The flehmen response of bulls and cows

The response of dairy bulls to the urine of cows in various stages of the reproductive cycle was quantified by presenting 200 ml of urine in a stainless steel bowl to the stanchioned bulls for 10 min. Estrous mucus was also presented in the same manner. Sniffs, nose licks and flehmen responses were recorded. Of 15 bulls tested only 7, or 47%, met the criteria of two flehmens in response to estrous urine. Among these bulls, the rate of flehmen was higher to estrous urine 6.1 +/- 1 flehmen/10 min) than to nonestrous urine (3.5 +/- 0.6 flehmen/10 in, paired t = 3.1, P < 0.03). Flehmen duration was also longer in response to estrous urine (6.4 +/- 0.4 sec) than to nonestrous urine (5.7 +/- 0.4 sec, t = 2.65, P < 0.03). There were no significant differences between the sniff frequencies and durations or in the number of licks to estrous and diestrous urine. There were significantly more flehmen responses to estrous urine (7 +/- 1.4 10 min ) than to mucus (2.25 +/- 0.9 10 min , t = 4.75, P < 0.01). The response to water (0.6 +/- 0.3 10 min ) was not different from that to mucus (t = 2.37, P < 0.10). The spontaneous flehmen rate of dairy bulls in their home stalls was 3.2 +/- 0.7 24 h . Although estrous cows did not exhibit flehmen frequently, they did sniff bull urine more frequently (3.6 +/- 0.6 10 min ) than nonestrous cows (1.8 +/- 0.3 10 min , t = 2.4, P < 0.03).

Crib-biting in US horses: breed predispositions and owner perceptions of aetiology

REASONS FOR PERFORMING STUDY

Crib-biting is an equine stereotype that may result in diseases such as colic. Certain breeds and management factors have been associated.

OBJECTIVES

To determine: breed prevalence of crib-biting in US horses; the likelihood that one horse learns to crib-bite from another; and owner perceptions of causal factors.

METHODS

An initial postal survey queried the number and breed of crib-biting horses and if a horse began after being exposed to a horse with this habit. In a follow-up survey, a volunteer subset of owners was asked the number of affected and nonaffected horses of each breed and the extent of conspecific contact. The likelihood of crib-biting given breed and extent of contact was quantified using odds ratio (OR) and significance of the association was assessed using the Chi-squared test.

RESULTS

Overall prevalence was 4.4%. Thoroughbreds were the breed most affected (133%). Approximately half of owners believed environmental factors predominantly cause the condition (54.4%) and crib-biting is learned by observation (48.8%). However, only 1.0% of horses became affected after being exposed to a crib-biter. The majority (86%) of horses was turned out in the same pasture with other horses and extent of contact with conspecifics was not statistically related to risk.

CONCLUSION

This is the first study to report breed prevalence for crib-biting in US horses. Thoroughbreds were the breed more likely to be affected. More owners believed either environmental conditions were a predominant cause or a combination of genetic and environmental factors contributes to the behaviour. Only a small number of horses reportedly began to crib-bite after being exposed to an affected individual, but approximately half of owners considered it to be a learned behaviour; most owners did not isolate affected horses.

POTENTIAL RELEVANCE

Genetic predisposition, not just intensive management conditions and surroundings, may be a factor in the high crib-biting prevalence in some breeds, and warrants further investigation. Little evidence exists to suggest horses learn the behaviour from other horses, and isolation may cause unnecessary stress.

Effect of castration on rabbits housed in littermate pairs

Conventional solitary caging for research rabbits precludes many postural and social behaviors. Several studies that have investigated enrichment strategies for rabbit does have found intact males usually too aggressive for paired or group housing. This study investigated the possibilities that male siblings will remain compatible if never separated from birth and that castration will improve compatibility among young sibling male rabbits. As a side benefit of pair housing for all rabbits, the larger cages (modified dog cages) allowed rest and other postures not possible in conventional single cages. In addition, there was no evidence of the stereotypies observed among individually housed rabbits. Castrated, post-weanling, male, Flemish Giant x Giant Chinchilla rabbit littermates demonstrated a significantly higher level of living together compatibly than did the intact controls. All rabbits chose to rest in close proximity or contact, although this preference was stronger in castrated males. During puberty, intact males displayed more serious aggression. We conclude that young adult littermate rabbits can live compatibly as pairs and that castration improves compatibility among males. Paired rabbits exhibit many postures and behaviors that are not possible in the small, solitary cages currently listed as minimum recommendations.

