (Comp-ca) for the InAuB-fn. By comparing the Comp-ca with the area of remaining sensitivity, it was determined that they defined essentially the same regions. On the opposite side of each dog, the InAuB-fn were surgically transected and the resultant areas of anesthesia were determined approximately 1 week after the sectioning was done. The cutaneous region thus delineated represented a zone solely innervated by these branches of the fn. Next, the ca for the rostral auricular nerve, dorsal cutaneous branch of the second cervical nerve, and great auricular nerve to the pinna’s concave surface were determined electrophysiologically in each dog. The cutaneous zone enclosed by the margins of the ca of these 3 nerves represented the composite autonomous zone for the InAuB-fn. The behaviorally determined area of anesthesia was essentially the same area as the composite autonomous zone. The skin lining the vertical portion of the external ear canal was supplied by all 3 branches of the InAuB-fn. The skin lining the horizontal portion of the external ear canal was supplied by the lateral branch of the InAuB-fn and the external acoustic meatus branch of the auriculotemporal nerve.
Evaluation of evoked-muscle potentials from stimulation of ulnar nerves of the dog
Authors: Nafe L. A. , Lee A. F.
Published: February 2025

Evoked muscle potentials were evaluated in 19 anesthetized dogs after stimulation of the ulnar nerve. Subsequently, unilateral dorsal rhizotomy was performed on 6 dogs, and ulnar nerve stimulation was repeated. The evoked muscle potentials were begun at 1 V and increased. Threshold, optimum, and maximum stimuli for the M wave, and the reflex-evoked response (H reflex) were recorded. Threshold voltages for the M wave and the H reflex were 4.4 V and 4.0 V, respectively. The latencies for these stimuli also were recorded for the H reflex from proximal and distal sites. The optimal latency for the proximal and the distal sites were 15.4 ± 2.5 ms and 18.3 ± 2.6 ms, respectively (mean ± sd). The motor nerve conduction velocity was 68 ± 11 m/s. In addition, a mixed orthodromic sensory-antidromic motor conduction velocity was 75.2 ± 13.3 m/s. Ratios between thoracic limb length and H reflex latency were 27.5 ± 3.9 from the proximal site and 23 ± 2.7 from the distal site. A waveform with a latency less than that of the H reflex, but greater than that of the M wave was observed inconsistently.

An additional group of low amplitude waves was observed with a latency greater than the H reflex latency. The H reflex latency/limb length ratio may be clinically useful in evaluation of proximal neuropathies in the dog.
Identification of the carrier of the Bedlington Terrier copper disease
Authors: Owen Charles A. , McCall John T.
Published: February 2025

Copper (Cu) was assayed in serial liver biopsy specimens of 5 pups resulting from a mating of 2 Bedlington Terrier carriers of inherited Cu toxicosis; the latter were sibling offspring of an affected Bedlington Terrier and a normal dog. Between 5 and 7 months of age, 1 of the pups had acceptable hepatic Cu values in each of 6 specimens. The hepatic concentration of Cu in another pup increased steadily from 801 to 3,874 μg/g dry weight.

The other 3 pups may be heterozygotes (carriers); in 1—the hepatic Cu peaked at 1,043 μg/g at 9 months, in the 2nd—at 636 μg/g at 7 months, and in the 3rd—at 492 μg/g at 7 months. Acceptable concentrations were present in these 3 dogs at 9 to 14 months. Results in the present study indicate that heterozygotes may have 1 normal and 1 abnormal controller gene for regulating their hepatic Cu metabolism, thus accounting for the increased hepatic Cu concentration only in the early months of life.

The affected Bedlington Terrier with 2 abnormal genes was unable to suppress the progressive hepatic accumulation of Cu. Paired liver biopsy specimens obtained at 5 to 7 months and at 14 or 15 months of age might distinguish the heterozygote from the normal and the affected Bedlington Terrier pups.
Ultrastructure of parathyroid glands of growing chickens with vitamin D deficiency rickets
Authors: Okada K. , Fujimoto Y. , Itakura C. , Goto M.
Published: February 2025

Ultrastructural studies were conducted on the parathyroid glands (ptg) of 2- to 7-week-old nontreated control growing broiler chickens (group A, 6 chickens); the same aged chickens with experimentally induced vitamin D deficiency rickets (18 morbid chickens each from groups B, C, and D); and in 4- to 9-week-old chickens naturally affected with rickets (group E, 8 chickens). Four types of principal cells were classified in the ptg of clinically normal birds and in ptg of birds with secondary hyperparathyroidism as follows: Type I cell (small cell in the resting phase); type II cell (medium-sized cell with well-developed rough-surfaced endoplasmic reticulum in the synthesizing phase); type III cell (large cell with well-developed Golgi apparatus and cytoplasmic organelles in the packaging and secretory phase); and type IV cell (mediumsized cell with poor cytoplasmic organelles in the involuting phase).

