Clinical Signs in Veterinary Medicine and Zootics

Conceptual Foundations of Veterinary Clinical Evaluation

Clinical Semiology is defined as a branch of medicine that functions as both a science and an art. It dedicatedly studies the systemic manifestations of diseases through the identification and interpretation of symptoms and signs. This discipline serves as the fundamental pillar of clinical practice, enabling practitioners to reach a correct diagnosis of diseases with observable manifestations. Etymologically, the term is derived from the Greek roots semeion-, meaning sign, and -logia, meaning study.

A Clinical Sign is a signal or manifestation produced by the body or organism as an effect of its functioning, which may be either normal or abnormal. These signs must be detectable, subsequently measured, and either quantified or qualified. The information or data obtained from this process allows for the analysis and judgment of an individual's health status. The term originates from the Latin signus-, meaning signal or mark. In contrast, a Symptom is defined as a revealing manifestation of a disease. It represents a physical or mental problem presented by an animal, indicating a specific or general disease or clinical affection.

Categories of Clinical Signs and Systemic Evaluation

The clinical evaluation involves the assessment of various signs categorized to provide a holistic view of the animal's state. These include the following:

• Vital Signs: This category includes Temperature, Respiration, Heartbeat, Pulse, and Blood Pressure.
• General Signs: These encompass signs that are not localized to a single system but reflect overall health, such as Mucous Membrane Color, Capillary Refill Time, Skin Tent (Pliegue Cutáneo), and Body Condition.
• Systemic Signs: Detailed evaluations are conducted based on the specific organ systems involved, including the Circulatory, Respiratory, Reproductive, Locomotor, Urinary, Digestive, Nervous, Endocrine, Immune, Integumentary, and Lymphatic systems.

Physiological Constants in Domestic Animals

The following table outlines the physiological ranges for temperature, heart/pulse rate, and respiratory rate across various domestic species and age groups as detailed in Table 6.1:

• Dog (Perro):
    - Small Breeds: Temperature: $38,5-39,2\,^{\circ}C$; Respiration: $24-36\,\text{breaths/min}$.
    - Miniature Breeds: Heart Rate: Above $180\,\text{beats/min}$.
    - Large Breeds: Temperature: $37,5-38,5\,^{\circ}C$; Heart Rate: $60-140\,\text{beats/min}$; Respiration: $18-30\,\text{breaths/min}$.
    - Puppies (Cachorros): Temperature at 4 weeks: $38,5\,^{\circ}C$; Heart Rate: Superior to $220\,\text{beats/min}$; Respiration: $20-30\,\text{breaths/min}$.
• Cat (Gato): Temperature: $37,8-39,2\,^{\circ}C$; Heart Rate: $120-240\,\text{beats/min}$; Respiration: $20-30\,\text{breaths/min}$.
• Horse (Caballo):
    - Adult: Temperature: $37,5-38,5\,^{\circ}C$; Heart Rate: $28-46\,\text{beats/min}$; Respiration: $8-16\,\text{breaths/min}$.
    - Foals (Potros) 1 week - 6 months: Temperature: $37,5-38,9\,^{\circ}C$; Heart Rate: $40-60\,\text{beats/min}$; Respiration: $10-25\,\text{breaths/min}$.
    - Foals (Potros) < 1 week: Temperature: $37,2-38,9\,^{\circ}C$; Heart Rate: $60-120\,\text{beats/min}$; Respiration: $20-40\,\text{breaths/min}$.
• Cow/Bull (Vaca/Toro): Temperature: $37,8-39,2\,^{\circ}C$; Heart Rate: $60-72\,\text{beats/min}$; Respiration: $20-30\,\text{breaths/min}$.
• Calf (Ternero): Temperature: $38,5-39,5\,^{\circ}C$; Heart Rate: $80-120\,\text{beats/min}$; Respiration: $24-36\,\text{breaths/min}$.
• Sheep/Ram (Oveja/Carnero): Temperature: $38,5-40\,^{\circ}C$; Heart Rate: $70-90\,\text{beats/min}$; Respiration: $20-30\,\text{breaths/min}$.
• Lamb (Cordero): Temperature: $39-40\,^{\circ}C$; Heart Rate: $80-90\,\text{beats/min}$; Respiration: $36-48\,\text{breaths/min}$.
• Sow/Boar (Cerda/Verraco): Temperature: $37,8-38,5\,^{\circ}C$; Heart Rate: $60-90\,\text{beats/min}$; Respiration: $10-20\,\text{breaths/min}$.
• Piglet (Lechón): Temperature: $38,9-40\,^{\circ}C$; Heart Rate: $100-120\,\text{beats/min}$; Respiration: $24-36\,\text{breaths/min}$.
• Goat (Cabra): Temperature: $38,6-40,2\,^{\circ}C$; Heart Rate: $70-90\,\text{beats/min}$; Respiration: $20-30\,\text{breaths/min}$.
• Kid (Cabrito): Temperature: $38,8-40,2\,^{\circ}C$; Heart Rate: $100-120\,\text{beats/min}$; Respiration: $36-48\,\text{breaths/min}$.