Efficacy of amitriptyline as a pharmacological adjunct to behavioral modification in the management of aggressive behaviors in dogs

The efficacy of amitriptyline as a pharmacological adjunct to behavioral modification in the clinical management of aggressive behaviors in dogs was evaluated in two phases. Twelve dogs presenting for aggressive behaviors were treated sequentially with amitriptyline (2 mg/kg body weight, per os [PO] bid) and a placebo for 4 weeks in a prospective, randomized, double-blind, placebo-controlled trial. Standardized protocols for behavior modification were implemented throughout the trial. Owners maintained behavioral records and reported on the number of aggressive incidents as well as the dog's overall improvement at the end of each 4-week period. In the second phase, 27 cases of dogs presenting for aggressive behaviors and treated with amitriptyline were reviewed, and clients were contacted to record each dog's response to treatment. Reports were compared to those for dogs receiving behavior modification alone (i.e., placebo phase of prospective study). No significant difference was observed in the patients' responses to adjunctive amitriptyline versus behavior modification alone.

Attitudes of owners regarding tendonectomy and onychectomy in cats

OBJECTIVE

To compare the incidence of behavior problems following tendonectomy or onychectomy in cats, as well as attitudes of owners following these procedures.

DESIGN

Nonrandomized clinical trial.

ANIMALS

18 cats that underwent tendonectomy and 39 cats that underwent onychectomy.

PROCEDURE

Owners of cats that underwent tendonectomy or onychectomy between February 1993 and May 1998 were contacted by telephone and asked several questions regarding reasons for surgery as well as complications and behavioral changes in cats following surgery.

RESULTS

The most common reason for considering tendonectomy or onychectomy was to avoid damage caused by the cat scratching household materials. Avoidance of injury to humans or animals was chosen more often by owners whose cats underwent onychectomy than those that underwent tendonectomy. Tendonectomy was more likely to have been recommended by veterinarians than onychectomy. Significantly more cats that underwent tendonectomy (67%) than onychectomy (44%) returned to normal activity within 3 days after surgery. Significant differences were not detected regarding behavior problems after surgery.

CONCLUSIONS AND CLINICAL RELEVANCE

Although tendonectomy and onychectomy involved some medical complications and behavior changes following surgery, owners had positive attitudes regarding both surgeries after the immediate postoperative period. Tendonectomy may be a humane alternative to onychectomy, although owners need to be advised that nail trimming is still necessary in cats after surgery.

Evaluation of treatments for separation anxiety in dogs

OBJECTIVE

To evaluate treatment outcome in dogs with separation anxiety and owner compliance with and perception of effectiveness of discharge instructions.

DESIGN

Cohort study.

ANIMALS

52 dogs with separation anxiety.

PROCEDURE

Sex, age at which the owner obtained the dog, age at which separation anxiety was first noticed, age at behavioral examination, and discharge instructions were obtained from medical records of each dog. Between 6 and 64 months after the behavioral examination, owners were contacted by telephone and questioned about the outcome of treatment, their compliance with discharge instructions, and their perception of the effectiveness of each instruction.

RESULTS

Thirty-two (62%) dogs had improved, whereas 20 were the same, were worse, or had been euthanatized or given away. Mixed-breed dogs were significantly less likely to improve than purebred dogs. Compliance varied according to discharge instruction. Significantly fewer dogs with owners that were given > 5 instructions improved or were cured, compared with those with owners given fewer instructions. Twenty-seven dogs were also treated with amitriptyline or other medication; 15 (56%) improved.