Many coated vesicles were observed in type II and type III cells. In young control chickens, principal cells of the ptg were considered in the resting phase; in older control chickens, there were increased numbers of cells in the synthesizing phase. In the vitamin D deficiency groups, principal cells were in the synthesizing and packaging and secretory phases. In birds with naturally occurring rickets, principal cells were in packaging and secretory phases, with a small number of cells in the involuting phase. The ultrastructural changes of the ptg from the initial to final phases in growing chickens with secondary hyperparathyroidism were demonstrated.
Pasteurella haemolytica cytotoxin: Production by recognized serotypes and neutralization by type-specific rabbit antisera
Authors: Shewen Patricia E. , Wilkie Bruce N.
Published: February 2025

A sterile culture supernatant from each of the 12 recognized serotypes of Pasteurella haemolytica was toxic to bovine alveolar macrophages when assayed by 51Cr release. Types appeared to differ in their ability to liberate cytotoxin, although this may have reflected strain variation rather than serotype-related differences. Toxicity was partially neutralized by type-specific rabbit antisera, with neutralization of the homologous toxin being more effective than that of the heterologous serotype.
Comparison of sulfobromophthalein and indocyanine green clearances in the dog
Authors: Center S. A. , Bunch S. E. , Baldwin B. H. , Hornbuckle W. E. , Tennant B. C.
Published: February 2025

Sulfobromophthalein (bsp) and indocyanine green (icg) were given in single-dose iv injections to dogs and plasma disappearances were measured. The bsp was given at a dose of 5 mg/kg of body weight, and icg was given at doses of 1.0 and 1.5 mg/kg. The half-life for bsp was 4.2 ± 0.8 minutes, and for icg at the 1.0 mg/kg dose, 9.0 ± 2.0 minutes, and at the 1.5 mg/kg dose, 8.4 ± 1.9 minutes. The disappearance rate (percentage per minute) for bsp was 17.0 ± 3.2, and for icg at the small dose level, 8.1 ± 1.7, and at the large dose level, 8.7 ± 2.2. The clearances (ml/min/kg) for bsp were 15.4 ± 6.2 and for icg at the small dose level, 3.7 ± 0.7, and at the large dose level, 3.9 ± 0.7. The 30-minute percentage retentions for bsp were 1.9 ± 1.1 and for icg at the small dose level, 14.7 ± 5.0, and for icg at the large dose level, 11.4 ± 3.0. All of the differences between bsp and icg means for these values measured were statistically significant (P < 0.01). There were no significant differences between sexes or between the icg doses for any of the values (P > 0.05).
Survival of carrier erythrocytes in splenectomized calves
Authors: DeLoach John R. , Wagner G. G.
Published: February 2025

Carrier erythrocyte survival was investigated in intact and splenectomized calves. Survival curves for both were biphasic, with a characteristic early loss of 10% to 15% of the carrier cells in intact calves followed by a half-life of 22 to 24 days. In splenectomized calves, 50% to 75% of the carrier cells disappeared from circulation in the first 24 hours. The 2nd phase of survival showed a 44-day half-life for the remaining carrier cells. Erythrocytes from splenectomized calves appeared to be permeable to [14C]sucrose and were more susceptible to irreversible hemolysis from the dialysis encapsulation procedure. Blood volume determination showed a 22% decrease after splenectomy.
Effect of gastrointestinal parasite infection in calves on the preparation of carrier erythrocyte ghosts and on erythrocyte survival
Authors: DeLoach John R. , Fincher G. Truman
Published: February 2025

