Consideration of Epidemiology

Repeated efforts to obtain a complete history in chronologic order of development of clinical signs may be necessary to

■ BOX 4.5

■ BOX 4.6

Infectious Causes of Fever in Ruminants

Common Causes

Mastitis

Metritis

Pneumonia: viral, mycoplasma, bacterial

Traumatic reticuloperitonitis (B)

Peritonitis (from other causes, e.g., ruptured abomasal ulcer, uterine tear)

Septicemia, osteomyelitis, infectious arthritis, omphalophlebitis (neonates)

Toxemia from gastrointestinal disorders

Enteritis

Abscesses

Liver Pharyngeal/retropharyngeal Internal lymph nodes (C, O) Associated with foot

Endocarditis

Pericarditis (B)

Listerosis

Tetanus

Bovine viral diarrhea (BVD), mucosal disease (B)

Foot rot

Otitis media, interna (Mycoplasma bovis) (B) Clostridial infections

Blackleg (Clostridium chauvoei) Clostridium perfringens types D, A (C, O)

Contagious ecthyma (C, O)

Histophilus somni infection (thromboembolic meningoen- cephalomyelitis)

Mycoplasma species arthritis, septicemia (C) M.

Verminous pneumonia (B)

Less Common Causes

Rabies

Anaplasmosis

Leptospirosis Bluetongue (O)

Vesicular stomatitis

Malignant catarrhal fever (B)

Verminous pneumonia (C, O) Cystitis, pyelonephritis

Epididymitis (C, O)

Balanoposthitis (O) Enzootic abortion(C, O)

Epizootic abortion (B)

Caprine arthritis encephalomyelitis (C)

Uncommon Causes

Neoplasms (see list in Box 4.7)

Infectious necrotic hepatitis (Clostridium novyi) Sarcocystosis (B)

Tuberculosis (B)

Systemic candidiasis, aspergillosis

Eperythrozoonosis Brainstem, pituitary abscess Systemic toxoplasmosis (C, O) Tularemia

Pseudorabies

Brucellosis

Ovine progressive pneumonia

Chlamydial sporadic bovine encephalomyelitis

B, Bovine; C, caprine; O, ovine.

Neoplastic Causes of Fever in Horses

Common Causes

Metastatic melanomas Lymphosarcoma

Squamous cell carcinoma Fibrosarcoma

Less Common Causes

Granulosa cell tumors in mares

Undifferentiated reticuloendothelial cell sarcomas Adenocarcinomas

Myeloproliferative diseases

Uncommon Causes

Hemangiosarcoma Mesothelioma

Pheochromocytoma Osteosarcoma

Myeloma of the gastrointestinal tract

■ BOX 4.7

Neoplastic Causes of Fever in Ruminants

Common Causes

Lymphosarcoma

Less Common Causes

Adenocarcinoma

Metastatic melanoma (C)

Liver neoplasia Mesothelioma

Uncommon Causes

Skeletal neoplasia Malignant neuroblastoma

C, Caprine.

■ BOX 4.8

Immunologic Causes of Fever in Horses

Common Causes

Purpura hemorrhagica

Urticaria

Drug-induced fever

Less Common Causes

Immune-mediated hemolytic anemia, thrombocytopenia

Combined immunodeficiency of foals

IgM deficiency

Pemphigus foliaceus

Chronic necrotizing vasculitis

Neonatal isoerythrolysis

Uncommon Causes

Connective tissue disorders, rheumatoid arthritis

Transient agammaglobulinemia of foals

Bullous pemphigoid

Common variable immunodeficiency

IgM, Immunoglobulin M.

■ BOX 4.9

Immunologic Causes of Fever in Ruminants

Common Causes

Drug allergies

Urticaria (milk allergy in cattle)

Less Common Cause

Neonatal isoerythrolysis (B)

Uncommon Cause

Pemphigus foliaceus (C)

B, Bovine; C, caprine.

■ BOX 4.10

Noninfectious Inflammatory and Miscellaneous Causes of Fever in Horses

Hepatic disorders

Hyperlipidemia, equine hepatic lipidosis Acute hepatic necrosis (Theiler disease) Chronic active hepatitis

Cholelithiasis

Hyperkalemic periodic paralysis

Foreign bodies

Nasal, oral, pharyngeal, tracheal, bronchial

Thrombophlebitis

Ocular trauma, recurrent uveitis

Burns, smoke inhalation

Snake bite

Acute renal failure

Idiopathic interstitial pneumonia

*Appropriate for species and history such as EIA for horses

FIG. 4.3 Approach to fever of unknown origin. CBC, Complete blood count; EIA, equine infectious anemia; MDB, minimum database; PE, physical examination; UR, upper respiratory.

■ BOX 4.11

Noninfectious Inflammatory and Miscellaneous Causes of Fever in the Ruminant

Phlebitis, thrombophlebitis

Salt toxicity, water deprivation

Acute bovine pulmonary emphysema Fat necrosis (B)

Burn, smoke inhalation

Ocular trauma

Snake bite

Acute renal failure

Primary photosensitization

Cholelithiasis (B)

Postparturient hemoglobinuria (B)

B, Bovine.

extract all the information pertaining to the individual animal. A knowledge of forage available, presence of nutrient deficien­cies and excesses, toxic plants, and infectious organisms indigenous to the area, as well as the threat of exotic diseases, is necessary for the present and past geographic environment of the animal.