CONCLUSIONS AND CLINICAL RELEVANCE

Owners complied with instructions that involved little time such as omitting punishment and providing a chew toy at the time of departure. Owners were also willing to increase the dog's exercise but were not willing to uncouple the cues of departure from real departures or desensitize the dog to impending departure. Administration of psychoactive medication may be necessary to augment behavior modification techniques designed to reduce separation anxiety in dogs.

Effect of water restriction on equine behaviour and physiology

Six pregnant mares were used to determine what level of water restriction causes physiological and/or behavioural changes indicative of stress. Nonlegume hay was fed ad libitum. During the first week of restriction, 5 l water/100 kg bwt was available, during the second week 4 l/100 kg bwt and, during the third week, 3 l/100 kg bwt. Ad libitum water intake was 6.9 l/100 kg bwt; at 3 l/100 kg bwt water intake was 42% of this. Daily hay intake fell significantly with increasing water restriction from 12.9 +/- 0.75 kg to 8.3 +/- 0.54 kg; bodyweight fell significantly for a total loss of 48.5 +/- 8.3 kg in 3 weeks. Daily blood samples were analysed; osmolality rose significantly with increasing water restriction from 282 +/- 0.7 mosmols/kg to 293.3 +/- 0.8 mosmols/kg bwt, but plasma protein and PCV did not change significantly. Cortisol concentrations fell from 8.1 ng/ml to 6.4 ng/ml over the 3 week period. Aldosterone fell from 211.3 +/- 74.2 pg/ml to 92.5 +/- 27.5 pg/ml at the end of the first week. The behaviour of 4 of the 6 mares was recorded 24 h/day for the duration of the study. The only significant difference was in time spent eating, which decreased with increasing water restriction from 46 +/- 3% to 30 +/- 3%. It is concluded that water restriction to 4 l/100 kg bwt dehydrates pregnant mares and may diminish their welfare, but is not life- or pregnancy-threatening.

A retrospective study of canine house soiling: diagnosis and treatment

A retrospective study was conducted to determine the relative frequency and type of elimination problem seen in dogs at a university referral practice and to evaluate the efficacy of the suggested treatments. Cases presented to the Animal Behavior Clinic at Cornell University between 1987 and 1996 were reviewed. Of 1,173 cases, 105 (9%) were house-soiling cases. Of these cases, the authors obtained outcome information from 70. Within the diagnosis of house soiling, incomplete housebreaking (n=59; 84%) were the most frequent referral cases, of which 48 cases (81%; 95% confidence interval, 69% to 90%) improved. Separation anxiety was considered the second most common underlying cause (n=27; 39%), of which 85% (n=23; 95% confidence interval, 66% to 96%) improved. Behavior modification was the most often suggested treatment (n=58), with 48 (83%) cases improving. Behavior modification consisted of accompanying the dog to the preferred elimination area, rewarding the dog for eliminating there, and punishing the dog only when caught in the act of house soiling. These results suggest that correct house training, behavior modification involving positive reinforcement, and appropriate punishment are essential to diminish house-soiling problems in dogs.

Prevalence and characteristics of foal rejection in Arabian mares

Separate surveys of Thoroughbred, Paint, and Arabian mare owners revealed a higher than expected rate of foal rejection in Arabian mares. A behavioural history form was submitted by owners of foal rejecting and nonrejecting Arabian mares, and maternal behaviour and management practices compared. Four generation pedigrees of rejecting and nonrejecting Arabian mares were also examined. Foal rejecting mares were more likely to avoid, threaten, squeal at, chase, bite, and kick their foals post partum than nonrejecting mares. Nonrejecting mares were more likely to lick, nicker and defend their foals post partum than rejecting mares. No statistically significant relationship was found between foal rejection and the type of breeding method (natural vs. artificial insemination), the presence of people at birth, the presence of nearby horses at birth, or assistance of the first nursing bout. The presence at least once of 1 of 2 related sires was statistically higher in the pedigrees of rejecting vs. nonrejecting mares. Inherited and learned or environmental factors are likely to affect the expression of foal rejection behaviour.