Calves were inoculated with helminths to induce a severe anemia. Increased erythrocyte mean cell volume caused by acute parasitism made erythrocytes more resistant to osmotic stress as reflected in the percentage of encapsulation parameters. Preparation of resealed carrier erythrocytes before and during parasitosis was studied. Low percentage of encapsulation of the marker [14C]sucrose could be corrected by extended dialysis time. Typically, 40% encapsulation was found in erythrocytes from healthy calves, whereas only 20% encapsulation was found for erythrocytes from helminth-infected animals.
Effects of dietary aluminum on magnesium status of cows
Authors: Kappel L. C. , Youngberg Helen , Ingraham R. H. , Hembry F. G. , Robinson D. L. , Cherney J. H.
Published: February 2025

Observations made on 32 cows at 5 locations within 200 km of Baton Rouge, La, indicated that cows with clinical grass tetany had significantly higher concentrations of aluminum (Al) in the ruminal dry matter than did hypomagnesemic cows without clinical signs or control cows (3,382 vs 1,442 vs 1,666 μg/g). Cows with grass tetany had significantly lower concentrations of plasma calcium than did asymptomatic, hypomagnesemic cows (5.57 vs 8.51 mg/dl).

Blood and rumen samples were obtained 7 times during a 51-day period from a herd of 20 lactating beef cows. Significant changes occurred over time in ruminal dry matter Al and plasma magnesium (Mg). The minimal-maximal limits of mean ruminal Al and plasma Mg concentrations were 708 and 4,374 μg/g and 1.97 to 2.33 mg/dl, respectively. Increases in ruminal Al were not associated with a lowering of plasma Mg. Correlations between Al and Mg at each sampling day ranged from 0.24 to −0.30.

Six nonlactating Holstein or Jersey cows were used in each of 5 experiments to determine the effect of ingested aluminum sulfate and sodium (Na) sulfate on plasma Mg. Treatment provided Al in an amount equivalent to 4,000 μg/g of the diet and sodium sulfate provided sulfate in an amount equivalent to that provided by the Al treatment. When administered once daily for 4 days via rumen cannula to cows given a Bermuda grass hay diet, both compounds reduced plasma Mg by 34%. When mixed in the feed or administered via stomach tube, these compounds had no effect on plasma Mg of cows given a mixed ration containing a higher amount of available Mg. Both Al and Na sulfate caused a significant reduction in feed intake. When feeding levels were used as treatments, there was no significant difference in plasma Mg between cows given 5.5 or 2.25 kg of hay/day.
Effects of large doses of phenylbutazone administration to horses
Authors: MacKay Robert J. , French T. W. , Nguyen Hai T. , Mayhew I. G.
Published: February 2025

The effects of large doses of phenylbutazone were evaluated in clinically normal horses. The drug was given to 4 groups of 2 horses each at the rate of 30 mg/kg of body weight, orally, or 30, 15, or 8 mg/kg iv daily for up to 2 weeks. All horses became anorectic and depressed after 2 to 4 phenylbutazone treatments, and the horses given 15 or 30 mg/kg died on or between days 4 and 7 of treatment. A decrease in total blood neutrophil count occurred in all horses, and was associated with toxic left shift in horses given the 2 larger dosage schedules. The horses also had progressive increases in serum urea nitrogen, creatinine, and phosphorus concentrations, accompanied by decreasing serum calcium concentrations. There was a progressive decrease in total serum protein in all 8 horses. Gastrointestinal ulcerations, renal papillary necrosis, and vascular thromboses were the predominant postmortem findings.
Cumulative dose responses to gallamine, pancuronium, and neostigmine in halothane-anesthetized horses; Neuromuscular and cardiovascular effects
Authors: Klein Lin , Hopkins Judy , Beck Ernest , Burton Bridget
Published: February 2025

Relative neuromuscular potency, recovery rate, and pharmacologic reversibility of blockade with gallamine and pancuronium were studied in halothane-anesthetized horses. A cumulative dose-response method was used, and individual curves were plotted on a log-probit scale. The rate of spontaneous recovery to 50% control twitch tension was recorded. The degree of pharmacologic reversibility and dose requirements for neostigmine were compared, and cardiovascular responses to the blocking agents and antagonist were reported.
Demonstration of Anaplasma marginale in hemolymph of Dermacentor andersoni by animal inoculation and by fluorescent-antibody technique
Authors: Kocan Katherine M. , Oberst Richard D. , Ewing S. A. , Hair Jakie A. , Barron Selwyn J.
Published: February 2025