Clinical Evaluation of Mucous Membranes

The inspection of mucous membranes provides critical data regarding systemic circulation and oxygenation. The specific colors and their clinical interpretations are as follows:

• White [Pale Pink]: Indicates anemic states.
• Light Pink: Represents normal physiological status.
• Red [Deep Pink/Intense]: Indicates congestive states.
• Yellow: Indicates icteric (jaundice) conditions.
• Light Blue [Violet]: Indicates cyanotic conditions resulting from poor oxygenation.

Additional qualitative factors to assess include the Pulso [ppm], humidity (Dry vs. Humid), and the presence or absence of secretion from the membranes.

Body Condition Scoring Systems

Body condition scoring (BCS) is a qualitative method to evaluate the amount of fat and muscle on an animal. Two scales are utilized for clinical assessment.

Quantitative Scale (1-5)

• 1 - Severe Sub-conditioning: Occurs when the skeleton is extremely prominent with minimal tissue coverage.
• 2 - Obvious Skeleton: The skeletal structure is clearly visible underneath the skin.
• 3 - Good Balance: Represents an ideal state where there is a healthy balance between the skeleton and superficial tissues.
• 4 - Tissues > Skeleton: The superficial tissues are more obvious than the underlying skeletal frame.
• 5 - Severe Over-conditioning: Indicates obesity where skeletal landmarks are obscured by fat.

Qualitative Descriptive Scale (0-5)

• 0 - Very Poor: Characterized by a very sunken rump, deep cavity under the tail, skin tight over the bones, very prominent backbone and pelvis, and a marked ewe neck.
• 1 - Poor: Characterized by a sunken rump, cavity under the tail, easily visible ribs, prominent backbone and croup, and a narrow, slack ewe neck.
• 2 - Moderate: Flat rump on either side of the backbone, ribs are just visible, narrow but firm neck, and the backbone is well covered.
• 3 - Good: Characterized by a rounded rump and ribs that are just covered but can be easily felt. The neck is firm with no crest.
• 4 - Fat: Rump is well rounded with a gutter along the back. Ribs and pelvis are hard to feel, and a slight crest is present on the neck.
• 5 - Very Fat: Characterized by a very bulging rump, deep gutter along the back, buried ribs, a marked crest, and noticeable folds or lumps of fat.

Academic References and Resources

The following academic texts serve as the foundation for the material provided:

• König, H. E., & Liebich, H. G. (2005). Anatomía de los animales domésticos: texto y atlas en color (Vol. 1-2). Ed. Médica Panamericana.
• Grossman, J. D., & Sisson, S. (2000). Anatomía de los animales domésticos. Salvat.
• Dyce, K. M., Sack, W. O., & Wensing, C. J. G. (1991). Anatomía veterinaria. 3. ed. México: Manual Moderno.
• Shively, M. J., & Shively, M. J. (1993). Anatomía veterinaria: básica, comparativa y clínica.
• Evans, H. E., & de la Hunta, A. (2002). Disección del perro. McGraw Hill.
• Gil, J. (2005). Anatomía del perro: protocolos de disección.
• Evans, H. E., & De Lahunta, A. (2013). Miller's Anatomy of the Dog. Elsevier Health Sciences.
• Popesko, P. (1998). Atlas de anatomía topográfica de los animales domésticos: Tomos I, II, and III. Masson, SA.