Sexual behavior problems in dogs and cats

Sexual behavior problems do occur as a primary diagnosis, but excessive sexual behavior is a common secondary problem. Mounting occurs in almost half of dogs with behavior problems and 20% of cats with behavior problems.

Comparison of cerebrospinal fluid monoamine metabolite levels in dominant-aggressive and non-aggressive dogs

Aggression has been shown to be related to reduced serotonergic activity in humans and non-human primates, and in rodents. We now studied the relationship between cerebrospinal fluid (CSF) monoamine metabolites and canine aggression in 21 dominant-aggressive dogs (Canis familiaris) and 19 controls. The diagnosis of dominance-related aggression was based upon a history of biting family members in contexts associated with dominance challenges. Post-mortem CSF 5-HIAA, MHPG and HVA were measured by high-performance liquid chromatography using electrochemical detection. Concentrations of CSF 5-HIAA (P = 0.01) and HVA (P < 0.001) were lower in the aggressive group (median values: 5-HIAA 202.0 pmol/ml; HVA 318.0 pmol/ml) than in controls (5-HIAA 298.0 pmol/ml; HVA 552.0 pmol/ml). No differences were noted in CSF MHPG levels. Differences in 5-HIAA were maintained after controlling for breed and age of dogs, but HVA differences may have been breed-dependent. Lower levels of 5-HIAA (P = 0.02) and HVA (P = 0.04) were found in the subgroup of aggressive dogs with a history of biting without warning (5-HIAA 196.0 pmol/ml; HVA 302.0 pmol/ml) compared to dogs that warned (5-HIAA 244.0 pmol/ml; HVA 400.0 pmol/ml). This study suggests that reduced serotonergic function is associated with aggressive behavior and impaired impulse control in dogs, a finding that is consistent with observations in primates, and suggests that serotonin modulates aggressive behavior throughout mammals.

Comparison of two antibarking collars for treatment of nuisance barking

Two commercially available antibarking collars (i.e., a citronella spray collar and an electronic shock collar) were evaluated for efficacy and user satisfaction as reported by owners after a two-week trial period for each collar. While both collars were effective in decreasing barking (88.9% for the citronella spray collar and 44.4% for the electronic shock collar), most owners expressed a preference for the citronella spray collar. Owners perceived it as being more humane and indicated that they willingly would use it on a long-term basis to decrease their dogs' nuisance barking. While the citronella spray collar has some drawbacks, it is another tool for managing excessive barking.

Comparison of cerebrospinal fluid monoamine metabolite levels in dominant-aggressive and non-aggressive dogs

Aggression has been shown to be related to reduced serotonergic activity in humans and non-human primates, and in rodents. We now studied the relationship between cerebrospinal fluid (CSF) monoamine metabolites and canine aggression in 21 dominant-aggressive dogs (Canis familiaris) and 19 controls. The diagnosis of dominance-related aggression was based upon a history of biting family members in contexts associated with dominance challenges. Post-mortem CSF 5-HIAA, MHPG and HVA were measured by high-performance liquid chromatography using electrochemical detection. Concentrations of CSF 5-HIAA (P = 0.01) and HVA (P < 0.001) were lower in the aggressive group (median values: 5-HIAA 202.0 pmol/ml; HVA 318.0 pmol/ml) than in controls (5-HIAA 298.0 pmol/ml; HVA 552.0 pmol/ml). No differences were noted in CSF MHPG levels. Differences in 5-HIAA were maintained after controlling for breed and age of dogs, but HVA differences may have been breed-dependent. Lower levels of 5-HIAA (P = 0.02) and HVA (P = 0.04) were found in the subgroup of aggressive dogs with a history of biting without warning (5-HIAA 196.0 pmol/ml; HVA 302.0 pmol/ml) compared to dogs that warned (5-HIAA 244.0 pmol/ml; HVA 400.0 pmol/ml). This study suggests that reduced serotonergic function is associated with aggressive behavior and impaired impulse control in dogs, a finding that is consistent with observations in primates, and suggests that serotonin modulates aggressive behavior throughout mammals.