Hemolymph was collected from adult Dermacentor andersoni Stiles that had been infected with Anaplasma marginale Theiler as nymphs. Before hemolymph was collected, the adult ticks were either incubated and unfed at 37 C for 2.5 days or fed for 6 days on sheep. Hemolymph collected from groups of 100 ticks was inoculated into susceptible splenectomized calves. Smears of hemolymph from the same groups of ticks were prepared for examination by fluorescent antibody technique. Hemolymph from incubated ticks caused anaplasmosis in 2 of 4 trials, and hemolymph from feeding ticks caused anaplasmosis in 4 of 4 trials. Moderately fluorescing bodies were demonstrated in some hemocytes from incubated ticks, whereas hemocytes from feeding ticks contained numerous clusters of brightly fluorescing bodies. Fluorescing bodies were not observed in hemocytes from control ticks.
Diagnostic peritoneal lavage before and after abdominal surgery in dogs
Authors: Bjorling D. E. , Latimer K. S. , Rawlings C. A. , Kolata R. J. , Crowe D. T.
Published: February 2025

Complete blood cell counts and peritoneal lavage (pl) were done 2 days before and 2 days after abdominal surgery. Abdominal surgery consisted of intestinal resection/anastomosis and cystotomy in 18 dogs in group 1 and gastrotomy, pyloromyotomy, and repair of diaphragmatic laceration in 20 dogs in group 2.

Insertion of the dialysis catheter for pl preoperatively in a right paramedian location resulted in more pl samples contaminated with blood than when the catheter was inserted on the abdominal midline. The number of nucleated cells found in pl fluid when the catheter was inserted in a right paramedian location was not significantly different (P < 0.05) from that observed in pl fluid collected after insertion of the catheter through the abdominal midline. The predominant cell type in preoperative pl fluid was the segmented neutrophil.

In groups 1 and 2, wbc counts and nucleated cell counts in pl fluid were significantly increased (P < 0.05) postoperatively, Segmented neutrophils and macrophages were most frequently present in postoperative pl fluid. Degenerative neutrophils in postoperative pl fluid were associated with the appearance of immature neutrophils in the blood and increased rectal temperature. Dogs with these findings appeared to have more peritoneal inflammation at necropsy than did others in their groups.

Concentrations of alkaline phosphatase, alanine aminotransferase, amylase, and creatinine in preoperative pl fluid were extremely low. Except for creatinine in group 2, all of these were significantly increased (P < 0.05) post-operatively,

The complication rate associated with the performance of pl on dogs postoperatively was not greater than that which was observed preoperatively.
Reduction in mitogenic response of bovine lymphocytes by ketone bodies
Authors: Targowski S. P. , Klucinski W.
Published: February 2025

The effect of toxic or subtoxic concentrations of ketone bodies (acetone, β-hydroxybutyrate, acetoacetate) in blood on function of bovine lymphocytes was studied in vitro. Lymphocytes separated from peripheral bovine blood were distributed into the wells of Linbro Microtiter plates containing control medium and test medium with various concentrations of ketones and/or phytohemagglutinin. The mitogenic response of lymphocytes was measured by incorporation of [3H]thymidine into DNA of lymphocytes. Toxic and subtoxic concentrations of β-hydroxybutyrate or the toxic concentration of acetoacetate significantly affected the mitogenic response of bovine lymphocytes. The reduction in the mitogenic response also occurred when lymphocytes were only preincubated for 2 hours or longer with β-hydroxybutyrate or acetoacetate. The presence of the toxic concentration of acetone in the medium did not affect the mitogenic stimulation of lymphocytes.
Effect of surgery on the in vitro response of canine peripheral blood lymphocytes to phytohemagglutinin
Authors: Medleau Linda , Crowe Dennis T. , Dawe Donald L.
Published: February 2025

The effects of surgery (ovariohysterectomy) and anesthesia on phytohemagglutinin-induced lymphocyte blastogenesis were studied in vitro in 12 dogs. Four dogs had depressed lymphocyte blastogenic responses after surgery. This suppression was transient with normal blastogenic responses occurring in cells from all dogs 24 hours after surgery. Seemingly, T-lymphocyte function may be depressed, only transiently, after surgery.