Effect of dietary protein content on behavior in dogs

OBJECTIVE

To determine the effect that feeding diets containing a low (17%), medium (25%), or high (32%) protein content would have on behavior in dogs.

DESIGN

Prospective, controlled study.

ANIMALS

12 dogs with dominance aggression, 12 dogs with hyperactivity, 12 dogs with territorial aggression, and 14 control dogs without behavioral problems.

PROCEDURE

Dogs were fed each of the diets for a 2-week period, and owners were instructed to score their dogs' behavior on a daily basis.

RESULTS

Behavior of the dogs with dominance aggression, dogs with hyperactivity, and control dogs was unchanged by the dietary manipulations. Territorial aggression was significantly reduced when dogs were fed the low- or medium-protein diet, compared with territorial aggression when fed the high-protein diet. Post hoc analysis indicated that this effect was attributable to a marked reduction in aggression in a subset of the group (n = 7) in which territorial aggression was a result of fear.

CLINICAL IMPLICATIONS

Results of this study suggest that a reduction in dietary protein content is not generally useful in the treatment of behavior problems in dogs, but may be appropriate in dogs with territorial aggression that is a result of fear.

Risk factors for behavior-related euthanasia among dominant-aggressive dogs: 110 cases (1989-1992)

Establishing a prognosis for dogs with dominance-related aggression is difficult. Some dominant-aggressive dogs respond well to treatment; others continue to be serious risks for their owners. A study was performed to identify characteristics of dominance-related aggression and to identify risk factors associated with whether the aggressive behavior led to euthanasia. Medical records of 110 dogs with dominance-related aggression were examined retrospectively; characteristics of owner-directed aggression and eventual outcome of the dogs were recorded. By means of logistic regression, 2 different models were found to describe the association between behavior characteristics and outcome. In the first model, severe aggression in response to benign dominance challenges and body weight > 18.2 kg were associated with outcome. In the second model, unpredictability of aggression and a history of being purchased were associated with outcome. We concluded that dominance-related aggressive behavior can be subclassified according to severity and type and that outcome (ie, euthanasia) may be predictable in some cases.

Friendliness to humans and defensive aggression in cats: the influence of handling and paternity

This study was undertaken to examine and reduce the stress and aggressiveness associated with fear of handling in laboratory cats (Felis sylvestris catus). Thirteen litters of kittens from a specific pathogen-free breeding colony were divided into three treatment groups: two were early weaned, removed from the colony and caged individually with or without handling up to 8 weeks of age, and the third served as a control group, removed from the colony just before testing. Behavior tests measuring degree of friendliness to humans and response to physical restraint were performed at ages 8, 12, 16, and 20 weeks. Serum cortisol concentrations were measured after each test. Results indicate that litter and sire influenced tractability but that handling or individual caging of kittens did not. Posttest serum cortisol concentrations were below normal adult levels in most kittens, including those reacting fearfully during testing and aggressively during restraint, and, therefore, are not a reliable indicator of stress in juvenile cats.

Thirst and salt appetite in horses treated with furosemide

When a preliminary experiment in sodium-replete ponies revealed an increase, but not a significant increase, in salt consumption after furosemide treatment, the experiment was repeated using sodium-deficient horses in which aldosterone levels might be expected to be elevated to test the hypothesis that a background of aldosterone is necessary for salt appetite. Ten Standardbred mares were injected intravenously with furosemide or an equivalent volume of 0.9% sodium chloride as a control to test the effect of furosemide on their salt appetite and blood constituents. Sodium intake and sodium loss in urine, as well as water intake and urine output, were measured and compared to determine accuracy of compensation for natriuresis and diuresis. Plasma protein and packed cell volume showed significant increases in response to furosemide treatment (F = 29.31, P less than 0.001 and F = 11.20, P less than 0.001, respectively). There were no significant changes in plasma sodium concentration or osmolality in response to the treatment (P greater than 0.05). The furosemide-treated horses consumed 126 +/- 14.8 g salt, significantly more than when they were given the control injection (94.5 +/- 9.8 g; t = 2.22, P = 0.05). In response to furosemide, horses lost 962 +/- 79.7 and consumed 2,170 +/- 5 meq sodium; however, compared with control, they lost 955 meq more sodium and ingested only 570 meq more sodium, so they were undercompensating for natriuresis. The furosemide-treated horses drank 9.6 +/- 0.8 kg of water, significantly more than when they received the control injection (6.4 +/- 0.8 kg; t = 6.9, P less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Investigating equine ingestive, maternal, and sexual behavior in the field and in the laboratory

Some of the techniques that may be used to study social, reproductive, and ingestive behavior in horses are described in this paper. One of the aspects of equine social behavior is the dominance hierarchy or patterns of agonistic behavior. Paired or group feeding from a single food source may be used to determine dominance hierarchies quickly. Focal animal studies of undisturbed groups of horses may also be used; this method takes longer, but may reveal affiliative as well as agonistic relationships among the horses. Reproductive behavior includes flehmen, the functional significance of which can be determined using combinations of field observations of harem groups and laboratory studies of stallions exposed to female urine or feces in the absence of the donor mare. Ingestive behavior may include food, salt, or water intake. Direct and indirect measurements of intake can be made and used to answer questions regarding the ability of horses to control their energy intake when the diet is diluted, the effect of feral equids on the ecology of an area, and the abilities of horses to compensate for dehydration and hypovolemia.

Animal behavior and animal welfare

The value of behavioral techniques in assessing animal welfare, and in particular assessing the psychological well being of animals, is reviewed. Using cats and horses as examples, 3 behavioral methods are presented: (1) comparison of behavior patterns and time budgets; (2) choice tests; and (3) operant conditioning. The behaviors of intact and declawed cats were compared in order to determine if declawing led to behavioral problems or to a change in personality. Apparently it did not. The behavior of free ranging horses was compared with that of stabled horses. Using two-choice preference tests, the preference of horses for visual contact with other horses and the preference for bedding were determined. Horses show no significant preference for locations from which they can make visual contact with other horses, but they do prefer bedding, especially when lying down. Horses will perform an operant response in order to obtain light in a darkened barn or heat in an outside shed. These same techniques can be used to answer a variety of questions about an animal's motivation for a particular attribute of its environment.

Feeding and drinking behavior problems

The physiologic and behavioral basis of normal canine and feline feeding is given in detail. Abnormalities of ingestive behavior include obesity and anorexia in both species, flank or blanket sucking in Doberman Pinschers, coprophagia and stone chewing in dogs, and wool chewing in cats. Drinking behavior is discussed briefly, and the abnormalities of hypernatremia (a failure of thirst) and psychogenic polydipsia and polyphagia are reviewed.

Ingestive behavior

In summary, horses spend 60% or more of their time eating when grazing or when feed is available free choice. Grasses are their preferred food, but they supplement the grass with herbs and woody plants. Sweetened mixtures of oats and corn are the most preferred concentrate. Horses can increase or decrease the time spent eating and amount eaten to maintain caloric intake. Their intake is stimulated by drugs such as diazepam and by the presence of other horses. Horses stop eating when gastric osmolality increases; increases in plasma osmolality, protein, and glucose accompany digestion. Foals eat several times an hour and begin sampling solid food at the same time that their dam is eating. Several areas of particular importance to the equine industry have not been investigated. These areas include the effect of exercise on short- and long-term food intake and the influence of reproductive state on the feeding of mares.

Taste aversion learning in horses

The ability of ponies to learn to avoid a relatively novel food associated with illness was tested in three situations: when illness occurred immediately after consuming a feed; when illness occurred 30 min after consuming a feed; and when illness was contingent upon eating one of three feeds offered simultaneously. Apomorphine was used to produce illness. The feeds associated with illness were corn, alfalfa pellets, sweet feed and a complete pelleted feed. The ponies learned to avoid all the fees except the complete feed when apomorphine injection immediately followed consumption of the feed. However, the ponies did not learn to avoid a feed if apomorphine was delayed 30 min after feed consumption. They could learn to avoid alfalfa pellets, but not corn, when these feeds were presented with the familiar "safe foods," oats and soybean meal. Ponies apparently are able to learn a taste aversion, but there were constraints on this learning ability. Under the conditions of this study, they did not learn to avoid a food that made them sick long after consumption of the food, and they had more difficulty learning to avoid highly palatable feeds.

Stimuli of thirst in donkeys (Equus asinus)

A study of the stimuli of thirst was conducted on six feral donkeys. Donkeys were found to be stimulated to drink by overnight water deprivation, by the diuretic furosemide, and by hypertonic saline infusion, all in the absence of heat stress or work. Donkeys compensate accurately for the fluid deficit caused by overnight water deprivation. After 19 hr without water, they drank 8.8 +/- 2.4 (mean +/- SE) liters within 60 min. Their undeprived overnight intake was 8.4 +/- 1.5 liters. However, latency was longer and water intake was less than that of ponies with the same changes in blood parameters, suggesting that donkeys have a higher thirst threshold than ponies. Further, plasma volume fell less in donkeys, but osmotic changes were similar to those reported in ponies exposed to the same deprivation. Donkeys infused with 250 ml of 15% NaCl drank 0.7 +/- 0.6 liters of water within 45 min, and osmolality increased from 287 to 297 mosmol/kg water; they drank no water in the same time period when infused with 250 ml 0.9% NaCl (p less than 0.05). Donkeys injected IV with 2 mg/kg furosemide drank 3.8 +/- 1.1 liters within 3 hr. Plasma protein increased from 6.9 to 7.8 g/dl. When injected with 0.9% NaCl they drank 1.0 +/- 0.5 liters (p less than 0.05). In sum, the positive thirst responses of these donkeys to cellular and extracellular dehydration were similar to those earlier demonstrated in ponies, but the results suggest a less sensitive response, albeit combined with a better internal defense of blood volume.

The role of the Flehmen response in the behavioral repertoire of the stallion

The role of the Flehmen response in equine behavior was investigated under field and laboratory conditions. In Experiment 1, a field study made of five stallions on pasture with between three and eighteen mares each during the season indicated the following: 1) The Flehmen response was most frequently preceded by nasal, rather than oral, investigation of substances; 2) The stallions' rate of Flehmen varied with the estrous cycles of the mares; 3) The rate of Flehmen response did not show a variation with time of day; and 4) The Flehmen response was most frequently followed by marking behaviors rather than courtship behaviors. The results suggest that the Flehmen response is not an immediate component of sexual behavior, e.g., courtship of the stallion but may be involved in the overall monitoring of the mare's estrous cycle. Therefore the Flehmen response may contribute to the chemosensory priming of the stallion for reproduction. In Experiment 2 stallions were presented with urine or feces of mares in various stages of the reproductive cycle as well as with their own or other males' urine or feces. The occurrence of sniffing and Flehmen was used to determine the discriminatory ability of the stallions. Stallions can differentiate the sex of a horse on the basis of its feces alone, but cannot differentiate on the basis of urine. This ability may explain the function of fecal marking behavior of stallions.

Vasopressin in dehydrated and rehydrated ponies

Six pony mares deprived of water for 24 hours showed significant increases in plasma vasopressin (2.8 pg/ml) and osmolality (9 mosmol/kg). When water was made available the ponies drank rapidly (5 of 6 drank to satiety within 90 seconds) and corrected their fluid deficits precisely. Vasopressin did not return to predehydration levels until osmolality did after 15 minutes of access to water. The horse differs from rodents and humans, but is similar to pigs in that vasopressin levels do not fall before osmolality returns to normal. Oropharyngeal factors, therefore, may not be as important in vasopressin release in horses as in other species.

A tuna fish diet influences cat behavior

When observed in their home cages, cats fed commercial tuna fish cat food were less active, vocalized less, and spent more time on the floor and more time eating than cats fed commercial beef cat food. There were no differences in response to human handling between the two groups. There were no differences in learning ability on a two-choice point maze or in reversal learning in the same maze between beef- and tuna-fed cats. The behavior of the groups differed in a 15-min open field test only in the number of toys contacted. Cats fed the tuna had elevated tissue levels of mercury and selenium.

Body temperature and behaviour of mares during the last two weeks of pregnancy

Average daily core body temperature and behavioural patterns of pregnant mares were studied, in search of definitive signs of parturition within 24 h of the event. Nineteen pony mares were sampled twice daily for core body temperature. A significant temperature drop, averaging 0.1 degrees C (0.2 degrees F) was observed during the day prior to parturition. Between 18.00 h and 06.00 h, during the two weeks before parturition, Thoroughbred and Standardbred mares (n = 52) spent an average 66.8 per cent of their time standing, 27.0 per cent eating, 4.9 per cent lying in sternal recumbency, 1.0 per cent lying in lateral recumbency, and 0.3 per cent walking. On the night before parturition, mares spent significantly less time lying in sternal recumbency than on previous nights and on the night of parturition all behaviour patterns except eating were significantly different from the nights of the two weeks before parturition. There was an increase in walking (5.3 per cent), lying in sternal recumbency (8 per cent) and lying in lateral recumbency (5.3 per cent) whereas standing (53.3 per cent) was decreased. In 58 observed pregnancies, 54 mares (97 per cent) foaled in a recumbent position and 50 mares (86 per cent) foaled between 18.00 h and 06.00 h.

Effect of meal frequency on fluid balance and behavior of ponies

Twelve ponies were fed their total daily ration either as one large meal or divided into six small meals. Pre- and post-feeding behavior was recorded six times a day. Blood samples were taken for 30 min before and two hr after the meal. Plasma protein increased from 7.0 to a peak of 7.3 g/dl with small meals and from 7.3 to 8.1 g/dl with large meals, and returned to pre-feeding levels by 90 min post-feeding. Hematocrit rose from 33.3 to 34.1% with small meals and from 33.0 to 36.0% with large meals. These rapid and short-lived increases indicate a decrease in plasma volume. Plasma osmolality rose with feeding from 283 to 285 mosmoles/kg with small meals and from 281 to 288 mosmoles/kg with large meals. Water availability had no significant effect on blood changes. Digestibility and rate of passage were measured with chromic oxide, but there were no differences. Vocalizing (neighing) and walking occurred more often before than after feeding, while eating bedding and engaging in other oral behaviors were more frequent after feeding.

Abnormal behavior

Farm animals exhibit abnormalities of sexual, maternal, and other social behaviors as well as many stereotyped behaviors. The types and incidence of these abnormal behaviors may depend on the species, its diet, and the environmental conditions under which it is normally maintained. An understanding of the causes of various abnormal behavior patterns will enable the producer and veterinarian to better manage populations of livestock and improve their well-being.

Maternal behavior

Parturition in mares is rapid and is followed by a brief period of sensitivity to imprinting on a foal. There is large individual variation in normal maternal style, but normal mothers actively defend their foal, remain near the foal when it is sleeping, tolerate or assist nursing, and do not injure their own foal. Disturbance of a mare and foal during the early imprinting period can predispose a mare to rejection of her foal; therefore, it should be avoided. There are a variety of forms of foal rejection and numerous etiologies. Therefore, each case should be evaluated individually.

Stable vices and trailer problems

Stable vices include oral vices such as cribbing, wood chewing, and coprophagia, as well as stall walking, weaving, pawing, and stall kicking. Some of these behaviors are escape behaviors; others are forms of self-stimulation. Most can be eliminated by pasturing rather than stall confinement. Trailering problems include failure to load, scrambling in the moving trailer, struggling in the stationary trailer, and refusal to unload. Gradual habituation to entering the trailer, the presence of another horse, or a change in trailer type can be used to treat these problems.

Techniques for taking a behavioral history

A thorough behavioral history is essential for adequate assessment of a given case. In reviewing the chief complaint, a description of what actually happened, rather than the owner's interpretation of what happened, is required. Other behavior problems, environment, rearing history, and training need to be reviewed. Sample question sets for some common problems are given.